Microwave-synthesized self-supporting CoSe2/carbon fiber felt electrode for ultra–high cycling life flexible supercapacitors

Flexible electrodes are candidate for portable and wearable electronic storage devices. In this work, high-performance flexible self-supporting CoSe 2 /carbon fiber felt (CoSe 2 /CFF) electrode was prepared via the microwave method without any binder. The CoSe 2 /CFF electrodes exhibited superior electrochemical performance (621 F g −1 at 1 A g −1 ) and an ultra-high cycling life (84.7% capacitance retention after 100,000 cycles). When the CoSe 2 /CFF was used as the positive electrode for the flexible supercapacitor, the assembled device exhibited an outstanding energy density of 22.43 W h Kg −1 at a power density of 823.12 W kg −1 . Because of the excellent mechanical stability of the device, it maintained 91.3% of its initial C after bending from 0° to 180°. The CoSe 2 /CFF proposed in this work shows electrode promising applicability to a low-cost, small-sized wearable and portable energy storage device. • A flexible electrode of CoSe 2 -CFF was prepared at a 120 s heating time via microwave method. • The CoSe 2 -CFF electrodes exhibit superior specific capacitance of 621F g −1 at 1A g −1 . • The CoSe 2 -CFF electrodes shows ultra-high cycle life of 84.7% after 100,000 cycles. • The all-solid-state ASC delivers high energy density and outstanding mechanical flexibility.