Electrochemical materials including solid and liquid phases

Patent metadata

Field	Value
Publication number	US-11916231-B2
Application number	US-202016852308-A
Country	US
Kind code	B2
Filing date	Apr 17, 2020
Priority date	Jun 18, 2019
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

Electrochemical devices, and associated materials and methods, are generally described. In some embodiments, an electrochemical device comprises an electroactive material. The electroactive material may comprise an alloy having a solid phase and a liquid phase that co-exist with each other. As a result, such a composite electrode may have, in some cases, the mechanical softness to permit both high energy densities and an improved current density as compared to, for example, a substantially pure metal electrode.

First claim

What is claimed is:

1. An electrochemical device comprising:
a current collector;
a solid electrode disposed on the current collector, wherein the solid electrode comprises one or more alkali metals; and
an interfacial layer comprising an alloy disposed on the solid electrode, wherein the alloy comprises one or more alkali metals, wherein at least one alkali metal of the solid electrode and at least one alkali metal of the alloy are a same alkali metal such that the solid electrode and the alloy include different proportions of the same alkali metal, wherein the alloy comprises either: (i) a liquid phase when the alloy is at a temperature between or equal to 15° C. and 30° C.; or (ii) a solid phase and the liquid phase when the alloy is at the temperature between or equal to 15° C. and 30° C., and wherein the electrochemical device is configured such that the interfacial layer is disposed at an interface between the solid electrode and an electrolyte.

2. The electrochemical device of claim 1 , wherein the alloy comprises at least two alkali metals.

3. The electrochemical device of claim 1 , wherein the alloy comprises lithium (Li), sodium (Na), and/or potassium (K).

4. The electrochemical device of claim 1 , wherein a ratio of the solid phase to the liquid phase in the alloy is at least 50%.

5. The electrochemical device of claim 1 , wherein a ratio of the solid phase to the liquid phase in the alloy is at least 80%.

6. The electrochemical device of claim 1 , wherein the liquid phase comprises Li, Na, and/or K.

7. The electrochemical device of claim 1 , wherein the solid phase comprises Li, Na, and/or K.

8. The electrochemical device of claim 1 , wherein the solid phase comprises Li in an amount greater than or equal to 50 mol. % based on a total number of moles in the solid phase.

9. The electrochemical device of claim 1 , wherein the solid phase comprises Li in an amount greater than or equal to 90 mol. % based on a total number of moles in the solid phase.

10. The electrochemical device of claim 1 , wherein the solid phase comprises Li and the liquid phase comprises Li, and the solid phase comprises a greater mol. % of Li than the liquid phase, based on a total number of moles in the alloy.

11. The electrochemical device of claim 1 , wherein the solid phase comprises Na and the liquid phase comprises Na, and the solid phase comprises a greater mol. % of Na than the liquid phase, based on a total number of moles in the alloy.

12. The electrochemical device of claim 1 , wherein the solid phase comprises K and the liquid phase comprises K, and the solid phase comprises a greater mol. % of K than the liquid phase, based on a total number of moles in the alloy.

13. The electrochemical device of claim 1 , wherein the electrochemical device is a battery.

14. An electroactive material comprising:
a solid electrode comprising one or more alkali metals; and
an interfacial layer comprising an alloy disposed on the solid electrode, wherein the alloy comprises two or more alkali metals, wherein at least one alkali metal of the solid electrode and at least one alkali metal of the alloy are a same alkali metal such that the solid electrode and the alloy include different proportions of the same alkali metal, and wherein the alloy comprises either:
(i) a liquid phase when the alloy is at a temperature between or equal to 15° C. and 30° C.; or (ii) a solid phase and the liquid phase when the alloy is at the temperature between or equal to 15° C. and 30° C.

15. The electroactive material of claim 14 , wherein the two or more alkali meals are selected from the group consisting of Li, Na, and K.

16. The electrochemical device of claim 1 , wherein the electrolyte is a solid electrolyte.

17. The electrochemical device of claim 16 , wherein the solid electrolyte is LLZTO.

18. The electrochemical device of claim 1 , wherein a thickness of the interfacial layer is less than or equal to 60 micrometers.

19. The electrochemical device of claim 1 , wherein the alloy comprises Na and K.

20. The electrochemical device of claim 1 , wherein the solid electrode is a first electrode and the electrochemical device comprises a second electrode, wherein the interfacial layer is disposed between the first electrode and the second electrode.

21. The electrochemical device of claim 20 , further comprising the electrolyte, and wherein the electrolyte is disposed between the first electrode and the second electrode.

22. The electrochemical device of claim 1 , wherein the alloy is configured such that an atomic ratio of the solid phase to the liquid phase changes during operation of the electrochemical device.

23. The electrochemical device of claim 22 , wherein the atomic ratio of the solid phase to the liquid phase changes by less than or equal to 30% and greater than or equal to 1% during operation of the electrochemical device.

24. The electrochemical device of claim 1 , wherein the same alkali metal is Li.

25. The electroactive material of claim 14 , wherein the same alkali metal is Li.

Assignees

• Massachusetts Inst Technology
• Univ Carnegie Mellon

Inventors

• Chiang Yet-Ming
• Park Richard
• Viswanathan Venkatasubramanian
• Sripad Shashank
• Hong Zijian
• Guan Pinwen

Classifications

• H01M4/405 Primary

  Alloys based on lithium · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/36

  Accumulators not provided for in groups H01M10/05-H01M10/34 · CPC title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title