CrS Doped MOF-Derived Carbon Implanted CoNi Particles as Exceedingly Effectual Oxygen Electrocatalysts in Sustainable Zinc-Air Batteries.

Abstract

Utilizing affordable bifunctional catalysts per strong ORR/OER (oxygen reduction and evolution reactions) ability and superior zinc-air battery performance is yet difficult due to the diverse mechanisms of ORR/OER. This work uses CoNi-MOF (metal-organic framework) as a self-template to yield the CrS doped CoNi/C bifunctional catalyst. Comparable to Pt/C and IrO₂ commercial catalysts, the CrS@CoNi/C catalyst exhibits improved electrocatalytic activity toward OER and ORR due to its linked pellet architecture and intact metal sulfide@carbon structure. The CrS@CoNi/C catalyst has the most intriguing ORR/OER performance, with a significantly lower potential and an exceptionally extended cycle duration (E_1/2 = 0.72 V and η₁₀ = 260 mV). The CrS@CoNi/C-based aqueous zinc-air battery shows long-term charge-discharge stability (more than 100h/600 cycles) together with significant specific capacity (789.7 mAh g^-1 _Zn) and power density (132.2 mW cm^-2). Most significantly, after charge-discharge stability, the recharged CrS@CoNi/C-based alkaline zinc-air battery has been employed to exhibit less structural deformation for the cathode and more zincate ion production for the anode side electrodes, which is employed through TEM analysis.