Unveiling the electrochemical mechanism of Cr2O3, CuCr2O4, and CuCr2O4/Ti3C2Tx composites for high-performance aqueous hybrid supercapacitors

In this study, nanostructured Cr 2 O 3 and CuCr 2 O 4 are prepared via a simple and cost effective co-precipitation method. The structural and morphological characteristics of materials are thoroughly analyzed using diverse analytical techniques. The electrochemical performance is evaluated in 2M KOH electrolyte. CuCr 2 O 4 exhibits a significantly higher capacity of 84.17 mAh g −1 at 1 A g −1 than Cr 2 O 3 (47.64 mAh g −1 ). Furthermore, capacity of CuCr 2 O 4 is significantly enhanced upon incorporation of Ti 3 C 2 T x MXene, resulting in an improved capacity of 121.39 mAh g −1 . Owing to better performance of CuCr 2 O 4 /Ti 3 C 2 T x , hybrid supercapacitor is designed by CuCr 2 O 4 /Ti 3 C 2 T x (positive electrode)and activated carbon (AC) (negative electrode). The resulting CuCr 2 O 4 /Ti 3 C 2 T x //AC delivers energy density of 39.40 W h kg −1 at 775 W kg −1 . Moreover, CuCr 2 O 4 /Ti 3 C 2 T x //AC is used to power the LEDs, toy motor fan, digital thermo-hydrometer and kitchen timer.