Ceramic/polymer matrix for electrode protection in electrochemical cells, including rechargeable lithium batteries
Articles and methods for forming ceramic/polymer composite structures for electrode protection in electrochemical cells, including rechargeable lithium batteries, are presented.
1. An electrode for an electrochemical cell, comprising:
a base layer comprising an active electrode species; and
a protective structure including at least a first composite layer comprising a patterned array of cavities within a matrix, wherein a polymer or a ceramic material forms the matrix, and the other of the polymer or ceramic material fills at least a portion of the cavities,
wherein the protective structure has an average ionic conductivity of at least 10 −7 S/cm.
2. The electrode of claim 1 , comprising a second composite layer.
3. The electrode of claim 2 , wherein the second composite layer is directly adjacent the first composite layer.
4. The electrode of claim 2 , wherein a continuous ceramic material layer is positioned between the first and second composite layers.
5. The electrode of claim 2 , wherein the cavities in the second composite layer are aligned with the cavities in the first composite layer.
6. The electrode of claim 2 , wherein the electrode comprises at least a third composite layer comprising a polymer matrix having a third plurality of cavities and a ceramic material filling at least two cavities of the third plurality of cavities.
7. The electrode of claim 1 , wherein the protective structure is impervious to an electrolyte to be used with the electrochemical cell.
8. The electrode of claim 1 , wherein the patterned array comprises repeat units.
9. The electrode of claim 1 , wherein a gel layer is positioned adjacent the first composite layer on a side opposite the base layer.
10. The electrode of claim 1 , wherein the polymer content in the protective structure is at least 2% by weight.
11. The electrode of claim 1 , wherein a ratio of the sum of the surface areas of the ceramic-filled cavities to the surface area of the electrode is at least 0.3.
12. The electrode of claim 1 , wherein the electrode is an anode comprising lithium.
13. The electrode of claim 1 , wherein the ceramic material is conductive to lithium ions.
14. The electrode of claim 1 , wherein the ceramic material is selected from the group consisting of Li 2 O, Li 3 N, Al 2 O 3 , ZrO 2 , SiO 2 , CeO 2 , Al 2 TiO 5 , oxy-sulfide glass, and combinations thereof.
15. The electrode of claim 1 , wherein an elastic modulus of the polymer is at least 2 times smaller than an elastic modulus of the ceramic material.
16. The electrode of claim 1 , wherein the polymer is substantially non-swellable in an electrolyte to be used with the electrochemical cell.
17. The electrode of claim 1 , wherein a volume fraction of the ceramic material in the first composite layer varies across the first composite layer.
18. The electrode of claim 17 , wherein the volume fraction of the ceramic material in the first composite layer is lower at an edge of the first composite layer than in a center of the first composite layer.
19. The electrode of claim 1 , wherein a size of the cavities of the patterned array varies across the first composite layer.
20. A method of fabricating a protected electrode, the method comprising:
forming a base layer comprising an active electrode species attached to a protective structure, wherein the protective structure is formed by:
positioning on a substrate at least one layer of a matrix comprising a polymer or a ceramic material, the matrix comprising a patterned array of cavities;
filling at least a portion of the cavities with the other of the polymer or the ceramic material to form a composite layer,
wherein the composite layer has an average ionic conductivity of at least 10 −7 S/cm.