锂离子电池硅基负极研究进展 <p> </p>-中国材料进展

文章信息/Info

Author(s):: BIE Yitian; YANG Jun; School of Chemistry and Chemical Engineering，Shanghai Jiao Tong University

摘要:: 硅由于具有超石墨10倍的高理论容量和相对适中的放电平台而备受关注，是最具潜力的下一代锂离子电池负极材料之一。然而，硅的本征电导率低，且在嵌锂的过程中有着巨大的体积变化（＞300%），会导致材料粉化，电极崩塌，失去电接触。此外，在电解液中硅表面的SEI膜重复形成也导致了极化增大，库伦效率降低和电解液消耗等问题。为了解决上述问题，实现硅电极的商业化应用，改善硅基电极的途径主要有：制备新型硅基材料抑制体积效应和提高电导率，改进粘结剂来加强电极结构防止电极崩塌，改进电解液以提高SEI膜质量和库伦效率。当前，改进硅基负极材料性能的主要策略是纳米化、孔隙化和复合化。粘结剂的改性也可分为开发新型粘结剂和修饰已有粘结剂。主要从硅基材料和粘结剂两方面论述了近年来的发展状况，并展望了其未来的发展方向。

Abstract:: Silicon has attracted enormous attentions because of its theoretical capacity ten times higher than that of graphite and its proper discharge potential, which makes silicon one of the most promising anode materials for lithium-ion batteries. However, silicon has poor electronic conductivity and enormous volume change（＞300%）during lithiation process, which lead to the pulverization of materials, crash of electrode and electrical contact loss.Moreover, continuous formation of SEI layer on the silicon surface in the electrolytecauses the problems like polarization increase, low coulombic efficiency and electrolyte consumption.Approachesto overcome these hinders and realize the commercial application of silicon based electrodes mainly include preparing advanced silicon-based materials to suppress the volume effect and rise the conductivity, improving the binder to strengthen the electrode structure and prevent its collapse, and ameliorating electrolyte to enhancethe quality of SEI film andcoulombic efficiency. Currently, the main strategies of improving the performance of Si materials are the structure designs towards nanoscale, porosity and composite.The improvement of binder can be divided into two aspects: developing new binders and ameliorating existing binders. This paper summarizes the recent process from two aspects of silicon-based materials and binder, and discusses the development trends.