Study Of One-dimensional Self-standing High-performance Anode Materials For Lithium-ion Batteries

With the rapid development of flexible and wearable electronic devices,flexible lithium-ion batteries have become the hotspot and one of frontiers in research field of the energy storage.Till date,the key factors and the main difficulties to realize flexible lithium-ion batteries is to design and fabricate flexible electrode materials own self-standing structure and with stable and high performance in the condition of repeated.To this issue,in this paper,one-dimensional hierarchically porous highly nitrogen-doped nanofiber networks which suitable for using as promising anode materials in flexible lithium-ion batteries were controllably prepared by adopting three kind of soft/hard templates to produce pore and using methods of electrospinning,nitrogen-doping,the templates-activation method,carbonization and chemical treatment.In this work,self-standing one-dimensional hierarchically porous highly nitrogen-doped carbon anodes were firstly prepared by electrospining polyacrylonitrile?PAN?and addition of two kind of soft templates?PMMA and PS?and one kind of hard template?MnOx-CeO₂-Al₂O₃?,along with the subsequent carbonization-activation and post-etching.These three kinds of one-dimensional hierarchically porous highly nitrogen-doped nanofiber networks which suitable for using as promising anode materials all exhibited a higher specific surface area,well-developed hierarchically porous structure and relatively high-level nitrogen doping.The collected three kind of one-dimensional hierarchically porous highly nitrogen-doped nanofiber networks all exhibited superior electrochemical performance when they were directly used as anodes in LIBs,without adding any other polymeric binders or conductive additives.The superior electrochemical performance can be ascribed to their unique hierarchically porous structure,relatively high-level of nitrogen doping,one-dimensional nanostructure and great amount of pyridinic nitrogen.Among these three kind of one-dimensional hierarchically porous highly nitrogen-doped nanofiber networks,the hierarchically porous highly nitrogen-doped nanofiber networks in which the PMMA as template to produce pore showed ultrahigh capacity of 1576.5 mAh g^-1,which was higher than that of most other reported carbon-based anode materials.The hierarchically porous highly nitrogen-doped nanofiber networks in which the MnOx-CeO₂-Al₂O₃ as template showed relatively best cycling stability,it can maintain about 90%of its original capacity after 50 cycles.