Thin and porous anode materials enable short ion migration distances and high-rate performance. However, the current freestanding anode materials are too thick (typically around 100 μm) for high-rate lithium ion batteries (LIBs). Here, we have developed a facile and scalable process to synthesize ultra-thin (<400 nm) freestanding films. In comparison to other chemical and physical deposition methods that yield thin films (<500 nm), our freestanding films do not require the substrate material, achieving a 100% loading of active material. Our ultra-thin carbon nanofiber films exhibit an exceptional specific capacity of 599 mAh/g even after 10,000 cycles at a current density of 10 A/g. Compared to thick carbon nanofiber films, the utilization of ultra-thin carbon nanofiber films as anode materials exhibits a remarkable enhancement of more than tenfold in cycling performance

Currently, the anode of sodium-ion battery is mainly made of carbon material, and the carbon black made of acetylene has the advantages of low cost, high purity and simple process, etc. The particle size of carbon black has a great influence on the storage capacity of sodium ions, in this study, carbon black particles with different particle sizes were prepared by chemical vapour deposition method by changing the temperature and gas flow rate, and the effects of the temperature and the gas flow rate on the size of the carbon black were investigated, and the effect of the particle size of carbon black on the performance of the battery was studied. The effect of temperature and gas flow rate on the particle size of carbon black was investigated, and then the effect of the particle size of carbon black on the battery performance was studied. The larger the gas flow rate of acetylene, the smaller the particle size of carbon black generated. The carbon black CB-3 generated by holding at 900 ℃ and an acetylene flow rate of 300 mL/min for 30 min kept the capacity of 112.36 mAh/g after 180 cycles, and the specific capacity of the first discharge was 414.66 mAh/g, and the reversible specific capacity at 2 A/g still had 92.12 mA/g. This work helps to provide new ideas for research in enhancing the electrochemical performance of sodium-ion battery materials.

In our pursuit of high-performance lithium-ion battery (LIB) anodes, we developed a hybrid electrospun membrane consisting of MoO3 nanorods (MoO3 NRs) integrated with carbon nanofibers (CNFs), termed MoO3@CNFs. Serving as an anode, this membrane boasts several advantages. Firstly, it capitalizes on the novel structure of MoO3@CNFs, enabling rapid ion/electron transport pathways. Secondly, due to the carbon skeleton, MoO3 is protected from coming into direct contact with the electrolyte. Thirdly, the consistent internal structure of MoO3@CNFs enhances conductivity. Experimental findings reveal that the anode with a relatively low MoO3 content, specifically 33

To develop an efficient anode for lithium ion batteries (LIBs), we prepare an ultralong oxygen-deficient titanium dioxide nanotubes (TNTs)-based hybrid electrospun carbon nanofibers (CNFs) membrane (TNT@CNFs). As an anode, this membrane possesses several advantages, including fast ion/electron trans-port path due to the TNTs' novel structure, protection from direct contact between TNTs and electrolyte owing to the carbon skeleton, improved electrical conductivity on account of the internal structural con-sistency of TNTs, and enhanced ion transport because of oxygen vacancies. As a result, the anode with a relatively low content of TNT (33TNT@CNFs) exhibits an ultra-high reversible specific capacity of 350 mAh/g after 200 cycles at a relatively low current density (0.2 A/g), while the anode with a high content of TNT (50TNT@CNFs) exhibits an ultra-high rate performance of 187 mAh/g at 10 A/g after 10,000 cycles, in-dicating its superior electrochemical kinetics at high-rate and long cyclic lifespan. This can find proof from the dynamic analysis that both the surface capacitance process and the diffusion-controlled insertion have a great contribution. The strategy employed in this work can facilitate access to a variety of one-dimensional (1D) nanostructured composites and can promote new research on electrodes for ultrafast rechargeable LIBs.& COPY; 2023 Elsevier B.V. All rights reserved.

The significant capacity loss and pulverization caused by the dramatic increase in volume of Sn-based anodes during redox reactions severely limit their practical application in lithium-ion batteries. Herein, with the ultralong cycle life and high capacity Sn-based compounds (SnS-C/NS@CNFs), a self-supporting anode was prepared by electrospinning followed by the calcination scheme, which is a superb material for lithium storage since the buffer matrix reduces the volume expansion of Sn. In this strategy, SnS nanoparticles are scattered into a porous carbon framework using Sn-MOFs as a pore-forming template, which allows for easier extraction-insertion of Li-ions due to their inherent layered structure. Moreover, the nitrogen and S-doped carbon nanofibers not only serve as a barrier to impede the aggregation and volume expansion of SnS during cycling but also act as electrical pathways to enhance the conductivity of the electrodes. Having profited from the desirable nanostructures, the flexible three-dimensional cross-linked nanofibers were straightly used as a self-supporting anode for LIBs, displaying ultralong cycle life (455.8 mAh/g after 1000 cycles at 1 A/g) and exceptional rate performance (481 mAh/g at 2 A/g). This work offers a reliable and efficient method for fabricating flexible self-standing and durable electrodes.

多硫化锂穿梭效应依然是阻碍下一代储能锂硫电池发展和应用的关键难题.为此,利用静电纺丝技术,将PAN与PMMA、PS、PVP等 3 种聚合物进行混合纺丝得到纳米纤维膜(ANMMA@NFs、ANS@NFs、ANVP@NFs).随后利用高温碳化制备多孔碳纳米纤维(ANMMA@CNFs、ANS@CNFs、ANVP@CNFs),以此探究PMMA、PS、PVP等 3 种不同聚合物种类对纳米纤维的造孔影响.借助其发达的多孔结构,实现了碳结构中的熔融扩散载硫,制备出多孔碳复合硫正极材料(ANMMA@CNFs-S、ANS@CNFs-S、ANVP@CNFs-S).测试结果表明,多孔结构减轻了体积膨胀,物理吸附多硫化物改善了硫的利用率.其中,ANMMA@CNFs在0.2C电流密度下的初始放电比容量为696.01 mAh/g,显示出较好的电化学性能.

The availability of lithium sulfur (Li-S) batteries is significantly constrained by the severe shuttle effect and sluggish conversion kinetics of polysulfides (LiPSs). Here, we construct the catalytic NiCoSe4/carbon nanofibers interlayer composite (NiCoSe4 @CNFs) to restrict shuttle effect and accelerate the polysulfides conversion. The NiCoSe4 derived from metal organic framework (MOF) retains the advantage of CoSe2 in chemical adsorption for polysulfide, and Ni doping offers superior electrocatalytic activity. Meanwhile, the carbonization of MOF ensures the NiCoSe4 superior electrical contact with the derived carbon materials. In addition, CNFs build conductive carbon matrix for the growth of NiCoSe4 on the surface to facilitate the electron transfer during charging and discharging process. Benefit from the unique structure, NiCoSe4 @CNFs as interlayer can quickly and effectively carry out the strategy of polysulfides adsorption followed by simultaneously catalysis. Batteries with a NiCoSe4 @CNFs interlayer can deliver excellent performance with a stable cycle performance after 500 cycles (residual capacity of 74 %) at 2 C and a high discharge specific capacity of 1019.5 mAh g-1 at 0.5 C. Achieving robust polysulfide adsorption and electrocatalytic activity in NiCoSe4/carbon nanofibers interlayer opens previously unexplored avenues towards advanced separation technologies and energy-harvesting devices.