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In this paper, a series of iron oxide/reduced graphene oxide/carbon nanotube composites (K3‐Fe2O3‐rGO/CNT) with well‐dispersedFe2O3 particles are prepared by in situ reaction and then heat‐treatment, and its electrochemical and battery performancesare studied as the anode material of lithium‐ion batteries. The results show that the introduction of reduced graphene oxide/carbon nanotube (rGO/CNT) improves the electrochemical and battery performances of the prepared electrode material. In particular, the K3‐Fe2O3‐rGO/CNT (30 %) composite material has a reversible capacity of 1559 mAh g−1 after 100 charge/discharge cycles at 100 mA g−1. And its specific discharge capacityis 641.1, 639.7, 609.5, 578.6 and 543 mAh g−1at the current density of 100, 200, 500, 1000 and 2000 mA g−1, respectively,with 84.7 % of capacity retention even with a 10 times increase in current density. The research of charge storage indicates that the electrochemical process is a mixed control process of diffusion and capacitance. The improved electrochemical and battery performancesfor the composite electrode material can be attributed to the enhanced dispersion of the Fe2O3 and the enhanced conductive network provided by rGO/CNT composite carbon. It makes a promising way to prepare high performance of anode material for lithium‐ion battery. [ABSTRACT FROM AUTHOR]

In this paper, we design a binder GG-CA-GLY (abbreviation: GGC) for silicon negative electrode by guar gum as the backbone chain with self-healing function, combing and straightening the guar molecular chain of guar gum through the plasticizing effect of glycerol. The condensation reactions between the exposed hydroxyl sites of guar gum and the carboxyl groups of citric acid create a stronger hydrogen bond, so as to achieve the effect of self-healing and cope with the serious volume expansion effect of silicone-based materials. [Display omitted] • A easy polycondensation reaction is used to create a mechanically strong self-healing polymer (GGC). • GGC adhesives have excellent mechanical properties and facilitate rapid self-healing. • GGC@Si electrodes were prepared with excellent rate capability and higher cycling stability. • GGC adhesives have the ability to repair cracks and other damage on prepared silicon anodes, returning them to their original state. Silicon is a promising anode material for lithium-ion batteries with its superior capacity. However, the volume change of the silicon anode seriously affects the electrode integrity and cycle stability. The waterborne guar gum (GG) binder has been regarded as one of the most promising binders for Si anodes. Here, a unique steric molecular combing approach based on guar gum, glycerol, and citric acid is proposed to develop a self-healing binder GGC, which would boost the structural stability of electrode materials. The GGC binder is mainly designed to weaken van der Waals' forces between polymers through the plasticizing effect of glycerol, combing and straightening the guar molecular chain of GG, and exposing the guar hydroxyl sites of GG and the carboxyl groups of citric acid. The condensation reaction between the hydroxyl sites of GG and the carboxyl groups of citric acid forms stronger hydrogen bonds, which can help achieve self-healing effect to cope with the severe volume expansion effect of silicone-based materials. Silicon electrode lithium-ion batteries prepared with GGC binders exhibit outstanding electrochemical performance, with a discharge capacity of up to 1579 mAh/g for 1200 cycles at 1 A/g, providing a high capacity retention rate of 96%. This paper demostrates the great potential of GGC binders in realizing electrochemical performance enhancement of silicon anode. [ABSTRACT FROM AUTHOR]

Herein, we propose a comprehensive chemical experiment that include the preparation, characterization and lithium storage performance evaluation of mesoporous carbon-coated iron oxide nanoparticles. Students are guided to acquaint themselves with the characterization methods of material structure, the operation of battery assembly and battery testing technique. This experiment will disclose the interrelationship between material structure and performance to students, and cultivate their experiment skills, scientific literacy, and practical innovation ability. Furthermore, this experiment serves as a gateway for students to explore the frontier in new energy, and stimulate their scientific interest. Therefore, this experiment is recommended as a comprehensive chemical experiment course for senior undergraduates majoring in materials chemistry or applied chemistry. [ABSTRACT FROM AUTHOR]

Li3VO4 (LVO) is a highly promising anode material for lithium-ion batteries, owing to its high capacity and stable discharge plateau. However, LVO faces a significant challenge due to its poor rate capability, which is mainly attributed to its low electronic conductivity. To enhance the kinetics of lithium ion insertion and extraction in LVO anode materials, a conductive polymer called poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is applied to coat the surface of LVO. This uniform coating of PEDOT:PSS improves the electronic conductivity of LVO, thereby enhancing the corresponding electrochemical properties of the resulting PEDOT:PSS-decorated LVO (P-LVO) half-cell. The charge/discharge curves between 0.2 and 3.0 V (vs. Li+/Li) indicate that the P-LVO electrode displays a capacity of 191.9 mAh/g at 8 C, while the LVO only delivers a capacity of 111.3 mAh/g at the same current density. To evaluate the practical application of P-LVO, lithium-ion capacitors (LICs) are constructed with P-LVO composite as the negative electrode and active carbon (AC) as the positive electrode. The P-LVO//AC LIC demonstrates an energy density of 107.0 Wh/kg at a power density of 125 W/kg, along with superior cycling stability and 97.4% retention after 2000 cycles. These results highlight the great potential of P-LVO for energy storage applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Anodes based on silicon/carbon composites promise their commercial prospects for next-generation lithium ion batteries owing to their merits of high specific capacity, enhanced ionic and electronic conductivity, and excellent compatibility. Herein, a series of carbonaceous framework/Si composites are designed and prepared by rational waste utilization. N, P codoped foam-like porous carbon/Si composites (FPC@Si) and N, P codoped carbon coated Si composites (NPC@Si) are fabricated by utilizing expired milk powder as a carbon source with facile treatment methods. The results indicate that the porous carbon skeleton and carbon shell can improve the conductivity of Si and stabilize the solid electrolyte interfaces to avoid direct contact between active material and electrolyte. Moreover, the influence of drastic volume expansion of Si on the anode can be efficiently alleviated during charge/discharge processes. Therefore, the Si/C composite electrodes present excellent long-term cycling stability and rate capability. The electrochemical performance shows that the reversible capacity of FPC@Si and NPC@Si can be respectively maintained at 587.3 and 731.2 mAh g−1 after 1000 charge/discharge cycles under 400 mA g−1. Most significantly, the optimized Si/C composite electrodes exhibit outstanding performance in the full cell tests, promising them great potential for practical applications. This study not only provides a valuable guidance for recycling of waste resources, but also supports a rational design strategy of advanced composite materials for high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

Copper phosphide has shown remarkable development potential in the anode materials of lithium ion batteries (LIBs) due to its high mass/volume ratio capacity. Nevertheless, the low conductivity and volumetric expansion in the cycling process restrict its practical application. Herein, we ingeniously designed and successfully prepared copper phosphide (Cu 3 P)@carbon (C) nanocomposite with multi-stage pore inverse opals (Cu 3 P@C MSPIOs), including possessed the ordered macropores with the mean aperture of ∼100 nm induced by polystyrene (PS) sphere templates and the mesoporous structure with the pore size range of 3.0-9.5 nm and 16–27 nm derived from metal-organic framework (MOF) precursor. Compared to the Cu 3 P@C particles prepared without PS sphere templates, the Cu 3 P@C MSPIOs as the anode materials demonstrated exceptional lithium storage performance. At a high current density of 2 A g-1, the discharge specific capacity of Cu 3 P@C MSPIOs was 295 mA h g-1 in the 1st cycle while that dropped to 204 mA h g-1 during the 2nd one, and then gradually stabilized. After 1500 cycles, the discharge specific capacity can still reach to 166.3 mA h g-1, maintaining 81% capacity compared to the 2nd discharge specific capacity, which indicates the Cu 3 P@C MSPIOs as the anode material presented good cycling stability. Apparently, the multi-stage pore structure, which can effectively resolve the volumetric change problem during lithium ion (Li+) intercalation/deintercalation as well as facilitate contact between electrolyte and anode, is primarily responsible of the superior Li-ion storage property of Cu 3 P@C MSPIOs. At the same time, MOF derived carbon can improve electrical conductivity, accelerate the formation of a stable solid electrolyte interface membrane and also provide buffer layers to further alleviate volumetric expansion. [ABSTRACT FROM AUTHOR]

As a potential anode material for lithium-ion batteries (LIBs), metal tin shows a high specific capacity. However, its inherent "volume effect" may easily turn tin-based electrode materials into powder and make them fall off in the cycle process, eventually leading to the reduction of the specific capacity, rate and cycle performance of the batteries. Considering the "volume effect" of tin, this study proposes to construct a carbon coating and three-dimensional graphene network to obtain a "double confinement" of metal tin, so as to improve the cycle and rate performance of the composite. This excellent construction can stabilize the tin and prevent its agglomeration during heat treatment and its pulverization during cycling, improving the electrochemical properties of tin-based composites. When the optimized composite material of C@Sn/NSGr-7.5 was used as an anode material in LIB, it maintained a specific capacity of about 667 mAh g−1 after 150 cycles at the current density of 0.1 A g−1 and exhibited a good cycle performance. It also displayed a good rate performance with a capability of 663 mAh g−1, 516 mAh g−1, 389 mAh g−1, 290 mAh g−1, 209 mAh g−1 and 141 mAh g−1 at 0.1 A g−1, 0.2 A g−1, 0.5 A g−1, 1 A g−1, 2 A g−1 and 5 A g−1, respectively. Furthermore, it delivered certain capacitance characteristics, which could improve the specific capacity of the battery. The above results showed that this is an effective method to obtain high-performance tin-based anode materials, which is of great significance for the development of new anode materials for LIBs. [ABSTRACT FROM AUTHOR]

Development of high-performance lithium-ion batteries (LIBs) is boosted by the needs of the modern automotive industry and the wide expansion of all kinds of electronic devices. First of all, improvements should be associated with an increase in the specific capacity and charging rate as well as the cyclic stability of electrode materials. The complexity of experimental anode material selection is now the main limiting factor in improving LIB performance. Computer selection of anode materials based on first-principles and classical molecular dynamics modeling can be considered as the main paths to success. However, even combined anodes cannot always provide high LIB characteristics and it is necessary to resort to their alloying. Transmutation neutron doping (NTD) is the most appropriate way to improve the properties of thin film silicon anodes. In this review, the effectiveness of the NTD procedure for silicene/graphite (nickel) anodes is shown. With moderate P doping (up to 6%), the increase in the capacity of a silicene channel on a Ni substrate can be 15–20%, while maintaining the safety margin of silicene during cycling. This review can serve as a starting point for meaningful selection and optimization of the performance of anode materials. [ABSTRACT FROM AUTHOR]

Lignin, as the second most abundant natural polymer, has not been fully utilized in the industrial field due to the complex structure and functional groups. In this paper, polyvinyl chloride (PVC) coated lignin‐silica composites (PLS) with excellent cycling performance are prepared from rice husk and PVC through the method of alkali extraction and acid precipitation and mechanical mixing process. Due to the existence of functional groups on the surface of lignin, it can be closely combined with PVC to form a stable structure. The first discharge specific capacity and Coulombic efficiency of PLS is 1436 mA h g−1 and 56 %, respectively, and the reversible capacity is 720 mA h g−1 after 200 cycles at 0.1 A g−1, showing a stable cycling performance. This work promotes the application of lignin in the SiO2/C anode material of lithium ion battery, and confirms the stable combination between PVC and organic carbon. [ABSTRACT FROM AUTHOR]

The oxide glass‐based anodes for lithium‐ion Batteries (LiBs) still suffer from two critical drawbacks, that is, low reversible capacity and low electrical conductivity. Here, we report a new way to overcome the two drawbacks. Specifically, we chose 50Fe2O3–50P2O5 (50Fe50P) glass as the anode material for LiBs, and then thermally treat it at 1118 K (Tg+345 K) for 0.5 h under reducing atmosphere (5 mol% H2+95 mol% Ar). The thermal reduction treatment led to formation of Fe2(P4O12) and Fe2Fe5(P2O7)4 crystals. The reduced glass‐based anode for LiBs exhibits the capacity of 373 mA h g−1 after 1 000 charge/discharge cycles at 1 A g−1, which is higher than that of the oxidized one. The reduction treatment greatly lowers the charge transfer resistance in the glass anode, indicating the enhancement of the electrical conductivity. This performance improvement could arise from the increase of accessible active sites for Li+ ion storage and transfer due to the existence of crystal–crystal/crystal–glass boundaries, as well as from the improvement of the electron transfer between Fe2+ and Fe3+ during cycling. This reduction–crystallization approach could help develop high‐performance oxide glass‐ceramics based anodes for advanced LiBs. [ABSTRACT FROM AUTHOR]

Silicon-carbon (Si/C) composite materials have been proven to be one of the most promising anode materials for the next generation of lithium-ion batteries (LIBs) due to their high theoretical capacity. However, the substantial volume changes during alloying/dealloying processes have posed significant challenges to the working lifespan of Si-based anodes. In this study, we designed a dual-carbon-layer-structured Si composite anode material (DCS-Si). Using ladderlike polysilsesquioxanes as a precursor, we employed a zinc thermal reaction to internally reduce the Si– O –Si framework to Si0. Simultaneously, the phenyl groups directly connected to Si atoms served as a carbon source for the internally dense coating layer. The obtained product underwent further coating controllable pyrolysis reactions to form an external carbon coating layer. As anode for LIBs, DCS-Si delivered a reversible specific capacity exceeding 1000 mAh g−1. Even after 1350 cycles at a current density of 0.3 A g−1, the specific capacity remained above 500 mAh g−1. Moreover, even under a high current density of 3 A g−1, after nearly 1000 cycles, the capacity retention rate still exceeded 70%. Further testing of the full cell also indicated that DCS-Si is a highly promising high-energy-density anode, with potential applications in future commercial lithium-ion batteries. [Display omitted] • A dual-carbon-layer-structured Si composite was successfully synthesized. • The dual-carbon-coating demonstrates a synergistic effect. • The inner and outer carbon coating layers possess distinct advantages. • The DCS-Si anode shows outstanding cycling stability and high rate capability. • The full-cell performance with DCS-Si anode and NCM811 cathode was evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] Titanium niobate (TiNb 2 O 7 , TNO) possesses attractive discharge voltage and reversibility, which is considered to be an ideal anode material of lithium ion battery (LIB). However, its rate capability is strictly limited by their poor conductivity. To improve this issue faced by traditional TNO electrodes, a hierarchical conductive optimization strategy has been proposed and fabricated by a facile spray drying approach. For the construction, TiNb 2 O 7 @ultrathin carbon layer (TNO@C) is entangled into carbon nanotubes network to synthesize a highly conductive porous TNO@C/CNTs microsphere. This ultrathin carbon layer and evenly intertwined carbon nanotubes can ensure the superior charge transfer pathway, facilitating the transportation of electrons and Li ions. Additionally, CNTs can provide robust mechanical strength framework, beneficial to the structural stability of composite microspheres. As expected, the TNO@C/CNTs exhibits elevated conductivity and cyclic durability with charge capacities of 343.3 mAh·g−1 at 0.25 C after 300 cycles and 274.9 mAh·g−1 at 10 C after 1000 cycles. This study intends to explore the effect of the attached carbon materials on the TNO-based electrode conductivity and LIBs performances. [ABSTRACT FROM AUTHOR]

Tin dioxide (SnO 2) is a promising anode material for lithium-ion and sodium-ion batteries. However, the huge volume expansion during cycling makes it far away from practical application. Herein, we report a template-free "heterogeneous carbonization" strategy for fabricating SnO 2 /carbon/void/carbon nanofibers (SCVC) compound membrane with finite spatial domain in carbon matrix as buffer layer for volume changes of SnO 2. Reduced graphene oxide (rGO) is also imported into the SCVC membrane, acting as conductive binders to construct a free-standing SCVC-rGO electrode with exceptionally conductive network. The resultant SCVC-rGO anodes in lithium/sodium-ion batteries could deliver excellent electrochemical performances of higher reversible capacity, longer lifespan and superior rate capability. As lithium-ion battery anode, the SCVC-rGO electrode shows specific capacities of 950 mA h g−1 after 400 cycles at a current of 0.5 A g−1, and 824 mA h g−1 after 650 cycles at 1 A g−1. In sodium-ion batteries, the SCVC-rGO electrode gives rise to the specific capacity of 407 mA h g−1 after 2000 cycles at the current of 1 A g−1 with exceptional capacity retention. SnO 2 /carbon/void/carbon nanofibers membrane combined with reduced graphene oxide (SCVC-rGO) is constructed by a template free, one-step heterogeneous carbonization strategy. The internal void formed in situ in SnO 2 /C can be used as confined space to accommodate its volume expansion, while the residual ultrathin carbon layer on SnO 2 nanocrystals can prevent their amalgamation and recrystallization. The SCVC-rGO anodes exhibit excellent cycling stability and rate capability in LIBs and SIBs. [Display omitted] • One-step strategy of heterogenous carbonization to in-situ form buffering voids. • Based on the different carbon yields from various precursors and without the help of templates and corrosives. • Internal voids and residual ultrathin carbon layer ensure the complete reversibility of electrochemical reactions. • Excellent cycling stability and rate capability in half cells of LIBs and SIBs have been achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • LPL consisting of AlF 3 and PAA is employed on Si anode for high energy density LIBs. • AlF 3 acts a role of constructing a LiF-rich SEI layer on the Si anode. • PAA in the LPL mitigates the severe volume change of the Si anode. • LPL@Si anode shows outstanding electrochemical performances. Silicon (Si) is considered as one of the most promising anode materials with an extremely high specific capacity (3579 mAh/g), which is beyond the limit of conventional graphite anodes in lithium (Li) ion batteries (LIBs). However, large volume changes during the lithiation/delithiation process and formation of an unstable solid electrolyte interface (SEI) layer hinder the practical application of Si anodes. To address these issues, constructing a stable protective layer at the interface between anode and electrolyte is a desirable strategy. In this study, a LiF-rich SEI inducing protective layer (LPL) comprising aluminum fluoride (AlF 3) and poly(acrylic acid) (PAA) is introduced onto Si anode to construct a stable LiF–rich SEI layer and mitigate the volume changes of the Si anodes during cycling. Owing to the synergetic effects of AlF 3 and PAA, a LiF-rich SEI layer with robust physicochemical properties is uniformly formed on the Si anode. As a result, the LPL coated Si (LPL@Si) anodes exhibit outstanding electrochemical properties in Li metal cell tests. In addition, a full-cell prepared with the LPL@Si anode and LiNi 0.8 Co 0.1 Mn 0.1 O 2 as a cathode exhibits an excellent cycling performance and mitigated volume changes, demonstrating the potential of this strategy to protect the Si anodes for the development of high-energy–density LIBs. [ABSTRACT FROM AUTHOR]

In this study, we introduce a novel method for designing microstructures of Sn-45Zn alloy foils utilizing the accumulative roll bonding (ARB) technique, which is one of severe plastic deformation techniques that have been used for refining the microstructures of bulk metals. The electrochemical properties of Sn-Zn foil anodes with various microstructures achieved through the ARB method followed by annealing are investigated in lithium-ion batteries. The degree and characteristics of microstructural damage during electrochemical cyclic tests are also examined in detail to provide insights into the microstructural parameters that critically influence the capacity and cyclic behavior of the Sn-Zn alloy foil anode. Our findings suggest that the ARB-processed Sn-Zn alloy foil, characterized by nearly ultrafine grains composed of Sn and Zn phases with the Zn phase forming a continuous network, exhibits superior battery capacity and cycle life compared to the sample processed using the conventional rolling method. This superiority can be attributed to its unique microstructure obtained through ARB, which reduces pore density, suppresses pore interlinkage, decreases charge transport resistance and nucleation overpotential, and enhances Li-ion diffusivity in the electrode. [Display omitted] • The Sn-Zn alloy foil could be fabricated using accumulative roll bonding. • The ultrafine grains with a continuous Zn-phase network were obtained. • The obtained microstructure was effective in minimizing damage evolution. • Enhanced capacity and cycle life were achieved from this unique microstructure. [ABSTRACT FROM AUTHOR]

A simple and facile approach to synthesis Co 3 O 4 nanocrystals by a two–step pyrolysis process of bis (8–hydroxyquinoline) cobalt complex under Ar and air atmospheres successively. The structures and physical properties of the complex, Co@C intermediate and the Co 3 O 4 nanocrystals are characterized by the following techniques: FTIR, XRD, TGA–DTG, Raman, FESEM, HRTEM, N 2 adsorption/desorption measurement and XPS. As anode materials in lithium ion batteries, the Co 3 O 4 nanocrystals exhibit high charge/discharge specific capacity, excellent rate performance and remarkable cycle stability. The superior electrochemical properties of the Co 3 O 4 nanocrystals could be attributed to the nanoscaled particle size, high crystallinity and high specific surface area, which is helpful to increase the number of active sites, shorten the diffusion path of lithium ions and electrons, alleviate the volume expansion effect as well as improve the dynamic characteristics during cycling. Co 3 O 4 nanocrystals are synthesized by a two–step pyrolysis process of bis (8–hydroxyquinoline) cobalt complex. As the anode materials of lithium ion batteries, the as–obtained Co 3 O 4 active material shows high discharge specific capacities, outstanding cyclic stability and excellent rate capability. The excellent lithium storage performance could be attributed to the nanoscaled particle size, high crystallinity, high specific surface area as well as excellent dynamic characteristics of the Co 3 O 4 nanocrystals during charge/discharge cycle. [Display omitted] [ABSTRACT FROM AUTHOR]

High entropy oxides (HEOs) have attracted the attention of researchers due to their high theoretical specific capacity and structural stability. However, the effect of elements in HEOs on material properties is unknown. In this work, HEOs (FeNiCrMnZn) 3 O 4 and (FeNiCrMnMg) 3 O 4 were successfully synthesized and used as anode materials for lithium ion batteries. The effects of Zn and Mg on the properties of HEOs were studied from the aspects of crystal structure, micro morphology, and surface valence. Results show that Zn enhances the lithium storage performance of HEOs theoretically, which is verified in the later electrochemical performance tests. (FeNiCrMnZn) 3 O 4 is better than (FeNiCrMnMg) 3 O 4 in all aspects of rate properties, cycle performance, and electrochemical impedance spectroscopy. Therefore, the introduction of electrochemically active metals, such as Zn, can improve the performance of HEOs, thereby providing ideas for the subsequent design and application of HEOs. [ABSTRACT FROM AUTHOR]

Silicon (Si) containing materials cannot be used in commercial lithium ion batteries due to the mechanical stress problem triggered by volume expansion during cycling. The high-volume change causes mechanical instability of Si anode materials during charging/discharging, resulting fast capacity fading. It is thought that piezoelectric materials can be a solution for the volume expansion problem because of their ability to generate electric field when pressure is applied on them. For this purpose, PZT-8 and PZT-5H type piezoelectric materials were mixed with silicon and multiwalled carbon nanotube (MWCNT) to obtain anode composites and tested electrochemically versus lithium metal. The piezoelectiric effect on the electrochemical activity of these anodes is investigated by preparing the anode composite without any piezoelectric material additive (Sample #3). At the end of the 50 charge/discharge cycles, the capacities reached 420 mAh/g, 300 mAh/g and 100 mAh/g for PZT-8-added, PZT-5H-added and no-PZT samples, respectively. These results showed that PZT addition improves capacity performance of Si-MWCNT anodes. Additionally, the obtained anode composites were characterized with X-ray diffraction and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

Synergistic effect improves the electrochemical properties of metal oxide anode materials for lithium ion-batteries. The influence of different ratios of nickel and manganese on the microscopic morphology and the contribution of pseudocapacitance were investigated. The ternary Prussian blue analog Ni x Mn y [Fe(CN) 6 ] 2 (x + y = 3) manufactured by adjusting the ratio of Ni-Mn mixed salt was used to obtain the ternary transition metal oxide. When the ratio of Ni and Mn is 8:2 or 2:8, the synergistic effect of oxide anode materials between the ternary transition metals is strong. The corresponding materials have excellent cycle stability, higher reversible capacity, lower charge transfer resistance and higher proportion of pseudocapacitance contribution. The calcined product is NiFe 2 O 4 -FeMnO 3 , which has a core-shell structure when the ratio of Ni and Mn is 2:8, and the first cycle discharge capacity is 1697.6 mAh/g. It can provide a reversible capacity 536.1 mAh/g after 500 cycles at 500 mA/g. The analysis of electrode dynamics shows that the pseudocapacitance contribution can reach 46.8% at 0.1 mV/s. [ABSTRACT FROM AUTHOR]

The unbearable volume expansion of silicon hinders its application for lithium-ion batteries (LIBs). The utilization of carbon coating to silicon has significantly improved its performance. However, the carbon coatings prepared via traditional methods are often too fragile to prevent the carbon-silicon electrode from pulverization during the long-term cycling process. Herein, a new, convenient, low-cost method is developed to prepare silicon-nickel-carbon composites with high mechanical strength and ion diffusivity for LIBs. Graphenic carbon network materials embedded with Si and Ni nanoparticles are prepared by using in-situ generated Ni0 as catalysts to the thermal polymerization of polycyclic asphalt molecules. The composites show excellent LIB performance, superior to those prepared conventionally without the addition of nickel. The composite with 73.7 wt% Si shows an initial Coulombic efficiency of 87.5% and a charge capacity of 3191 mA h g−1. The electrode expands only 16.5% in thickness after cycled 300 times at 2 A g−1. Moreover, the composites with 19.6 wt% and 33.8 wt% Si exhibit capacities of 342 and 680 mA h g−1 after cycled 500 times at 2 A g−1, with capacity retention of 97% and 85%, respectively. The results show that the present method is promising for the preparation of stable silicon-carbon anode materials. [Display omitted] [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]

Sn@Graphene composites as anode materials in Lithium-ion batteries have attracted intensive interest due to the inherent high capacity. On the other side, the high atomic ratio (Li 4.4 Sn) induces the pulverization of the electrode with cycling. Thus, suppressing pulverization by designing the structure of the materials is an essential key for improving cyclability. Applying the nanotechnologies such as electrospinning, soft/hard nano template strategy, surface modification, multi-step chemical vapor deposition (CVD), and so on has demonstrated the huge advantage on this aspect. These strategies are generally used for homogeneous dispersing Sn nanomaterials in graphene matrix or constructing the voids in the inner of the materials to obtain the mechanical buffer effect. Unfortunately, these processes induce huge energy consumption and complicated operation. To solve the issue, new nanotechnology for the composites by the bottom-up strategy (Organic Molecule Confinement Reaction (OMCR)) was shown in this report. A 3D organic nanoframes was synthesized as a graphene precursor by low energy nano emulsification and photopolymerization. SnO 2 nanoparticles@3D organic nanoframes as the composites precursor were in-situ formed in the hydrothermal reaction. After the redox process by the calcination, the Sn nanoparticles with nanovoids (~100 nm, uniform size) were homogeneously dispersed in a Two-Dimensional Laminar Matrix of graphene nanosheets (2DLM G) by the in-situ patterning and confinement effect from the 3D organic nanoframes. The pulverization and crack of the composites were effectively suppressed, which was proved by the electrochemical testing. The Sn nanoparticles@2DLM G not delivered just the high cyclability during 200 cycles, but also firstly achieved a high specific capacity (539 mAh g−1) at the low loading Sn (19.58 wt%). [ABSTRACT FROM AUTHOR]

With the assistance of silane coupling agent kh550, the RWSi particles are functionalized via surface-engineering treatment, which is conducive to form a uniform PMMA shell. A PMMA-derived uniform carbon shell-protective layer coated recycled silicon-based anode is facilely constructed after carbonization, delivering excellent electrochemical performance for lithium-ion battery. • Uniform carbon shell coated Si anode is prepared by surface-engineering method. • Kh550 is employed to functionalize recycled Si particles via a silanization reaction. • PMMA precursor is transferred into a uniform carbon shell after carbonization. • RWSi@PMMA-C anodes deliver an excellent capacity and structural stability. • The work provides a facile strategy for Si-based anode with carbon uniform shell. Yolk-shell silicon/carbon composite encapsulated by uniform carbon shell (Si@C) are becoming an effective method to mitigate volume-related issues of Si-based anodes and maintain an excellent performance for lithium-ion batteries (LIBs). However, a uniform carbon shell in Si@C is difficult to guarantee. Herein, a facile surface-engineering-assisted strategy is described to prepare Si@C composite with low-cost modified recycled waste silicon powders (RWSi) as core coated by a uniform carbon shell-protective layer derived from the pyrolysis of poly (methyl methacrylate) (PMMA) as carbon source (m-RWSi@PMMA-C). In this process, surface-engineering is performed with silane coupling agent kh550 to functionalize the RWSi particles via a silanization reaction, guaranteeing a uniform PMMA coating which will be transformed into carbon shell-protective layer after carbonization. The m-RWSi@PMMA-C electrode delivers an optimal discharge capacity of 1083 mAhg−1 at 200 mAg−1 after 200 cycles with an initial capacity of 3176.2 mAhg−1 and a high initial Coulombic efficiency (ICE) of 75.6%. Based on these results, the recycled silicon-based anode with a uniform carbon shell-protective layer displays great application potential and it also brings a new perspective on silicon-based anodes via surface-engineering method for LIBs. [ABSTRACT FROM AUTHOR]

In this work, the commercial detonation nanodiamonds (DNDs) are introduced to the anodes of lithium ion battery (LIBs) consisting of anatase titanium dioxide (TiO2) and synthesized graphite by a microwave treatment process. The compound TiO2/DND/graphite anodes are favorable for improving the LIB performance, where the LIBs have lithium storage capacities of 540 mA h g−1 at 0.5 C after 100 cycles and 300 mA h g−1 at 5 C after 1000 cycles, which are greatly higher than the theoretical data (168 mA h g−1) from TiO2 anode alone. The high capacity, as well as excellent cycling performance and stability of the LIBs, are attributed to the synergistic effect of DND (larger surface area, low expansion, high lithium adsorption capacity, chemical inertness), TiO2 (high Li+ insertion/extraction voltage, robust structural stability, lower volumetric expansion) and the improved ionic conductivity of the anode with additional fabricated graphitic powders. [ABSTRACT FROM AUTHOR]

Electrode material is a key factor for high-energy storage battery. In this paper, graphene oxide/poly(o-phenylenediamine) (GO/PoPD) hybrid composite is prepared by combining the self-assembly process to form graphene oxide/o-phenylenediamine hydrogel and subsequently the in situ oxidation polymerization, which exhibits the open porous morphology with high BET surface area of 347 m2/g. As the anode of lithium ion battery, GO/PoPD possesses the double lithium storage mechanisms from graphene oxide and poly(o-phenylenediamine). Meanwhile, it exhibits an initial discharge-specific capacity of 1632.4 mAh/g and the improved cycling stability. Even after 43 cycles, it still keeps a capacity of 839.5 mAh/g, which is obviously higher than that of GO and PoPD. Furthermore, GO/PoPD hybrid composite presents the enhanced rate performances with the discharge-specific capacities of 1411.7, 718.2, 621.2, and 576.3 mAh/g at current rates of 50, 100, 200, and 500 mA/g, respectively. The improved electrochemical performances are attributed to the formed stable porous morphology, which facilitates the electrolyte ion to penetrate into the electrode matrix during the redox reaction and then results in the improved cell performances. [ABSTRACT FROM AUTHOR]

The strong demand on high-performance lithium ion batteries has brought up an attention upsurge in the research society and the commercial market. Carbon materials have shown the great potential as anode materials for lithium ion batteries since they are low-cost, safe, abundant, and electrochemically stable. In this work, we report a selenium-doped carbon anode through carbonizing the mixture of selenium and an organic compound of naphthalenetetracarboxylic dianhydride. Benefiting from the porous structure, enlarged BET specific area, and active defects from the doping of Se, the material shows excellent rate capability. It delivers a high specific capacity of 450 mAh g−1 after 580 cycles at the current density of 500 mA g−1 and a specific capacity of 170 mAh g−1 after 2400 cycles at the current density of 1000 mA g−1. The superb performance of this material proves its potential as anode for high-performance lithium ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • A composite binder composed of polyvinyl alcohol and squaric acid is developed. • A complete multi-binder network is constructed by further electrochemical growth. • Electroactive squaric acid promotes the formation of a robust SEI film. • The binder network stabilizes the macro- and micro-structures of Si electrodes. • Improved electrochemical performance is obtained in both half cells and full cells. Silicon (Si) is a promising alternative anode material for lithium-ion batteries due to its ultra-high theoretical capacity and suitable voltage platform. However, its practical application is limited by the rapid capacity fading caused by the instability of the solid electrolyte interphase (SEI) film, the collapse of Si particle structure and the mechanical failure of Si electrodes. Herein, we develop a multifunctional composite binder (denoted as PS) composed of multi-hydroxyl polyvinyl alcohol (PVA) and electroactive squaric acid (SA). The complete binder network derived from the efficient crosslinking reactions between SA and PVA chains, as well as the beneficial electrochemical synergistic decomposition reactions between SA and fluoroethylene carbonate additive, can effectively stabilize the macro- and micro-structures of Si electrodes, induce the beneficial decomposition components of electrolytes to build a robust SEI film, and promote the Li+ transport rate. Based on these beneficial effects, the optimized PS61-based Si anode exhibits higher initial coulombic efficiency (89.8 %), much improved rate performance (2041.5 mAh g−1 at 10 C), and better cycling stability (1582.1 mAh g−1 after 400 cycles) than that of the PVA-based Si anode. Furthermore, the NCM523//Si (PS61) full cell achieved a high reversible capacity of 140.8 mAh g−1 after 300 cycles, demonstrating the positive function of PS binder on promoting the practical application of Si anodes. [ABSTRACT FROM AUTHOR]

Magnetic transition-metal oxides show great prospect as alternatives to prevail anodic carbonaceous substances for lithium ion battery in virtue of their splendid theoretical capacity. However, in addition to their intrinsic poor electronic conductivity, the severe agglomeration of the forming magnetic metal nanoparticles during discharging will deteriorate their actual electrochemical performance in a strong magnetic field environment. Here, we demonstrate a 3D spatially-confining magnetic anode to settle all these dilemmas, in which conversion-type magnetic Fe 3 O 4 nanoparticles with a thin carbon encapsulation layer are anchoring onto 3D nickel nanotube arrays skeleton (Ni/Fe 3 O 4 @C NTAs). The carbon shell spatially confines the agglomeration of Fe nanoparticles and maintains the exceptional integrity of structure. The Ni/Fe 3 O 4 @C NTAs anode exhibits high-capacity lithium storage (∼1286 mAh g−1 at 0.1 C) and superior rate/cycle capability (retaining ∼97 % of initial reversible value at 1 C after long-term 1000 cycles). [Display omitted] • A monolithic hybrid electrode of Ni/Fe 3 O 4 @C NTAs is fabricated. • The carbon shell acts as an isolation layer to spatially confine the Fe nanoparticles from agglomeration. • The hybrid anode exhibits superior rate and cycling stability. [ABSTRACT FROM AUTHOR]

Chromium-based transition metal sulfide such as chromium hemi trisulfide (Cr 2 S 3) gradually emerges as a potential lithium-ion host material considering its relatively large specific capacity along with low cost advantage. However, some excruciating issues such as serious particle aggregation, large volume expansion and insufficient inherent conductivity always result in an inferior Li-storage behavior such as low reversible capacity, limited cycling life and poor high-rate performance. Rational structure design and effective combination with suitable component are crucial to achieve superior Li-storage performance. Herein, a heterostructured composite with small Cr 2 S 3 nanosheets embedded into phenanthroline-derived N-doped porous carbon skeleton (Cr 2 S 3 /NC) has been synthesized through a calcination and sulfuration route. In as-prepared Cr 2 S 3 /NC composite, Cr 2 S 3 nanosheets are well confined by carbon matrix, which is conductive to an effective suppression on aggregation and volume change. Meanwhile, porous conductive carbon framework supplies desirable expressway for fast electron delivery and reduces the distance for lithium ions diffusion. Consequently, the Cr 2 S 3 /NC anode delivers a remarkably elevated Li-storage performance. • Cr 2 S 3 /NC composite with a hierarchical porous structure was fabricated via a facile annealing route. • Cr 2 S 3 nanosheets in composite were anchored on the phenanthroline-derived nitrogen-doped carbon sheets. • The composite demonstrated an enhanced Li-storage property. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous SiO x @C nanocomposites were succesfullly synthesized at mild conditions. • The carbon layer derived from in-situ anchored organics shows multiple advantages. • The pSiO x @C anode shows excellent cycling stability and high rate capability. • The full-cell performance with pSiO x @C anode and LCO cathode was evaluated. SiO x @C anodes have been regarded as one of the most attractive candidates for next-generation high-capacity lithium-ion batteries (LIBs). However, the uneven thickness and lack of continuity in the carbon coating have led to a decrease in capacity, lifespan, and coulombic efficiency. Thus, there is a pressing need to address the atomic-level construction of the Si/C interface. In this study, we present a simple interfacial engineering approach to achieve an in-situ compact carbon layer on porous SiO x @C (pSiO x @C) anodes through low-temperature zinc thermal reduction. Following prelithiation, the pSiO x @C anode demonstrates excellent performance, including a high initial Coulombic efficiency (93.4%), a reversible capacity exceeding 900 mAh/g, long-term cycling stability (1300 charge/discharge cycles at 0.3 A/g) and remarkable rate capability. Furthermore, when coupled with the LiCoO 2 (LCO) cathode, the pSiO x @C//LCO full cell exhibits superior Li-ion storage performance, achieving a high reversible capacity of 147 mAh/g at 0.2 A/g. This work provides valuable insights into the design of SiO x -based anode materials for high-energy–density LIBs. [ABSTRACT FROM AUTHOR]

In order to avoid side reactions with liquid electrolyte for the prelithiation method using metal lithium for the improvement of initial coulombic efficiency and prelithiation efficiency, we propose the solid electrochemical corrosion (SEC) of lithium replacing liquid electrolyte with solid electrolyte of lithium phosphorus oxynitride (LiPON) in previous works. However, the low prelithiation rate of solid electrochemical corrosion with LiPON interlayer between anode and lithium hinders its possible large-scale application. Here, an ultrathin film of Bi 2 O 3 is introduced as the interface layer to improve the prelithiation rate of SEC, the prelithiation effects are investigated on both graphite and SiO x /C anodes by morphological, spectroscopic and electrochemical characterizations. The initial coulombic efficiencies of graphite and SiO x /C anodes can be respectively increased by about 5.1% and 9.7% after the prelithiation. The prelithiation efficiency values are as high as 79.3% for graphite and 86.7% for SiO x /C with SEC prelithiation. Our results demonstrate that SEC prelithiation with Bi 2 O 3 interface layer could be applied to improve the capacity and cycling performance of lithium-ion batteries. • Li 3 Bi/Li 2 O mixed layer was adopted for solid electrochemical corrosion prelithiation. • The electrochemical performances were compared with that LiPON interlayer. • Capacity improvement mechanisms were studied for graphite and SiO x /C anodes. [ABSTRACT FROM AUTHOR]

A new covalent organic framework is synthesized and used as an anode material for lithium-ion batteries for the first time. Both the imine bond (C=N) and aromatic C=C bond of the TAACOF can store lithium ions reversibly, a total of up to 14 electrons participating in the redox reaction, corresponding to a high theoretical capacity of 1330.8 mAh/g. [Display omitted] • A novel covalent organic framework is synthesized under mild conditions. • The covalent organic framework is used as the anode for lithium ion batteries. • A total of up to 14 electrons are involved in the redox reaction. • Both the C = N and aromatic C = C bond can store lithium ions reversibly. • A high capacity of 1035.7 mAh g−1 is obtained after 800 cycles at 500 mA g−1. Covalent organic frameworks (COFs) have been widely used in various fields due to their abundant elemental resources, easy structure control, and abundant tunable porous structures. COFs containing electroactive organic groups with reversible redox behavior are potential electrode materials for next-generation high-performance lithium-ion batteries (LIBs). However, the aromatic conjugated structure of the backbone moiety in most reported COFs cannot participate in redox reactions, resulting in low capacity of COFs. At the same time, the synthesis processes of COFs are usually complicated and generally requires high temperature and high pressure. On this basis, an imine bond-rich COF (TAACOF) with reversible Li-ion bonding is developed, which has the advantages of facile preparation and low energy consumption. In particular, the lone pair electrons of the N atom in the imine bond can induce lithium ions to combine with the aromatic conjugated structure, which greatly improves the capacity of the TAACOF electrode. After 800 cycles, the active sites of the TAACOF are fully activated, and after a 14-electron redox reaction, the specific capacity can reach as high as 1035.7 mAh/g. [ABSTRACT FROM AUTHOR]

Reasonably designing and synthesizing advanced electrode materials is significant to enhance the electrochemical performance of lithium ion batteries (LIBs). Herein, a metal–organic framework (MOF, Mil‐125) was used as a precursor and template to successfully synthesize the porous mooncake‐shaped Li4Ti5O12 (LTO) anode material assembled from nanoparticles. Even more critical, SmF3 was used to modify the prepared porous mooncake‐shaped LTO material. The SmF3‐modified LTO maintained a porous mooncake‐shaped structure with a large specific surface area, and the SmF3 nanoparticles were observed to be attach on the surface of the LTO material. It has been proven that the SmF3 modification can further facilitate the transition from Ti4+ to Ti3+, reduce the polarization of electrode, decrease charge transfer impedance (Rct) and solid electrolyte interface impedance (Rsei), and increase the lithium ion diffusion coefficient (DLi), thereby enhancing the electrochemical performance of LTO. Therefore, the porous mooncake‐shaped LTO modified using 2 wt % SmF3 displays a large specific discharge capacity of 143.8 mAh g−1 with an increment of 79.16 % compared to pure LTO at a high rate of 10 C (1 C=170 mAh g−1), and shows a high retention rate of 96.4 % after 500 cycles at 5 C‐rate. [ABSTRACT FROM AUTHOR]

Mesoporous hollow hierarchical structures play an important role in enhancing the lithium storage performances of Co 3 O 4 anode materials. In this work, Co 3 O 4 with mesoporous hollow structure has been successfully fabricated by simple impregnation and subsequently air calcination using poplar branch as bio-template. The product calcined at 600 °C (PB-Co 600) perfectly duplicates the 3D aligned microchannels structure of poplar branch. Importantly, the wall of aligned microchannels in PB-Co 600 is constructed by a lot of irregular cross-linked Co 3 O 4 nanoparticles and there are abundant mesopores on the surface. As an anode, it exhibits high reversible capacity and remarkable long-cycle stability. At 0.1 A g-1, it can deliver a high specific capacity of 1153.7 mA h g-1 after 100 cycles, and even at 1 A g-1, the reversible specific capacity of 555.7 mA h g-1 can be retained after cycling 1000 times. The excellent lithium storage performance of PB-Co 600 may be attributed to its unique hierarchical structure, which is not only favorable to the rapid transfer of substances and Li+ ion diffusion, but also alleviates the volume change during the charge/discharge cycle. Furthermore, the existence of oxygen vacancies and pseudo-capacitance also contributes significantly to the superior lithium storage performance of the PB-Co 600 electrode. Therefore, the PB-Co 600 prepared by a large-scale and eco-friendly route can be used as a potential candidate anode for LIBs. Image 1 [ABSTRACT FROM AUTHOR]

Metal oxide anodes which can achieve high lithiation capacities by conversion mechanism are promising in lithium storage systems. The main obstacle to their practical applications is poor cycling performance. Regulating element ratio of multi-metal materials is effective for improving their electrochemical properties. Herein, optimized Mn–Ni–Co–O anode materials with long-cycle stability are reported. The improvement is associated with proper element ratio, which enables accelerated Li+ ion diffusion and high-stability LiF-rich solid electrolyte interphase (SEI) layer. As a result, (Ni 0 · 1 Co 0 · 3 Mn 0.6) 3 O 4 materials deliver lithiation capacities of 500 mAh g−1 after 1500 cycles at the current density of 1 A g−1. It is greatly better than other samples with different element ratio. Then, application properties of (Ni 0 · 1 Co 0 · 3 Mn 0.6) 3 O 4 materials are evaluated by assembled with active carbon and LiFePO 4 for energy storage devices, respectively. The obtained Li-ion capacitor exhibits high energy densities of 112 Wh kg−1 based on total mass of oxides and active carbon. The obtained Li-ion battery also shows good cycle stability. These results suggest lithiation capacity fade of metal oxide anodes can be mitigated by controlling their component contents. This low-cost and high effective way is to promote commercial applications of metal oxide anode materials in energy storage systems. [ABSTRACT FROM AUTHOR]

Co@Co3O4@Nitrogen doped carbon (Co@Co3O4@NDC) composite is synthesized by high temperature carbonization of ionic liquids followed by low temperature thermal oxidation. In the process of high temperature carbonization, cobalt ions are reduced to metallic cobalt, producing Co@Nitrogen doped carbon (Co@NDC). Co@Co3O4@NDC composite is obtained after low temperature oxidation, in which a part of the metallic cobalt is oxidized to Co3O4. The structural characterizations indicate that the composite is composed of three crystalline phases (carbon, Co and Co3O4). The results of transmission electron microscopy study show that the carbon materials not only coat the Co@Co3O4 nanoparticles, but also form carbon network that connects the Co@Co3O4 nanoparticles. This conductive carbon network is beneficial to improve the electrochemical performance of the composite. The electrochemical test results show that the Co@Co3O4@NDC composite exhibits excellent electrochemical performance, delivering the discharge capacities of 790 and 304 mAh˙g−1 after 1500 cycles at 5 C and 10 C. This excellent electrochemical performance is due to synergistic effects of Co3O4, cobalt nanoparticles embedded in carbon which has high conductivity, and nitrogen functional groups. [ABSTRACT FROM AUTHOR]

Silicon has attracted a lot of attention as a potential anode material for next‐generation lithium ion batteries (LIBs) because of its high energy density, high theoretical capacity, and abundance. Herein, we introduce an effortless synthesis of coral‐like silicon powders with a three‐dimensional (3D) interlinked network using a scalable method that consist of magnesiothermic reduction and chemical vapor deposition. The porous structure achieved by silicon nanospheres can create room for the volume expansion and alleviate the built strain that would occur upon lithiation. In addition, intertwined coral‐like framework provides a shortened path for lithium ion diffusion, which can improve the ionic conductivity of the cells. At a high current rate of C/2, a reversible capacity of 3172 mAh g−1 was delivered by the silicon‐carbon nanocomposite electrode, and the capacity still remains as high as 1018 mAh g−1 after 500 cycles, while the Columbic efficiency is higher than 99%. The inexpensive, effective, and scalable fabrication of porous silicon‐carbon nanocomposite spheres possessing a 3D interlinked network could establish a basis for developing high energy density anode materials to be used in next‐generation LIBs. [ABSTRACT FROM AUTHOR]

Nanoscale metal oxides based binder-free electrodes have application prospects in the energy storage field. In this work, Fe2O3 nanosheets composited with carbon matrix were prepared via the electrochemical deposition on the dopamine treated stainless steel substrate, followed by annealing treatment. The electrode delivers discharge capacity of 1242 mAh·g−1 at 600 mA·g−1 current density after 100 cycles. Furthermore, the electrode exhibited outstanding rate capability and its reversible capacity reaches to 960 mAh·g−1 at 1800 mA·g−1 current density. The properties of full-cells comprising LiFePO4 cathode were also studied. The improved cycle performance could be attributed to high electronic, ionic conductivity and strong tolerance to volume change benefited from the unique nanostructure and amorphous carbon structure. This work may provide a facile and efficient method for the synthesis of high performance Fe2O3 anode materials. [ABSTRACT FROM AUTHOR]

Summary: Hybrid metal oxide heterostructures have been considered as ideal and potential anode materials for lithium ion batteries (LIBs) due to their better electrochemical performances, such as reversible capacity, structural stability and electronic conductivity. Herein, we have demonstrated synthesis of NiCo2O4/BiVO4 heterostructures by simple hydrothermal strategy to construct hybrid xNiCo2O4/(1–x)BiVO4 heterostructures with four selected compositions, that is, x = 10%, 20%, 30% and 40%. XRD shows the phases of NiCo2O4 and BiVO4 and FE‐SEM data revealed strong interface coupling between NiCo2O4 nanowires and BiVO4 dendrites. Upon testing for electrochemical properties, the optimized composition of 30%NiCo2O4‐70% BiVO4 showed higher reversible capacity of 408.6 mAh/g at a constant current rate of 0.5 A/g after 1000 cycles with columbic efficiency around 99% suggesting potential electrode material for high‐performance LIBs. The higher capacity is mainly attributed to the large surface area which can provide more channels and locations for fast Li ion intercalation/de‐intercalation into electrode materials. Additionally, improved Li ion storage capacity with superior rate capability of BN‐30 electrode could be attributed to its lower charge‐transfer resistance. The dendritic and nanowire heterostructure novel system with good stable capacity for LIBs is hitherto unattempted. [ABSTRACT FROM AUTHOR]

Summary: Hybrid metal oxide heterostructures have been considered as ideal and potential anode materials for lithium ion batteries (LIBs) due to their better electrochemical performances, such as reversible capacity, structural stability and electronic conductivity. Herein, we have demonstrated synthesis of NiCo2O4/BiVO4 heterostructures by simple hydrothermal strategy to construct hybrid xNiCo2O4/(1–x)BiVO4 heterostructures with four selected compositions, that is, x = 10%, 20%, 30% and 40%. XRD shows the phases of NiCo2O4 and BiVO4 and FE‐SEM data revealed strong interface coupling between NiCo2O4 nanowires and BiVO4 dendrites. Upon testing for electrochemical properties, the optimized composition of 30%NiCo2O4‐70% BiVO4 showed higher reversible capacity of 408.6 mAh/g at a constant current rate of 0.5 A/g after 1000 cycles with columbic efficiency around 99% suggesting potential electrode material for high‐performance LIBs. The higher capacity is mainly attributed to the large surface area which can provide more channels and locations for fast Li ion intercalation/de‐intercalation into electrode materials. Additionally, improved Li ion storage capacity with superior rate capability of BN‐30 electrode could be attributed to its lower charge‐transfer resistance. The dendritic and nanowire heterostructure novel system with good stable capacity for LIBs is hitherto unattempted. [ABSTRACT FROM AUTHOR]

An anode material with Li 4 Ti 5 O 12 nanocrystals entangled by carbon nanotubes is prepared by polymerization of titanium tetra-isopropoxide with ethylene glycol in the presentence of carbon nanotubes. The resulted polymer is hydrolyzed in LiOH/H 2 O solution, and then thermally decomposed to obtain the topic anode material. The characterizations show that the synthesis method yields a type of material that has both of high electronic conductivity and high lithium ion diffusion rate. The material has stable deep discharge capability (down to 0.01 V), high specific capacity (237 mAhg−1 at 0.30 Ag-1), and long cycling life time (254 mAhg−1 at 0.10 Ag-1, more than 500 discharge/charge cycles). High specific capacities of 258 and 158 mAhg−1 are obtained at current densities of 0.10 and 3.00 Ag-1, respectively. The deep discharge capability of the material offers an average voltage below 1.0 V (vs metal Li), which is lower than that of pristine Li 4 Ti 5 O 12 (1.55 V). Image 1 • Carbon nanotube entangled Li 4 Ti 5 O 12 nanocrystal anode material is synthesized. • The anode material is good conductor for both electrons and lithium ions. • High rate capability of 158 mAhg−1 at 3.0 Ag-1 has been reached. • Stable high specific capacity of 254 mAhg−1 at 0.10 Ag-1 has been confirmed. • Very less capacity fading (1.6%) is observed within 500 (dis)charge cycles at 0.10 Ag-1. [ABSTRACT FROM AUTHOR]

Poor rate and cycling performance are the most critical drawbacks for Si-based anodes on account of their inferior conductivity and colossal volumetric expansion during lithiation/delithiation. Here we report the fabrication of structurally-integrated urchin-like Si anode, which provides prominent structural stability and distinguished electron and ion transmission pathways for lithium storage. The inexpensive solid Si waste from organosilane industry after acid-washed and further ball-milling serves as the pristine Si-source in this work. Carbon nanotubes (CNTs) are in-situ grown outside Si microparticles, resulting in an urchin-like structure (Si/CNTs). The optimized Si/CNTs presents ascendant invertible capacity and rate performance, achieving up to 920 mAh g−1 beyond 100 cycles at 100 mA g −1, and a capacity of 606.2 mAh g−1 at 1 A g −1 after long cycling for 1000 cycles. The proposed scalable synthesis can be adopted to advance the performance of other electrode materials with inferior conductivity and enormous volume expansions during cycling. [ABSTRACT FROM AUTHOR]

In virtue of high capacity and low manufacturing expense, transition metal carbonates (TMCs) have recently arisen enormous research interests as the anode materials for rechargeable lithium ion batteries (LIBs). However, the low electrical conductivity and unstable cycle performance impeded their further development. In this work, Co-B compounds are surface-engineered for the first time onto the mixed single-phase Mn 0.33 Co 0.67 CO 3 microspheres to accelerate the reaction kinetics and suppress the volume fluctuation of the electrodes during Li+ insertion/extraction. Specifically, Co-B nanoflakes not only function as the robust mechanical bridges between Mn 0.33 Co 0.67 CO 3 primary nanoparticles, but also provide extra pathways for electron/charge transport, both of which facilitate the improvement of electrochemical behaviors. Morever, the synergetic effect between Mn 0.33 Co 0.67 CO 3 and Co-B nanoflakes allow a high flux of Li+ across the interface to provide signifcantly boosted Li+ diffusivity. Impressively, the Mn 0.33 Co 0.67 CO 3 @Co-B electrode delivers a high reversible capacity of 806 mA h g−1 over 500 cycles at a high rate of 1.0 A g−1, demonstrating its superior cycling stability. Therefore, surface engineering of borides may be an effective and promising way to improve the electrochemical behaviors of conversion type anodes like TMCs. Image 1 [ABSTRACT FROM AUTHOR]

The improvement in electrode materials to upgrade lithium ion battery (LIB) is at heart of research related to energy devices. Herein, we report on the prospects of using 2H–SiC as an anode material in LIB on the basis of first principles based theoretical predictions. The energy profiling of high symmetry structural sites pointed out that the site T C related to tetrahedral configuration with carbon is favorable intercalation site in the host. The reaction of Li with stoichiometric as well as non-stoichiometric 2H–SiC are found endothermic which points to their unsuitability for lithiation process in LIBs. However, Li intercalation into the host in presence of Si monovacancy appeared an exothermic process which motivated us to study this system in detail. The Li atom after intercalation into the host is found ionized thereby donating its 2s electron to carbon atoms. The average value of the lithium insertion voltage and theoretical capacity are calculated as 1.87 V and 85 mA h/g respectively for the host simulated in the form of supercell Li x Si 15 C 16. The diffusion barrier faced by lithium atom while moving along crystalline a-axis is minimum (among all the paths considered here) when it follows a path that links hexagonal rings while passing carbon atoms. On the other hand, in case of motion along c-axis, similar results are found for minimum energy path that is along Tc site. The low diffusion barrier will facilitate the lithium ion to move quickly that points to fast charging capability of the battery. [ABSTRACT FROM AUTHOR]

Polymer-derived-ceramics (PDCs) and PDC-based fibers are being studied as potential high capacity electrode materials for electrochemical energy storage applications. Among these, silicon oxycarbide (SiOC) has shown most promise, especially as electrodes in lithium ion batteries (LIB). The study of PDCs for supercapacitor electrodes is, however, very limited. This work investigates the fabrication of SiOC-based PDC fiber mats via electrospinning and pyrolysis of three commercial pre-ceramic silicone resins (MK, H44, RSN) of varying composition, and their use as supercapacitor and LIB electrodes. Electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy was performed to study the effect of precursor chemical composition, pyrolysis time and temperature on the morphology, polymer to ceramic transformation and free carbon content. As supercapacitor electrodes, the H44 (a methyl-siloxane) derived SiOC showed the best performance with maximum specific capacitance of 50 F g-1 with capacity retention of ~100% after 2000 cycles. Similarly, as LIB electrodes, H44 derived SiOC fiber mat showed highest reversible capacity of 578 mAh g-1 at a current density of 50 mA g-1. [ABSTRACT FROM AUTHOR]

Manganese monoxide (MnO) is a promising anode material for lithium ion batteries, but it often shows poor electrochemical performance due to some inevitable drawbacks including intrinsic low electrical conductivity, poor stability, and severe polarization. In this work, a 1D core‐shell MnO@S, N co‐doped carbon material (MnO@SNC) was obtained by pyrolysis of MnO2@PPy precursor at 600 °C in N2 atmosphere. When evaluated as an anode for lithium ion batteries, the unique structure and composition advantages endow the as‐formed material with excellent lithium storage performance in terms of high specific capacity (955.5 mAh g−1 at a current density of 500 mA g−1), long‐term cycling stability (up to 500 cycles), and superior rate capability (458.7 mAh g−1 at a current density of 2 A g−1). The outstanding electrochemical performance could be attributed to the unique 1D core‐shell structure, abundant graphited carbon and MnO nanorods. [ABSTRACT FROM AUTHOR]

Nitrogen-doped aqueous alkyd resin carbons are prepared by polymerization methods with biorenewable, biodegradable, and cheap raw materials (soybean oil) as precursor, and NH 3 ·H 2 O as nitrogen source, and ZnCl 2 as template pore-forming agent, followed by carbonization process. The effect of carbonization temperature on the pore structures and electrochemical properties of nitrogen-doped aqueous alkyd resin carbons is studied. Carbon materials prepared at higher carbonization temperature (PC-800) exhibits the higher graphitization and better porosity. The PC-800 maintains a high discharge specific capacity after 300 charge and discharge at a low current density. In addition, it shows good cycling stability, high rate capability and excellent reversible capacity, due to the good pore structure and N doping. Nitrogen-doped aqueous alkyd resin carbons with superior electrochemical performances as anode active material of lithium ion battery provide a new strategy to solve energy shortages. Image 1 • A N-doped porous carbon was prepared by polymerization methods with soybean oil as precursor. • The effect of carbonization temperature on the electrochemical properties of N-doped porous carbon was studied. • Carbon materials prepared at higher carbonization temperature showed good cycling stability and high capacity. [ABSTRACT FROM AUTHOR]

• MoS 2 /Cu NWs are successfully synthesized via microwave-assisted self-assembly. • The stability of 1T MoS 2 is enhanced by in-situ Cu doping. • MoS 2 /Cu NWs anode exhibits improved rate capability and prolonged cycling life. 1T MoS 2 has recently attracted growing interests for energy storage due to the excellent conductivity, expanded layer space and extra exposed active sites. However, its application is still limited due to the complicated synthesis under harsh condition and poor structural stability. Herein, we report a novel MoS 2 /Cu nanowires (NWs) by microwave-assisted self-assembly of ultrathin 1T MoS 2 onto Cu NWs with interconnected conductive network and robust one-dimensional (1D) structure. As anode material for LIBs, 1T MoS 2 /Cu NWs exhibits high capacity and stability owning to the enhanced electron transport and lithium ions intercalation. Meanwhile, the enriched nanovoids supply extended space for buffering the volume change and boosting electrolyte penetration during cycling process. Moreover, Cu doped MoS 2 could also stabilize the 1T phase, leading to the excellent anode durability. It delivers a high reversible capacity of 570.6 mAh g−1 after 250 cycles at a current density of 0.5 A g−1. Enhanced rate performance is also achieved with excellent capacity retention of 914.6 mAh g−1 at 0.1 A g−1 and 465.2 mAh g−1 at 2 A g−1, respectively. [ABSTRACT FROM AUTHOR]

SnO 2 is considered as a high capacity anode material for lithium ion batteries. However, the poor cycling stability has seriously hindered its practical applications. In this work, we designed and prepared Al 2 O 3 /SnO 2 /CNTs composites by uniformly and conformally depositing SnO 2 and Al 2 O 3 on carbon nanotubes (CNTs) via a simple two-step atomic layer deposition (ALD) process. The thicknesses of SnO 2 and Al 2 O 3 were precisely controlled by tuning the number of ALD-cycle to optimize the cycling performance of Al 2 O 3 /SnO 2 /CNTs electrodes. The ultrathin SnO 2 layer with a thickness of approximate 2.8 nm on CNTs exhibits a high capacity and an enhanced cycling stability due to the buffering effect of CNTs and limited SnO 2 crystallization after the first step deposition. On this basis, Al 2 O 3 /SnO 2 /CNTs electrodes exhibit a significantly improved cycling stability, rate capability and Coulombic efficiency due to surface stability and the structural integrity brought by Al 2 O 3 passivation after the second step deposition. Especially, 10-Al 2 O 3 /SnO 2 /CNTs electrode deliveries a discharge capacity of 581.6 mAh g−1 at a current density of 100 mA g−1 and capacity retention is 90.85% against 2nd cycle after 200 charge-discharge cycles. We believe that this work provides an effective way for the design of high performance anode materials in advanced batteries. [ABSTRACT FROM AUTHOR]

Silicon is a promising anodic material used in lithium-ion battery (LIB) to improve the specific energy. While the huge volume change during lithiation/delithiation and low intrinsic conductivity has been a bottle neck of silicon anode. For this sake, carbon shell was used to enhance the conductivity, and hollow structure to buffer the volume swelling/shrinking during cycles. In this work, we synthesized a hollow yolk-shell structure Si/SiC/C (SSC) anode by one-step magnesiothermic reductive reaction. At first, polydopamine (PODA) was used as carbon source to optimize the dosage of magnesium powder and reaction temperature. Then resorcinol formaldehyde (RF) resin was used as another carbon source to prepare several samples with different carbon shell thicknesses. A vital parameter, critical thickness, about 10nm of final shell was proposed to keep the hollow yolk-shell morphology. During this one-step exothermic reaction, Si and C spontaneously reacted and formed inter SiC layer with high modulus. The half-cell with SSC anode delivered a capacity of 505.8 mA h g-1 after 220 cycles at a current density of 100 mA g-1. This novel method is facile to realize and might be used in other fields like composite plating and material modification etc. [ABSTRACT FROM AUTHOR]