Heat-resistant electrolyte materials and electrochromic devices including them

• US 9,933,680 B2
• Filed: 04/22/2015
• Issued: 04/03/2018
• Est. Priority Date: 04/28/2014
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Taya, Minioru, Ananadan, Nishita
• Primary Examiner(s): Lester, Evelyn A
• Application Number:
  US14/693,642
• Publication Number:
  US 20150309383A1
• Time in Patent Office: 1,077 Days
• Field of Search: 205414, 429 67, 429126, 429422, 429475, 429477, 429482, 429491, 359265-275
• CPC Class Codes: G02F 1/0018 Electro-optical materials
• CPC Class Codes: G02F 1/15 based on an electrochromic effect
• CPC Class Codes: G02F 1/15165 Polymers
• CPC Class Codes: G02F 1/1523 comprising inorganic material
• CPC Class Codes: G02F 1/1524 Transition metal compounds
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 1/161 Gaskets; Spacers; Sealing of cells; Filling or closing of cells
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2001/15145 the electrochromic layer comprises a mixture of anodic and cathodic compounds
• CPC Class Codes: G02F 2001/1555 Counter electrode
• CPC Class Codes: G02F 2201/44 Arrangements combining different electro-active layers, e.g. electrochromic, liquid crystal or electroluminescent layers

Abstract

The present disclosure relates to relates to heat-resistant gel electrolyte materials and their uses, for example, in electrochromic devices such as electrochromic windows. In certain embodiments, the disclosure provides an electrolyte material including a polymer of ethyleneimine, optionally at least partially crosslinked (e.g., with an epoxide crosslinker such as the diglycidyl ether of bisphenol A); a lithium salt (e.g., lithium perchlorate); and a high-boiling solvent (e.g., DMSO). The electrolyte materials can be used in electrochromic devices, such as electrochromic windows, e.g., for use as automobile sunroofs.

Claims

1. An electrolyte material comprising:

about 35 to about 65 wt % of a polymer of ethyleneimine having at least 90 wt % ethyleneimine subunits, the polymer being at least partially crosslinked with residues from a polyfunctional epoxide crosslinker in an amount of about 0.1 to about 4 wt %;

about 0.2 to about 5 wt % of a lithium salt; and

about 20 to about 64 wt % of a high-boiling solvent.

2. The electrolyte material according to claim 1, wherein the polymer of ethyleneimine has a molecular weight in the range of about 1000 g/mol to about 100,000 g/mol.

3. The electrolyte material according to claim 1, wherein the polymer of ethylene imine) is present in the electrolyte material in an amount in the range of about 40 wt % to about 60 wt %.

4. The electrolyte material according to claim 1, wherein the polymer of ethyleneimine has at least about 95 wt % ethyleneimine subunits.

5. The electrolyte material according to claim 1, wherein the polymer of ethyleneimine is poly(ethyleneimine).

6. The electrolyte material according to claim 1, wherein the lithium salt is lithium perchlorate.

7. The electrolyte material according to claim 1, wherein the lithium salt is present in the electrolyte material in an amount in the range of about 0.2 wt % to about 3 wt %.

8. The electrolyte material according to claim 1, wherein the high-boiling solvent is DMSO.

9. The electrolyte material according to claim 1, wherein the high-boiling solvent is present in an amount in the range of about 26 wt % to about 53 wt %.

10. The electrolyte material according to claim 1, wherein the sum of the amounts of the high-boiling solvent, the polymer of ethyleneimine, the lithium salt and the crosslinking residues is at least about 80 wt % of the electrolyte material.

11. The electrolyte material according to claim 1, consisting essentially of the high-boiling solvent, the polymer of ethyleneimine, the lithium salt, and the crosslinking residues.

12. The electrolyte material according to claim 1, consisting essentially of DMSO, the polymer of ethyleneimine, lithium perchlorate and diglycidyl ether of bisphenol A.

13. An electrochromic device comprising

an electrochromic material;

a counterelectrode; and

the electrolyte material according to claim 1 disposed between the electrochromic material and the counterelectrode,

the counterelectrode being capable of electrochemically reversibly absorbing lithium ions from the electrolyte and releasing lithium ions into the electrolyte.

14. The electrochromic device according to claim 13, wherein the electrochromic material, the counterelectrode and the electrolyte material are disposed between two bodies of transparent media.

15. The electrochromic device according to claim 13, further comprising a voltage source operatively coupled to the electrochromic material and the counterelectrode.

16. The electrochromic device according to claim 13, wherein the electrochromic material is a polythiophene and the counterelectrode is formed from V₂O₅—

TiO₂.

17. The electrochromic device according to claim 16, configured as an automobile.

18. The electrolyte material according to claim 1, having a % transmittance at 580 nm of at least about 50% per 100 μ

m thickness at 60°

C.

19. An electrolyte material comprising:

a polymer of ethyleneimine;

a lithium salt; and

a high-boiling solvent,

the electrolyte material having a % transmittance at 580 nm of at least about 50% per 100 μ

m thickness at 60°

C.

20. The electrolyte material according to claim 19, wherein the polymer of ethyleneimine has at least about 90 wt % ethyleneimine subunits.

21. The electrolyte material according to claim 19, wherein the sum of the amounts of the high-boiling solvent, the polymer of ethyleneimine, the lithium salt and any crosslinker or residues crosslinking the polymer of ethyleneimine is at least about 80 wt % of the electrolyte material.