Hollow Raspberry-like CoS_x/C Sub-Microspheres as a Highly Active Air Cathode Catalyst for Rechargeable Zinc-Air Batteries

Abstract

Rechargeable zinc-air batteries (ZABs) are considered one of the most promising energy devices owing to their high theoretical capacity, environmental friendliness, low cost, and high safety. However, their practical applications are still limited by the lack of low cost, high activity, and stable air cathode catalysts toward both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). In this study, hollow, raspberry-like CoS x /C sub-microspheres were designed and fabricated. The synthesized catalyst exhibited high catalytic performance toward both the ORR and OER, requiring a half-wave potential of 0.87 V for the ORR and an ultralow overpotential of 160 mV to achieve 10 mA cm–2 for the OER. When used as an air cathode catalyst, it provided a ZAB with a maximum power density of 341.9 mW cm–2 and exhibited excellent cycling stability. After continuous and steady operation for 1000 cycles (corresponding to 333.3 h) at 5 mA cm–2, no obvious decay in performance was observed. The catalyst’s high performance and stability will make it find its potential use in practical and commercial applications. Also, the present strategy can be easily translated to the rational designing and fabrication of bifunctional oxygen catalysts with both high activity and stability for ZABs and other eco-friendly and future-oriented energy techniques.

Polypyrrole-coated cobalt sulfide as an effective host for sulfur cathode

“…Meanwhile, due to the non-renewable characteristic of fossil energy, the energy crisis is creeping in, and the research on electrochemical energy storage systems is imminent. 1,2 Among these new energy storage systems, lithium-sulfur batteries (LSBs) have received widespread attention for their superior theoretical specific capacity and low cost. [3][4][5] However, LSBs face several issues, such as the shuttle effect of lithium polysulfides (LiPSs), the poor electronic conductivity of sulfur and LiPSs, and the volume expansion of sulfur cathodes, which hinder their commercialization progress.…”