A flexible all-solid-state asymmetric supercapacitors based on hierarchical carbon cloth@CoMoO4@NiCo layered double hydroxide core-shell heterostructures

Abstract

Abstract Flexible and lightweight wire-shaped supercapacitors are important energy storage devices used for portable or wearable electronics. However, practical applications of flexible supercapacitors are still limited by the relatively poor performances. Herein, the hierarchical carbon cloth@CoMoO4@NiCo-LDH core-shell nanowire arrays supported have been synthesized via a facile two-step hydrothermal route coupled with annealing treatment. In addition, a possible mechanism for the growth of NiCo-LDH nanosheets (NSs) shell onto CoMoO4 nanowires (NWs) core is put forward based on the time-dependent experiments. The CC@CoMoO4@NiCo-LDH-12 h electrode exhibits a high specific capacitance of 2024 F g−1 at 1 A g−1, with 80.3% retention of the initial specific capacitance at 20 A g−1 and outstanding cycling stability. In addition, we have fabricated a flexible all-solid-state asymmetric supercapacitor (ASC) which achieves a maximum energy density of 59.5 Wh kg−1 at a power density of 800 W kg−1 and long-term cycling stability (89.7% device capacitance retention over 5000 cycles). The remarkable electrochemical performance can be ascribed to the rational combination of two electroactive materials and the reasonable array configuration.