Sodium zinc hexacyanoferrate with a well-defined open framework as a positive electrode for sodium ion batteries

A modified Prussian blue analogue, Na2Zn3[Fe(CN)(6)](2)center dot xH(2)O, was investigated as a positive electrode material. Utilizing a well-defined channel structure, the compound exhibits a clear electrochemical activity at around 3.5 V vs. Na/Na+ with a reversible capacity of 56.4 mA h g(-1) and good cycle life.