A MXene modification strategy of Prussian blue cathodes toward a stable cathode electrolyte interphase and suppressed Mn dissolution

Manganese-based Prussian blue analogues (PBA) have garnered widespread attention as the promising cathode materials for sodium-ion batteries. However, the inevitable Jahn-Teller distortion and the formation of unstable and uneven cathode electrolyte interphase (CEI) result in severe Mn dissolution and poor cycling stability. Herein, we report a simple MXene modification strategy cold pressing method to embed Prussian blue cathode materials into MXene nanosheets. This highly conductive protective barrier not only mitigates the Jahn-Teller distortion in Mn-PBA and maintains the integrity of the particles during charge–discharge cycles, but also partially suppresses side reactions between the electrolyte and cathode interface through surface functional groups (−F), resulting in a thin and uniform CEI. The protection of the stable CEI and MXene nanosheets simultaneously alleviate the Jahn-Teller effect and suppress the Mn dissolution during long cycling, thus allowing the cathode material to retain ∼ 80 % of its capacity after 1000 cycles at a current density of 1000 mA g −1 . This study highlights the importance of stabilizing the cathode interface and provides a novel approach for preparing highly stable manganese-based PBA cathode.