Protective films for printed electrochemical cells and methods of packaging electrochemical cells
Electrochemical cells with a protective film that is permeable to hydrogen, or that include a catalyst that facilitates formation of mobile hydrogen species, that promotes sequestration or gettering of hydrogen or oxygen, and/or that facilitates conversion of hydrogen or oxygen to H 2 O, are disclosed.
1. An electrochemical cell, comprising:
a cathode;
an anode;
an electrolyte, in contact with the cathode and the anode;
a first current collector, in contact with the cathode;
a second current collector, in contact with the anode;
a protective film, finitely permeable to H 2 gas and O 2 gas, disposed directly on or around the cathode, the anode, the electrolyte, the first current collector, and the second current collector, configured to allow an H 2 gas in the electrochemical cell to exit from the electrochemical cell, and having a permeation ratio of the H 2 gas to an O 2 gas greater than or equal to 10:1; and
a substrate, comprising an electrical insulator and a metal foil thereon, wherein the metal foil is in contact with one of the first current collector or the second current collector, and wherein the cathode, the anode, the electrolyte, and the first current collector and the second current collectors are positioned and sealed between the protective film and the substrate.
2. The electrochemical cell of claim 1 , wherein the electrochemical cell is a multivalent ion electrochemical cell.
3. The electrochemical cell of claim 1 , wherein the electrochemical cell has an O 2 gas transmission rate near or at operating or storage conditions of the electrochemical cell of greater than 10 cc/m 2 /day.
4. The electrochemical cell of claim 1 , further comprising water, disposed in at least the electrolyte.
5. The electrochemical cell of claim 1 , wherein the electrolyte comprises an ionic liquid, a metal salt, and/or water.
6. The electrochemical cell of claim 1 , wherein the protective film comprises a zeolite additive.
7. The electrochemical cell of claim 1 , wherein the protective film conforms around a stack formed by the cathode, the anode, the electrolyte, the first current collector, and the second current collector.
8. The electrochemical cell of claim 1 , wherein the protective film conforms around a first tab and a second tab and seals the first tab and the second tab together with the substrate, wherein the first tab is in contact with the first current collector, and wherein the second tab is in contact with the second current collector.
9. The electrochemical cell of claim 8 , wherein one of the first tab or the second tab is part of the metal foil of the substrate.
10. The electrochemical cell of claim 1 , wherein the protective film comprises a pressure-sensitive adhesive, contacting at least one of the cathode, the anode, the electrolyte, the first current collector, or the second current collector.
11. The electrochemical cell of claim 1 , wherein the protective film comprises a metal oxide top coat, controlling, at least in part, the permeation ratio of the H 2 gas to the O 2 gas.
12. The electrochemical cell of claim 1 , wherein the electrochemical cell is a printed electrochemical cell.
13. The electrochemical cell of claim 1 , wherein the cathode comprises MnO 2 .
14. The electrochemical cell of claim 1 , wherein the protective film comprises an opening, exposing a portion of at least the first current collector or the second current collector.
15. The electrochemical cell of claim 1 , wherein the protective film has a thickness of between 10 micrometers and 200 micrometers.
16. An electrochemical cell, comprising:
a cathode;
an anode;
an electrolyte, in contact with the cathode and the anode;
a first current collector, in contact with the cathode;
a second current collector, in contact with the anode;
a protective film, finitely permeable to H 2 gas and O 2 gas, disposed directly on or around the cathode, the anode, the electrolyte, the first current collector, and the second current collector, comprising a first additive that promotes (i) forming monatomic or mobile hydrogen species or (ii) sequestering or gettering hydrogen or oxygen; and
a substrate, comprising an electrical insulator and a metal foil thereon, wherein the metal foil is in contact with one of the first current collector or the second current collector, and wherein the cathode, the anode, the electrolyte, and the first current collector and the second current collectors are positioned and sealed between the protective film and the substrate.
17. The electrochemical cell of claim 16 , wherein the first additive comprises an oxidizable metal film, oxidizable metal particles, or a film or particles of a metal or metal oxide in which hydrogen is soluble.
18. The electrochemical cell of claim 16 , wherein the protective film has an oxygen permeation rate of less than 10 cc/m 2 /day.
19. The electrochemical cell of claim 16 , wherein the anode comprises a second additive that promotes (i) forming monatomic or mobile hydrogen species or (ii) sequestering or gettering hydrogen or oxygen.
20. An electrochemical cell, comprising:
a cathode;
an anode;
an electrolyte, in contact with the cathode;
a first current collector, in contact with the anode;
a second current collector, in contact with the anode;
a protective film, finitely permeable to H 2 gas and O 2 gas, disposed directly on or around the cathode, the anode, the electrolyte, the first current collector, and the second current collector, comprising a first additive that promotes oxidation of hydrogen to H 2 O or reduction of oxygen to H 2 O; and
a substrate, comprising an electrical insulator and a metal foil thereon, wherein the metal foil is in contact with one of the first current collector or the second current collector, and wherein the cathode, the anode, the electrolyte, and the first current collector and the second current collectors are positioned and sealed between the protective film and the substrate.