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Flexible organic cathodes with 3,4,9,10-perylenetetracarboxylic diimide (PDI) as the active component, carbon black (CB) as the conductive agent and thermoplastic polyurethane (TPU) as the elastomeric matrix are obtained in this work via a solution-based phase inversion approach. In the resulting PDI/CB/TPU cathodes, the mass ratios of the three components manifest profound influences on their composition, flexibility, conductivity and lithium storage behavior. The integrated PDI/CB/TPU cathode with optimized ratio can deliver impressive rate capability and good cycling stability in lithium ion batteries (LIBs). More importantly, the full LIBs with PDI/CB/TPU cathode and carbon cloth anode exhibit excellent electrochemical performances, which show no decay even at bending states, demonstrating the appealing prospects of the solution-processed organic cathodes in wearable secondary batteries. Obtained from a solution-based phase inversion approach, the flexible PDI/CB/TPU cathodes manifest excellent electrochemical performances and good mechanical stability in lithium ion batteries. Image 1 [ABSTRACT FROM AUTHOR]

• A Box-Behnken design for graphite anodes slurries optimization was presented to highlight the importance of the component's interactions to obtained higher performed anodes of lithium-ion batteries customization. • The carbon black content is the most significant effect in both materials which is reflected in higher capacities and coulombic efficiencies. • For the overall behavior, the binder/carbon black interactions are relevant in terms not only of electrochemical performance but also in the obtention of more homogeneous and better adhesion anodes. The technological application of lithium-ion batteries (LIB) grows constantly, making customization of the batteries a current necessity and sometimes a challenge. In this paper we described carbon-slurry optimization process for anodes of lithium-ion batteries customization by using a surface response statistical experiment with four response variables such specific discharge capacity, coulombic efficiency, anodes mass deviation, and capacity retention. We studied two commercial graphite active materials by characterizing the materials via Raman spectroscopy, SEM, and electrochemical techniques. We corroborate the graphite structure for both materials but with morphological differences such as shape and particle size. The binder composition seems to interfere with the active carbon materials capabilities while it generates better performance for one of them. Although the chemical structure of both materials was confirmed to be the same via Raman experiments, SEM images shows critical morphological differences that interferes with the final slurry thus, affecting the electrochemical performance of the anodes. Further studies are required to understand ECSA and its possible effect on the charge/discharge capacities of the anodes. [Display omitted] [ABSTRACT FROM AUTHOR]

An acid-pasting approach is developed in this work to prepare the composites of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and carbon black (CB) by mixing both components in concentrated sulfuric acid. Different from the traditional powder processing, the solution-based fabrication strategy easily renders the effective combination of PTCDA and CB in the resultant CB/PTCDA composites, thus greatly improving their electrochemical performances. As the results, the composite with 20 wt% PTCDA shows excellent rate performances as the cathode material for both lithium ion battery (88 mAh g −1 at 5000 mA g −1 ) and sodium ion battery (100 mAh g −1 at 1000 mA g −1 ). As a facile and efficient processing strategy, the acid-pasting approach is expected to have wide application in the fabrication of organic electrodes in secondary batteries. [ABSTRACT FROM AUTHOR]

In this work, a facial in-situ polymerization strategy is developed for the first time to fabricate the composites of polyimide and carbon black (PI/CBs) by the condensation of 1,2,4,5-benzenetetracarboxylic anhydride and p -phenylenediamine with the presence of carbon black. This composition method can effectively suppress the crystallization of PI and thus allows the sufficient contact of PI and carbon black. As the cathode material in LIBs, the PI/CB composite manifests an extraordinary capacity of 182 mAh g −1 at 0.1 A g −1 , close to the theoretical value of PI. Moreover, the capacity of the PI/CB composite can be retained as 116 m Ah g −1 even at an ultrahigh current density of 10 A g −1 , outperforming the recently reported polymer LIB cathodes. Under the same conditions, the mechanical mixture of highly crystallized PI sheets and carbon black shows a much poorer performance. The approach demonstrated herein is expected to be further applied as an effective processing method to build up high performance electrodes with organic species in secondary batteries. [ABSTRACT FROM AUTHOR]

This work presents a comprehensive analysis of the impact of carbon nanotubes (CNT) and carbon nanofibers (CNF) composition on the performance of nano-Si anodes in lithium-ion batteries. The nano-Si anode suffers from chemo-mechanical issues caused by its large volumetric change (e.g., 280%) during cycling. One of the promising solutions in electrode level is to establish a robust electronic conduction pathway in Si anodes by incorporating CNT and CNF with high aspect ratios. The objective of this work is to quantitatively measure the performance improvement achieved by CNT and CNF based on their compositions and analyze the improvement mechanism through electrochemical methods. The results indicate that substituting a portion of carbon black with CNT and CNF in a range of 1 – 10 wt% can enhance the capacity retention (from 44% to around 60%) and the fast-charging and fast-discharging capabilities. Electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analyses revealed that 5% – 10% CNT and CNF conductors effectively suppressed contact impedances growths in Si anodes. In summary, our findings highlight the importance of precise control over the composition of CNT and CNF to achieve good electrode morphology and electrochemical properties for nano-Si anodes. [ABSTRACT FROM AUTHOR]

A flexible and free-collector-current of silicon-based anode is facilely prepared just by coating carbon black (CB) and silicon powders layer-by-layer. The resultant electrodes with a “sandwich” structure (CB/Si/CB) are assembled into half-cell and its electrochemical properties are tested. This type of anode exhibits excellent cycling and outstanding rate capability. The superior electrochemical performances are ascribed to both flexible CB-layers to offset the volume expansion of Si-particle. And, the CB-layer with high electric conductivity can provide efficient electron conductive pathways when Si particles react with lithium. More importantly, the CB/Si/CB electrodes without the collerctor (copper-foil) are exhibited high energy density, due to the weight proportion of copper foil is exceeded 60%. The CB/Si/CB electrode is used to assemble full-cell with the same structure as free-collector LCO/CB cathode material. It imposes the energy density of 200 Wh kg −1 , and can keep stable charging-discharging capability at various deformations of shapes. And the flexible-cell of high performance is obtained to meet diverse applications in energy storage devices. Until now, many flexible batteries are put forward by researchers, but these product is faced with the complex production-process, high-cost material, low energy-density. This CB/Si/CB structure is produced with the matching current manufacturing industry and the common raw material, and to get a full-cell of the high energy density. [ABSTRACT FROM AUTHOR]

This work aims at better understanding the interactions existing between the liquid electrolyte and the solid composite electrode in a Li-ion battery. We substituted the common active material (e.g. LiNi 1/3 Mn 1/3 Co 1/3 O 2 or LiFePO 4) by an insulating (inactive) γ-Al 2 O 3 compound in order to detect and evidence the interaction between the carbon black electronic additive and the liquid electrolyte. Our study presents the characterization of charge (electrons and ions) transport at different scales by combining a high-frequency analysis performed by broadband dielectric spectroscopy (BDS, up to 1010 Hz), along with a low-frequency analysis performed by electrochemical impedance spectroscopy (EIS, down to 10−3 Hz). Two carbon black materials with two different specific surface areas (80 m2.g−1 and 65 m2.g−1, respectively) were studied. The electronic percolation threshold and the kinetics of impregnation of the hierarchical composite electrode by the liquid electrolyte have been determined with respect to the carbon black content. The significant influence of the adsorbtion of ions at the carbon black surface on the electrons transport is particularly highlighted and explained. [ABSTRACT FROM AUTHOR]

Large scale preparation of graphene-like carbon nanospheres (GCNSs) was performed by direct-current arc discharge using C 2 H 2 as carbon resources. The morphology and structure of the obtained products were investigated by field-emission scanning electron microscope, high-resolution transmission electron microscope, Raman spectroscope, X-ray diffraction and nitrogen adsorption. The GCNSs consist of quasi-spherically concentric graphitic shells with high purity and quality, and its size distribution is in the range of 30–50 nm. The high-quality GCNSs also exhibit highly electrical conductivity of ∼30.3 S cm −1 , and can act as conductive agent to significantly improve the electrochemical performance of LiFePO 4 (LFP) cathode, compared with the conventional carbon black (CB). Discharge capacity of the LFP (GCNSs) cathode reaches up to 155.6 mAh g −1 at 0.1 C, which is slightly higher than that of the LFP (CB). However, The LFP (GCNSs) cathode still delivers high capacities of 114.9 mAh g −1 and 65.2 mAh g −1 at 1 C and 10 C rates, respectively, which are much higher than those of the LFP (CB). At the same time, the discharge capacities reach up to 114.9 mAh g −1 and 80.9 mAh g −1 at 1 C and 5 C discharge rates for the first discharge, and the corresponding capacities decrease down to 108.5 mAh g −1 and 79.9 mAh g −1 after 100 cycles, respectively. This indicates excellent cyclic stability, especially at high rate charge/discharge cycles. Thus, the mass production, high crystalline and highly electrical conductivity may make the GCNSs find applications in energy conversion and storage. [ABSTRACT FROM AUTHOR]

• Facile vacuum-assisted filtration method was used to assemble ERGO/MoS 2 -based films. • USER reaction quickly expanded the structure of graphene oxide-based films. • The most electrochemically active film was with the ratio 1:1 of ERGO to ex-MoS 2. • The displayed discharge capacity of ERGO/MoS 2 –1 (ratio 1:1) is 916 mAh/g. • Reduced graphene oxide-based films electrodes do not utilize non-active materials. In this paper, thin free standing films based on ultrafast self-expanded reduced graphene oxide (ERGO) and exfoliated molybdenum disulfide (ex-MoS 2) were prepared via vacuum-assisted filtration and tested as anodes in Li-ion half-cells. Three films with GO to ex-MoS 2 ratio of 1:1, 1:2 and 2:1 were assembled (ERGO/MoS 2 –1, ERGO/MoS 2 –2, ERGO/MoS 2 –3, respectively). Reduction of GO-based films was conducted via ultrafast self-expanded reaction (USER) in Ar atmosphere. This process not only immediately reduced GO but also significantly expanded films structure. The sample with the highest specific capacity and the highest stability consisted of GO and ex-MoS 2 with ratio of 1:1. The anode composed of this film showed approximately 6 times higher discharge capacity (916 mAh/g at 50 mA/g) than reference film (RGO/MoS 2 –1) where graphene oxide was thermally reduced in a furnace (145 mAh/g at 50 mA/g). Such high performance is associated with the expanded structure of ERGO allowing better lithiation yield and served as a protection of ex-MoS 2 against overexpanding upon charging/discharging process. What is more, the proposed Li-ion half-cells are free of any non-active materials e.g. carbon black or poly(vinyl difluoride) which are commonly used in batteries increasing the cost of the whole energy storage device. [Display omitted] [ABSTRACT FROM AUTHOR]

A hybrid air-electrode composed of a mixture of fluorinated carbon (CF x ) and Ketjen black (KB) active carbon composite materials was prepared to improve performance of Li-O 2 battery. In the hybrid air-electrodes, four kinds of CF x materials including fluorinated graphite, fluorinated carbon fiber, fluorinated coke and fluorinated black carbon were utilized as lithium insertion materials. The physical properties and morphologies of the KB and CF x carbon materials were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM) measurements. Compared with the conventional KB air-electrode, all the CF x /KB hybrid air-electrodes in Li-O 2 batteries showed higher specific discharge capacity, especially at high current density. Among these CF x /KB hybrid air-electrodes, the fluorinated graphite based electrode showed the best electrochemical performance in Li-O 2 battery due to its highest discharge capacity of the fluorinated graphite material in the Li/CF x primary battery, highest specific surface area, and highest total pore volume. The electrochemical performance of Li-O 2 and Li-air batteries using the hybrid air-electrodes with the different fluorinated graphite: KB weight ratio, including specific charge and discharge capacity, cycling stability and rate capability were systematically investigated. At a current density of 0.5 mA cm −2 , the fluorinated graphite based air-electrode delivered a high specific discharge capacity of 1138 mAh g −1 in Li-O 2 batteries, which was more than four times than that of the conventional KB air-electrode (265 mAh g −1 ) under same testing conditions. The battery assembled with the fluorinated graphite based air-electrode exhibited better cycling stability than that of the battery assembled with the conventional KB air-electrode. [ABSTRACT FROM AUTHOR]

A homogeneous nanocomposite of SnSe and carbon black, denoted as SnSe/C nanocomposite, was fabricated by high energy ball milling and empolyed as a high performance anode material for both sodium-ion batteries and lithium-ion batteries. The X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy observations confirmed that SnSe in SnSe/C nanocomposite was homogeneously distributed within carbon black. The nanocomposite anode exhibited enhanced electrochemical performances including a high capacity, long cycling behavior and good rate performance in both sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). In SIBs, an initial capacitiy of 748.5 mAh g −1 was obtained and was maintained well on cycling (324.9 mAh g −1 at a high current density of 500 mA g −1 in the 200 th cycle) with 72.5% retention of second cycle capacity (447.7 mAh g −1 ). In LIBs, high initial capacities of approximately 1097.6 mAh g −1 was obtained, and this reduced to 633.1 mAh g −1 after 100 cycles at 500 mA g −1 . [ABSTRACT FROM AUTHOR]

As a novel anode material for lithium-ion batteries, Pb(NO3)2can deliver an initial discharge capacity as high as 1310.8 mAh g−1. However, its capacity retention is poor upon repeated cycles. In this work, carbon black (CB), graphene (GN) and carbon nanotube (CNT) are used as conductive additives to fabricate Pb(NO3)2/CB, Pb(NO3)2/GN and Pb(NO3)2/CNT, respectively. It is observed that CB and GN fail to form uniform three-dimensional conductive network for Pb(NO3)2. As a result, Pb(NO3)2/CB and Pb(NO3)2/GN do not show obviously improved electrochemical properties compared to bare Pb(NO3)2. For comparison, CNTs provide cross-linking conductive cages for Pb(NO3)2particles. It can be found that CNT coating can significantly enhance the electrochemical property of Pb(NO3)2. Pb(NO3)2/CNT reveals a reversible charge capacity of 495.2 mAh g−1after 45 cycles at a current density of 50mAg−1, which is much higher than that of bare Pb(NO3)2(227.4 mAh g−1), Pb(NO3)2/CB (278.0 mAh g−1), Pb(NO3)2/GN (327.2 mAh g−1). Even cycled at 200mAg−1, Pb(NO3)2/CNT can maintain a reversible lithium storage capacity of 411.7 mAh g−1. All these results suggest that Pb(NO3)2/CNT is a promising anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate a simple method for enhancing the electrochemical performance of air electrodes of Li–air batteries using a polydopamine coating on the surface of carbon. A thin polydopamine layer on Ketjen black carbon clearly modified the surface properties of the air electrode, in turn resulting in improved electrolyte filling. The coating also passivates surface carbon defects, which may be helpful in suppressing parasitic reactions during cycling. Electrochemical tests of the electrode indicate that the introduction of the polydopamine layer is beneficial in that it increases the capacity, lowers the overpotential, and improves the cyclic performance of Li–air cells. These effects may be associated with the increased active catalytic area of the electrode, mostly resulting from the improved wetting characteristics. The suppression of parasitic reactions due to the passivation of carbon defects also contributes to the enhanced cyclic performance of the polydopamine-treated electrode. [Copyright &y& Elsevier]

Abstract: The dispersion properties of carbon black (CB) slurries as well as the accompanying electrochemical properties of Li(Ni1/3Co1/3Mn1/3)O2 (NCM) electrodes were investigated by controlling the amine value of polyurethane-based dispersants. The increase in amine value of dispersants leads to an increase in adsorption level on CB surface due to a strong acid/base interaction between dispersants and CB particles, providing the improvement of steric repulsion between particles at the solid–liquid interface. This results in the enhancement of the dispersion stability of CB and the related microstructure of the electrodes. Electrochemical experiments indicated that the rate capabilities and cycle performance of the electrodes are in good agreement with dispersion properties of CB slurries. However, it was found that the excessive addition of the dispersant was deleterious to electrochemical properties because the non-adsorbed dispersants act as an electronic conduction barrier between solid phases. Therefore, it is suggested that the amine value of dispersant and tailored amount of dispersant addition can be key roles for obtaining the optimized dispersion stability of CB and the corresponding excellent electrochemical properties of the cathode. [Copyright &y& Elsevier]

• Nanosized VC was synthesized by disproportionation of V(IV) ions in molten salt. • The VC powder have excellent dispersibility and uniform size distribution. • The VC exhibits desirable electrochemical performances as an anode in LIBs and SIBs. • It is a new insight into the synthesis of high-performance carbide as anode in metal-ion batteries. Nanosized VC with an average particle size of ∼40 nm was synthesized by disproportionation of V(IV) ions on acetylene black template in molten (Na,K)Cl at 950 °C holding for 5 h. The as-synthesized VC has exhibited desirable electrochemical performances as an anode in lithium-ion batteries (LIBs), delivered a reversible discharge capacity of 597.8 mAh g−1 at 0.1 A g−1 and ∼397.8 mAh g−1 at 0.5 A g−1 in 200 consecutive cycles. It is noteworthy that nanosized VC also displayed impressive charge-discharge capacities in sodium-ion batteries (SIBs), released ∼252.5 mAh g−1 at 0.1 A g−1. This work provides a new insight into the preparation of high-performance carbide ceramics as anodes in metal-ion batteries. [Display omitted] Well-distributed nanosized VC was synthesized by a convenient and efficient synthesis method, utilizing disproportionation reaction of V(IV) in molten salt, exhibits excellent electrochemical performances in lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: Recently, we reported a simple method for obtaining nanosized silicon with promising electrochemical properties as an anode material for lithium-ion batteries; the method involves the formation of a composite electrode with cellulose fibers. It is demonstrated that the performance of these electrodes can be enhanced by the addition of conductive carbon black (CCB). This beneficial effect is not only a result of the improvement of electrical conductivity and inter-particle contacts, but also due to a reduction of the expansion and shrinkage undergone by the electrode when Li is inserted into Si or extracted from Li x Si, as revealed by in situ electrochemical dilatometry measurements. The best results were obtained with a CCB of high surface area and porosity. The Si/cellulose fiber/carbon electrodes obtained delivered charge capacities as high as 1800mAhg−1 and exhibited good capacity retention on cycling. These electrodes also exhibited lower expansion/shrinkage compared to carbon-free electrodes on discharging and charging the cell, respectively. [Copyright &y& Elsevier]

Abstract: A spinel LiMn2O4/C composite was synthesized by hydrothermally treating a precursor of manganese oxide/carbon (MO/C) composite in 0.1M LiOH solution at 180°C for 24h, where the precursor was prepared by reducing potassium permanganate with acetylene black (AB). The AB in the precursor serves as the reducing agent to synthesize the LiMn2O4 during the hydrothermal process; the excess of AB remains in the hydrothermal product, forming the LiMn2O4/C composite, where the remaining AB helps to improve the electronic conductivity of the composite. The contact between LiMn2O4 and C in our composite is better than that in the physically mixed LiMn2O4/C material. The electrochemical performance of the LiMn2O4/C composite was investigated; the material delivered a high capacity of 83mAhg−1 and remained 92% of its initial capacity after 200 cycles at a current density of 2Ag−1, indicating its excellent rate capability as well as good cyclic performance. [Copyright &y& Elsevier]

Amorphous metal-organic gel (MOG) can be applied as anode for lithium ion batteries (LIBs) due to its advantages of the controllable structure and the adjustable pore size. In this work, M-MOGs (M=Ni, Zr, Fe, Al, Cr) membranes were fabricated by drop casting method and used as LIB anodes for the first time. They exhibited the excellent electrochemical performance, which were much better than metal-organic frameworks (MOFs) or MOGs without membrane formation of the same metal atom. There was no need to add carbon black, binder or organic solvent when fabricating the membrane electrode which can be attributed to the excellent electronic conductibility of membrane and the viscosity of MOGs. At the same time, the prepared MOGs have the self-healable property which can effectively restrain volume expansion during the lithium ion intercalation/extraction process. In five membrane electrodes, Ni-MOG membrane had a great specific capacity reaching to 1710.1 mA h g−1 at the current density of 100 mA g−1, and remained at 1245.5 mA h g−1 after 30 cycles with high rate performance. Furthermore, the coulombic efficiency was nearly 100% after 100 cycles at a high current density of 2 A g−1 or 5 A g−1. The conductivities of the five MOG membranes were between 10−8 and 10−7 S m−1, indicating that the membrane anodes had semiconductor property. It can be seen that amorphous MOG membrane is a promising anode material for LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

Development of high-performance SnO 2 anodes is hampered by its peculiar electrochemical behavior, characterized by two processes: conversion and alloying reactions. The conversion reaction being irreversible leads to specific capacities lower than theoretical, however rational design of nanosized SnO 2 can mitigate this issue, though SnO 2 low conductivity and electrode pulverization justify the need of carbon matrices. Some carbon structures proved to be strongly effective at laboratory-scale, but most are too expensive or complicated to obtain for scaling-up. Herein, we exploit the high concentration of oxide and carboxylic surface functional groups of C-NERGY™ Super C45 carbon black for one-pot synthesis of ultrafine SnO 2 nanoparticles over the carbon surface. These functional groups accomplish the hydrolysis/oxidation of SnCl 2 , resulting in finely dispersed SnO 2 nanoparticles (5 nm in average size) growth over C45. Presence of oxygen species on C45 surface, accessible to tin, prevent fast formation of Li 2 O, allowing to achieve high capacity and extreme electrode stability. The assembled cells with SnO 2 /C45 exhibit for more than 400 cycles the reversible capacity of 560 mA h g−1 per pure SnO 2 (after subtracting C45 contribution) at 1C, demonstrating prolonged cycling operation thus providing an interesting opportunity for scalable production of stable and high-capacity battery anodes alternatively to graphite. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Lots of lithium ion battery (LIB) products contain lithium metal oxide LiNi 5 Co 2 Mn 3 O 2 (LNCM) as positive electrode active material. To increase the conductivity, conductive carbon-based materials including acetylene black and carbon black become necessarily consisted in electrodes. Recently, carbon nano-tube (CNT) appears as a popular choice for 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 comparing to conventional carbon black is also a problem. In this work, we are going to introduce 'short length' and 'long length' carbon nano-tube (S-CNT and L-CNT) into electrode in order to design a reduced-amount conductive carbon electrode. The whole experiment will be done in 1 Ah commercial type pouch LIB. By decreasing conductive carbon as well as increasing the active material in positive electrode, the energy density of LNCM-based 1Ah pouch type LIBs with only 0.16% of L-CNT inside LNCM positive electrode could reach 224 Wh/kg and 549 Wh/L, in weight and volume energy density, respectively. Also, this high energy density LIB with L-CNT reveals stable cyclability may become a valuable progress in portable devices and electric vehicle (EV) applications. [ABSTRACT FROM AUTHOR]

• Successfully fabricated SbNPs/rGO anode on Cu foil by electrophoretic deposition. • Tailoring the ratio of SbNPs and rGO entails a stable anode for LIBs/SIBs. • SbNPs/rGO exhibits excellent cycle performance and rate capability. • Electrophoretic deposition is suitable for fabrication of binder-free metal/alloy anodes. Antimony (Sb) is a well-studied anode for lithium-ion/sodium-ion batteries (LIBs/SIBs) owing to its exceptionally high theoretical capacity (~660 mAhg−1). However, abrupt capacity decay due to severe volumetric swelling (~300%) associated with a fully lithiated/sodiated phase(s) impede the commercial applications. Even though various synthesis strategies able to control the volumetric swelling of Sb but the delamination of active mass from the Cu foil cannot be avoided. Keeping in mind that traditional doctor-blade slurry coating cannot prevent Sb delamination, herein, we show that electrophoretic deposition (EPD) of antimony nanoparticles (SbNPs) embedded in reduced graphene oxide (rGO) sheets on Cu foil is a viable technique to fabricate binder-free electrodes in quick time (~3 min) preventing Sb delamination. In particular, nanostructured SbNPs/rGO derived from a hydrothermal method is successfully deposited on Cu foil using nickel nitrates/poly(acrylic acid) as dispersant and carbon black as a conductive agent in propanol. The SbNPs/rGO electrodes exhibit an exceptionally stable capacity of 370 mAhg−1 at 1C, and 350 mAhg−1 at 0.2C current rate for LIBs and SIBs, respectively, up to 100 cycles. Importantly, the rate capability of the electrodes also found excellent with capacity remains ~170 mAhg−1 and Coulombic efficiency ~99% at 6C current rate for LIBs. The SIBs also show similar performance and able to maintain capacity ~235 mAhg−1 and Coulombic efficiency ~99% at 4C current rate. Ex-situ phase and microstructural analysis reveal that cycled electrodes form a graphene nanoribbons interspersed with Sb nanoparticles and Li 3 Sb/Na 3 Sb phase during charge-discharge. It is proposed that hybrid nanostructure and synergy between uniquely placed graphene sheets and SbNPs generated by electrophoretic deposition prevents the active phase delamination and catastrophic failure ushering a time-saving strategy to fabricate binder-free electrodes for LIBs/SIBs. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Solid-electrolyte interface (SEI) between the active material and the electrolyte is critically important to the electrochemical performance of a lithium-ion battery. In this work, a depth profile measurement of the SEI layer after prolonged electrochemical cycling is reported in order to quantify the influence of conducting additives in the development of this layer in mesocarbon microbeads (MCMB) electrodes. It is shown that the SEI in the electrodes having multiwalled carbon nanotubes (CNT) as conductive additive is primarily a multi-layered structure consisting of an outer organic layer near the electrolyte/SEI interface and an inner inorganic layer near the SEI/electrode interface. The chemical analysis of such electrodes exhibits that the inorganic layer is made up of compounds such as Li 2 O, LiF and Li 2 CO 3, while the outer layer consists mainly of organic carbonates, oligomers, traces of randomly distributed Li x PO y F z and undissociated LiPF 6. The chemical analysis of electrodes with carbon black (CB) as conducting additive reveals a similar composition of the outer layer, whereas the inner layer shows a relatively uniform molar amount of organic and inorganic carbonates and species like Li x PO y F z and Li x PO y , resulting in a porous SEI layer which as confirmed in AFM and SEM characterizations. On the other hand, the electrodes containing hybrid (CB-CNT) conducting additives show a relatively higher oligomer content than the electrodes with CNT only. The SEI formed on electrodes with CB-CNT as additives is shown to offer increased flexibility to accommodate partial strain generated due to volume change with narrow cracks exhibited in the SEM micrographs. Further, the variation in surface features and roughness augment the XPS findings. [ABSTRACT FROM AUTHOR]

A nano-sized Si anode material was synthesized by a novel and highly efficient route of ball-milling assisted low-temperature aluminothermic reduction at 150–180 °C in a eutectic NaCl/KCl/AlCl 3 mixture, using white carbon black and coarse-grained Al powder as the starting materials. After extending the duration of ball-milling assisted aluminothermic reduction to 10 h, the obtained Si yield reached as high as 94%. The synthesized nano-Si mainly consisted of irregular porous agglomerates constructed by ultrafine primary particles with a particle size less than 50 nm. The nano-Si anode showed a superior electrochemical performance. Its maximum discharge and charge capacities at a current density of 0.05 A g−1 were 3075 and 2597 mAh g−1, respectively, leading to a high initial Coulumbic efficiency of 84.5%. The nano-Si anode exhibited reversible capacities of 2458 mAh g−1 at 0.2 A g−1, and of 1169 mAh g−1 at a high current density of 5 A g−1. After cycling at 1 A g−1 for 400 cycles, it still delivered a high reversible capacity of 804 mAh g−1. The synthetic strategy, which is not only facile and highly efficient, but also low-cost and environmentally benign, is thus promising to be applied for mass production of nano-Si anode materials for next-generation Li-ion batteries. [ABSTRACT FROM AUTHOR]