Prussian Blue Analogues with Optimized Crystal Plane Orientation and Low Crystal Defects toward 450 Wh kg−1 Alkali‐Ion Batteries

cathodes for lithium-ion batteries. Remarkably, unconventional highly-reversible phase evolution and redox-active pairs were identified by multiple in situ techniques for the first time. The preferred guest-ion storage sites and migration mechanism were systematically analysed through theoretical calculations. We believe these results could inspire the design of safe with high energy density.