Three-Dimensional Self-Supporting TiC with MoS and CuO 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 TiC with MoS and CuO nanocrystal composites for supercapacitor applications. MoS was incorporated in TiC using a hydrothermal method, and CuO was embedded in two-dimensional nanosheets by in situ chemical reduction. The resulting composite electrode showed a synergistic effect between the components. TiC served as a conductive additive to connect MoS nanosheets and facilitate charge transfer. MoS acted as an active spacer to increase the interlayer space of TiC and protect TiC from oxidation. CuO effectively prevented the collapse of the lamellar structure of TiC-MoS. Consequently, the optimized composite exhibited an excellent specific capacitance of 1459 F g at a current density of 1 A g. Further, by assembling an all-solid-state flexible supercapacitor with activated carbon, a high energy density of 60.5 W h kg was achieved at a power density of 10 W kg. 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.