锂离子电池氧化亚硅负极结构优化和界面改性研究进展

Research Progresses on Structural Optimization and Interfacial Modification of Silicon Monoxide Anode for Lithium-Ion Battery

氧化亚硅(SiO)作为锂离子电池负极材料,具有较高的理论比容量(~2043 mAh·g^(−1))以及合适的脱锂电位(<0.5 V),且原料储量丰富、制备成本较低、对环境友好,被认为是下一代高能量密度锂离子电池负极极具潜力的候选材料。然而,SiO在脱/嵌锂过程中存在着较严重的体积效应(~200%),易导致材料颗粒粉化、脱落,严重影响了SiO负极电极的界面稳定性和电化学性能。近年来,人们围绕SiO负极结构优化和界面改性开展了大量工作。本文先从SiO负极材料的结构特点出发,阐述了该材料面临的主要瓶颈问题;继而从SiO的结构优化、SiO/碳复合和SiO/金属复合等三方面,系统总结了迄今已有的SiO负极结构设计和界面调控策略,并分别对其方法特点、电化学性能以及二者间关联规律进行了比较和归纳,最后对SiO负极材料结构和界面改性的未来发展方向进行了展望。

Owing to the rapid development of scientific technology,the demand for energy storage equipment is increasing in modern society.Among the current energy storage devices,lithium-ion batteries(LIBs)have been widely used in portable electronics,handy electric tools,medical electronics,and other fields owing to their high energy density,high power density,long lifespan,low self-discharge rate,wide operating temperature range,and environmental friendliness.However,in recent years,with rapid development in various technological fields,such as mobile electronics and electric vehicles,the demand for batteries with much higher energy densities than the current ones has been increasing.Hence,the development of LIBs with a high energy density,prolonged cycle life,and high safety has become a focal interest in this field.To achieve the above objectives,it is important to strategically use novel anode materials with relatively high specific capacities.At present,artificial graphite is commonly used as an anode material for commercialized traditional LIBs,which can only deliver a practical capacity of 360–365 mAh·g^(−1).Therefore,LIBs using graphite anodes have limited room for improvement in energy density.In the past two decades,considerable efforts have been devoted to silicon-based anode materials,which belong to the same family as carbon.To date,common silicon anode materials primarily include nano-silicon(nano-Si),silicon monoxide(SiO),suboxidized SiO(SiOx),and amorphous silicon metal alloy(amorphous SiM).Among them,SiO has attracted the most attention for use as a negative electrode material for LIBs.As an anode for lithium-ion batteries(LIBs),silicon monoxide(SiO)has a high specific capacity(~2043 mAh·g^(−1))and suitable charge(delithiation)potential(<0.5 V).In addition,with the abundance of its raw material resource,low manufacturing cost,and environmental friendliness,SiO is considered a promising candidate for next-generation high-energy-density LIBs.Based on the testing of existing commercialized SiO materials,the reversible specific capacity of pure SiO can reach 1300–1700 mAh·g^(−1).However,when acting as the anode for LIBs,SiO undergoes a severe volume change(~200%)during the lithiation/delithiation process,which can result in severe pulverization and detachment of the anode material.Meanwhile,lithium silicate and lithium oxide are irreversibly formed during the initial discharge–charge cycle.Moreover,the electrical conductivity of SiO is relatively low(6.7×10^(−4) S·cm^(−1)).These shortcomings seriously impact the interfacial stability and electrochemical performance of SiO-based LIBs,leading to a low initial Coulombic efficiency and poor long-term cycling stability,which has significantly restricted its commercial application.In recent years,substantial efforts have been made on structural optimization and interfacial modification of SiO anodes.However,there is still a lack of a more comprehensive summary of these important developments.Therefore,this review aims to introduce the research work in this area for readers interested in this emerging field and to summarize in detail the research work on the performance optimization of SiO in recent years.Based on the structural characteristics of the SiO anode material,this review expounds the main challenges facing the material,and then summarizes the structural and interfacial modification strategies from the perspectives of SiO structure optimization,SiO/carbon composites,and SiO/metal composites.The methods and their features in all the studies are concisely introduced,the electrochemical performances are demonstrated,and their correlations are compared and discussed.Finally,we propose the development of the structural and interfacial optimization of the SiO anode in the future.