Aqueous manganese ion battery
An alternative grid energy storage system is described herein. In one embodiment, an electrochemical cell comprises a high specific surface area cathode (e.g., a cathode comprising a carbon nanofoam paper, a carbon nanotube mesh, a particulate carbon material, electrolytic manganese dioxide, or a manganese dioxide film), a zinc or lead anode (e.g., Zn or Pb foil), a selective ion-conductive separator that does not conduct zinc ions (e.g., a NAFION sulfonated tetrafluoroethylene based fluoropolymer-copolymer separator) between the anode and the cathode, and an aqueous electrolyte comprising a manganese salt (e.g., aqueous manganese sulfate) contacting the electrodes and the separator. A battery comprising two or more of the electrochemical cells electrically connected together in series, parallel, or both, also is described.
1. An aqueous manganese ion electrochemical cell comprising a high specific surface area cathode, an anode, a selective ion-conductive separator between the anode and the cathode, and an aqueous electrolyte comprising a manganese salt contacting the anode, the cathode, and the separator; wherein the anode comprises metallic Zn or metallic Pb; the cathode has an area-to-volume specific surface area greater than or equal to 10 6 m −1 ; and wherein the separator does not conduct zinc ions, thereby preventing the passage of zinc ions from the anode to the cathode.
2. The electrochemical cell of claim 1 , wherein the cathode comprises at least one material selected from the group consisting of (a) a carbon nanofoam paper, (b) a carbon nanotube mesh, (c) nanoparticulate manganese dioxide dispersed in a carbon nanotube mesh, and (d) a particulate material coated on a current collector; wherein the particulate material comprises a particulate carbon material, a particulate manganese dioxide material, or a combination thereof.
3. The electrochemical cell of claim 1 , wherein the cathode comprises a nanoparticulate carbon material coated on a metal current collector.
4. The electrochemical cell of claim 3 , wherein the nanoparticulate carbon material comprises at least one material selected from the group consisting of carbon nanotubes, carbon nanofibers, multi-walled carbon nanotubes, and graphene.
5. The electrochemical cell of claim 1 , wherein the cathode comprises a carbon nanofoam paper.
6. The electrochemical cell of claim 5 , wherein the carbon nanofoam paper has an area-to-volume specific surface area greater than or equal to 1.5×10 8 m −1 .
7. The electrochemical cell of claim 1 , wherein the anode comprises metallic Zn.
8. The electrochemical cell of claim 1 , wherein the manganese salt comprises manganese sulfate, manganese chloride, manganese nitrate, or a combination of two or more thereof.
9. The electrochemical cell of claim 1 , wherein the manganese salt is present in the electrolyte at a concentration in the range of about 0.05 to about 5 molar (M).
10. The electrochemical cell of claim 1 , wherein the separator comprises a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.
11. The electrochemical cell of claim 2 , wherein the particulate material is coated on the current collector with a polymeric binder.
12. The electrochemical cell of claim 1 , wherein the current collector comprises carbon or a metal.
13. The electrochemical cell of claim 1 , wherein the current collector comprises stainless steel, aluminum, or titanium.
14. An aqueous manganese ion electrochemical cell comprises a cathode, an anode, a selective ion-conductive separator between the anode and the cathode, and an aqueous electrolyte comprising a manganese salt contacting the anode, the cathode, and the separator; wherein the anode comprises metallic Zn; the cathode comprises at least one material selected from the group consisting of (a) a carbon nanofoam paper, (b) a carbon nanotube mesh, (c) nanoparticulate manganese dioxide dispersed in a carbon nanotube mesh, and (d) a particulate material coated on a current collector; wherein the particulate material comprises a particulate carbon material, a particulate manganese dioxide material, or a combination thereof; and wherein the separator does not conduct zinc ions, thereby preventing the passage of zinc ions from the anode to the cathode.
15. The electrochemical cell of claim 14 , wherein the cathode has an area-to-volume specific surface area greater than or equal to 10 6 m −1 .
16. The electrochemical cell of claim 14 , wherein the manganese salt is present in the electrolyte at a concentration in the range of about 0.05 to about 5 M.
17. The electrochemical cell of claim 14 , wherein the separator comprises a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.
18. The electrochemical cell of claim 14 , wherein the cathode comprises at least one particulate carbon material selected from the group consisting of carbon nanotubes, multi-walled carbon nanotubes, carbon nanofibers, and graphene.
19. A battery comprising a plurality of electrochemical cells of claim 1 electrically connected together in series, in parallel, or in both series and parallel.
20. A battery comprising a plurality of electrochemical cells of claim 14 electrically connected together in series, in parallel, or in both series and parallel.