硅尺寸对硅碳复合负极的性能影响及失效分析
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- 英文论文题名：Electrochemical Performance and Failure Analysis of Si/C Composite Anode Based on Silicon of Various Dimensions
- 论文作者：刘柏男 ; 陆浩 ; 褚赓 ; 罗飞 ; 郑杰允 ; 李泓 ; 陈立泉
- 英文论文作者：Bonan Liu ; Hao Lu ; Geng Chu ; Fei Luo ; Jieyun Zheng ; Hong Li ; Liquan Chen ; Beijing National Laboratory for Condensed Matter Physics ; Institute of Physics ; CAS ; Tsinghua University ; Department of Chemistry ; Jiangxi Zichen Technology Co.Ltd.
- 年：2016
- 作者机构：中国科学院物理研究所;清华大学化学系;江西紫宸科技有限公司;
- 论文关键词：硅碳复合 ; 裂纹 ; SEI
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第三十分会：化学电源
- 语种：中文
- 分类号：TM912;TB332
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第三十分会 ; 化学电源
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：191k
- 原文格式：D
- 会议级别：全国
摘要
硅基材料由其高容量、低嵌锂电位、低成本等优势被认为是下一代锂离子电池极具潜力的负极材料。然而,硅负极材料实际应用至少必须解决两个关键问题:硅颗粒在脱嵌锂时伴随着的体积膨胀和收缩以及硅颗粒表面固体电解质层(SEI)的持续生长。已有研究针对纯硅负极总结出断裂机制,临界尺寸等一系列信息~(1-3)。然而,硅碳复合材料的类似研究情况很少见于报道。考虑到硅碳复合材料是目前最有竞争优势的硅基负极商业化的路线之一,将沥青分别与30,100,500,3000nm的硅颗粒混合后热处理,得到体系简单的硅碳复合模型材料。利用SEM,TEM,RAMAN,EIS以及FIB对模型材料的电化学性能,表面及内部的结构变化与裂纹扩展进行分析。研究发现,小尺寸硅粉能够表现出更好的电化学性能;裂纹在首周嵌锂态出现,随着循环的进行不断扩展,在材料表面出现裂纹后,电解液沿着裂纹渗入,不断生成SEI:进一步研究发现,硅颗粒的大小在500nm以下时,裂纹不会沿硅/碳界面扩展。本文同时也研究了不同充放电倍率下复合材料的断裂行为。
The volume change of the silicon and the formation of SEI on silicon have always been the main problems impeding the application of Si-based anode.We obtain a series of Si/C composite material based on pitch and Si powder with dimension of 30,100,500,3000 nm,respectivily.SEM,TEM,RAMAN,EIS and FIB were employed to study the electrochemical performance,exterior and interior structure and crack evolution of different material.It was found that the electrochemical performance become better with the decreasing dimension of Si particle.Flaws appears from the first cycle,and once the composite material cracks,electrolyte would permeate inside,leading to continuous growth of SEI.Nevertheless,the cracks didn't propagate along the Si/C interface while the size of silicon particle below 500 nm.The fracture of composite material while cycling by different rate were also studied.
The volume change of the silicon and the formation of SEI on silicon have always been the main problems impeding the application of Si-based anode.We obtain a series of Si/C composite material based on pitch and Si powder with dimension of 30,100,500,3000 nm,respectivily.SEM,TEM,RAMAN,EIS and FIB were employed to study the electrochemical performance,exterior and interior structure and crack evolution of different material.It was found that the electrochemical performance become better with the decreasing dimension of Si particle.Flaws appears from the first cycle,and once the composite material cracks,electrolyte would permeate inside,leading to continuous growth of SEI.Nevertheless,the cracks didn't propagate along the Si/C interface while the size of silicon particle below 500 nm.The fracture of composite material while cycling by different rate were also studied.
引文
[1]Liu X.H.;Zhong,L.;Huang S.;Mao S.X.;Zhu T.;Huang J.Y.Acs Nano,2012,6:1522.
[2]Zhao K.;Pharr M.;Wan Q.;Wang W.L.;Kaxiras E.;Vlassak J.J.;Suo Z.J.Electrochem.Soc,2012,159:A238.
[3]Luo F.;Liu B.;Zheng J.;Chu G.;Zhong K.;Li H.;Huang X.;Chen L.J.Electrochem.Soc.2015,162:A2509.
[2]Zhao K.;Pharr M.;Wan Q.;Wang W.L.;Kaxiras E.;Vlassak J.J.;Suo Z.J.Electrochem.Soc,2012,159:A238.
[3]Luo F.;Liu B.;Zheng J.;Chu G.;Zhong K.;Li H.;Huang X.;Chen L.J.Electrochem.Soc.2015,162:A2509.