SiO用作锂离子电池负极材料的研究进展

Research Progress on SiO as Anode Material for Lithium-ion Batteries

锂离子电池(LIBs)具有使用寿命长、能量密度高、自放电率低等优点,目前已广泛应用于新能源汽车、便携式电子设备、清洁能源存储等领域,这也对锂离子电池的性能提出了更高要求。传统的商业化石墨理论容量仅为372 mAh·g^(-1),作为锂离子电池负极已不能满足对更高容量、更稳定电极的需求。SiO材料具有高比容量(2400 mAh·g^(-1))、原料丰富、制备简单等特点,近年来得到研究人员的广泛关注。然而,SiO负极材料在循环过程中存在较大的体积变化(约200%)和较差的导电性,阻碍了其大规模商业化的应用。研究人员通过多种方法来改善SiO在嵌脱锂时的体积变化以及其带来的影响,提高其在循环过程中的结构稳定性。本文主要综述了SiO负极材料的最新研究进展,重点总结以下四种改性策略:微纳结构工程、复合结构改性、粘结剂优化工程以及预锂化,并对所得SiO基负极材料的结构特点以及电化学性能进行了对比和总结。最后对SiO基负极材料存在的问题进行分析和展望,为制备高容量、长循环性能的锂离子电池SiO负极材料提供重要指导。

Lithium-ion batteries(LIBs)are advantageous because of their long cycle life,high energy density,and low self-discharge rate.Thus,they are widely used in new energy vehicles.Many other fields such as portable electronic equipment and clean energy storage place higher demands on the performance of LIBs.Traditional LIB’s anodes,such as commercial graphite materials,are unable to satisfy higher demands in terms of larger capacity and better stability.SiO is a material that has been extensively studied in recent years because of its high specific capacity(2400 mAh·g^(-1)),abundant raw material,and simple preparation.However,the large volume change(~200%)and poor electrical conductivity of SiO in the cycle process hinder its large-scale commercial application as anode material.Many strategies have been explored to control the volume change and the accompanying effects during lithiation for the improvement of structure stability.In this paper,the latest research progress on SiO anode materials is reviewed,with a focus on four aspects of the explored strategies:micro-nano structure engineering,composite structure modification,binder optimization engineering,and pre-lithium methods.The structural characteristics and electrochemical performance of SiO-based anode materials are compared and summarized as well.Finally,some challenges faced by SiO-based anode materials are discussed and the prospects are also analyzed.All in all,this paper is expected to provide meaningful guidelines for the preparation of lithium-ion batteries with high capacity and long stability.