High performance MnO₂@Ni(OH)₂ core/shell structure nanowire arrays supported on carbon cloth as advanced electrodes for asymmetric supercapacitors

Abstract

MnO2@Ni(OH)2 core/shell structure nanowire arrays (NWAs) supported on carbon cloth were successfully synthesized by a two-step method, applied in flexible all-solid-state asymmetric supercapacitors (ASCs). The Ni(OH)2 nanosheets wrapped on the surface of each MnO2 nanowire uniformly, which can increase the capacitance of MnO2 NWAs to a high specific capacitance of 432.8F/g at 5mV/s. The electrode also exhibits good cycling ability, 92.3% of the initial capacity can be remained after 2000 cycles at 5A/g. The assembled MnO2@Ni(OH)2//MnO2 asymmetric device with a maximum voltage of 1.8V has been fabricated, delivering both high energy density (69.2Wh/kg) and power density (4.5kW/kg at 54.6Wh/kg). These results show that MnO2@Ni(OH)2 NWAs with large specific surface area, combined with the flexible carbon cloth substrate can be applied in supercapacitor field in large scale.

Keywords

• mno₂@ni(oh)₂ nanowire arrays
• core/shell structure
• carbon cloth
• asymmetric super-capacitor
• energy storage