Mn–Fe Prussian blue analogs (PBAs) cathode materials suffer from poor cycling reversibility and capacity retention during phase transition from cubic to tetragonal phase, which is related to the large structural deformation of Mn−N₆ octahedra caused by Jahn-Teller distortion. Herein, we explore a controllable strategy for creating unconventional cation Mn vacancies (V_Mn) on the surface of Mn–Fe PBAs by utilizing a strong chelating agent—ethylenediaminet etraacetic acid disodium. The V_Mn in Mn–Fe PBAs can restrain the movement of Mn−N bonds and thereby mitigate the Jahn-Teller distortion of Mn−N₆ octahedra, leading to highly reversible phase transitions of Mn–Fe PBAs as well as an outstanding long-term cycling stability and capacity retention for both the half-cell (72.3% after 2,700 cycles at 0.5 A g⁻¹) and full cell (75.5% after 550 cycles at 0.1 A g⁻¹). This work opens up a universal avenue to explore the relationship between vacancies and electrochemical performances, even in other materials beyond PBAs.

Mn-Fe普鲁士蓝类似物（PBA）阴极材料在从立方相到四方相的相变过程中，循环可逆性和容量保持能力很差，这与由Jahn-Teller变形引起的Mn-N ₆八面体的大结构变形有关。在这里，我们探索通过使用强螯合剂乙二胺四乙酸二钠在Mn-Fe PBA表面上形成非常规阳离子Mn空位（V _Mn）的可控策略。Mn-Fe PBA中的V _Mn可以抑制Mn-N键的运动，从而减轻Mn-N ₆的Jahn-Teller变形八面体，导致Mn–Fe PBA的高度可逆相变，以及半电池（0.5 A g ^-1的2700次循环后为72.3％）和全电池（75.5）的出色的长期循环稳定性和容量保持能力在0.1 A g ^-1的550次循环后的％。这项工作为探索空位与电化学性能之间的关系开辟了一条通用途径，即使在PBA以外的其他材料中也是如此。