Fiber-based all-solid-state asymmetric supercapacitors based on Co₃O₄@MnO₂ core/shell nanowire arrays

With the rapid development of portable and wearable electronics, fiber-based supercapacitors as one type of flexible and lightweight energy storage devices have attracted intensive attention. However, most of the reported fiber-based supercapacitors are based on a symmetric device configuration, whose narrow operating voltage window and low energy densities as well as the poor electrochemical performance hinder the practical applications of fiber-based supercapacitors. In this report, we developed a fiber-based flexible all-solid-state asymmetric supercapacitor, using nickel wire/Co₃O₄@MnO₂ nanowire arrays and carbon fibers/graphene as the two electrodes. The fiber-based all-solid-state asymmetric supercapacitor exhibited remarkable electrochemical performance with high capacitance (13.9 mF cm^-2 at 0.1 mA cm^-2) and high cycling stability (82% retention, even after 1000 cycles at 0.6 mA cm^-2). The obtained fiber-based supercapacitor is a promising power source candidate for flexible, portable and wearable electronics.