锂离子电池硅/碳复合网状整体电极的制备与性能  

A binder-free web-like silicon-carbon nanofiber-graphene hybrid membrane for use as the anode of a lithium-ion battery

作　　者：吴军雄 秦显营[1] 梁葛萌 韵勤柏 贺艳兵[1] 康飞宇[1,2] 李宝华[1] 

机构地区：[1]清华大学深圳研究生院下一代动力与储能电池关键技术工程实验室,炭功能材料工程实验室,广东深圳518055 [2]清华大学材料学院先进材料教育部重点实验室,北京100084

出　　处：《新型炭材料》2016年第3期321-327,共7页New Carbon Materials

基　　金：国家重点基础研究发展计划(2014CB932400);国家自然科学基金(51202121,51232005);NSAF(U1330123)~~

摘　　要：基于静电喷雾沉积技术制备了硅-纳米炭纤维-石墨烯杂化膜(Si/CNF/G),其中纳米硅颗粒包覆在多孔炭基体中,由纳米硅和多孔炭组成的二次结构被镶嵌在由纳米炭纤维和石墨烯组成的三维交联炭网络中,最终构成无粘结剂的硅/碳复合整体电极。Si/CNF/G三维杂化膜用作锂离子电池电极时,表现高的可逆比容量、长的循环寿命和良好的倍率性能。0.2 A·g^(-1)恒定电流密度下,首次可逆比容量为957mAh·g^(-1),经100圈循环容量保持率为74.4%;2 A·g^(-1)恒定电流密度下,可逆比容量为539mAh·g^(-1)。多孔炭基体可有效缓冲硅的体积变化,促进形成稳定的固态电解质界面;纳米炭纤维和石墨烯构建的三维炭网络既稳定了电极的整体结构,又可为电子和离子提供快速传输通道。A binder-free silicon-carbon nanofiber-graphene （Si-CNF-G） hybrid membrane was prepared by embedding Si particlesencapsulated in a porous carbon in a cobweb-like carbon scaffold composed of CNFs and G nanosheetsproduced using the coaxial electrospraying method. The binder-free Si-CNF-G electrode delivered an initial reversible specific capacity of 957 mAh·g-1 with a retention of 74.4% after 100 cycles at 0. 2 A·g-1,and a rate capability of 539 mAh·g-1 at 2 A·g-1,which was much better than that of a Si electrode. This can be attributed to the fact that the porous carbon matrix was able to buffer the large volume expansion and contraction of Si during charging and discharging, and that the interconnected carbon scaffold not only created efficient pathways for electron conduction and ion transfer, but also improved the structural stability of the whole electrode.

关 键 词：锂离子电池 硅/碳负极 电化学性能 静电喷雾沉积 

分 类 号：TM912[电气工程—电力电子与电力传动]