Closely packed Si@C and Sn@C nano-particles anchored by reduced graphene oxide sheet boosting anode performance of lithium ion batteries  

作　　者：Chaoye Zhu Yao Zhang Ziqiang Wu Zhihong Ma Xinli Guo Fuyi Guo Jiakun Zhang Yushu Li 

机构地区：[1]School of Materials Science and Engineering,Jiangsu Key Laboratory of Advanced Metallic Materials,Southeast University,Nanjing,211189,China [2]School of Materials Science and Engineering,Baise University,Baise,533000,China

出　　处：《Journal of Materials Science & Technology》2021年第28期18-28,共11页材料科学技术（英文版）

基　　金：financially supported by the Jiangsu Key Laboratory for Advanced Metallic Materials(No.BM2007204),China;the Open Fund of the Guangdong Provincial Key Laboratory of Advance Energy Storage Materials(No.AESM201701),China;the SEU-Baotou Graphene Research Institute Collaboration Project(No.8512000513),China。

摘　　要：Both silicon and tin are promising anodes for new generation lithium ion batteries due to high lithium storage capacities(theoretically 4200 mA h g^(-1) and 992 mA h g^(-1),respectively).However,their large volumetric expansions(both are above 300%)usually lead to poor cycling stability.In this case,we synthesized closely packed Si@C and Sn@C nano-particles anchored by reduced graphene oxide(denoted as Si@C/Sn@C/rGO)by the way of solution impregnation and subsequent hydrogenation reduction.Sn particles with a diameter of 100 nm are coated by carbon and surrounded by Si@C particles around 40 nm in average diameter through the high-resolution transmission electron microscopy.Expansions of Si and Sn are alleviated by carbon shells,and reduced graphene oxide sheets accommodate their volume changes.The prepared Si@C/Sn@C/rGO electrode delivers an enhanced initial coulombic efficiency(78%),rate capability and greatly improved cycle stability(a high reversible capacity of nearly 1000 mA h g^(-1) is achieved after 300 cycles at a current density of 1000 mA g^(-1)).It can be believed that packing Sn@C nano-particles with Si@C relieves the volume expansion of both and releases the expansion stresses.Sn@C particles enhance anode process kinetics by reducing charge transfer resistance and increasing lithium ion diffusion coefficient.The present work provides a viable strategy for facilely synthesizing silicon-tin-carbon composite anode with long life.

关 键 词：Sn-Si-C nano-composites ANODE Lithium ion batteries 

分 类 号：TM912[电气工程—电力电子与电力传动] TB383.1[一般工业技术—材料科学与工程]