RECHARGEABLE AQUEOUS MG BATTERY WITH A SOLID-STATE POLYMERELECTROLYTE

1 . A rechargeable aqueous Mg battery comprising:

a Mg metal anode,

a solid-state aqueous polymer-based electrolyte, and

an intercalation-type Prussian blue analogue cathode for ion storage in the form of a cubic lattice structure.

2 . The rechargeable aqueous Mg battery of claim 1 wherein the solid-state aqueous polymer-based electrolyte is a solid-state MgCl 2 -polyethylene oxide (PEO) electrolyte.

3 . The rechargeable aqueous Mg battery of claim 2 wherein the the MgCl 2 -PEO electrolyte has a MgCl 2 ·6H 2 O:PEO (MW=2,000,000):H 2 O mass ratio of 4:1:1

4 . A method of forming a rechargeable aqueous Mg battery comprising the steps of:

providing a Mg anode,

providing a solid-state aqueous polymer-based electrolyte, and

providing an intercalation-type Prussian blue analogue cathode for ion storage in the form of a cubic lattice structure,

mixing components of the electrolyte by magnetic stirring under a hot water bath at about 60° C. overnight,

cooling the mixture to room temperature,

pressing the resulting solid-state electrolyte into approximately 2 mm-thick films for use,

assembling a single cell as a layered structure, where the solid-state electrolyte is inserted between a pure Mg foil and a carbon paper substrate coated with CuHCF ink,

connecting an electrode to a piece of silver foil which acts as the current collector, and

housing the cell in a poly(methyl methacrylate) (PMMA) cell.

5 . The method of claim 4 wherein the solid-state aqueous polymer-based electrolyte is a solid-state MgCl 2 -polyethylene oxide (PEO) electrolyte.

6 . The method of claim 4 wherein the Prussian blue cathode is an analogue of copper hexacyanoferrate (CuHCF) with a chemical formula of Cu2[Fe(CN)6], said cathode providing storage sites for ion insertion and extraction in the form of a cubic lattice structure.

7 . The method of claim 4 wherein single cells are combined into multiple cells to increase voltage and/or capacity.