Abstract:
Transition metal oxynitride (TMON) based electrode materials are explored for supercapacitor applications. In this work, simple and scalable synthesis methodologies are deployed in place of conventional ammonothermal process for bypassing usual challenges associated with toxicity and complexity associated with oxynitride synthesis. Firstly, electrodes are fabricated using CrOXNY nanomaterials made in house. This gives rise to a highly cyclable symmetric supercapacitor. This device exhibited excellent capacitance retention of 98% even after 10,000 charge discharge cycles. Thereafter bimetallic cobalt chromium oxynitride (CoCr2ON) is explored to improve its specific capacitance further. An asymmetric device is fabricated with expanded voltage window of 1.6 V to get improved energy and power density values. For the last part of the thesis, we have fabricated an all oxynitride asymmetric device and tested it up to 105cycles. It shows a capacitance retention of 87% even after 105 cycles. Finally, the as fabricated asymmetric device is tested in real time and in harsh operating conditions (humidity of RH 50%, temperatures (-30 oC to 70 oC) using an environmental climate chamber.