Stabilization of battery electrodes using polymer coatings
View Patent ↗An electrochemical device (e.g., a battery (cell)) including: an aqueous electrolyte and one or two electrodes (e.g., an anode and/or a cathode), one or both of which is a Prussian Blue analogue material of the general chemical formula A x P[R(CN) 6−j L j ] z .nH 2 O, where: A is a cation; P is a metal cation; R is a transition metal cation; L is a ligand that may be substituted in the place of a CN − ligand; 0≦x≦2; 0≦z≦1; and 0≦n≦5, the electrode including a polymer coating to reduce capacity loss.
1. An electrochemical apparatus, comprising:
an aqueous electrolyte having a plurality of ions;
a first electrode disposed in said aqueous electrolyte, said first electrode including a first Prussian Blue analogue material having a general chemical formula A x P y [R(CN) 6−j L j ] z ·nH 2 O, where: A is a cation, P is a metal cation, R is a transition metal cation, and L is a ligand substitutable in the place of a CN − ligand, and 0≦j≦6, 0≦x≦2, 0<y≦4, 0<z≦1, and 0≦n≦5 wherein said first Prussian Blue analogue material has a first specific chemical formula conforming to said general chemical formula including a first particular cation P 1 and a first particular cation R 1 and wherein said first Prussian Blue analogue material has a first rate of electrochemical capacity loss when disposed in said aqueous electrolyte;
a first conformal polymer layer disposed on said first electrode, said first conformal polymer layer conductive to said plurality of ions;
wherein said first electrode with said first conformal polymer layer has a second rate of electrochemical loss less than said first rate of electrochemical capacity loss when said first electrode is disposed in said aqueous electrolyte;
a second electrode disposed in said aqueous electrolyte, said second electrode including a second Prussian Blue analogue material having said general chemical formula wherein said second Prussian Blue analogue material has a second specific chemical formula conforming to said general chemical formula different from said first specific chemical formula, and wherein said second Prussian Blue analogue material has a third rate of electrochemical capacity loss when disposed in said aqueous electrolyte;
a second conformal polymer layer disposed on said second electrode, said second conformal polymer layer conductive to said plurality of ions;
wherein said second electrode with said second conformal polymer layer has a fourth rate of electrochemical loss less than said third rate of electrochemical capacity loss when said second electrode is disposed in said aqueous electrolyte; and
wherein said first electrode, said second electrode, and said aqueous electrolyte are configured as a rechargeable energy storage cell.
2. The electrochemical apparatus of claim 1 wherein said first conformal polymer layer includes a polypyrrole compound.
3. The electrochemical apparatus of claim 1 wherein said first conformal polymer layer includes a polythiophene compound.
4. The electrochemical apparatus of claim 2 wherein said first Prussian Blue analogue material includes copper hexacyanoferrate.
5. The electrochemical apparatus of claim 3 wherein said first Prussian Blue analogue material includes copper hexacyanomanganate.
6. The electrochemical apparatus of claim 2 wherein said first Prussian Blue analogue material includes manganese hexacyanomanganate.
7. The electrochemical apparatus of claim 3 wherein said first Prussian Blue analogue material includes manganese hexacyanomanganate.
8. The electrochemical apparatus of claim 1 wherein said aqueous electrolyte includes one or more additives selected from the group consisting of an amine or an oxide of an amine, and combinations thereof.
9. The electrochemical apparatus of claim 8 wherein said amine or said oxide of an amine includes pyridine-n-oxide.
10. The electrochemical apparatus of claim 1 wherein said aqueous electrolyte includes a plurality of anion X such that a reaction of said anion X with said first particular cation P 1 is configured to form an insoluble compound containing first particular cation P 1 and anion X, wherein anion X includes one or more anions selected from the group consisting of fluoride, carbonate, oxalate, or phosphate, and combinations thereof.
11. The electrochemical apparatus of claim 1 wherein said aqueous electrolyte includes one or more additives selected from the group consisting of a simple thiol or a complex thiol group, and combinations thereof.
12. The electrochemical apparatus of claim 11 wherein said simple thiol includes decanethiol.
13. The electrochemical apparatus of claim 11 wherein said complex thiol group includes cysteine.
14. The electrochemical apparatus of claim 1 wherein said first electrode includes a first potential window when disposed in said aqueous electrolyte and wherein said first conformal polymer layer forms a dissolution product in said aqueous electrolyte with said dissolution product chemically inactive within said first potential window.
15. The electrochemical apparatus of claim 1 wherein said first particular cation P 1 includes one or more cations selected from the group consisting of a copper cation, a manganese cation, a zinc cation, or an iron cation, and combinations thereof.
16. The electrochemical apparatus of claim 1 wherein said general chemical formula includes:
A is one or more cations selected from the group consisting of Na + , K + , Li + , NH 4 + , Mg2 + , or Ca2 + and combinations thereof;
P is one or more metal cations selected from the group consisting of V 2+ , V 3+ , Cr 2+ , Cr 3+ , Mn 2+ , Mn 3+ , Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Ni 2+ , Cu + , Cu 2+ , Zn 2+ , Al 3+ , Sn 2+ , In 3+ , or Pb 2+ and combinations thereof;
R is one or more transition metal cations selected from the group consisting of V 2+ , V 3+ , Cr 2+ , Cr 3+ , Mn 2+ , Mn 3+ , Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Ru 2+ , Ru 3+ , Os 2+ , Os 3+ , Ir 2+ , Ir 3+ , Pt 2+ , or Pt 3+ and combinations thereof; and
L is one or more ligands that may be substituted in the place of a CN − ligand selected from the group consisting of CO (carbonyl), NO (nitrosyl), or Cl − and combinations thereof.