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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]

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]

• 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]

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]

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]