Three-Dimensional Self-Supporting Ti3C2 with MoS2 and Cu2O Nanocrystals for High-Performance Flexible Supercapacitors

The three-dimensional (3D) architecture of electrode materials with excellent stability and electrochemical activity is extremely desirable for high-performance supercapacitors. In this study, we develop a facile method for fabricating 3D self-supporting Ti 3 C 2 with MoS 2 and Cu 2 O nanocrystal composites for supercapacitor applications. MoS 2 was incorporated in Ti 3 C 2 using a hydrothermal method, and Cu 2 O was embedded in two-dimensional nanosheets by in situ chemical reduction. The resulting composite electrode showed a synergistic effect between the components. Ti 3 C 2 served as a conductive additive to connect MoS 2 nanosheets and facilitate charge transfer. MoS 2 acted as an active spacer to increase the interlayer space of Ti 3 C 2 and protect Ti 3 C 2 from oxidation. Cu 2 O effectively prevented the collapse of the lamellar structure of Ti 3 C 2 –MoS 2 . Consequently, the optimized composite exhibited an excellent specific capacitance of 1459 F g –1 at a current density of 1 A g –1 . Further, by assembling an all-solid-state flexible supercapacitor with activated carbon, a high energy density of 60.5 W h kg –1 was achieved at a power density of 10 3 W kg –1 . Additionally, the supercapacitor exhibited a capacitance retention of 90% during 3000 charging–discharging cycles. Moreover, high mechanical robustness was retained after bending at different angles, thereby suggesting significant potential applications for future flexible and wearable devices.