摘要
硅-石墨(Si-Gr)复合负极结合硅的高比容量与石墨的结构稳定性,被视为下一代高能量密度锂离子电池的关键负极材料。然而,硅在嵌/脱锂过程中的严重体积效应,其与石墨在物理化学性质和嵌锂机制上的显著差异,导致了复杂的内部相互作用。这些作用引发了如颗粒破碎、不稳定的固体电解质界面膜持续重构以及离子传输动力学恶化等多尺度结构失效问题,严重制约了复合负极的商业化进程。本文从多物理场视角出发,系统性地梳理了现有硅-石墨复合负极内部的相互作用机制的研究进展,指出锂化不均匀性和机械应力的累积是限制电极性能的核心因素,为理解复合电极的失效机制提供了深刻见解,并提出未来研究应从被动地适应体积变化,转向主动地调控电极内部的应力-电化学环境,实现长寿命、高能量密度硅基负极材料的产业化。
Silicon-graphite(Si-Gr)composite anodes,which combine the ultrahigh specific capacity of silicon with the structural stability of graphite,are considered key materials for next-generation high-energy-density lithium-ion batteries.However,the substantial volumetric variation of silicon during lithiation/delithiation,coupled with the pronounced differences in physicochemical properties and lithiation mechanisms between Si and graphite,leads to complex internal interactions.These interactions induce multiscale structural failures,including particle pulverization,continuous reconstruction of an unstable solid-electrolyte interphase,and deteriorated ion transport kinetics,severely constraining the commercialization of Si-Gr composite anodes.From a multiphysics perspective,this study systematically reviews the interaction mechanisms within Si-Gr composite anodes.Nonuniform lithiation and the associated accumulation of mechanical stress are identified as the core factors limiting electrode performance.This work provides deep insights into the failure mechanisms of composite electrodes and suggests that future research should shift from passive volume-change accommodation to active regulation of internal stress and the electrochemical environment to achieve long-life,high-energy-density silicon-based anodes.
作者
王世宁
方遒
李叶晶
王雪锋
WANG Shining;FANG Qiu;LI Yejing;WANG Xuefeng(Institute of Physics,Chinese Academy of Science,Beijing 100190,China;College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;University Of Science&Technology Beijing,Beijing 100083,China)
出处
《储能科学与技术》
北大核心
2025年第12期4399-4411,共13页
Energy Storage Science and Technology
基金
国家重点研发计划(2022YFB2502200)
国家自然科学基金项目(52172257)
中国博士后科学基金(2023M743739)
中国博士后科学基金国家资助博士后研究人员计划(GZC20232939)。
关键词
锂离子电池
石墨负极
硅负极
作用机制
体积膨胀
lithium-ion battery
graphite anode
silicon anode
interaction mechanism
volume expansion
