Design of 2D Self-Supported Hybrid CuSe@PANI Core/Shell Nanosheet Arrays for High-Performance Flexible Microsupercapacitors

All-solid-state micro-supercapacitors (MSCs) are ideal energy storage devices for fast-growing and high-integrated small electronic devices. In this paper, 2D self-supported hybrid CuSe@PANI core/shell nanosheet arrays have been prepared successfully for constructing high-performance MSCs. The unique self-supported core/shell structure can provide numerous open channels and enlarge specific surface area of PANI, which is extremely beneficial to ion adsorption/desorption and ion diffusion of electrolyte. Electrochemical tests indicate that the self-supported hybrid CuSe@PANI nanosheet array shows the outstanding electrochemical performance (308.9 mF cm(-2)) with excellent cycling stability (89.80% of capacitance retention after 30 000 circles). As for practical applications, the prototype of flexible all-solid-state MSC displays a maximum energy density of 7.55 mW h cm(-3) and achieves a highest power density of 2307 mW cm(-3). The device shows superior cycling stability with 92.30% capacitance retention after 13 500 cycles. The synthesis of 2D self-supported hybrid CuSe@PANI core/shell nanosheet array and its successful application in MSCs offer new opportunities for developing micro energy storage devices.