A lithium and zinc ion bi-polar battery includes, in one example, a plurality of carbon or titanium bi-polar current collectors arranged with cells to form a stack of bi-polar configuration such that each of the bi-polar current collectors is between and in direct contact with a zinc electrode and lithium-ion intercalation electrode of an adjacent pair of the cells.

TECHNICAL FIELD

This disclosure relates to bi-polar batteries with a lithium-ion and zinc-ion chemistry.

BACKGROUND

A secondary cell may include an electrolyte, separator, anode, and cathode. A bi-polar battery may include anodes and cathodes stacked in series.

Chemical reactions of a secondary cell are reversible. When the cell is being charged for example, the anode may become positive, and the cathode may become negative. When the cell is being discharged, it behaves like a primary cell.

SUMMARY

A bi-polar lithium and zinc ion battery is contemplated. In one example, a zinc anode and a lithium intercalation cathode share a common current collector. The current collector can be a chemically inert and conductive substrate or metallic zinc as part of the anode. This design may reduce the number of current collectors needed in the electrode stack or eliminate them completely, and reduce the number of electrode tabs. This design may also reduce cost, increase energy density, and increase power.

DETAILED DESCRIPTION

Embodiments are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.

Various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.

A challenge of lithium-zinc-ion acidic battery systems is the limited options and cost of the chemically compatible current collectors, along with the volume and weight added by these current collectors. Two of these current collector materials are titanium and carbon. While titanium provides a mechanically robust and chemically resistant current collector, the amount required in a mono-polar design can significantly add cost, weight, and volume to the battery. The cost of carbon current collectors is much lower and is chemically compatible with the acidic electrolyte. The carbon, however, is not as mechanically robust and tabbing from the electrodes is an issue. The inventors have discovered that overall cell resistance can be reduced with a bi-polar design, as opposed to the mono-polar design due to the elimination of tab welds or connections.

A lithium-zinc-ion bi-polar design will thus mitigate the current collector issues mentioned above or eliminate the need for a current collector all together. By the anode and cathode utilizing a common current collector material, such as titanium, the cost, weight, and volume of the battery will be reduced over the traditional mono-polar design.

Zinc foil anodes may also be used in the lithium-zinc-ion chemistry, which would allow for the anode to act as both the active material and current collector. Dense zinc foil is conductive and would be chemically resistant, as the plating and dissolution of the zinc ions in the electrolyte would occur at the outer surface of the foil and not the internal area used as the current collector. This design can also help to reduce resistance by limiting interfacial resistance to the cathode side. This particular design may require a hermetic and conductive coating disposed in contact with the zinc electrode and the lithium-ion intercalation electrode.

The current collector itself can also act a as a substrate for plating and de-plating zinc ions from the electrolyte depending on whether the cell is charged or discharged, respectively. This design would eliminate the need for manufacturing the cell with a zinc electrode.

Referring toFIG.1, a bi-polar lithium-zinc-ion battery10includes a plurality of cells12and a plurality of current collectors14(e.g., carbon or titanium current collectors) stacked together such that each of the current collectors14(not adjacent to an outside surface of the battery10) is disposed directly between and in contact with an adjacent pair of the cells12. Each of the cells12includes a lithium-ion intercalation electrode16(e.g., lithium iron phosphate (LFP), lithium manganese oxide (LMO), lithium cobalt oxide (LCO), lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum (NCA), lithium nickel manganese oxide (LNMO), vanadium oxides, and Prussian blue/white), a zinc electrode18(e.g., metallic zinc foil, expanded zinc metal sheet, slurry coated metallic zinc particles, and plated/deposited metallic zinc), a separator20(e.g., a micro porous, tortuous, electrolyte retaining, ionically conductive, and electronically insulating separator) disposed directly between and in contact with the lithium-ion intercalation electrode16and zinc electrode18, and an acidic (e.g., chloride-based, nitrate-based, triflate-based) electrolyte22, containing zinc ions and lithium ions, distributed among the lithium-ion intercalation electrode16, zinc electrode18, and separator20. The zinc ions and lithium ions thus facilitate ionic communication between the lithium-ion intercalation electrode16and zinc electrode18.

So arranged, the lithium-ion intercalation electrode16of one of the cells12and the zinc electrode18of another of the cells12are on opposite sides of and in direct contact with one of the current collectors14(provided the cells12are adjacent to each other and the lithium-ion intercalation electrode16or zinc electrode18is not adjacent to an outside surface of the battery10). That is, adjacent pairs of the cells12each share one of the current collectors14.

Referring toFIG.2, a bi-polar lithium-zinc-ion battery24includes a plurality of cells26stacked together. Each of the cells26includes a lithium-ion intercalation electrode28, a zinc (foil) electrode30, a separator32disposed directly between and in contact with the lithium-ion intercalation electrode28and zinc electrode30, and an acidic (e.g., chloride-based, nitrate-based, triflate-based) electrolyte34, containing zinc ions and lithium ions, distributed among the lithium-ion intercalation electrode28, zinc electrode30, and separator32. Each of the cells26also includes a hermetic and conductive coating36(e.g., carbon-based, conductive polymer, etc.) on an exterior surface of each of the lithium-ion intercalation electrode28and zinc electrode30. The zinc ions and lithium ions thus facilitate ionic communication between the lithium-ion intercalation electrode28and zinc electrode30.

So arranged, the hermetic and conductive coating36on the lithium-ion intercalation electrode28of one of the cells26and the hermetic and conductive coating36on the zinc electrode30of another of the cells26are in direct contact with each other (provided the cells26are adjacent to each and the lithium-ion intercalation electrode28or zinc electrode30is not at an end of the battery24).

Referring toFIG.3, a bi-polar lithium-zinc-ion battery38includes a plurality of cells40and a plurality of current collectors42(e.g., carbon or titanium current collectors) stacked together such that each of the current collectors42is disposed directly between and in contact with an adjacent pair of the cells40(provided that the current collector42is not at an end of the battery38). Each of the cells40includes a lithium-ion intercalation electrode44, a separator46, and an acidic (e.g., chloride-based, nitrate-based, triflate-based) electrolyte48, containing zinc ions and lithium ions, distributed among the lithium-ion intercalation electrode44and separator46. During charge, zinc ions plate the current collectors42to form deposits50thereon.

So arranged, the lithium-ion intercalation electrode44of one of the cells40and the separator46of another of the cells40are on opposite sides of and in direct contact with one of the current collectors42(provided the cells40are adjacent to each other and the lithium-ion intercalation electrode40or separator42is not adjacent to an end of the battery34). That is, adjacent pairs of the cells36each share one of the current collectors38.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure.