Oxygen-vacancy-rich hydrated bimetallic chloride for supercapacitor cathode with remarkable enhanced performance

Summary In this study, a series of nickel/vanadium composites were acquired via a simple in situ growth strategy with the sodium chloride as a regulator. The phase, component, and electrochemical energy storage behavior of the as-prepared electrodes were investigated. Thanks to the addition of sodium chloride for the accession of oxygen vacancy, the prepared composite electrodes show excellent supercapacitor behavior. The resultant NVC-1.8Ov electrode demonstrates a impressive specific capacitance of 9.41 F cm −2 at a current of 10 mA cm −2 , which is about 1.5 times than the NVC electrode. After 5000 charge-discharge cycles under a current of 40 mA cm −2 , the retained 75.7% of its initial capacitance indicate a good cyclic stability. In addition, the NVC-1.8Ov and activated carbon (AC) was used to assemble NVC-1.8Ov//AC asymmetric supercapacitor, which deliver a maximum energy density of 0.471 mWh cm −2 at a power density of 9.319 mW cm −2 . This work provides a new and simple strategy for the preparation of high specific capacitance of asymmetric supercapacitor positive electrode.