In this work, few-layer structured graphene-like m-SnS 2 −SnO 2 /C materials were synthesized successfully with a facile hydrothermal reaction followed by heat treatment in an Ar atmosphere. In these materials, a SnS 2 −SnO 2 heterostructure modified with a carbon coating (SnS 2 −SnO 2 /C) has been fabricated, and their electrochemical performance as a cathode catalyst for aprotic electrolyte Li−O 2 batteries was evaluated and comparatively investigated. It was shown that the battery with 225-SnS 2 −SnO 2 /C in the cathode delivers the best performance. This work added a new promising index to the dictionary for developing highperformance cathode catalysts of Li−O 2 batteries.
Developing bi-functional catalyst is an effective way to improve the kinetics of oxygen electrochemistry and promote the performance of Li-O 2 batteries. In this study, spinel NiCo 2 S 4 with urchin-like and yolk-shell morphologies were successfully synthesized and evaluated as cathode catalysts for rechargeable Li-O 2 batteries. The results demonstrate both NiCo 2 S 4 materials are catalytically active toward ORR/OER, but the urchin-like NiCo 2 S 4 performs better with faster kinetics, higher capacity, lower polarization and longer cycle life. Moreover, cycling performance of the Li-O 2 batteries with urchin-like NiCo 2 S 4 is evidently better than the reported data in literatures for the batteries with many other transition metal sulfides.
Layer‐structured SnS2 powders with plate‐like and flower‐like morphologies have been successfully synthesized through a facile hydrothermal method with different sources of sulfur. Their potential application as cathode catalysts of rechargeable Li−O2 batteries were electrochemically evaluated and analyzed with diverse physicochemical techniques. The results reveal that both SnS2 materials are capable of catalyzing oxygen reduction reaction as well as oxygen evolution reaction in the cathode of Li−O2 batteries, while the plate‐like ones perform much better. Moreover, the performance of SnS2 is also comparatively discussed with the opponent of tin oxides to identify the superiority of transition metal sulfides to transition metal oxides as cathode catalysts of Li−O2 batteries.
Transition metal sulfides (TMSs) are attracting great attention as cathode catalysts of Li-O 2 batteries. In this article, both γ-MnS and α-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 α-MnS demonstrates higher activity and better reversibility. The batteries fabricated with α-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 (MnO 2 ) of MnS.
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