Abstract Regulation of ion transport at the reaction interface of electrodes is essential for the design and development of high‐rate sodium‐ion batteries. Herein, a controlled self‐converted strategy is reported to construct iron oxides (Fe x O y ) ion‐regulated interphase on Fe‐based Prussian blue analogs (FePBAs) via a facile etching method in acetic acid media. Notably, this process simultaneously triggers an unexpected increase in sodium–ion storage sites within the bulk FePBAs. Uniquely, the designed Fe x O y interphase modulates the local solvation structure, restructures the Helmholtz layer, and thereby establishes a stable and uniform cathode‐electrolyte interphase to facilitate high‐flux ion transport. Meanwhile, increased sodium‐ions in the bulk phase will also boost ion transport flux by establishing a concentration gradient driving force between the electrolyte and the bulk lattice. The synergistic effect between Fe x O y interphase and increased bulk sites enhances ion transport kinetics through accelerated adsorption‐desolvation‐diffusion cascades, and finally achieves high‐flux ion transport (0.0854 mol m 2 h −1 ), superior to the pristine counterpart (0.0694 mol m −2 h −1 ). Consequently, the modified FePBAs cathodes exhibit exceptional rate capability and extraordinary long‐term cycling stability, retaining 80% capacity after 5000 cycles at 5 C. This work sets a new paradigm on interface/site engineering for the construction of high‐power energy storage systems.
Chen et al. (Thu,) studied this question.