Hybrid solid-state cell with a 3D porous cathode structure
An electrochemical cell is provided, which includes a cathode comprising a three dimensional (3D) porous cathode structure, an anode, an electrolyte separator, comprised of a ceramic material, located between the cathode and the anode, and a cathode current collector, wherein the cathode is located between the cathode current collector and the electrolyte separator. The 3D porous cathode structure includes ionically conducting electrolyte strands extending through the cathode from the cathode current collector to the electrolyte separator, pores extending through the cathode from the cathode current collector to the electrolyte separator, and an electronically conducting network extending on sidewall surfaces of the pores from the cathode current collector to the electrolyte separator.
1. A method for forming a 3D porous cathode structure for an electrochemical cell including a cathode, an anode, an electrolyte separator, comprised of a ceramic material, located between the cathode and anode, and a cathode current collector, wherein the cathode comprising the 3D porous cathode structure is located between the cathode current collector and the electrolyte separator, the method comprising:
mixing a first precursor material and a second precursor material together to form a mixture;
depositing the mixture as a layer where the cathode is to be formed; and
sintering the mixture to form the 3D porous cathode structure with ionically conducting electrolyte strands extending through the cathode from the cathode current collector to the electrolyte separator, pores extending through the cathode from the cathode current collector to the electrolyte separator, and an electronically conducting network extending on sidewall surfaces of the pores from the cathode current collector to the electrolyte separator,
wherein the second precursor material is a sacrificial material configured to decompose during formation of the pores by the sintering using the second precursor material, and the first precursor material is a material which forms a coating of the electronically conducting network on the sidewall surfaces of the pores formed by sintering the second precursor material.
2. The method of claim 1 , wherein the mixture of the first and second precursor materials comprises a powder deposition mixture.
3. The method of claim 2 , wherein the second precursor material is comprised of a powder of a sacrificial pore forming material.
4. The method of claim 2 wherein the powder deposition mixture is fixed with a binder material by a binder jet printing operation prior to the sintering.
5. The method of claim 1 , wherein the mixture of the first and second precursor materials comprises a slurry including powders for the first and second precursor materials, a binder and a solvent.
6. The method of claim 5 , further comprising depositing the slurry by a coating technique selected from a group consisting of tape casting, screen printing, slot-die coating, and inkjet printing.
7. The method of claim 1 , wherein the first precursor material comprises a metal carbonate.
8. The method of claim 1 , wherein the electrochemical cell is configured to be used to form a lithium-ion battery, and further comprising filling a cathode material in the pores, in direct contact with the electronically conducting network, wherein the cathode material is comprised of a material in which lithium ions are released from a cathode active material during charging of the electrochemical cell, throughout the pores, to move through the electrolyte strands toward the electrolyte separator, and in which electrons are released from the cathode active material during charging of the electrochemical cell, throughout the pores, to transfer to the electronically conducting network.
9. The method of claim 1 , wherein the mixture includes a third precursor material comprised of a material that densities a solid electrolyte material during the sintering to form the ionically conducting electrolyte strands upon completion of formation of the pores.
10. The method of claim 1 , wherein first precursor material includes at least one material selected from an organic material or inorganic material or combinations thereof.
11. The method of claim 1 , further comprising controlling a size, shape and porosity of the 3D porous cathode by controlling one or more of a size, shape and concentration of the second precursor material.
12. The method of claim 11 , wherein a diameter of the pores is less than 10 μm.
13. The method of claim 11 , wherein a diameter of the pores is less than 5 μm.
14. The method of claim 1 , wherein the second precursor material comprises an organic material, an inorganic material, or a combination thereof.
15. The method of claim 1 , wherein the first precursor comprises an organic material or an inorganic material or combinations thereof consisting of at least one element selected from a group consisting of: carbon; nickel; silver; and aluminum.
16. The method of claim 1 , wherein the second precursor material comprises a metal carbonate.
17. The method of claim 1 , wherein the anode is disposed in an anode receptive space, the cathode is disposed in a cathode receptive space, and the cathode receptive space includes a filling aperture including a seal configured to isolate the anode from catholyte material contained in the cathode receptive space.
18. The method of claim 17 , wherein the seal is configured to provide pressure relief for the cathode receptive space.
19. The method of claim 17 , wherein the catholyte includes liquid catholyte material filled into the cathode receptive space through the filling aperture.
20. The method of claim 17 , wherein the catholyte includes powder catholyte material located in the cathode receptive space.
21. The method of claim 1 , wherein the electronically conducting network comprises a web or mesh type structure on the sidewall surfaces of the pores.
22. A method for forming 3D porous cathode and anode structures for an electrochemical cell including a cathode, an anode, an electrolyte separator, comprised of a ceramic material, located between the cathode and anode, a cathode current collector, and an anode current collector, wherein the cathode comprising the 3D porous cathode structure is located between the cathode current collector and the electrolyte separator, and the anode comprising the 3D porous anode structure is located between the anode current collector and the electrolyte separator, the method comprising:
mixing a first precursor material and a second precursor together to form a mixture;
depositing the mixture as a layer where the cathode and anode are to be formed; and
sintering the mixture to form the 3D porous cathode structure and the 3D porous anode structure with ionically conducting electrolyte strands extending through the cathode from the cathode current collector to the electrolyte separator, ionically conducting electrolyte strands extending through the anode from the anode current collector to the electrolyte separator, pores extending through the cathode from the cathode current collector to the electrolyte separator, pores extending through the anode from the anode current collector to the electrolyte separator, an electronically conducting network extending on sidewall surfaces of the pores in the cathode from the cathode current collector to the electrolyte separator, and an electronically conducting network extending on sidewall surfaces of the pores in the anode from the anode current collector to the electrolyte separator,
wherein the second precursor material is a sacrificial material configured to decompose during formation of the pores of the cathode and the anode by the sintering using the second precursor material, and the first precursor material is a material which forms a coating of the electronically conducting network on the sidewall surfaces of the pores of the cathode and the anode formed by sintering the second precursor material.
23. The method of claim 22 , wherein the mixture includes a third precursor material comprised of a material that densifies a solid electrolyte material during the sintering to form the ionically conducting electrolyte strands upon completion of formation of the pores.
24. The method of claim 22 , wherein the mixture to be deposited as a layer where the cathode is to be formed and the mixture to be deposited as a layer where the anode is to be formed are a same composition.
25. The method of claim 22 , wherein the mixture to be deposited as a layer where the cathode is to be formed and the mixture to be deposited as a layer where the anode is to be formed are different compositions.
26. The method of claim 22 , wherein the first precursor material used for forming a coating of the electronically conducting network on the sidewall surfaces of the pores of the cathode and the first precursor material used for forming a coating of the electronically conducting network on the sidewall surfaces of the pores of the anode are the same composition.
27. The method of claim 22 , wherein the first precursor material used for forming a coating of the electronically conducting network on the sidewall surfaces of the pores of the cathode and the first precursor material used for forming a coating of the electronically conducting network on the sidewall surfaces of the pores of the anode are different compositions.