Wire spherical-shaped Co-MOF electrode materials for high-performance all-solid-state flexible asymmetric supercapacitor device

Highlights: ●A non-calcined approach to synthesize nanowire microsphere shaped Co-BTC (CBNWM) successfully. ●The electrochemical performance of CBNWM has been significantly improved compared to the Co-BTC crystal (CBC). ●CBNWM exhibits a superior specific capacity (1020 F g⁻¹ at 5 mV s⁻¹ or 657 F g⁻¹ at 0.5 Ag⁻¹) and cyclic stability. ●The flexible device CBNWM//AC achieves an energy density of 34.4 W h kg⁻¹ at a power density of 375.3 W kg⁻¹. -- Abstract: The exploration of an inexpensive, low-energy consumption and environmentally friendly preparation process to synthesize high capacitance performance MOF-based electrode materials is an important prerequisite for their commercialization. We propose a non-calcined strategy to synthesize nanowire microsphere shaped Co-BTC (CBNWM). Making MOF into one-dimensional nanowire structure can effectively increase its active sites and the ion transfer rate. After the MOF nanowires are entangle and reunite into microspheres, their mechanical property and chemical stability are improved. Therefore, compared with Co-BTC crystal (CBC), the electrochemical properties of CBNWM have been significantly improved. The specific capacity of CBNWM reaches 1020 F g⁻¹ at 5 mV s⁻¹ or 657 F g⁻¹ at 0.5 Ag⁻¹ with the capacity remains 81.4% after 3000 cycles. Subsequently, a flexible asymmetric device of CBNWM//AC was fabricated, whose maximum energy density can achieve 34.4 W h kg⁻¹ with the related power density of 375.3 W kg⁻¹.