Highly active and stable Cu9S5-MoS2 heterostructures nanocages enabled by dual-functional Cu electrocatalyst with enhanced potassium storage

The intrinsic poor electrical conductivity, severe dissolution of K x S y intermediates, and inferior conversion reaction reversibility extremely impede the practical application of the transition-metal chalcogenides (TMDs) anode for potassium-ion batteries (PIBs). Herein, a rationally designed Cu 9 S 5 /MoS 2 /C heterostructure hollow nanocage was synthesized with assistance from metal-organic frameworks (MOFs) precursor. During the K-storage process, the homogeneously distributed the sulfiphilic nature of Cu 0 reaction product could act as a dual-functional catalyst, not only facilitating the rapid charge transfer but also effectively anchoring (K x S y ) polysulfides, thus boosting K-storage reactions reversibility during the conversion reaction process. When applied as an anode for PIBs, the as-prepared heterostructure exhibits excellent reversible capacity and long cycle lifespan (350.5 mAh g –1 at 0.1 A g –1 and 0.04% per cycle capacity decay at 1 A g –1 after 1000 cycles). Additionally, the potassium storage mechanism is distinctly revealed by in-situ characterizations. The nanoarchitecture designing strategy for the advanced electrode in this work could provide vital guidance for relevant energy storage materials.