Asymmetric device based on bimetallic cobalt chromium oxynitride as a positive electrode material. (15th November 2022) - Kumar, U. Naveen
Abstract: In this work, soft urea assisted aerogel spray method is used to synthesize cobalt chromium oxynitride (CoCr2 ON) nanoparticles. These nanoparticles are used to fabricate asymmetric coin cell devices, where CoCr2 ON is used as a positive electrode and activated carbon (AC) is used as the negative electrode material. The fabricated asymmetric device is subjected to electrochemical characterization techniques such as cyclic voltammetry, galvanostatic charge-discharge (GCD), leakage current analysis, and electrochemical impedance spectroscopy (EIS). From CV measurement, it is seen that CoCr2 ON electrode exhibits a maximum specific capacity of 46.60 mAh g −1 at 10 mV s −1 . Even after 3000 cycles in a three-electrode set up, it shows an excellent capacitance retention of 76.8 %. The as-fabricated asymmetric device shows an excellent performance with specific capacity of 16.80 mAh g −1 at 10 mV s −1 and capacitance retention of 71.5 % even after 3000 charge discharge cycles. As a proof of concept, we lit a blue LED by connecting three coin cells in series resulting in an approximate voltage window of 4 V . The promising nature of the fabricated device and its superior performance was attributed to the hollow nano, high electronic conductivity and stability of the bimetallic oxynitride electrode material when compared to the standard counterparts (corresponding oxides). Highlights: CoCr2 ON nanoparticles are prepared using a soft urea coupled aerogel spray process. As synthesized CoCr2 ON nanomaterials are employed as a supercapacitor-electrode material. CoCr2 ON exhibits maximum specific capacity of 46.60 mAh g -1 and good rate capability (66.4% capacity retention). Asymmetric device (coin cell mode) exhibits high cyclability~71.2%, and capacitance-retention after 3000 cycles. Device exhibits high rate capabilities even at very high scan-rates ~ 80 V s -1 .