WATER SOFTENING INTERCALATION MATERIALS

An electrode for use in a device configured to remove ions from a solution. The electrode includes an intercalation material including a binary transition metal Prussian blue analogue compound, a ternary transition metal Prussian blue analogue compound, or a combination thereof. The binary compound may have a general formula: ABC[Fe(CN)], where A=Li, Na, or K; B=Mn, Fe, Ni, Cu, or Zn; C=Mn, Fe, Ni, Cu, or Zn; 0≤x≤1; 0≤y≤1; and 0≤z≤1. The ternary compound may have the general formula: ABCD[Fe(CN)], where A=Li, Na, or K; B=Mn, Fe, Ni, Cu, or Zn; C=Mn, Fe, Ni, Cu, or Zn; D=Mn, Fe, Ni, Cu, or Zn; 0≤x≤1; 0≤y≤1; 0≤z≤1; 0≤w≤1.