Metallic Co: A promising electrode materials to boost electrochemical performances of Co3O4 for energy storage

Abstract Polymer materials and inorganic non-metallic materials have been extensively investigated as electrode materials, but there is very little research on metal materials. Herein, we report a simple NH3-induced reduction process to synthesize metallic Co nanoparticles, and explore them as electrode materials for supercapacitors for the first time. The metallic Co presents a specific capacity of 80C g−1 (209F g−1) at 0.5 Ag−1, higher than the 40C g−1 (105F g−1) of Co3O4. And the capacity retention is 114% after 10,000 cycles. Besides, the as-assembled metallic Co//activated carbon hybrid supercapacitor can achieve the maximum energy density of 12.8 W h kg−1 at 197.1 W kg−1.