摘要
针对硅基阳极在循环过程中体积变化大、SEI膜不稳定、电子电导率和离子电导率低等固有缺陷,采用简单方法合成双壳层Si/TiO2/CFs复合材料。内部刚性TiO2壳层可缓解锂化脱锂过程中纳米硅的巨大体积膨胀,外部弹性碳纤维壳层的交错多孔结构有利于电子和离子的快速传输。该方法制备的Si/TiO2/CFs复合材料具有优异的可逆比容量(583.4 mA h/g)、高倍率性能和良好的循环性能。这种双壳层包覆方法亦可用于合成在循环过程中具有较大体积变化的其他电极材料。
A dual-shell Si/TiO2/CFs composite was synthesized through a simple method to deal with the intrinsic drawbacks of silicon-based anode,in terms of huge volume change,unstable SEI films,and low electronic and ionic conductivity.The inner rigid TiO2 shell alleviates the huge volume expansion of the nano silicon,and the outer resilient carbon fiber,which is porous and staggered,is beneficial to the rapid transport of electrons and ions.The as-prepared Si/TiO2/CFs composite displays a superior reversible specific capacity of 583.4 mA·h/g,high rate capability and decent cycling performance.The dual-shell encapsulation method provides a guideline for other anode materials with huge volume expansion during the cycling process.
作者
曾婧
彭超群
王日初
刘雅敬
王小锋
刘军
Jing ZENG;Chao-qun PENG;Ri-chu WANG;Ya-jing LIU;Xiao-feng WANG;Jun LIU(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Hunan Provincial Key Laboratory of Electronic Packaging and Advanced Functional Materials,Changsha 410083,China)
基金
Project(51772331)supported by the National Natural Science Foundation of China
Project(2018YFB1106000)supported by the National Key Technologies R&D Program of China
关键词
双壳层
硅阳极
静电纺丝
溶胶凝胶法
锂离子电池
dual-shell
Si-based anode
electrospinning
sol-gel method
lithium-ion batteries
