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Sodium iron phosphate-pyrophosphate, Na4Fe3(PO4)2P2O7 (NFPP) emerges as an excellent cathode material for sodium-ion batteries. Because of lower electronic conductivity, its electrochemical performance depends drastically on the synthesis method. Herein, we provide a simple and unified method for synthesis of composites between NFPP and reduced graphene oxide (rGO) and standard carbon black, designed as electrode materials for both sodium- and lithium-ion batteries. The carbon additives affect only the morphology and textural properties of the composites. The performance of composites in sodium and lithium cells is evaluated at elevated temperatures. It is found that NFPP/rGO outperforms NFPP/C in both Na and Li storage due to its hybrid mechanism of energy storage. In sodium half-cells, NFPP/rGO delivers a reversible capacity of 95 mAh/g at 20 °C and 115 mAh/g at 40 °C with a cycling stability of 95% and 88% at a rate of C/2. In lithium half-cells, the capacity reaches a value of 120 mAh/g at 20 and 40 °C, but the cycling stability becomes worse, especially at 40 °C. The electrochemical performance is discussed on the basis of ex situ XRD and microscopic studies. The good Na storage performance of NFPP/rGO at an elevated temperature represents a first step towards its commercialization. [ABSTRACT FROM AUTHOR]

Lithium-ion battery cathode slurries have a microstructure that depends sensitively on how they are processed due to carbon black's (CB) evolving structure when subjected coating flows. While polyvinylidene difluoride (PVDF), one of the main components of the cathode slurry, plays an important role in modifying the structure and rheology of CB, a quantitative understanding is lacking. In this work, we explore the role of PVDF in determining the structural evolution of Super C65 CB in N-methyl-2-pyrrolidinone (NMP) with rheo-electric measurements. We find that PVDF enhances the viscosity of NMP resulting in a more extensive structural erosion of CB agglomerates with increasing polymer concentration and molecular weight. We also show that the relative viscosity of all suspensions can be collapsed by the fluid Mason number (M n f) , which compares the hydrodynamic forces imposed by the medium to cohesive forces holding CB agglomerates together. Using simultaneous rheo-electric measurements, we find at high M n f , the dielectric strength (Δ ε) scales with M n f , and the power-law scaling can be quantitatively predicted by considering the self-similar break up of CB agglomerates. The collapse of the relative viscosity and scaling of Δ ε both suggest that PVDF increases the hydrodynamic force of the suspending medium without directly changing the CB agglomerate structure. These findings are valuable for optimizing the rheology of lithium ion battery cathode slurries. We also anticipate that these findings can be extended to understand the microstructure of similar systems under flow. [ABSTRACT FROM AUTHOR]

In this study, multi-walled carbon nanotubes (MWCNTs) were modified by thermal fluorination to improve dispersibility between MWCNTs and Li4Ti5O12 (LTO) and were used as additives to compensate for the disadvantages of LTO anode materials with low electronic conductivity. The degree of fluorination of the MWCNTs was controlled by modifying the reaction time at constant fluorination temperature; the clear structure and surface functional group changes in the MWCNTs due to the degree of fluorination were determined. In addition, the homogeneous dispersion in the LTO was improved due to the strong electronegativity of fluorine. The F-MWCNT conductive additive was shown to exhibit an excellent electrochemical performance as an anode for lithium ion batteries (LIBs). In particular, the optimized LTO with added fluorinated MWCNTs not only exhibited a high specific capacity of 104.8 mAh g−1 at 15.0 C but also maintained a capacity of ~116.8 mAh g−1 at a high rate of 10.0 C, showing a capacity almost 1.4 times higher than that of LTO with the addition of pristine MWCNTs and an improvement in the electrical conductivity. These results can be ascribed to the fact that the semi-ionic C–F bond of the fluorinated MWCNTs reacts with the Li metal during the charge/discharge process to form LiF, and the fluorinated MWCNTs are converted into MWCNTs to increase the conductivity due to the bridge effect of the conductive additive, carbon black, with LTO. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dispersion/aggregation of acetylene black determines settling time of cathode slurry. • Strength and recoverability of conductive network structure affect cathode properties. • Hydrostatic pressure change of slurry linked to cathode density/volume resistivity. Hypothesis: It is important to elucidate the effect of the particle dispersion/aggregation state of electrode slurries on resulting electrodes for the development of superior lithium-ion batteries. Many studies have been conducted to characterize cathode slurries for lithium-ion batteries; however, the particle dispersion state of cathode slurries remains unclear. This study investigates the rheological behavior and the packing ability of the cathode slurries for obtaining a denser electrode with lower electric resistance. Experiments: In addition to the conventional flow curve measurement, we measured the changes in the hydrostatic pressure of the slurries with time to evaluate their packing ability. The relationship between the properties of the cathode slurries and those of the as-cast cathodes was also investigated. Findings: It was found that a slurry in which acetylene black powder forms a network structure, with sufficient strength and the ability to rapidly recover after breaking, yields a cathode with comparatively high density and comparatively low volume resistivity. It was also found that the normalized settling time of a cathode slurry determined from its change in hydrostatic pressure over time correlates well with both the density and volume resistivity of a resulting as-cast cathode. [ABSTRACT FROM AUTHOR]

Silicon is a promising anode material that can increase the theoretical capacity of lithium-ion batteries (LIBs). However, the volume expansion of silicon remains a challenge. In this study, we employed a novel combination of conductive additives to effectively suppress the volume expansion of Si during charging/discharging cycles. Rather than carbon black (CB), which is commonly used in SiO anodes, we introduced single-walled carbon nanotubes (SWCNTs) as a conductive additive. Owing to their high aspect ratio, CNTs enable effective connection of SiO particles, leading to stable electrochemical operation to prevent volume expansion. In addition, we explored a combination of CB and SWCNTs, with results showing a synergetic effect compared to a single-component of SWCNTs, as small-sized CB particles can enhance the interface contact between the conductive additive and SiO particles, whereas SWCNTs have limited contact points. With this hybrid conductive additive, we achieved a stable operation of full-cell LIBs for more than 200 cycles, with a retention rate of 91.1%, whereas conventional CB showed a 74.0% specific capacity retention rate. [ABSTRACT FROM AUTHOR]

• Introduces fabrication-scale solvent-free dry electrode process with PTFE binder. • Defines unit process, equipment, intermediate products, and characterization methods. • Interprets the relationship between intermediate products and cell performance. Conventional wet-electrode manufacturing encounters challenges in producing thicker electrodes due to issues related to solvent evaporation. This study introduces a novel method for fabricating solvent-free dry electrodes using polytetrafluoroethylene (PTFE) as a binder, representing a significant advancement in electrode manufacturing processes. By eliminating the use of solvents, this method not only addresses these challenges but also offers a scalable and practical solution for mass production. The process is meticulously structured into sequential unit operations, each specifically tailored for a distinct function, utilizing the distinctive fibrillation properties of PTFE. Intermediate product specifications for each phase are clearly defined, accompanied by a comprehensive analysis of both physical and electrochemical performances. This analysis highlights the influence of varying PTFE contents and properties on the microstructure of the dry electrode. Notably, the study achieves a significant breakthrough with an electrode formulation of NCM811/PTFE/carbon black (CB)/carbon nanotube (CNT) = 96/2.0/1.8/0.2, which demonstrates exceptional discharge rate capability of 80 % at a 0.5 C-rate (5 mA/cm2) under the demanding parameters of 10 mAh/cm2 and 3.8 g/cc. This approach not only enhances the microstructural properties of dry electrodes but also paves the way for environmentally friendly and efficient electrode manufacturing for future energy storage applications. [ABSTRACT FROM AUTHOR]

In this study, novel CuIn 2 S 4 (CIS) material is synthesized through a hydrothermal technique. The as-prepared materials are characterized the structural, chemical and electrochemical properties. The electrochemical performance is evaluated by utilizing as a novel anode material for Li-ion storage. The pristine CuIn 2 S 4 material used cell exhibits Li-ion reversible capacities of 349 and 176 mAh g−1 at the current densities of 0.2 and 1 A g−1, respectively. Furthermore, to improve the electrochemical performance of pristine CIS modified with carbon black (CIS/C) through high-energy ball-milling technique. The resultant CIS/C composite shows an improving reversible discharge capacity of 717 mAh g−1 at 0.2 A g−1 and 591 mAh g−1 at 1 A g−1, respectively. Moreover, the CIS/C composite preserves a high discharge capacity of 376 mAh g−1 over 500 cycles without cyclic decay at 5 A g−1. Additionally, the ex-situ XRD and cyclic voltammetry (CV) analyses expose a Li-ions stored into CIS via conversion reaction mechanism. Overall, this work indicates that the novel material utilization of energy storage device and improvement of storage performance for future high-energy Li and post Li-ion batteries applications. [Display omitted] • CuIn 2 S 4 and CuIn 2 S 4 /C are applied for Li-Ion storage anode for the first-time. • The Li-ion storage mechanism is proposed through CV and ex-situ XRD analyses. • The CIS/C electrode cell exposed better electrochemical performance than bare CIS. • CIS/C composite preserves a high discharge capacity of 376 mAh g−1 over 500 cycles at 5 Ag−1. [ABSTRACT FROM AUTHOR]

The development of elastic nanostructured Si-based anodes holds promise for advancing lithium-ion batteries due to the high theoretical specific capacity exhibited by Si. Combining nanostructured Si with C proves to be a successful strategy in addressing the challenges tied to the substantial volume expansion of Si during lithiation. In this work, a novel Si-based anode is fashioned through a simple and universal strategy, integrating Si nanoparticles with 1D nano-carbonaceous fillers (CPPy-NT) featuring nanotubular morphology and N atoms, and a water-based binder (poly(acrylic acid)). CPPy-NT are derived by carbonizing pre-synthesized polypyrrole nanotubes (PPy-NT). A clear correlation is established among the carbonization temperature for CPPy-NT preparation, N content in CPPy-NT, electrical conductivity, and the electrochemical performance of the ensuing Si/CPPy-NT anode. For comparative analysis, the electrochemical properties of the Si-based anode employing Super P (commercial carbon black) or PPy-NT are contrasted with those of Si/CPPy-NT. Notably, the Si/CPPy-NT anode with CPPy-NT bearing the highest amount of graphitic N sites exhibits a substantial improvement in initial charge capacity (approximately 2200 mAh g−1) and enhanced cycling stability. These findings underscore the potential to elevate the electrochemical activity of the C filler by carefully optimizing morphology, conductivity, and the incorporation of an appropriate amount of graphitic N. [Display omitted] • Synthesis of N-containing 1D nano-carbonaceous fillers with tailored properties. • Integration of N-containing 1D nano-carbonaceous fillers in Si-based anodes. • Development of novel Si/C anodes using an environmentally friendly approach. • Beneficial role of N in enhancing the electrochemical properties of Si/C anodes. [ABSTRACT FROM AUTHOR]

High energy and power density are key requirements for next-generation lithium-ion batteries. One way to improve the former is to reduce the binder and conductive additive content. Carbon black is an important additive that facilitates electronic conduction in lithium-ion batteries and affects the conductive binder domain although it only occupies 5–8% of the electrode mass. However, the function of the structure of carbon black on short- and long-range electronic contacts and pores in the electrode is still not clear and has not been systematically researched in detail. In this work, five carbon blacks with different BET surface areas, oil absorption numbers and ordered graphitic carbon content were investigated. It was found that the ratio of disordered amorphous carbon to ordered graphitic carbon in carbon blacks strongly influences the short- and long-range electrical conduction, and the BET surface area highly affects the pore structure and ionic conductivity in the electrode. Its optimum ratio, indicated by the Raman density I D / I G , is 0.93–0.95. The recommended BET surface area was 130–200 m2/g for this experimental range. The results of this study can provide guidance for the screening of carbon blacks in the lithium-ion battery industry. • Ratio of disordered to ordered carbon highly influences the electronic conduction. • BET surface area highly influences the pore structure and ionic conductivity. • Recommended ratio of carbon is 0.93–0.95 indicated by I D / I G of Raman spectroscopy. • Recommended BET surface area is 130–200 m2/g. [ABSTRACT FROM AUTHOR]

The electrolyte filling process of battery cells is one of the time-critical bottlenecks in cell production. Wetting is of particular importance here, since only completely wetted electrode sections are working. In order to accelerate and facilitate this process, the authors of this study developed a method to significantly increase the wettability of graphite-based anodes by a laser surface modification using low energy nanosecond laser pulses. The anode surface microstructure was evaluated by means of white-light interferometry and scanning electron microscopy. The assessment of wettability was done by drop test and capillary rise test of the liquid electrolyte. The results show that there is a predominantly selective ablation process for laser energy inputs below 2 J/m by which the graphite active material remains unaffected and the binder material is decomposed. The observed increase in surface roughness correlates with the increasing wettability. Investigations using Raman spectroscopy showed that laser treatment leads to a damage on the crystalline structure of the graphite particle surface. However, treating an entire anode including 6 wt% binder and conductive carbon black has shown that the overall amorphous content of the anodes surface can be reduced by 32% through treating the surface with a laser energy of 1.29 J/m. Up to that point, which is the resulting parameter range for the selective process, it is possible to ablate the amorphous binder and carbon black phase coevally exposing graphite particles while keeping their crystalline structure. Exceeding that range, ablation of the whole anode composite dominates and amorphization of the graphite surface occurs. The electrode's capacity was tested on half-cells in coin cell format. For the whole laser parameter range investigated, the anodes capacity matches the mass loss caused by laser ablation. No additional capacity loss was observed due to amorphization of the exterior graphite particle's surface. [ABSTRACT FROM AUTHOR]

In this study, within the defined orthogonal array of Taguchi design, the hydrothermal process parameters have been optimized for fabricating the smallest particle sized iron oxide (Fe2O3) particles. The finest particle size (210 nm) has been achieved when 0.02 M FeCl3 solution at pH 10 is hydrothermally treated for 90 min with an autoclave filling ratio of 100% (D3). Afterwards, to improve the physical properties of iron oxide particles, carbon black powder is added into the precursor solution as the seeding agent before the hydrothermal treatment. Structural and morphological analyses show that upon the existence of carbon in the precursor solution, C-supported Fe2O3 (D5) is fabricated. In the latter, carbon is present in graphitic form and no carbide formation is detected. Electrochemical test results verify that unlike to Fe2O3 (D3), C-supported Fe2O3 (D5) electrode performs lower charge transfer resistance and polarization leading to higher first coulombic efficiency, capacity retention, and improved rate performance, eventually. Thanks to the favorable characteristics of the latter, after 150 cycles, D5 performs 550, 390, and 333 mAh g−1 discharge capacities under loads of 50 mA g−1, 500 mA g−1, and 1.5 A g−1, respectively. Finally, to understand the contribution of capacitive and diffusion-controlled reactions to the total stored charge, an adopted sweep rate method has been used. The calculated voltammograms reveal that fabricating C-supported Fe2O3 particles led to improved rate performance because faradaic reactions that occur at the surface of the material prevail. [ABSTRACT FROM AUTHOR]

MoO 3 is passionately examined as anode materials for lithium-ion batteries (LIBs), because of its exclusive interest due to high theoretical capacity (1117 mAhg−1). This article reports the synthesis of MoO 3 nanoparticles by a simple solution combustion method using tamarind seed powder as a novel fuel where it produces in situ excess carbon by which it can eliminate the addition of acetylene black during the preparation of electrodes for LIB as a conducting material. The prepared MoO 3 nanoparticles were characterized by XRD for structural analysis, vibrational bonding's through FTIR, CHN elemental analysis, BET for pore size distribution and specific surface area, morphology by SEM and TEM. Presence of carbon content in MoO 3 nanoparticles show an excellent electrochemical performance by showing initial discharge capacity of 1171 mAhg−1 and stabilized to 162 mAhg−1 after 200 cycles and Columbic efficiency close to 100%. [ABSTRACT FROM AUTHOR]

Locust Bean Gum (LBG, carob bean gum) was investigated as an environmentally friendly, natural, and water-soluble binder for cathode (LFP) and anode (LTO) in lithium-ion batteries (Li-ion). For the first time, we show LBG as an electrode binder and compare to those of the most popular aqueous (CMC) and conventional (PVDF) binders. The electrodes were characterized using TGA/DSC, the galvanostatic charge–discharge cycle test, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Thermal decomposition of LBG is seen to begin above 250 °C with a weight loss of about 60 wt% observed at 300 °C, which is sufficient to ensure stable performance of the electrode in a Li-ion battery. For CMC, weight loss at the same temperature is about 45%. Scanning electron microscopy (SEM) shows that the LFP–LBG system has a similar distribution of conductive carbon black particles to PVDF electrodes. The LTO–LBG electrode has a homogeneous dispersion of the electrode elements and maintains the electrical integrity of the network even after cycling, which leads to fast electron migration between LTO and carbon black particles, as well as ion conductivity between LTO active material and electrolyte, better than in systems with CMC and PVDF. The exchange current density, obtained from impedance spectroscopy fell within a broad range between 10−4 and 10−2 mA cm−2 for the LTO|Li and LFP|Li systems, respectively. The results presented in this paper indicate that LBG is a new promising material to serve as a binder. [ABSTRACT FROM AUTHOR]

Black phosphorus (BP) has attracted extensive attention in high-rate lithium-ion batteries due to its high theoretical capacity and moderate lithiation potential. However, the large volume expansion and the low conductivity of BP nanostructures in the electrochemical cycle have inhibited the rate performance and long-term cycle stability. In this paper, by combining the glucose-assisted ball-milling and carbonization method, a black-phosphorus/carbon (BP@C) composite anodic material is developed, in which the nano-sized BP nanoparticles are homogeneously embedded in the amorphous carbon matrix. Both the phosphorus-oxygen-carbon bonds and the phosphorus-carbon bonds improve the cross-link between BP and the surface-coated carbon matrix. The unique well-embedded structure promotes the cycling stability and the rate performance of BP@C. The composite shows a high discharge specific capacity of about 1881 mAh g−1 at 0.1 A g−1, the specific capacity at 4 A g−1 is about 63% of the low current capacity, and the discharge specific capacity retains 1130 mAh g−1 after 300 charge-discharge cycles at 0.5 A g−1. Moreover, the significant role of the active unsaturated groups for building the well-embedded composite is further revealed. These results indicate that dual regulation of surface coating and structure optimization offers great potential for further optimizing phosphorus-based anode materials. • Glucose promoted BP homogeneously coated by amorphous carbon matrix. • Carbon matrix improves the conductivity and inhibits the volume expansion. • Different carbon sources influent the cross-linking of BP and the conductive matrix. [ABSTRACT FROM AUTHOR]

An all-solid-state battery (ASSB) with a new structure based on glass-ceramic that forms Na2FeP2O7 (NFP) crystals, which functions as an active cathode material, is fabricated by integrating it with a β″-alumina solid electrolyte. Two important factors that influence the rate capability of this ASSB were optimised. First, the particle size of the precursor glass powder from which the NFP crystals are formed was decreased. Consequently, the onset temperature of crystallisation shifts to a lower temperature, which enables the softening of NFP crystals and their integration with β″-alumina at a low temperature, without the interdiffusion of different crystal phases or atoms. Second, the interface between the β″-alumina solid electrolyte and cathode active materials which consisted of the NFP-crystallised glass and acetylene black used as a conductive additive, is increased to increase the insertion/release of ions and electrons from the active material during charge/discharge processes. Thus, the internal resistance of the battery is reduced considerably to 120 Ω. Thus, an ASSB capable of rapid charge/discharge that can operate not only at room temperature (30 °C) but also at −20 °C is obtained. This technology is an innovative breakthrough in oxide-based ASSBs, considering that the internal resistance of liquid electrolyte-based Li-ion batteries and sulphide-based ASSBs is ~10 Ω. [ABSTRACT FROM AUTHOR]

A simple method was applied to control the morphology of LiMn2O4 and Li1.05Mn1.97Nb0.03O4 in the sintering process by premixing a suitable proportion of acetylene black in the raw material. Both specific discharge capacity and cycling stability of the samples were improved. The results demonstrated that the doped samples showed excellent electrochemical performance at both 25 °C and 55 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • Modified Box-Behnken L15 matrix used to define the experimental space. • Selected experimental outputs divided on two groups: feasibility and performance. • Mono- and multi-variant analysis of six experimental outputs performed. • Derringer-Suich's desirability functions applied to find the optimum. The battery R&D process should be accelerated towards a faster transition to a greener economy. However, typical battery electrode/electrolyte optimization process is still based on heuristic trial-and-error methodology, which is simple and robust but requires multiple attempts and, as a result, is high resource-time consuming. Therefore, a holistic algorithm for the optimization of a four-component (graphite, carbon black, thickener and binder) waterborne negative electrode formulation for lithium-ion batteries is proposed to improve efficiency, spend fewer resources, and speed-up the whole process. Briefly, the experimental space of possible electrode formulations is defined using a modified Box-Behnken cube matrix L15. Each inactive component's pre-selected range of content is divided into three symmetric levels. Fifteen slurries-electrodes are prepared and comprehensively studied by different experimental methods to obtain six preliminarily selected experimental outputs divided into two groups: feasibility (slurry rheology and electrode peel resistance) and electrochemical performance in half coin cells (initial coulombic efficiency and discharge capacity under 2D discharge C-rate) and full coin cells (inverse capacity degradation slope under 2C/2D cycling protocol and inverse internal cell resistance). Finally, a multi-variant analysis of the obtained experimental data array coupled with Derringer-Suich desirability functions specially defined for each experimental output are applied to find out an optimal negative electrode formulation with the best combination of the feasibility and electrochemical performance. [ABSTRACT FROM AUTHOR]

As the Direct Recycling of Lithium-ion batteries may become imperative, centrifugal separation of electrode materials is studied as a potential key process step. The focus here lies on Lithium Iron Phosphate (LFP) and Carbon Black fractionation in a tubular centrifuge and its digital real-time representation. A real-time model is therefore elaborated, which is an enhancement of the existing compartment approach and relies on mass balances for particle sizes and species. In addition, it requires material parameters for accurate representation of hindered settling and sediment compression. Global sensitivity analysis with Latin-Hypercube One-At-A-Time Sampling confirms the parameters' significance and the respective development over process time. A correspondingly tailored optimization procedure incorporating a Genetic Algorithm is designed in order to derive the searched material parameters from actual process data. Results indicate that Genetic Algorithms are promising, robust tools in this application. Also, the model can be validated with appropriate material parameters. • Real-time compartment model of a tubular centrifuge for multiple solid species. • Settling and sediment analysis for LFP and Carbon Black (carbon, agglomeration). • Time-resolved sensitivity analysis. • Genetic Algorithm finds optimal material parameters for fractionation modeling. • Model with optimized material functions is validated against experimental data. [ABSTRACT FROM AUTHOR]

Sedimentation of opaque suspensions of carbon black and lithium-iron-phosphate was investigated by spin-echo-based magnetic resonance imaging. Optical methods are usually applied to determine settling velocities, but are limited with respect to high concentrations and optical transparency. The presented method uses intensity data from the noninvasively measured magnetic resonance signal of the sample. The settling velocity is obtained from the evolution of the signal intensity profiles based on the contrast in 1H magnetic resonance imaging between particles and liquid. New insights into the sedimentation in opaque suspensions are provided, since the 1H images uncover the spatial distribution of the particles and its agglomerates, as well as the shape of the settling front. Additionally, the sedimentation was experimentally studied using a sedimentation balance, which gravimetrically measures the increase in mass fraction over time due to the settling of particles. By parallel usage of these two methods, the sedimentation processes of opaque suspensions of lithium-ion-battery electrode materials were investigated. The sedimentation balance covers high, technically relevant concentrations. Limiting factors of the methods are discussed, which are mainly signal intensity in the magnetic resonance imaging and the increasing viscosity of highly concentrated suspensions. [ABSTRACT FROM AUTHOR]

Graphical abstract Obtained by a solution-based acid-pasting approach, the composite of perylene diimide and carbon black (PTCDI/CB) exhibits excellent electrochemical performances as the organic cathode material in both lithium and sodium ion batteries. Abstract An acid-pasting approach is developed in this work to fabricate the composite of perylenetetracarboxylic diimide (PTCDI) and carbon black in concentrated sulfuric acid. Different from traditional mechanical mixing, the solution-based fabrication strategy enables the sufficient blending of PTCDI as active component and carbon black as conductive agent in the PTCDI/CB composite. Serving as the cathode material, the PTCDI/CB composite shows excellent electrochemical performances in both lithium ion battery (137 mAh g−1 at 100 mA g−1 and 110 mAh g−1 at 2000 mA g−1) and sodium ion battery (134 mAh g−1 at 100 mA g−1 and 99 mAh g−1 at 1000 mA g−1), which are comparable to the state-of-art organic/inorganic cathode materials. Considering the simplicity of the processing procedures and the low cost of the starting materials, the acid-pasting approach is a highly attractive method for the solution-based manufacturing of organic secondary battery electrodes. [ABSTRACT FROM AUTHOR]

Abstract Recently, in order to increase the electrical conductivity of the phosphorus-based anode materials and to alleviate the deterioration of the electrochemical performance caused by the volume expansion of red phosphorus, the composite material made of red phosphorus and carbon matrix has become the mainstream route for lithium ion batteries. In this work, we used one-pot ball milling method to synthesize an unique rebar-reinforced concrete structure hybrid of nanosized phosphorus particles, multi-walled carbon nanotubes, and carbon black (CNTs/CB@P composites). The carbon nanotubes formed a primary frame network structure and the CB formed a regional secondary network structure in the CNTs/CB@P composites, which makes red phosphorus covered by double network structure. Such a structure greatly improves the conductive network of CNTs/CB@P composites for lithium ion batteries. Furthermore, this one-pot ball milling method was simple, continuous, and much suitable for industrial production. When the ratio of multi-walled carbon nanotubes to carbon black was 3:2, the CNTs/CB@P composites had the cycling performance with a reversible capacity of ~ 474.9 mAh g−1 and a capacity retention of ~ 56.3% after 50 cycles. [ABSTRACT FROM AUTHOR]

Conductive carbon additives play very important roles on the performance of Li-ion batteries (LIBs) although they only occupy a very small mass percentage in both cathode and anode. Building up a multidimensional carbonaceous conductive network on cathode with the optimized mass ratio of carbon black, carbon nanotubes (CNTs) and graphene has been verified to be able to enhance the Li-ion storage performance. Herein, we further demonstrate that applying ternary conductive additives is also very effective in improving the rate and cycle performances of graphite anode although the active material already possess high electronic conductivity. A conductive additive assembly of 2 wt% Super P, 1 wt% CNTs and 1 wt% graphene can weave up an efficient conducting pathway on the mesocarbon microbeads (MCMB) anode and enhance the cycle stability (344 mAh g−1 at 1 C after 200 cycles) and rate performance (226 mAh g−1 at 3 C). The coin-type full cell assembled with the optimized MCMB anode and NCM811 cathode also displays much improved rate capability and cycle stability. As is revealed, the multidimensional conducting network might has led to a more uniform and ion conductive SEI film on MCMB anode, which lowers the polarization and energy barrier for Li+ transportation. [Display omitted] • A multidimensional conducting network is constructed on MCMB anode by modifying the dispersion solvent. • A specific capacity of 344 mAh g−1 is preserved after 200 cycles at 1 C. • The multidimensional conducting network promotes the Li+ transfer in MCMB anode. • Using ternary conductive additives in graphite anode is a practical way to improve the performance of LIBs. [ABSTRACT FROM AUTHOR]

The high theoretical capacity of silicon (Si) makes it an attractive anode for lithium-ion batteries (LIBs). However, the poor cycle performance due to the volumetric expansion of Si during the charging-discharging process hinders its practical applications. A composite of graphene and silicon can buffer effectively the volumetric expansion of Si during the charging and discharging process of the battery. Herewith we describe a honeycomb structure constructed with Si nanoparticles (NPs), acetylene black (ACET), and reduced graphene (rGO). In this 3D structure, ACET and Si formed a Si/C composite by mechanical ball milling and it was then encapsulated in a graphene oxide (GO) suspension. After reduction with hydrazine hydrate (N 2 H 4 ·H 2 O) to create rGO, a stable composite Si/C/rGO was obtained. As an anode for LIB, the Si/C/rGO composite exhibited excellent cycle and rate performance. Firstly, the initial coulombic efficiency (ICE) of the battery is very high, exceeding 85%. Secondly, the reversible capacity was retained at 1004 mAh/g after 270 cycles at a current density of 1 A/g. The composite maintained good cycling stability even at current densities of 2 and 3 A/g. Finally, in the rate cycle test, the reversible capacity was up to 450 mAh/g at 5 A/g. [Display omitted] • Forming N-C, C-O-N chemical bonds in Si/C/rGO composite. • Initial coulombic efficiency exceeded 85%. • Specific capacity remained 1004 mAh/g at 1 A/g after 270 cycles. • Rate performance was excellent with capacity of 460 mAh/g at 5 A/g. [ABSTRACT FROM AUTHOR]

We systematically investigate the role of carboxymethyl cellulose (CMC) and show how it affects the slurry dispersion according to the slurry preparation process. We find that CMC plays various roles as a dispersant, thickener, and gelling agent in the anode slurry depending on its content. CMC acts as a dispersant at lower content than the optimum graft density at which the two particles (carbon black, graphite) are adsorbed and saturated. When the CMC content increases above the optimum graft density, the adsorbed CMC still acts as a dispersant, but the extra free CMC acts as a thickener or a gelling agent depending on the content. In the meanwhile, CMC shows similar adsorption and dispersion mechanism for the two particles. Therefore, at a CMC content lower than the optimum graft density, the adsorption selectivity of CMC for both particles is significantly affected by the mixing sequence of CMC and two particles, resulting in a significant difference in slurry dispersion. On the other hand, at higher CMC content, the slurry dispersion is rarely affected by the CMC mixing sequence as both particles are eventually adsorbed and saturated in the final mixing stage. This study reports for the first time that the adsorption selectivity of the binder for the two particles can be controlled through the slurry preparation process, and that the slurry dispersion can be differently affected by the preparation process depending on the binder content. [Display omitted] • Carboxymethyl cellulose (CMC) binder plays a variety of roles depending on the content. • Adsorbed CMC and free CMC differently affects the inter-particle interactions. • Mixing sequence of CMC significantly affects the slurry dispersibility at CMC content lower than the optimum graft density. • This is attributed to the adsorption selectivity of CMC on the particles. • Role of binder should be considered in designing and understanding the slurry preparation process. [ABSTRACT FROM AUTHOR]

Recycling high-valuable metal elements (such as Li, Ni, Co, Al and Cu elements) from scrapped lithium ion batteries can bring significant economic benefits. However, recycling and reusing anode material has not yet attracted wide attention up to now, due to the lower added-value than the above valuable metal materials and the difficulties in regenerating process. In this paper, a novel regeneration process with significant green advance is proposed to regenerate anode material recycled from scrapped Li-ion batteries for the first time. After regenerated, most acetylene black (AB) and all the styrene butadiene rubber (SBR), carboxymethylcellulose sodium (CMC) in recycled anode material are removed, and the surface of anode material is coated with pyrolytic carbon from phenolic resin again. Finally, the regenerated anode material (graphite with coating layer, residual AB and a little CMC pyrolysis product) is obtained. As expected, all the technical indexs of regenerated anode material exceed that of a midrange graphite with the same type, and partial technical indexs are even closed to that of the unused graphite. The results indicate the effective regeneration of anode material recycled from scrapped Li-ion batteries is really achieved. [ABSTRACT FROM AUTHOR]

We report experimental evidence for the specific Li-storage at turbostratic graphene edges of a well-known and cheap Super P ® carbon black (Csp) material, which is usually used as a conductive additive in composite electrodes. Indeed, operando XRD and HR-TEM consistently demonstrate Li insertion occurs with zero expansion of graphene layer up to a composition of Li 0.4 C 6 (150 mA h/g) that is reached at 0.01 V vs. Li + /Li. 7 Li NMR substantiates these results and suggests that the weak electronic transfer from the carbon host to the intercalant could help local reorganization of the layer order as suggested by the unexpected reversible changes of the (002) Bragg peak intensity during the charge-discharge process. Our observations also indicate this insertion mechanism is kinetically favored resulting in remarkable cycling stability over 1000 cycles and power capability allowing to sustain 110 mA h/g at 8 A/g (21 C) in half cell. The capability of Csp as an efficient anode is ultimately demonstrated in a lithium hybrid capacitor against a positive electrode of activated carbon. The full cell delivers a maximum energy of 120 Wh/kg (4.3–2 V) and remarkable capacity retention over 1800 cycles. [ABSTRACT FROM AUTHOR]

The mechanism of non-stoichiometric MnCo 2 O 4+δ to stoichiometric MnCo 2 O 4 structural transformation in the calcination temperature range of 350–650 °C and its morphology evolution from nanoplates with {112} facets to quasi nanoplates with {110} facets in the preferential orientation of [220] direction is investigated in detail and confirmed using XPS, HRTEM, TGA, and XRD analysis. By having a profound understanding of this mechanism, MnCo 2 O 4 with a well-controlled structure and morphology was synthesized via co-precipitation as the anode for Li-ion batteries to overcome the capacity fading issue. Moreover, the anode microstructure was optimized based on the correlation between Li+ storage, electrode durability, and interfacial resistance through the electrochemical response of electrode components, including MnCo 2 O 4 , carbon black, and binder. The optimum electrode exhibited a high initial discharge capacity of 2063 mAh g−1 at 400 mA g−1, excellent rate capability (807 mAh g−1 at 1000 mA g−1), and outstanding cycling performance (709 mAh g−1 at 400 mA g−1 after 150 cycles). These are attributed to the balance between the high surface area and robust architecture of MnCo 2 O 4 , and the stability, conductivity, and porosity of the electrode. [Display omitted] • Phase studies show that increasing the temperature to 650 °C resulted in the evacuation of excess oxygen in MnCo 2 O 4+δ. • By increasing the temperature, {112} facets alter to {110} facets in the preferential orientation of [220] direction. • The optimized electrode exhibited a stable reversible capacity of 709.5 mAh g−1 over 150 cycles at 400 mA g−1. [ABSTRACT FROM AUTHOR]

A crystalline electrode made up of 75% active material (boron-incorporated diamond, BID), 10% poly vinylidene fluoride + 1-methyl-2pyrrolidinone and 15% carbon black was synthesized using the combustion technique at 1173 K for one hour to make homogeneous distribution of sub-micron sized particles. Characterization of the electrode material has been performed through X-ray diffraction, Raman Spectroscopy and Scanning electron microscopy before using it in lithium-ion batteries. The amount of Li in the boron-doped diamond strongly affects its electrochemical performance as electrode. Electrochemical measurements have illustrated much better cycling stability in the -4.0 to 4.5V range at different rates of current. The successful electrochemical activity of boron-incorporated diamond electrode along with lithium electrode insertion in Li+ ion batteries has been reported and discussed here. The peak current shows an almost linear relationship with square root of the scan rate. In addition, effective electrode area was estimated to be 0.54 cm2.Electronic properties of Li-containing electrodes were investigated using DFT approach which showed polaronic conducting behavior which seems advantageous for high power capability. [ABSTRACT FROM AUTHOR]

All-solid-state lithium-ion batteries (ASSLIBs) are promising candidates for next-generation electric vehicle batteries. The contact interface between the active material (AM) and solid electrolyte (SE) is an important factor that affects the performance of ASSLIB. Composite particles, which are SE-coated AM particles, can form electrodes with large AM-SE contact interfaces. However, they can decrease in cell capacity because of the SE coating layer with electrical non-conductance. This study designed composite particles with conductive additives (CAs) using dry-coating. Acetylene black (AB) and vapor-grown carbon fiber (VGCF) were used as typical CAs, and the composite particles with these CAs were compared with those without CAs and simple mixture. Although the addition of CAs improved the cell capacity and decreased internal resistance, the type of CA significantly affected the rate performance. Because the VGCFs were barely incorporated into the SE coating layer, the incorporation of VGCFs did not improve the rate performance. However, the ABs were effectively incorporated into SE coating layer, resulting in the best rate performance in this study. This difference was due to the ease of supplying electrons to the AM particles. Therefore, AB was suitable for the CA of the composite particles to improve the performance of the ASSLIB. [Display omitted] • Preparation and characterization of composite particles with conductive additives. • VGCF more likely to be placed on the surface of the composite particles. • Acetylene black more likely to be incorporated into the SE coating layer. • Composite particles with acetylene black showed a higher battery performance. • Ease of supplying electrons to the active material affects the rate performance. [ABSTRACT FROM AUTHOR]

Herein, we introduce a multifunctional materials dry coating strategy on LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) at 1 wt% with a thickness of ca. 100 nm. The materials included high chemical stable Al 2 O 3 (0.33 wt%) to reduce parasitic reactions, high electrical carbon black (0.33 wt%) to reduce internal charge transfer resistance, and high ionic conductive Li 7 La 3 Zr 2 O 12 (0.33 wt%) to enhance Li+ diffusion. The scalable dry coating mechanofusion used can also generate a smooth surface of spherical NMC811 particles enhancing its stability. With an exceptional property of mixed multi-functional materials, the cell of encapsulated NMC811 can perform up to 1000 cycles with 80% capacity retention. Whilst the pristine NMC811 cell can maintain only 39%. The coated NMC811 provides a two-fold specific capacity at a high C-rate (2.0C) compared to the pristine one. Moreover, it also offers excellent safety based on the UN38.3 standard at 18650 cylindrical cells. This multifunctional coating concept may lead to the further development of high-performance Li-ion batteries. [Display omitted] • Reducing intrinsic drawbacks of NMC811with a multifunctional materials coating. • Carbon black-Al 2 O 3 – Li 7 La 3 Zr 2 O 12- NMC811 strong bond at the interface. • Carbon black can reduce internal resistance of NMC811 Li-ion batteries. • Al 2 O 3 can reduce parasitic reactions of NMC811. • Li 7 La 3 Zr 2 O 12 can enhance Li-ion diffusion. [ABSTRACT FROM AUTHOR]

To investigate geometric and electrochemical characteristics of Li ion battery electrode with different packing densities, lithium cobalt oxide (LiCoO 2 ) cathode electrodes were fabricated from a 94:3:3 (wt%) mixture of LiCoO 2 , polymeric binder, and super-P carbon black and calendered to different densities. A synchrotron X-ray nano-computed tomography system with a spatial resolution of 58.2 nm at the Advanced Photon Source of the Argonne National Laboratory was employed to obtain three dimensional morphology data of the electrodes. The morphology data were quantitatively analyzed to characterize their geometric properties, such as porosity, tortuosity, specific surface area, and pore size distribution. The geometric and electrochemical analysis reveal that high packing density electrodes have smaller average pore size and narrower pore size distribution, which improves the electrical contact between carbon-binder matrix and LiCoO 2 particles. The better contact improves the capacity and rate capability by reducing the possibility of electrically isolated LiCoO 2 particles and increasing the electrochemically active area. The results show that increase of packing density results in higher tortuosity, but electrochemically active area is more crucial to cell performance than tortuosity at up to 3.6 g/cm 3 packing density and 4 C rate. [ABSTRACT FROM AUTHOR]

Due to its high theoretical capacity, silicon is a promising active material candidate for the negative electrode of lithium ion batteries. One way to reduce the severe degradation of silicon during charge/discharge cycling, is to use blends of different active materials and a well-balanced ratio of active and inactive materials. To ensure high-energy densities while still maintaining good electronic conductivity and ionic mobility, the necessity of nano-scale conductive carbons within a graphite/silicon composite was evaluated in this study. In particular, the correlation of silicon particle size and the presence of conductive additive was studied in electrodes, predominantly consisting of graphite (15 wt% silicon). Carbon black as conductive additive has a high contact surface area, which can enhance the electronic conductivity within the electrode and thus the rate capability, however, it can also propagate parasitic side reactions. It was determined that composite electrodes containing micron-sized silicon particles depend on the addition of conductive additives with regard to electrochemical performance. Due to high contact area and small transport distances, electrodes based on nano-sized silicon showed comparable capacity retention and a higher specific discharge capacity. Omitting conductive particles from these composite electrodes allowed lower binder amounts, while maintaining a good mechanical electrode integrity. [Display omitted] • Optimization of C/Si-based composite electrode formulation. • Impact of different Si particle sizes varying from nano-to micro-scale. • Evaluation of the necessity of conductive additives in C/Si-based electrodes. • Reduction of inactive material content to maximize energy density. [ABSTRACT FROM AUTHOR]

Electrode processing and performance strongly depend on the active material. Maximizing the active material content of positive composite electrodes enables low cost and high energy density. However, this maximization cannot reach 100%, as composite electrodes additionally consist of binder to provide mechanical integrity and conductive additive to enhance electronic conductivity, which in combination create a flexible porous microstructure for appropriate electron and lithium transport. In this study, the influence of three positive active material classes, layered oxide LiNi 0.6 Mn 0.2 Co 0.2 O 2 , spinel-type LiMn 2 O 4 and olivine-type carbon-coated LiFePO 4 , were investigated regarding the optimum amount of polyvinylidene difluoride as binder and carbon black as conductive additive to achieve high mechanical stability as well as high electronic and ionic conductivity within composite electrodes. Formulation optimization was conducted and compared to a reference electrode formulation with regard to physical, mechanical, electronic and electrochemical properties. In a first step, the binder amount was optimized for each active material class by varying the ratio of binder content to surface area of the solid electrode components. In a second step, the critical conductive additive content was determined. Overall, this strategy allows to decipher material class dependent optimized electrode formulations for high energy density composite electrodes with maximized active material content. [Display omitted] • Strategy to develop material class dependent electrode formulations. • Active material particle surface and size affects binder and conductive additive amount. • Carbon-coated LiFePO 4 based composite electrodes show a high SOH with low conductive additive content. [ABSTRACT FROM AUTHOR]

Many studies have been recently conducted on Ni-rich cathodes to increase cell capacity. The improvement of cell capacity is reaching its limit by increasing Ni content of a cathode material. In addition, increasing Ni content of a cathode material is unsafe due to gas evolution. Thus, research on Ni-rich cathode should proceed in parallel with the development of cell design, i.e., thickening electrode. However, during a calendering process, upper layer particles with low mechanical strength can be fractured, which is a problem with a thick electrode. To solve this issue, electrodes were designed using single crystalline lithium nickel cobalt manganese oxides (NCM) of high mechanical strength together with existing polycrystalline NCM in the present study. Four types of electrodes were tested to determine the best design for the electrode. Among them, double layer of upper layer with single crystalline and lower layer with polycrystalline (DB) completely prevented particle fracturing in the upper layer while maintaining sufficient tortuosity within the electrode. The reaction within the electrode was much more uniform than in other samples. As a result, DB had higher capacity of 34.6 mAh g−1 than the pristine after 40 cycles and a higher capacity of 50.5 mAh g−1 at 2C. • Particles on the upper layer of electrode can be fractured by the pressing force. • The carbon black and PVDF of the upper layer can be agglomerated. • The upper layer of the DB was entirely made of SC, there was no upper layer crack. • The DB enabled a uniform reaction within the electrode without upper layer crack. [ABSTRACT FROM AUTHOR]

Distinct corroded behaviour and their difference between the solution and as-prepared slurry made by Maleic acid and NMP. Once the colourless and clarify solution (Maleic acid in NMP) contact the surface of clean copper foil, the solution will turn into pale-green then blue-green in several hours, and the ordered corroded product (brick-like structure) is observed. On the other side, when slurry casted on the copper foil, the corroded product formed the sphere structure for the coordination of binder (PVDF) and conductive agent (Acetylene black). Combined with the colour change of solution and the element distribution results, It's believed that the corrosion happened when we prepared the electrode with NMP as dispersant, relevant electrochemical performance tests also proof this conclusion. [Display omitted] • A new point of view is developed for lithium storage capability of maleic acid. • The possibility of corrosion with current collector is took into consideration. • An opinion for the adaptation between dispersant and organic electrode materials. Maleic acid, as a small molecular organic compound, has been manifested to demonstrate remarkable lithium storage capability with twelve electrons transferred in the reaction. Herein, we try to understand the underlying reasons for the gradual ascent of capacity during the first several cycles by focusing on the interface between the electrode slurry and the current collector copper foil. As the results show, a chemical reaction happens when the electrode slurry contacts the copper foil and a copper-bearing compound is in-situ constructed. Further investigations reveal that the capacity is mainly contributed by the corroded product of maleic acid instead of maleic acid itself. These findings offer new insights into the electrochemical behavior of maleic acid and provide a reference for the development of organic electrode materials in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gr coating reduces the dependence of ICE of SiO x on CB content. • Gr sheets slide on the interfaces between active particles and suppress the AG damage. • SiO x @Gr/AG anodes show self-adaptive behaviors during charge–discharge process. • Self-adaptive design improves capacity retention with high volumetric capacities. Si-based materials are promising high-capacity anodes, which can improve the energy density of Li-ion batteries (LIBs) that are required for the advancement of electric vehicles. Nevertheless, the severe volume change of Si-based materials during repeated cycles limits their widespread applications in LIBs. Here, we report a durable and high-energy blended anode composed of artificial graphite (AG) and graphene (Gr)-coated SiO x (SiO x @Gr) particles. The Gr coating reduces the electrode swelling during repeated cycles and increases the initial Coulombic efficiency of SiO x. This further increases the areal capacity owing to the reduction of carbon black (CB) content to 3 wt%. The SiO x @Gr/AG blended anode exhibits excellent properties compared to the bare SiO x /AG anode. These results can be attributed to the self-adaptive behavior by Gr sheets coated on SiO x particles, which mitigates the mechanical damage on the AG particles and maintains the electron conduction pathways. Hence, the reversibility of the charge–discharge reactions improves, as revealed by Raman spectral mapping and powder flowability measurements. Furthermore, the full-cell with the SiO x @Gr/AG anode exhibits good cycling stability and high volumetric capacities over 300 cycles compared to the full-cell with the bare SiO x /AG anode and AG-only anode, demonstrating the applicability of the high-capacity Si-based anodes for LIBs. [ABSTRACT FROM AUTHOR]

This study demonstrates the preparation of well aligned-carbon nanotube (WA-CNT) arrays onto a carbon paper substrate with a conductive carbon-black layer by the catalyst seed-impregnated chemical vapor deposition method. The prepared WA-CNT arrays were then characterized by scanning electron microscopy for different growth temperatures, standard linear velocities of feed vapors, and ferrocene-to-xylene ratios in the feed vapors. Results indicate that the optimal WA-CNT arrays of length 40–50 μm and diameter 30–40 nm were obtained at the growth temperature range of 750–800 °C, standard linear velocity of 1.40 cm s −1 , and ferrocene-to-xylene molar ratio of 1:50–1:30. These results provide new insights into the growth mechanism of CNT arrays, which involves cross-coupling of chemical reaction and mass transfer based on reaction engineering theory. The samples prepared in the study can be used as catalyst supports in air electrodes considering their three-dimensional porous structure, approximately linear channel, controllable length and diameter distribution, and excellent CNT conductivity. Electrochemical measurement indicated that the WA-CNT arrays/carbon-black layer/carbon paper substrate composites achieved relatively high discharge capacity of 2930 mAh g −1 (CNTs) at a current density of 0.05 mA cm −2 in Li–air batteries, which far exceeded other carbonaceous materials in Li–air batteries. [ABSTRACT FROM AUTHOR]

Conductive additives, like carbon black or graphite, are essential components of lithium ion batteries due to the limited electrical conductivity of most electrode materials. However, there is still a lack of knowledge about the optimized distribution of these materials within the electrode. A dry mixing process is used in order to prepare a conductive coating by depositing carbon black on the surface of Li(Ni 1/3 Mn 1/3 Co 1/3 )O 2 (NMC) cathode particles. It is demonstrated that this – from a theoretically point of view – favorable distribution does not allow the preparation of working electrodes without taking into account the role of the binder. After adding an organic binder to the slurry, the polymer deposits on top of the carbon shell during drying and inhibits the conductive contact between the particles. This can be avoided by a fraction of distributed carbon particles which are associated with the binder phase providing conductive paths through the isolating organic material. It is shown that carbon black and graphite are principally fulfilling this task, but both materials are leading to varying processing behavior and electrode properties. [ABSTRACT FROM AUTHOR]

We previously reported that lithium transition metal oxide, Li 1.14 (Ni 0.34 Co 0.33 Mn 0.33)O 2 (NCM), which are used as the cathode active material of lithium-ion batteries, was reacted with amine and graphene oxide (GO) to form composite particles. The reaction mechanism of the NCM and amine in the formation process, can be thought of as the ionic bonding reaction or the complex formation reaction between the transition metals and amine. This time, the composite reaction was carried out to elucidate this mechanism and to obtain hybrid composite particles with carbon black (CB), the anode active material of lithium-ion batteries. Hydrophilic substituents were introduced to CB surface by plasma treatment to create reaction points with organic materials. The hydrophilic CB became anionic in water and reacted with amine to form composite particles. Subsequent reaction with GO resulted in another composite particles. The hydrophilicity of the plasma-treated CBs was evaluated, and the composite state of the CBs, amines and GO was observed by scanning electron microscopy (SEM), and Raman spectral analysis was used to analyze the state change and film distribution of the particles. The fact that the hybrid composite particles were obtained by this method supports the mechanism that the NCM and amine were ionized and bound by electrostatic interaction. At the same time, it was found that even CBs had the means to enhance the reactivity, and organic and carbon materials could be easily combined. [Display omitted] • Ion-complex synthesis method enabled us to synthesize composite particles for lithium-ion batteries with multiple functions. • Plasma treatment improves the reactivity of the inert carbon black surface, making it easier to composite. • Raman can be used to analyze the bonding and dispersion state of carbon materials that could not be observed by IR or SEM. [ABSTRACT FROM AUTHOR]

• Natural-abundant biomass and commercial vanadium oxide are starting materials. • A combined strategy aided by salts and ball milling is demonstrated. • The optimized composite offers a high reversible capacity for Li/Na storage. • The composite exhibits a hierarchical structure with an even distribution of V 2 O 3. Transition metal oxides are potential electrodes for lithium/sodium-ion batteries, but they are generally characterized by low electronic conductivity and a large volume change during charge/discharge. Metal oxide/bio-carbon composites have shown tremendous promise, but traditional methods for the preparation of bio-carbon-based composites are incapable of achieving high porosity and even distribution. Herein, we used a combined strategy aided by salts and ball milling to facilely prepare vanadium oxide/biomass (i.e., black fungus)-derived carbon (BFC) composites for mass production. The optimized composite (e.g., V 2 O 3 /BFC), assembled in lithium-ion batteries, offers high reversible capacity of 461.9 and 377.2 mAh g−1 after 120 cycles at 0.5 and 1.0 A g−1, and demonstrates good capacity retention after experiencing rate-capability and long-term measurements. Notably, the V 2 O 3 /BFC composite further shows good cycle stability for sodium-ion batteries, with 253.3 mAh g−1 at 0.2 A g−1 after 160 cycles. The excellent electrochemical performance of V 2 O 3 /BFC can be attributed to the simultaneous introduction of salts and ball milling in effectively cracking bulk carbon and dispersing V 2 O 3 , leading to the formation of a hierarchically porous structure with a high specific surface area and a homogeneous distribution of V 2 O 3. Furthermore, the hierarchically porous structure favors ion/mass transport and alleviates the adverse impacts of volume expansion, while electrons are facilely transferred via the carbon framework. The work highlights a combination method that includes salts and ball milling, and the feasibility of employing natural-abundant biomass and commercial vanadium oxide for high-performance lithium/sodium-ion batteries. [ABSTRACT FROM AUTHOR]

The conductive network within a lithium-ion battery electrode is mainly influenced by the process parameters chosen for the dry mixing and wet dispersing step during the production of a coatable electrode slurry, consisting of well-defined components. This conductive network, which results from the electrode's microstructure, plays a major role for the resulting battery cell performance, especially for high performance and power applications. Notable differences can be observed in the subsequently manufactured electrodes due to process-related modifications in the carbon black agglomerate size; mechanical, electrical, and, thus, electrochemical properties are significantly changing with the process parameters set. To allow for a direct correlation of these properties with the electrode structure, a characteristic parameter to describe the carbon black structure in electrode coatings is developed. Based on mercury intrusion measurements, the internal porosity of carbon black particles was determined as a characteristic parameter for the conductive microstructure. For a wide variety of lithium-ion battery cathode samples, the carbon black porosity can be well related to important electrode properties. This underscores the relevance of this carbon black-based microstructure parameter for a knowledge-based process and product optimization. [Display omitted] • Carbon black porosity as a structural parameter for LIB is developed and proven. • Wet dispersion and dry mixing can be used to adjust the carbon black porosity. • Carbon black porosity determines C-rate performance in the form of an optimum curve. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanoporous Si particles are prepared from Mg 2 Si reduction of SiO 2 fumes. • Nanoporous Si is composited with Li 3 PS 4 to prepare anodes for all-solid-state lithium-ion batteries. • Electrical conductivity and charge capacity of Si composite anodes increase with conductive additive content. • There is an optimal amount of conductive additive to improve the discharge capacity and capacity retention of Si composite anodes. Si is the most promising anode active material for lithium-ion batteries owing to its high theoretical capacity and low operating potential. In this study, composite anodes consisting of nanoporous Si particles, Li 3 PS 4 solid electrolyte, and a conductive additive (CA) in weight ratios of 4:6: x (x = 1, 2, 3, and 4) are fabricated and tested. The electrical conductivities are 4.1 × 10-4 S cm−1 and 6.8 × 10-4 S cm−1 at × = 1 and 4, respectively. In addition, the charge capacity increases in proportion with CA content from 2700 mAh g−1 to 3015 mAh g−1. These results indicate that new conduction paths are created in the nanoporous Si composite anodes upon adding a CA. To the best of our knowledge, this is the first study to examine the effect of a CA on the electrochemical performance of all-solid-state lithium-ion batteries with Si-based anodes. Our findings provide valuable information that should be helpful in meeting the energy demands of next-generation applications. [ABSTRACT FROM AUTHOR]

To improve the electrochemical performance of Na 2 Li 2 Ti 6 O 14 , carbon black (CB), graphene (GN) and carbon nanotube (CNT) are introduced to fabricate high conductive Na 2 Li 2 Ti 6 O 14 /CB, Na 2 Li 2 Ti 6 O 14 /GN, Na 2 Li 2 Ti 6 O 14 /CNT and Na 2 Li 2 Ti 6 O 14 /CB/GN/CNT by a solid state method. It can be found that only CNT forms a complete three-dimensional conductive network which embeds the randomly distributed Na 2 Li 2 Ti 6 O 14 particles, leading to an improvement of electronic conductivity. The results of cyclic voltammetry, electrochemical impedance spectroscopy and charge–discharge tests reveal that Na 2 Li 2 Ti 6 O 14 /CNT obtains the lowest redox polarization and the highest peak current among all the five samples. As a result, Na 2 Li 2 Ti 6 O 14 /CNT shows the best cycling and rate performances among all the five samples. It reveals a charge capacity of 111.4 mAh g −1 at 100 mA g −1 , 110 mAh g −1 at 200 mA g −1 , 103.9 mAh g −1 at 300 mA g −1 and 98.9 mAh g −1 at 400 mA g −1 . For comparison, bare Na 2 Li 2 Ti 6 O 14 only displays a charge capacity of 89.9 mAh g −1 at 100 mA g −1 , 79.7 mAh g −1 at 200 mA g −1 , 73.7 mAh g −1 at 300 mA g −1 and 69.4 mAh g −1 at 400 mA g −1 . It indicates that the introduction of CNT is more effective to improve the performance of Na 2 Li 2 Ti 6 O 14 than CB, GN and CB/GN/CNT. [ABSTRACT FROM AUTHOR]

Exploiting fast-kinetics anode materials for lithium-ion batteries shows significant importance for promoting their power density. Herein, we exhibit a rational synthesis strategy of ultrafine spinel Li 4 Ti 5 O 12 nanocrystals and 3D hierarchical architectured composite by an aerosol process in which homogenous suspension of Li 4 Ti 5 O 12 , carbon black, and graphene oxide are atomized and assembled into spherical LTO/CB-G superstructure. The unique 3D architecture is well characterized, and its formation mechanism is discussed in detail. When applied in battery electrode, LTO/CB-G delivers superior rate performance and long cycling durability. Considering the potential large-scale production of graphene and the scalable aerosol-assisted process, 3D Li 4 Ti 5 O 12 -based nanocomposites hold great promise for high-power anodes in real applications of electric transportations. • Ultrafine LTO nanocrystals are synthesized via facile two-phase reaction. • Preparation of graphene-LTO nanocomposites is scalable from spray-drying. • The unique architecture enables superior rate and cycling performance. • The composites hold great promise for practical high-power LIBs anodes. [ABSTRACT FROM AUTHOR]

Metal chalcogenides undergoing alloying and conversion mechanism can give high capacity as anode for lithium-ion batteries. However, large volume change and phase segregation lead to poor cycle performance. In this study, we focus on Sb 2 Se 3 and develop methods to enhance its long-term stability and reversibility. In particular, we find that carbon encapsulation reduces volume change during lithiation/delithiation and facilitates the recombination process of Sb and Se even after long cycling. With an addition of 20 wt% acetylene black, the Sb 2 Se 3 /C nanocomposite material exhibits an excellent cycle performance with a charge capacity of 545 mAh g−1 at 250 mA g−1 after 1000 cycles, corresponding to a capacity retention of 99.3%. We also demonstrate a full cell with LiFePO 4 cathode and Sb 2 Se 3 /C anode that is capable of delivering a stable capacity of 340 mAh g−1 at 1 A g−1 (about 3 C rate) after 300 cycles. • Sb 2 Se 3 nanoparticles encapsulated with carbon matrix is synthesized via mechanical ball-milling. • Carbon matrix enhances the mechanical stability of the electrode and suppresses phase segregation. • Sb 2 Se 3 @20%AB delivers a stable capacity of 545 mAh g−1 over 1000 cycles. • Sb 2 Se 3 @20%AB/LiFeO 4 full cell shows good rate capability and cycle stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • A superior carbon black as conducting additive and LIB and NIB anodes is developed. • The superior carbon black is synthesized by amorphization and pre-lithiation/sodiation. • Electrochemical mechanism of the superior carbon black is elucidated using various analytical techniques. • The superior carbon black compensates ICE and increases the reversible capacity of anode materials. Carbon black (CB) is an inexpensive and widely used carbonaceous material. However, the reversibility between CB and Li or Na is very poor, and the initial coulombic efficiency (ICE) is so low that it cannot be used as an electrode material for rechargeable batteries. In this study, we successfully designed superior CB as a high-performance conducting additive for Li-ion batteries (LIBs) and Na-ion batteries (NIBs) using a simple two-step strategy: amorphization and pre-lithiation/sodiation. The Li- and Na-reversible capacities of amorphized CB increased significantly from 213 to 564 mAh g−1 for LIB and from 92 to 209 mAh g−1 for NIB; however, the corresponding ICEs of 61.5% for LIB and 33.5% for NIB are poor. The poor ICEs are supplemented via pre-lithiation/sodiation in the amorphized CB, which show over 100% ICEs with high Li- and Na-reversible capacities. Specifically, the modified CB has highly reversible capacities (>500 mAh g−1 for LIB, >300 mAh g−1 for NIB) with exceptionally high ICEs (133% ICE for LIB, 160% ICE for NIB), stable reversible capacities for over 100 cycles (470 mAh g−1 for LIB, 278 mAh g−1 for NIB), fast rate capabilities with highly reversible capacities at a 3C rate (~330 mAh g−1 for LIB, ~190 mAh g−1 for NIB), and excellent cycling behavior for over 300 cycles at a 1C rate. When used as a conducting additive, this CB contributes to high electrical conductivity and increase of ICE and the reversible capacity for LIB and NIB anode materials. These results are expected to have a significant impact on LIBs and NIBs. [ABSTRACT FROM AUTHOR]

Li-ion batteries (LIBs) employ porous, composite-type electrodes, where few weight percentages of carbonaceous conducting agents and polymeric binders are required to bestow electrodes with electrical conductivity and mechanical robustness. However, the use of such inactive materials has limited enhancements of battery performance in terms of energy density and safety. In this study, we introduced graphene/polyvinylidene fluoride (Gr/PVdF) composites in Ni-rich oxide cathodes for LIBs, replacing conventional conducting agents, carbon black (CB) nanoparticles. By using Gr/PVdF suspensions, we fabricated highly dense LiNi0.85Co0.15Al0.05O2 (NCA) cathodes having a uniform distribution of conductive Gr sheets without CB nanoparticles, which was confirmed by scanning spreading resistance microscopy mode using atomic force microscopy. At a high content of 99 wt.% NCA, good cycling stability was shown with significantly improved areal capacity (Qareal) and volumetric capacity (Qvol), relative to the CB/PVdF-containing NCA electrode with a commercial-level of electrode parameters. The NCA electrodes using 1 wt.% Gr/PVdF (0.9:0.1) delivered a high Qareal of ~3.7 mAh cm−2 (~19% increment) and a high Qvol of ~774 mAh cm−3 (~18% increment) at a current rate of 0.2 C, as compared to the conventional NCA electrode. Our results suggest a viable strategy for superseding conventional conducting agents (CB) and improving the electrochemical performance of Ni-rich cathodes for advanced LIBs. [ABSTRACT FROM AUTHOR]

Novel core-shell structure hard carbon/Si-carbon composites are prepared, and their electrochemical performances as an anode material for lithium-ion batteries are reported. Three different types of shell coating are applied using Si-carbon, Si-carbon black-carbon and Si-carbon black-carbon/graphite nanosheets. It appears that the use of n-Si/carbon black/carbon composite particles in place of n-Si for the shell coating is of great importance to achieve enhanced electrochemical performances from the core-shell composite samples, and additional wrapping with graphite nanosheets leads to a more stable cycle performance of the core-shell composites. [ABSTRACT FROM AUTHOR]

For a given proportion of active material, conductive agent, and binder, performance of the lithium ion battery depends on microstructure of the electrode. Uniform distribution of de-agglomerated particles of carbon black on the active material in the slurry is crucial for establishing a conductive network around the active particles and for improving the adhesion of the electrode to the current collector. Herein, we demonstrate that pre-mixing of carbon black and LiFePO 4 via dry ball-milling achieves the desired microstructure in the electrode coating. Homogeneity of slurry of LiFePO 4 in Poly(vinylidene fluoride)/N-methyl -2-pyrrolidone is demonstrated using measurement of viscosity and dynamic light scattering. Dried electrodes are shown to be uniform via SEM imaging and by a novel "linearly resolved electrical resistivity measurement" technique. Through peel tests it is shown that adhesion of the electrode to the current collector is improved. These improvements reflect in the electrochemical characteristics of the electrode such as increased cycling stability, higher exchange current density and ability of the electrode to perform at a higher C-rate. The electrodes prepared with this method, at an optimal composition, give a higher discharge voltage of ~3 V at 10 C compared to values of 2.4–2.8 V reported for unmodified LiFePO 4 so far. Image 1 • Pre-mixing of carbon black-LiFePO 4 for electrode's desired microstructure. • A novel "linearly resolved electrical resistivity measurement" technique. • The homogeneity of the slurry is measured using rheological properties. • Effective transfer of LFP properties to the electrode performance. [ABSTRACT FROM AUTHOR]

Lots of lithium ion battery (LIB) products contain lithium metal oxide LiNi5Co2Mn3O2 (LNCM) as the positive electrode's active material. The stable surface of this oxide results in high resistivity in the battery. For this reason, conductive carbon-based materials, including acetylene black and carbon black, become necessary components in electrodes. Recently, carbon nano-tube (CNT) has appeared as a popular choice for the conductive carbon in LIB. However, a large quantity of the conductive carbon, which cannot provide capacity as the active material, will decrease the energy density of batteries. The ultra-high cost of CNT, compared to conventional carbon black, is also a problem. In this work, we are going to introduce long-length carbon nano-tube s(L-CNT) into electrodes in order to design a reduced-amount conductive carbon electrode. The whole experiment will be done in a 1Ah commercial type pouch LIB. By decreasing conductive carbon as well as increasing the active material in the positive electrode, the energy density of the LNCM-based 1Ah pouch type LIB, with only 0.16% of L-CNT inside the LNCM positive electrode, could reach 224 Wh/kg and 549 Wh/L, in weight and volume energy density, respectively. Further, this high energy density LIB with L-CNT offers stable cyclability, which may constitute valuable progress in portable devices and electric vehicle (EV) applications. [ABSTRACT FROM AUTHOR]