A mechanism is presented for shielding a cathode in a metal cyanometallate battery. A battery is provided with an anode, a cathode, an electrolyte, and an ion-permeable membrane separating the anode from the cathode. The cathode is made up of a plurality of metal cyanometallate layers overlying the current collector. At least one of the metal cyanometallate layers is an active layer formed from an active material AXM1YM2Z(CN)N·MH2O, where “A” is an alkali metal, alkaline earth metal, or combination thereof. At least one of the metal cyanometallate layers is a shield layer comprising less than 50 percent by weight (wt %) active material. In response to applying an external voltage potential between the cathode and the anode, the method charges the battery. Upon discharge, the shield layer blocks metal particles from contacting active layers. Simultaneously, the shield layer transports metal ions from the electrolyte to the active layers.