Anode, secondary battery including the same, and the method of making anode
Alkali metal secondary batteries that include anodes constructed from alkali metal foil applied to only one side of a porous current collector metal foil. Openings in the porous current collectors permit alkali metal accessibility on both sides of the anode structure. Such anode constructions enable the utilization of lower-cost and more commonly available alkali metal foil thickness, while still achieving high cell cycle life at a significantly reduced cost. Aspects of the present disclosure also include batteries with porous current collectors having increased volumetric and gravimetric energy densities, and methods of manufacturing anodes with porous current collectors.
1. An anode for an alkali metal secondary battery, comprising:
a porous current collector foil having first and second opposing sides and a webbed structure defining openings each having a volume; and
an alkali metal foil laminated to one side of the porous current collector foil, wherein portions of the alkali metal foil extend through the openings from the first opposing side to the second opposing side and substantially fill the volumes of the openings.
2. The anode of claim 1 , wherein the alkali metal foil is laminated on the first opposing side and the second opposing side includes a continuous layer of alkali metal formed from the portions of the alkali metal foil that extruded through the openings.
3. The anode of claim 1 , wherein the alkali metal foil is laminated on the first opposing side, and the portions of the alkali metal foil present in the openings is flush with the second opposing side.
4. The anode of claim 3 , further comprising a second alkali metal laminated onto the second opposing side.
5. The anode of claim 3 , wherein the alkali metal foil comprises an alkali metal, and the anode further comprising an alkali metal coating applied to the second opposing side, wherein the alkali metal coating is made of the alkali metal.
6. The anode of claim 1 , wherein the openings in the porous current collector foil include a plurality of identically sized polygonal openings arranged with one another so as to define uniform web widths within the porous current collector foil between adjacent one of the identically sized polygonal openings.
7. The anode of claim 6 , wherein the identically sized polygonal openings are hexagonal in shape.
8. The anode of claim 6 , wherein the openings in the porous current collector foil define a percent open area that is greater than 80%.
9. The anode of claim 1 , wherein the porous current collector foil has a thickness in a range of 4 μm to 20 μm.
10. The anode of claim 1 , wherein the openings in the porous current collector foil define a percent open area that is greater than 40%.
11. The anode of claim 1 , wherein the openings in the porous current collector foil define a percent open area that is greater than 60%.
12. The anode of claim 1 , wherein the openings in the porous current collector foil define a percent open area that is greater than 80%.
13. The anode of claim 1 , wherein the openings have a width that is greater than 0.5 mm.
14. The anode of claim 1 , wherein the openings have a maximum width that is greater than 0.75 mm.
15. The anode of claim 1 , wherein the openings have a maximum width that is greater than 1.2 mm.
16. The anode of claim 1 , wherein the webbed structure of the porous current collector has a minimum web width extending between adjacent ones of the openings, wherein the minimum web width is less than 1 mm.
17. The anode of claim 1 , wherein the webbed structure of the porous current collector has a minimum web width extending between adjacent ones of the openings, wherein the minimum web width is less than 0.25 mm.
18. The anode of claim 1 , wherein the webbed structure of the porous current collector has a minimum web width extending between adjacent ones of the openings, wherein the minimum web width is less than 0.15 mm.
19. The anode of claim 1 , wherein the openings in the porous current collector foil define a percent open area that is greater than 75% and have a minimum spacing of less than 0.2 mm.
20. The anode of claim 1 , wherein the openings in the porous current collector foil define a percent open area that is greater than 75%, have a size greater than 1.2 mm, and have a minimum spacing of less than 0.2 mm.
21. The anode of claim 1 , wherein the openings in the porous current collector foil are polygonal in shape, define a percent open area that is greater than 75%, have a size greater than 1.2 mm, and have a minimum spacing of less than 0.2 mm.
22. The anode of claim 1 , wherein the openings in the porous current collector foil are polygonal in shape, define a percent open area that is greater than 75%, and have a minimum spacing of less than 0.2 mm.
23. The anode of claim 1 , wherein the openings in the porous current collector foil are polygonal in shape and have a minimum spacing of less than 0.2 mm.
24. The anode of claim 1 , wherein the alkali metal foil has a width that is greater than 55 mm.
25. The anode of claim 1 , wherein the anode includes a plurality of rows of the alkali metal foil positioned in a closely-spaced parallel arrangement across the porous current collector foil, wherein a width of the anode is 55 mm or more.
26. The anode of claim 25 , wherein the alkali metal foil is lithium metal foil having a thickness of 100 μm or less.
27. The anode of claim 25 , wherein the alkali metal foil is lithium metal foil having a thickness of 40 μm or less.
28. The anode of claim 1 , wherein the alkali metal foil is lithium metal foil having a thickness of 100 μm or less.
29. The anode of claim 1 , wherein the alkali metal foil is lithium metal foil having a thickness of 40 μm or less.
30. A secondary battery, comprising:
an alkali metal anode, a cathode, and a separator;
wherein the alkali metal anode is an anode according to any one of claims 1 - 29 .