纳米硅/还原氧化石墨烯复合纤维材料及其负极结构锂离子超级电容器  

Nano Silicon/r GO Composite Fiber Material and Its Anode Structure Lithium-Ion Supercapacitor

作　　者：王佩遥 邵枫 徐阳 胡南滔 张亚非 Wang Peiyao;Shao Feng;Xu Yang;Hu Nantao;Zhang Yafei(Key Laboratory of Thin Film and Microfabrication Technology(Ministry of Education),Department of Micro/Nano Electronics,School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学电子信息与电气工程学院微纳电子学系薄膜与微细技术教育部重点实验室,上海200240

出　　处：《微纳电子技术》2023年第5期706-719,共14页Micronanoelectronic Technology

摘　　要：通过湿法纺丝工艺成功制备了纳米硅/还原氧化石墨烯复合纤维材料,并对其进行形貌表征与电化学性能测试。纳米硅颗粒嵌入石墨烯层间褶皱的结构具有限制硅材料在储锂过程中体积膨胀的作用,适于作为锂离子电容器负极。同时,研究了锂离子电容器多孔活性炭正极材料的双电层电容特性,通过组装成对称超级电容器,对其电化学性能进行测试,并结合材料的形貌,分析其作为锂离子电容器正极的合理性。为使正负极电荷匹配,分别对负极硅碳纤维和正极活性炭材料组装的锂离子半电池的倍率、循环稳定性、电化学阻抗等电化学性能进行了测试。结果表明,纳米硅/还原氧化石墨烯复合纤维材料的比容量最高可达826.2 mA·h/g(在电流密度为0.2 A/g时),活性炭比容量可达39.9 mA·h/g。组装成的锂离子电容器在合理的匹配条件下,充放电首圈循环比容量可达58.2 mA·h/g (在电流密度为0.2 A/g时),能量密度为26.8 W·h/kg,循环100圈后,比容量保持率降至41.7%。Nano silicon/reduced graphene oxide(nano-Si r GO)composite fiber materials were successfully prepared by wet spinning process,and their morphology and electrochemical properties were tested.The structure of the graphene interlayer fold with nano silicon particles has the effect of limiting the volume expansion of silicon materials in the process of lithium storage,which is suitable for the negative electrode of lithium-ion capacitor.At the same time,the double-layer capacitance characteristics of porous activated carbon cathode material for lithium-ion capacitor were studied.By assembly into a symmetrical supercapacitor,its electrochemical performance was tested.Combined with the morphology of the material,the feasibility of it as the positive electrode of lithium-ion capacitor was analyzed.To match the positive and negative charges,the electrochemical properties of the lithium-ion half-cell assembled by negative silicon carbon fiber and positive activated carbon were tested respectively,such as the rate performance,cycle stability and electrochemical impedance.The results show that the maximum specific capacity of nano-Si/r GO composite fiber material is 826.2 m A·h/g(at current density of 0.2 A/g),and the specific capacity of activated carbon is up to 39.8 m A·h/g.Under reasonable matching conditions,the first-cycle specific capacity of charge and dischange of the assembled Li-ion capacitor can reach 58.2 m A·h/g(at current density of 0.2 A/g),and the energy density is 26.8 W·h/kg.The capacity retention rate decreases to 41.7%after 100 cycles.

关 键 词：锂离子超级电容器 锂离子电池 纳米硅 还原氧化石墨烯(rGO) 复合纤维材料 活性炭 硅碳负极 

分 类 号：TM53[电气工程—电器] TM911[一般工业技术—材料科学与工程] TB33