Charge sequestration methods for electrochromic devices

• US 10,705,403 B1
• Filed: 12/13/2017
• Issued: 07/07/2020
• Est. Priority Date: 12/13/2016
• Status: Active Grant

• Current Assignee: Halio Incorporated
• Original Assignee: Kinestral Technologies, Inc.
• Inventors: Bass, John, Duncan, Hugues, Ziebarth, Jonathan
• Primary Examiner(s): Beatty, Collin X
• Application Number:
  US15/841,097
• Time in Patent Office: 937 Days
• Field of Search: 359275
• CPC Class Codes: B32B 17/10513 Electrochromic layer
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 3/6722 with adjustable passage of light
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G09G 3/38 using electrochromic devices
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

A method of controlling an electrochromic device is provided. The method includes measuring an open circuit voltage between a first electrode and a reference electrode in the electrochromic device in a fully bleached state. The method includes calculating a charge Q to return the first electrode to a baseline state and darkening the first electrode in the electrochromic device to a darkened state. The method includes transferring charge from the first electrode in the darkened state to a redox element.

Claims

1. A method, comprising:

a) providing an electrochromic device comprising;

a first electrode comprising an electrochromic material;

a second electrode;

a redox element comprising a sequestration material and an auxiliary electrode material; and

a reference electrode comprising a consistent potential with respect to Li⁺/Li over time;

b) applying a first electrical potential between the first and the second electrodes until the electrochromic device is in a fully bleached state;

c) measuring a first open circuit voltage between the first electrode and the reference electrode in the electrochromic device in the fully bleached state;

d) calculating a charge Q to return the first electrode to a baseline state based on the first open circuit voltage measured in step c);

e) applying a second electrical potential between the first and second electrodes until the electrochromic device is in a darkened state; and

f) applying a third electrical potential between the first electrode and the redox element to transfer charge from the first electrode in the darkened state to the redox element.

2. The method of claim 1, wherein the transferring charge from the darkened first electrode to the redox element comprises N cycles, each cycle comprising:

a first step transferring a Q/N charge from the first electrode in the darkened state to the redox element; and

a second step allowing the electrochromic device to equilibrate.

3. The method of claim 2, wherein the duration of time transferring the charge Q/N is from 10 seconds to 1 min.

4. The method of claim 2, wherein the duration of time for the electrochromic device to equilibrate is from 10 min to 2 hours.

5. The method of claim 2, wherein the number of cycles N is from 10 to 100.

6. The method of claim 2, wherein the rate at which charge is moved from the first electrode to the redox element is from 10 mA to 10 A.

7. The method of claim 1, further comprising measuring a second open circuit voltage between the first electrode and the second electrode before measuring the first open circuit voltage between the first electrode and the reference electrode in the electrochromic device in the fully bleached state.

8. The method of claim 1, further comprising:

providing a smart window system comprising;

the electrochromic device, wherein the electrochromic device is an electrochromic smart window; and

a processor; and

providing instructions from a cloud network to the electrochromic smart window to perform steps b) through f) within the electrochromic smart window.

9. The method of claim 8, wherein the providing of instructions from the cloud network comprises:

contacting a smart gateway device in the smart window system, wherein the smart gateway device identifies a smart driver associated with the electrochromic device within the smart window system; and

communicating the instructions from the cloud network to the smart driver through the smart gateway to perform steps b) through f).

10. The method of claim 8, wherein the transferring charge from the darkened first electrode to the redox element comprises N cycles, each cycle comprising:

a first step transferring a Q/N charge from the first electrode in the darkened state to the redox element; and

a second step allowing the electrochromic device to equilibrate.

11. The method of claim 9, wherein the instructions to perform steps b) through f) are stored on the processor on the smart driver.

12. The method of claim 9, wherein the instruction to perform steps b) through f) are stored on the processor on the smart gateway.

13. The method of claim 8, wherein the system of smart windows comprises a group of smart windows wherein the baseline state of each of the smart windows within the group is the same.

14. The method of claim 8, wherein the smart window system comprises a plurality of electrochromic devices and wherein the baseline state of each of the plurality of electrochromic devices is the same.