A structure optimized Prussian blue analogue Na1.76Ni0.12Mn0.88[Fe(CN)6]0.98 (PBMN) is synthesized and investigated. Coexistence of inactive Ni2+ (Fe–CN–Ni group) with active Mn2+/3+ (Fe–CN–Mn group) balances the structural disturbances caused by the redox reactions. This cathode material exhibits particularly excellent cycle life with high capacity (118.2 mA h g−1).
