Freestanding Co3N thin film for high performance supercapacitors

Suitable electrode materials play a decisive role in the performance of supercapacitors. In recent years, transition metal nitrides come into view because of their advantages of superior electrical conductivity exceeding the corresponding metal oxides and higher specific capacitance compared with carbon-based materials. Herein, we have successfully synthesized the binder-free Co3N thin films for high-efficiency supercapacitor by reactive magnetron sputtering. Remarkedly, the Co3N thin film electrodes can reach a high specific capacity of 47.5 mC cm−2 at a current density of 1.0 mA cm−2 along with reasonable cycling stability (78.1% remaining after 10,000 cycles). These findings have proved that the Co3N thin films have great potential applications for supercapacitors or other electrochemical energy storage devices.