摘要
Potassium-ion batteries (PIBs) offer economic potential for next-generation energy storage but are limited by sluggish ion diffusion and poor kinetics due to the large K+ radius (1.38 & Aring;) and weak ion-electrode interactions, resulting in severe polarization. To address this, a magnetic substrate-based Mn1-xSnxSb2Se4 (MSSS) structure was developed to enhance ion and electron transport. Isoelectronic Sn substitution into the magnetic substrate formed a highly polar layered structure with low inversion symmetry and inherent Rashba effect. Applying an external electric field during cycling induced an electric dipole moment, further enhancing the Rashba effect and altering the DOS distribution. Extensive electrochemical testing and theoretical simulations identified MSSS-075 as the optimal composition. The Mn-rich, Sn-poor environment disrupted inversion symmetry, amplifying the Rashba effect and inducing pronounced band splitting and localized electronic states, which enhanced electron-ion coupling and facilitated energy-level transitions; concurrently, Mn's d-orbital electrons near the Fermi level accelerated K+ conversion reactions, while the Se-Mn-Se coordination promoted favorable electron localization-rendering Se electron-rich and Mn electron-deficient-thereby boosting K+ storage efficiency. This study demonstrates that polar structures, enhanced by the Rashba effect, can simultaneously improve ion and electron transport efficiency, representing a breakthrough in K+ reaction kinetics for PIB systems.