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 nanomaterial...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.展开更多
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)
文摘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.
