Modulation of pore-size in N, S-codoped carbon/Co9S8 hybrid for a stronger O2 affinity toward rechargable zinc-air battery

Abstract

The architecture of the electrode material is a significant factor during the optimization of electrocatalyst. To determine the role of architecture, we synthesize a series of interconnected N, S-codoped Carbon/Co9S8 carbon catalysts (NSC/Co9S8), which have uniform mesopores or macropores. After introducing porosity into the carbon structure, electrocatalytic activity for oxygen reduction reaction was promoted, which can be attributed to the improvement of the wetting property and the interaction with O2. It was found that the NSC/Co9S8 sample with average pores size of 200 nm denoted as the best catalytic activities toward ORR and OER, and was used as air electrodes in rechargeable liquid zinc-air batteries (ZAB), which shows significantly improved ORR/OER activities and excellent durability during cycling (power density: 176 mW cm−2 and excellent stability: 120 h (360 cycles). This contribution demonstrates a common and ingenious strategy for the regulation of advanced electrocatalytic materials, thus facilitates their applications in flexible, secure energy storage and conversion devices.