High-entropy NaCl-type metal chalcogenides as K-ion storage materials: role of the cocktail effect

The drastic volume expansion of active materials and the shuttle effect of polychalcogenides hindered the development of anode materials for potassium-ion batteries (PIBs). Thus, various strategies have been used to overcome the negative effects associated with potassiation. Here, we propose a NaCl-type high-entropy metal chalcogenide (HEMC) prepared using a simple melting method as an anode material for PIBs. Unlike traditional high-entropy materials comprising inactive metals, NaCl-type HEMCs can realize the occupancy of cationic sites by active metals. We show that AgSnSbSe1.5Te1.5, a HEMC, produces short-range tiny cells during phase-change energy storage reactions, reconciling the participation of active and inactive metals to form various hetero-interfaces and different functional metal nanoparticles. The kinetic and density functional theory analysis showed that the formation of heterointerfaces decreased the diffusion energy barrier of K+ and the inactive metal silver provided appropriate adsorption energy, suppressing the latent shuttle effect. The results show enhanced electrochemical performance owing to the elemental composition of high-entropy materials and the formation of tunable heterointerfaces and functional nanoparticles in electrochemical reactions, offering a new concept for the design of PIB anode materials.