One‐step construction of strongly coupled Co <sub>3</sub> V <sub>2</sub> O <sub>8</sub> /Co <sub>3</sub> O <sub>4</sub> /MXene heterostructure via in‐situ Co‐F bonds for high performance all‐solid‐state asymmetric supercapacitors
Ji Zhou, Binbin Liu, Hu Zheng, Wenqing Ma, Qian Li, Cai-Xia Xu
Abstract
Abstract Co 3 V 2 O 8 /Co 3 O 4 /Ti 3 C 2 T x composite was easily synthesized via one‐step succinct‐operated hydrothermal process. The interconnected Co 3 V 2 O 8 /Co 3 O 4 nanowires network can in‐situ grow and anchor on the surface of Ti 3 C 2 T x via the strong Co‐F bonds and contribute tremendously to depress Ti 3 C 2 T x self‐restacking. Profiting from the synergistically interplayed effect among the multiple interfaces and high conductivity of Ti 3 C 2 T x as well as outstanding stability of the as‐designed nanostructure, the optimum Co 3 V 2 O 8 /Co 3 O 4 /Ti 3 C 2 T x electrode reaches a commendable specific capacitance (up to 3800 mF·cm −2 ), great rate capability (80% capacitance retention after 20‐times current increasing), and preeminent cycling stability (95.4%/85.5% retention at 7000th/20,000th cycle). Moreover, the all‐solid‐state asymmetric supercapacitor based on Co 3 V 2 O 8 /Co 3 O 4 /Ti 3 C 2 T x and active carbon can deliver a high energy density of 84.0 μWh·cm − 2 at the power energy of 3.2 mW·cm −2 , and excellent cycling durability with 87.0% of initial capacitance retention upon 20,000 loops. This work provides a practicable pathway to tailor MXene‐based composites for high‐performance supercapacitor.