Method of charging an electrochemical cell

• US 8,988,047 B2
• Filed: 08/30/2012
• Issued: 03/24/2015
• Est. Priority Date: 08/30/2012
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Bartling, Brandon Alan, Vallance, Michael Alan, Hart, Richard Louis, Bogdan, David Charles Jr.
• Primary Examiner(s): Kik, Phallaka
• Application Number:
  US13/599,469
• Publication Number:
  US 20140062412A1
• Time in Patent Office: 936 Days
• Field of Search: 320/134, 320/129, 320/130, 320/139, 320/100, 429/52, 340/636.12, 340/636.15, 324/426
• US Class Current: 320/134
• CPC Class Codes: G01N 27/416 Systems G01N27/27 takes precedence
• CPC Class Codes: H01M 10/14 Assembling a group of electrodes or separators
• CPC Class Codes: H01M 10/39 working at high temperature
• CPC Class Codes: H01M 10/3918 characterised by the electrolyte
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2300/0088 Composites
• CPC Class Codes: H01M 4/582 Halogenides
• CPC Class Codes: H01M 50/138 adapted for specific cells, e.g. electrochemical cells operating at high temperature
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method of pulse charging a secondary electrochemical storage cell is provided. The secondary cell includes a negative electrode comprising an alkaline metal; a positive electrode comprising at least one transition metal halide; a molten salt electrolyte comprising alkaline metal haloaluminate; and a solid electrolyte partitioning the positive electrode from the negative electrode, such that a first surface of the solid electrolyte is in contact with the positive electrode, and a second surface of the solid electrolyte is in contact with the negative electrode. The method of charging includes polarizing the cell by applying a polarizing voltage greater than about 0.1 V above the cell'"'"'s rest potential for a first predetermined period of time; depolarizing the cell for a second predetermined period of time; and repeating the polarizing and depolarizing steps until a charging end-point is reached.

Claims

1. A method of pulse charging a secondary electrochemical storage cell, comprising the steps of:

polarizing the cell by applying a polarizing voltage greater than about 0.1 V above the cell'"'"'s rest potential for a first predetermined period of time;

depolarizing the cell for a second predetermined period of time; and

repeating the polarizing and depolarizing steps until a charging end-point is reached, wherein the cell comprises;

a negative electrode comprising an alkaline metal;

a positive electrode comprising at least one transition metal halide;

a molten salt electrolyte comprising alkaline metal haloaluminate; and

a solid electrolyte partitioning the positive electrode from the negative electrode, wherein a first surface of the solid electrolyte is in contact with the positive electrode, and a second surface of the solid electrolyte is in contact with the negative electrode.

2. The method of claim 1, wherein the alkaline metal haloaluminate comprises sodium chloroaluminate, and the transition metal halide comprises a transition metal chloride.

3. The method of claim 1, wherein the polarizing voltage is at least about 3% greater than a rest potential of the cell.

4. The method of claim 1, wherein a pulse pair of one polarizing and one depolarizing step constitutes charging less than about 1/50^th of the maximum capacity of the cell.

5. The method of claim 1, wherein the depolarizing step comprises applying a depolarization current greater than about 0.01 A to the cell for the second predetermined period of time.

6. The method of claim 5, wherein a magnitude of the maximum depolarization current is less than about 5% of the maximum current passed through the cell during the polarization step.

7. The method of claim 5, wherein the depolarizing current is applied for a time duration less than about 10 seconds.

8. The method of claim 5, wherein a ratio of the first predetermined period of time to the second predetermined period is greater than about 100.

9. The method of claim 1, wherein the depolarizing step comprises suspending current flow through the cell for the second predetermined period of time.

10. The method of claim 9, wherein the second predetermined period of time is less than about 2 minutes.

11. The method of claim 9, wherein a ratio of the first predetermined period of time to the second predetermined period of time is greater than about 20.

12. The method of claim 1, wherein the positive electrode comprises nickel chloride, and wherein the polarizing voltage is in a range from about 2.65 V to about 3.2 V.

13. The method of claim 12, wherein the polarizing voltage is in a range from about 2.7 V to about 3V.

14. A method of pulse charging a sodium metal halide cell, comprising the steps of:

polarizing the cell by applying a polarizing voltage in a range from about 2.7 V to 3.1 V to the cell for less than about 10 minutes;

depolarizing the cell, immediately after polarizing, by applying a depolarization current in a range from about 0.01 A to 0.1 A to the cell for less than about 5 seconds; and

repeating the polarizing and depolarizing of the cell sequentially at least 5 times, until a charging end-point is reached, wherein the cell comprises;

a negative electrode comprising sodium;

a positive electrode comprising nickel chloride;

a molten salt electrolyte comprising sodium chloroaluminate; and

a solid electrolyte partitioning the positive electrode from the negative electrode, wherein a first surface is in contact with the positive electrode and a second surface is in contact with the negative electrode.

15. A method of pulse charging a sodium metal halide cell, comprising the steps of:

polarizing the cell by applying a polarizing voltage in a range from about 2.7 V to 3.1 V to the cell for less than about 10 minutes;

depolarizing the cell, immediately after polarizing, by suspending current flow through the cell for less than about 1 minute; and

repeating the polarizing, and depolarizing of the cell sequentially at least 5 times, until a charging end-point is reached, wherein the cell comprises;

a negative electrode comprising sodium;

a positive electrode comprising nickel chloride;

a molten salt electrolyte comprising sodium chloroaluminate; and

a solid electrolyte partitioning the positive electrode from the negative electrode, wherein a first surface is in contact with the positive electrode and a second surface is in contact with the negative electrode.

16. A method of pulse charging a sodium metal chloride cell that comprises:

a negative electrode comprising sodium;

a positive electrode comprising nickel chloride;

a molten salt electrolyte comprising sodium chloroaluminate; and

a beta″

-alumina solid electrolyte partitioning the positive electrode from the negative electrode, wherein a first surface is in contact with the positive electrode and a second surface is in contact with the negative electrode,

said method comprising the steps of;

polarizing the cell by applying a polarizing voltage greater than about 0.15 V above the cell'"'"'s rest potential until the polarization in the cell is built up to a point wherein an open circuit voltage of the cell for about 10 seconds remains more than about 0.1 V above the cell'"'"'s rest potential;

depolarizing the cell immediately after polarizing, by applying a depolarization current in a range from about 0.01 A to 0.1 A to the cell until the polarization in the cell is reduced to a point wherein an open circuit voltage of the cell for about 10 seconds is less than about 0.1 V above the cell'"'"'s rest potential; and

repeating the polarizing, and depolarizing steps until a charging end-point is reached.