Binder-free V-doped CrN thin film electrode enables high performance symmetric supercapacitor

Transition metal nitrides (TMNs) are rapidly gaining prominence as attractive supercapacitor electrode materials due to their intriguing properties. Nevertheless, the quest for facile and green fabrication of TMNs electrodes with high supercapacitor performance remains a substantial challenge. In this study, we have successfully designed and prepared the binder-free V-doped CrN thin film electrodes through a one-step reactive magnetron co-sputtering in nitrogen and argon atmosphere without high temperature heating. Our experimental and DFT findings confirm that the V doping increases the number of active sites, enlarges the specific surface area, and enhances the electron concentration and electrical conductivity. Consequently, the CrVN thin film electrodes achieve a remarkable specific capacitance of 22.8 mF cm-2 at 1.0 mA cm-2, along with excellent cycling performance (93.9% capacitance retention after 20,000 cycles at 5.0 mA cm-2). Furthermore, the assembled CrVN symmetric supercapacitor device exhibits a substantial energy density of 11.2 mWh cm-3 and an impressive power density of 7.5 W cm-3, respectively. These encouraging outcomes open new avenues for developing ternary TMNs-based electrodes for high performance supercapacitors.