摘要
Flexible supercapacitors (SCs) are attractive energy storage devices for wearable electronics, but their applications are hindered by their low volumetric energy densities. Two dimensional (2D) non-carbon nanomaterials are the most promising pseudocapacitive materials for high volumetric capacitance electrodes. However, they are poorly conductive and prone to self-stacking, which results in unsatisfactory electrochemical performance. In this work, large-scale V2O5·nH2O ultrathin nanosheets are synthesized by a facile and scalable method and transformed into layered and compact composite films with one-dimensional carbon nanotubes (CNTs). The self-standing films show an optimized volumetric capacitance of 521.0Fcm^-3 with only 10 wt% of CNTs, which is attributed to dramatically enhanced electrical conductivity beyond the electrical percolation threshold, high dispersion of pseudocapacitive V2O5·nH2O nanosheets, and high mass density of the films. All-solid-state flexible SCs made of V2O5·nH2O/CNTs films show a maximum energy density of 17.4WhL^-1.
柔性超级电容器是一种引人注目的可穿戴设备的储能器件,但是其较低的体积能量密度限制了其应用.二维非碳基纳米材料是目前制备高体积容量超级电容器最有前景的电极材料.然而二维赝电容纳米材料导电性差且容易自发紧密堆叠,难以表现出理想的电化学性能.本论文通过简单规模化的方法制备了大尺寸的V2O5·nH2O超薄纳米片,并与一维碳纳米管复合制备成高密度的层状薄膜.当碳纳米管的质量分数达到10%时,复合薄膜中发生电荷渗透效应导致电子导电性大幅提升,同时V2O5·nH2O超薄纳米片被碳纳米管高效率分散,且复合薄膜依然具有高密度,因此这种自支撑的薄膜表现出高达521.0Fcm^-3的体积比容量.基于复合薄膜制备的全固态柔性超级电容器拥有高达17.4WhL^-1的体积能量密度.
作者
Kai Guo
Yiju Li
Chong Li
Neng Yu
Huiqiao Li
郭凯;李一举;李冲;喻能;李会巧(Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices, School of Chemistry, Biology and Materials Science, East China University of Technology, Nanchang 330013, China;Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China;Wuhan National Laboratory for Optoelectronics, School of Optics and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China;State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China)
基金
supported by the National Natural Science Foundation of China (51702048 and 21603157)
the National Basic Research Program of China (2015CB932600)
Jiangxi Provincial Department of Education (GJJ170459 and GJJ170457)
