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

Abstract

The ammonia reduction reaction strategy can optimize the electronic conductivity and the obtained Metallic Co has great electrochemical performance. • The ammonia reduction reaction strategy can optimize the electronic conductivity. • The work can achieve phase transformation of metal oxides into transition metals. • The metallic Co electrode shows a higher specific capacity than that of Co 3 O 4 . 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 NH 3 -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 Co 3 O 4 . 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 .