Transition metal hexacyanoferrate battery with single plateau charge/discharge curve
A transition metal hexacyanoferrate (TMH) cathode battery is provided. The battery has a A x Mn[Fe(CN) 6 ] y .zH 2 O cathode, where the A cations are either alkali or alkaline-earth cations, such as sodium or potassium, where x is in the range of 1 to 2, where y is in the range of 0.5 to 1, and where z is in the range of 0 to 3.5. The A x Mn[Fe(CN) 6 ] y .zH 2 O has a rhombohedral crystal structure with Mn 2+/3+ and Fe 2+/3+ having the same reduction/oxidation potential. The battery also has an electrolyte, and anode made of an A metal, an A composite, or a material that can host A atoms. The battery has a single plateau charging curve, where a single plateau charging curve is defined as a constant charging voltage slope between 15% and 85% battery charge capacity. Fabrication methods are also provided.
1. A transition metal hexacyanoferrate (TMH) battery cathode comprising:
A x Mn[Fe(CN) 6 ] y .z H 2 O;
where A cations are selected from a group consisting of alkali and alkaline-earth cations;
where x is in a range of 1 to 2;
where y is in a range of 0.5 to 1;
where z is in a range of 0 to 3.5; and,
where the A x MnFe[(CN) 6 ] y .zH 2 O has a rhombohedral crystal structure with Mn 2+/3+ and Fe 2+/3+ having the same reduction/oxidation potential.
2. The TMH battery cathode of claim 1 wherein the A cations are selected from a group consisting of sodium (Na) and potassium (K).
3. A transition metal hexacyanoferrate (TMH) cathode battery, the battery comprising:
a A x Mn[Fe(CN) 6 ] y .zH 2 O cathode;
where A cations are selected from a group consisting of alkali and alkaline-earth cations;
where x is in a range of 1 to 2;
where y is in a range of 0.5 to 1;
where z is in a range of 0 to 3.5;
where the A x Mn[Fe(CN) 6 ] y .zH 2 O has a rhombohedral crystal structure with Mn 2+/3+ and Fe 2+/3+ having the same reduction/oxidation potential;
an anode selected from a group consisting of an A metal, an A composite, and a material that can host A atoms; and,
an electrolyte.
4. The battery of claim 3 wherein the electrolyte is an organic solvent containing A-atom salts.
5. The battery of claim 3 wherein A is selected from a group consisting of sodium (Na) and potassium (K).
6. The battery of claim 3 wherein the battery has a single plateau charging curve, where a single plateau charging curve is defined as a constant charging voltage slope between 15% and 85% battery charge capacity.
7. The battery of claim 3 wherein the battery has a single plateau discharge curve, where a single plateau discharge curve is defined as a constant discharge voltage slope between 85% and 15% battery charge capacity.
8. The battery of claim 3 wherein the battery has a single plateau charging/discharging curve, where a single plateau charging/discharging curve is defined by a derivative of charge capacity to voltage (dQ/dV) of a completed charging/discharging curve having only one peak.
9. The battery of claim 3 wherein the battery has a discharge capacity of greater than 90 milliamp hours per gram (mAh/g).
10. The battery of claim 3 wherein the anode comprises a primary material selected from a group consisting of hard carbon and graphite.