Metal-ion battery with hexacyanometallate electrode
A method is provided for forming a metal-ion battery electrode with large interstitial spacing. A working electrode with hexacyanometallate particles overlies a current collector. The hexacyanometallate particles have a chemical formula A m M1 x M2 y (CN) 6 .zH 2 O, and have a Prussian Blue hexacyanometallate crystal structure, where A is either alkali or alkaline-earth cations. M1 and M2 are metals with 2+ or 3+ valance positions. The working electrode is soaked in an organic first electrolyte including a salt including alkali or alkaline earth cations. A first electric field is created in the first electrolyte between the working electrode and a first counter electrode, causing A cations and water molecules to be simultaneously removed from interstitial spaces in the Prussian Blue hexacyanometallate crystal structure, forming hexacyanometallate particles having the chemical formula of A m′ M1 x M2 y (CN) 6 .z′H 2 O, where m′<m and z′<z, overlying the working electrode.
1. A pre-fabricated metal-ion electrode, prior to exposure to an electrolyte in a battery, the electrode comprising:
hexacyanometallate particles overlying a current collector, the hexacyanometallate particles having a chemical formula A m′ M1 x M2 y (CN) 6 .z′H 2 O, and having a Prussian Blue hexacyanometallate crystal structure,
where A is selected from a group consisting of alkali cations;
where M1 is a metal selected from a group consisting of 2+ and 3+ valance positions;
where M2 is a metal selected from a group consisting of 2+ and 3+ valance positions;
where m′ is in a range of greater than 1 to 2;
where xx is in a range of 0.5 to 1.5;
where y is in a range of 0.5 to 1.5; and,
where z′ is 0.
2. The electrode of claim 1 wherein the A cations are selected from a group consisting of Na + and K + .
3. The electrode of claim 1 further comprising:
a solid-electrolyte interphase (SEI) layer overlying the electrode.
4. A metal-ion battery comprising:
a first electrode with hexacyanometallate particles overlying a current collector, the hexacyanometallate particles having a chemical formula A′ n A m′ M1 x M2 y (CN) 6 .z′H 2 O, and having a Prussian Blue hexacyanometallate crystal structure,
where A cations are selected from a group consisting of alkali cations;
where A′ cations are selected from a group consisting of alkali cations;
where M1 is a metal selected from a group consisting of 2 + and 3 + valance positions;
where M2 is a metal selected from a group consisting of 2 + and 3 + valence positions;
where m′ is in a range of greater than 1 to 2;
where x is in a range of 0.5 to 1.5;
where n is in a range of 0 to 2;
where y is in a range of 0.5 to 1.5;
where z′ is 0;
an organic electrolyte including A′ cations; and,
a counter electrode.
5. The battery of claim 4 wherein the first electrode is selected from a group consisting of an anode and a cathode.
6. The battery of claim 4 wherein the first electrode hexacyanometallate particles have the chemical formula of A m′ M1 x M2 y (CN) 6 , where n=0.
7. The battery of claim 4 wherein A cations are selected from a first group consisting of a Na + and K + ; and,
wherein the A′ cations are selected from a second group consisting of Na + and K + .
8. The battery of claim 4 further comprising:
a solid-electrode interphase (SEI) layer overlying the first electrode.
9. The battery of claim 4 wherein the counter electrode includes A′ cations.
10. A metal-ion battery comprising:
a first electrode with hexacyanometallate particles overlying a current collector, the hexacyanometallate particles having a chemical formula A m′ M1 x M2 y (CN) 6 .z′H 2 O, and having a Prussian Blue hexacyanometallate crystal structure,
where A is selected from a group consisting of alkali cations;
where M1 is a metal selected from a group consisting of 2 + and 3 + valence positions;
where M2 is a metal selected from a group consisting of 2 + and 3 + valance positions;
where m′ is in a range of greater than 1 to 2;
where x is in a range of 0.5 to 1.5;
where y is in a range of 0.5 to 1.5;
where z′ is 0;
an organic electrolyte including a salt containing A′ cations selected from the group of alkali cations; and,
a counter electrode comprising A′ elements, where A′ is selected from a group consisting of alkali elements.
11. The battery of claim 10 wherein the first electrode is selected from a group consisting of an anode and a cathode.
12. The battery of claim 10 wherein the A cations are selected from a first group consisting of Na + and K + ; and,
wherein the organic electrolyte A′ cations are selected from a second group consisting of Na + and K + .
13. The battery of claim 10 further comprising:
a solid-electrolyte interphase (SEI) layer overlying the first electrode.