ZnO@Mo-CNT-MnO2纳米阵列用于构筑超高倍率性 能的柔性非对称超级电容器

Abstract

Manganese dioxide possesses a high theoretical specific capacitance, low cost and environmental friendliness as a supercapacitor electrode material, but its low electrical conductivity and utilization impede its potential capacity. Here, ZnO nanorod arrays electrochemically grown on flexible carbon cloth were fabricated as the electrode substrate. Mo species and carbon nanotubes (CNTs) were anodically coelectrodeposited onto MnO2 film that epitaxially grew on the surface of ZnO nanorods by a facile electrochemical method, achieving a highly conductive and accessible MnO2 nanoarray electrode (denoted ZnO@Mo-CNT-MnO2 NA). The flexible ZnO@Mo-CNT-MnO2 NA electrode exhibits a superior specific capacitance of 237.5 F g−1 at an extremely high charge-discharge rate of 100 A g−1 and a high capacitance retention of 86% after 10,000 cycles. The aqueous asymmetric device assembled with our ZnO@Mo-CNT-MnO2 NA electrode in a bent state obtains a high energy density of 1.13 mW h cm−3 at a high power density of 132.35 mW cm−3 (5 mA cm−2) and a high capacitance retention of 88% after cycling 7600 times at a charge-discharge rate of 5 mA cm−2. The architecture of the MnO2-based NA provides a novel avenue to enhance conductivity and utilization for the design and fabrication of flexible metal oxide supercapacitor electrodes.