摘要
随着锂离子电池向电动汽车、可再生能源储能系统等大型应用领域发展,锂离子电池的能量密度、功率密度等性能指标需要进一步提高。在负极材料方面,传统的石墨碳负极材料的比容量有限,已经难以满足高能量密度电池的需求。以Si基材料为代表的新型高比容量负极材料受到了人们的广泛关注。其中,Si Ox材料在发挥高比容量的同时,具有相比纯Si更小的体积变化,因而在循环寿命方面更具实用潜力。本文对目前报道的Si Ox基负极材料的研究工作进行总结,系统阐述了Si Ox材料的基本电化学性能、结构模型、电化学机理及合成方法,分类介绍了改进Si Ox材料电化学性能的各类措施,并对其中Si O及无定形Si O2材料进行了重点论述。研究表明,氧含量、歧化程度、表面状态等对Si Ox材料的电化学性能具有重要影响;界面团簇混合(ICM)结构模型可更好地对其电化学机理进行理解;通过与第二相(碳、金属、金属氧化物等)复合,造孔,表面改性(包覆、刻蚀等)及其他手段(改变粘结剂及电解液)可有效提升Si Ox基材料的首次库仑效率和循环性能;部分使用Si Ox基材料的全电池具有循环600次后容量保持率达90%的优秀循环性能。Si Ox基材料已成为一种在高比能量锂离子电池中极具应用潜力的负极材料。
With rapidly growing application of lithium-ion batteries in electric vehicles and renewable energy storage, there is an increasing demand on high performance batteries in terms of energy density and power density. For anode materials, the traditional graphitized carbon materials cannot meet these requirements, novel high-capacity anode materials are being widely investigated, including Si-based materials. Among them, SiO~ is considered to be a promising anode material for the practical use because it can deliver a high canacity and at the same time produce relatively lower volume change upon cycling compared to pure silicon. This paper summarizes the published works on SiO,-based anode materials. The basic electrochemical performance, structure model, electrochemical reaction mechanism and synthesis methods of SiO powders are systematically reviewed. Methods used to improve electrochemical performance are classified and introduced, emphasized on those of SiO and amorphous SiOx. These works suggested that the oxygen content, disproportionation level and surface state of SiOx have significant influence on the electrochemical performance of SiO,. The interface clusters mixture （ICM） structural model can be used to better understand the nature of the electrochemical reaction processes of SiO . Introduction of second phase （carbon, metals, metal oxides, etc. ）, preparation of porous structure, surface modification and optimization of binder and electrolyte are proved to be effective methods to improve the coulombic eMciency and cycling performance of SiOx. electrode. Batteries with optimized SiO -based material showed good cycling stability with 90% capacity retention after 600 cycles. SiO,-based composite is one of the best promising anode materials for lithium-ion batteries with high energy density.
出处
《化学进展》
SCIE
CAS
CSCD
北大核心
2015年第4期336-348,共13页
Progress in Chemistry
基金
国家重点基础研究发展计划(973)项目(No.2013CB934003)
国家自然科学基金项目(No.21273019)
国家高技术研究发展计划(863)项目(No.2013AA050902)
上海市科技人才计划项目(No.12XD1421900)
上海市科委科技创新项目(No.12dz1200503
13dz2280200)资助~~
