High Performance Li-O₂ Batteries Enabled with Manganese Sulfide as Cathode Catalyst

Transition metal sulfides (TMSs) are attracting great attention as cathode catalysts of Li-O-2 batteries. In this article, both gamma-MnS and alpha-MnS are successfully synthesized and their performance is comparatively investigated when employed as cathode catalyst of Li-O-2 batteries. It reveals that both MnS materials are capable of catalyzing oxygen reduction reaction as well as oxygen evolution reaction, but alpha-MnS demonstrates higher activity and better reversibility. The batteries fabricated with alpha-MnS deliver higher discharge capacity, lower charge voltage, improved high-rate discharge ability and superior cycling performance. These results are discussed and analyzed with help of various physicochemical techniques and compared with the performance of other reported TMSs and a widely studied oxide counterpart (MnO2) of MnS. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.