Suppressing the Phase Transformation in Cubic Prussian Blue Analogues via a High-Entropy Strategy for Efficient Zinc-Ion Storage.

Prussian blue analogs (PBAs) are widely recognized as promising candidates for aqueous zinc-ion batteries (AZIBs) due to their stable three-dimensional framework structure. However, their further development is limited by their low specific capacity and unsatisfactory cycling performance, primarily caused by phase transformation during charge-discharge cycles. Herein, we employed a high-entropy strategy to introduce five different metal elements (Fe, Co, Ni, Mn, and Cu) into the nitrogen-coordinated M sites of PBAs, forming a high-entropy Prussian blue analog (HEPBA). By leveraging the cocktail effect of the high-entropy strategy, the phase transformation in the HEPBA was significantly suppressed. Consequently, the HEPBA as an AZIB cathode delivered a high reversible specific capacity of 132.1 mAh g at 0.1 A g, and showed exceptional cycling stability with 84.7% capacity retention after 600 cycles at 0.5 A g. This work provides innovative insights into the rational design of advanced cathode materials for AZIBs.