摘要
Variations in configurational entropy greatly influence the electrochemical behavior of materials; those featuring expanded surface areas, numerous active sites, and accelerated reaction kinetics are highly valued for their superior electrocatalytic properties. In this study, a Berthollide compound is introduced, designated as Cu3Sb0.93Bi0.06Sn0.01S2Se2 (C(ABT)(SSe)). This material, cations, and anions co-doped Cu3SbS4 (CAS), exhibit significantly enhanced storage performance in potassium-ion batteries (PIBs). The introduction of foreign elements improved conductivity, while dual-site conversion and alloying elements enhanced ion diffusion, charge transfer, and electrode kinetics. Regulating configurational entropy created more active sites for Sb. Using high-capacity Sb and S as primary components, material's configurational entropy is precisely adjusted through active element doping, forming a non-stoichiometric structure with thermodynamically stable defect active sites. The synergistic effect of trivalent active metals, particularly high-valence Sb5+, demonstrated superior electrochemical performance compared to materials with unregulated entropy values. Compared to CAS, with the increase in configurational entropy to 0.975 R, the K+ diffusion energy is reduced by 40% and increasing electronic conductivity by 2.6 times, boosting high rate performance (10 A g(-1)), and showing 49.5% higher capacity after 700 cycles. This novel entropy regulation strategy offers new insights into the design of multi-element configurational entropy PIBs.