Formation method for sodium ion cell or battery

Patent metadata

Field	Value
Publication number	US-10622665-B2
Application number	US-201615764126-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Oct 30, 2015
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

A method of operating a rechargeable sodium ion cell, wherein the cell comprises an anode material which is a disordered carbon and a nickel-containing sodium oxide cathode material comprises: in a formation charge phase, charging the cell to a first voltage at which sodium is irreversibly liberated from the cathode material; and in a subsequent charge-discharge cycle, charging the cell to a second voltage lower than the first voltage. The voltage to which the cell is charged in the formation charge phase may be selected such that the amount of sodium irreversibly liberated from the cathode material in the formation charge phase substantially equals the amount of sodium deposited in a surface electrolyte layer on the anode in the formation charge phase.

First claim

The invention claimed is:

1. A method of operating a rechargeable sodium ion cell, wherein the cell comprises an anode material which is a disordered carbon and a cathode material A u M 1 v M 2 w M 3 x M 4 Y M 5 z O 2±c , wherein
A comprises either sodium or a mixed alkali metal in which sodium is the major constituent;
M 1 is nickel in an oxidation state between +2 and +4;
M 2 comprises a metal in oxidation state +4 selected from one or more of manganese, titanium and zirconium;
M 3 comprises a metal in oxidation state +2, selected from one or more of magnesium, calcium, copper, zinc and cobalt;
M 4 comprises a metal in oxidation state +4, selected from one or more of titanium, manganese and zirconium;
M 5 comprises a metal in oxidation state +3, selected from one or more of aluminium, iron, cobalt, molybdenum, chromium, vanadium, scandium and yttrium;
U is in the range 0<U<1;
V is in the range 0.25<V<1;
W is in the range 0<W<0.75;
X is in the range 0≤X<0.5;
Y is in the range 0≤Y<0.5;
Z is in the range 0≤Z<0.5;
U+V+W+X+Y+Z≤3; and
c≥0.0;

wherein the method comprises:
in a formation charge phase, charging the cell to a first voltage at which sodium is irreversibly liberated from the cathode material; and
in a subsequent charge-discharge cycle, charging the cell to a second voltage lower than the first voltage.

2. A method as claimed in claim 1 wherein the first voltage is selected such that the amount of sodium irreversibly liberated from the cathode material in the formation charge phase substantially equals the amount of sodium deposited in a surface electrolyte layer on the anode in the formation charge phase.

3. A method as claimed in claim 1 or a wherein the first voltage is greater than 4.0V.

4. A method as claimed in claim 1 wherein the first voltage is less than 4.5V.

5. A method as claimed in claim 1 wherein the first voltage is between 4.1V and 4.3V.

6. A method as claimed in claim 1 wherein the second voltage is less than 4.0V.

7. A method as claimed in claim 1 wherein the second voltage is between 3.9V and 4.1V.

8. A method as claimed in claim 1 wherein the formation charge phase comprises charging the cell to the first voltage in at least two charge cycles.

9. A method as claimed in claim 1 , and comprising, before the formation charge phase, holding the temperature of the cell above room temperature.

10. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 30° C. for at least one hour.

11. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 50° C. for at least one hour.

12. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 70° C. for at least one hour.

13. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 50° C. for at least one day.

14. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 50° C. for less than 30 days.

15. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 70° C. for at least one day.

16. A method as claimed in claim 9 wherein holding the temperature of the cell above room temperature comprises holding the temperature of the cell above 70° C. for less than 30 days.

17. A method as claimed in claim 9 , and comprising applying a non-zero voltage across the cell while holding the temperature of the cell above room temperature.

18. A method as claimed in claim 17 wherein the non-zero voltage is greater than the open circuit voltage of the cell.

19. A method as claimed in claim 17 wherein the non-zero voltage is greater than 3V.

20. A method as claimed in claim 17 wherein the non-zero voltage is less than 4.5V.

Assignees

• Sharp Kk
• Faradion Ltd

Inventors

• Kendrick Emma
• Smith Katherine Louise
• Treacher Joshua Charles

Classifications

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/663

  containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres · CPC title

• H01M4/485 Primary

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M10/049 Primary

  Processes for forming or storing electrodes in the battery container · CPC title

• H01M4/50

  of manganese · CPC title