Method for screening lithium ion battery

• US 10,345,388 B2
• Filed: 06/08/2017
• Issued: 07/09/2019
• Est. Priority Date: 12/08/2014
• Status: Active Grant

• Current Assignee: Jiangsu Huadong Institute Of Li-Ion Battery Co. Ltd., Tsinghua University
• Original Assignee: Jiangsu Huadong Institute Of Li-Ion Battery Co. Ltd.
• Inventors: Yang, Yong, Zhang, Hong-Sheng, He, Xiang-Ming, Li, Jian-Jun, Wang, Li, Li, Guo-Hua, Li, Tuan-Wei, Wang, Shu-Hui
• Primary Examiner(s): Koval, Melissa J
• Assistant Examiner(s): Maini, Rahul
• Application Number:
  US15/618,078
• Publication Number:
  US 20170276732A1
• Time in Patent Office: 761 Days
• Field of Search: 324426-450, 320125, 320129, 320131
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: G01R 31/3865 related to manufacture, e.g. testing after manufacture
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for screening a lithium ion battery is provided. A number of lithium ion batteries are galvanostatically discharged a to an inflection point voltage at an inflection point of a discharge curve at a first constant current I₁. The number of lithium ion batteries are rested for a first rest time T₁ to raise an open circuit voltage of the number of lithium ion batteries to U₁. U₁ is greater than the inflection point voltage. The number of lithium ion batteries are galvanostatically discharged to the inflection point voltage at a second constant current I₂, in which I₂<<I₁. The number of lithium ion batteries are rested for a second rest time T₂ and the batteries are screened based on a self-discharge of the number of lithium ion batteries.

Claims

1. A method for screening a lithium ion battery, the method comprising:

galvanostatic discharging a plurality of lithium ion batteries to an inflection point voltage at an inflection point of a discharge curve at a first constant current I₁;

resting the plurality of lithium ion batteries for a first rest time T₁ to raise an open circuit voltage of the plurality of lithium ion batteries to U₁, wherein U₁ is greater than the inflection point voltage;

galvanostatic discharging the plurality of lithium ion batteries to the inflection point voltage at a second constant current I₂, wherein I₂«

I₁; and

resting the plurality of lithium ion batteries for a second rest time T₂ and screening the plurality of lithium ion batteries based on a self-discharge of the plurality of lithium ion batteries.

2. The method of claim 1, wherein the first constant current I₁ is in a range from about 0.5 C to about 1 C.

3. The method of claim 1, wherein the second constant current I₂ is less than or equal to one fifth of the first constant current I₁.

4. The method of claim 1, wherein the second constant current I₂ is in a range from about 0.1 C to about 0.2 C.

5. The method of claim 1, wherein the second constant current I₂ is in a range from about 0.01 C to about 0.05 C.

6. The method of claim 1, wherein the first rest time T₁ is in a range from about 5 minutes to about 10 minutes.

7. The method of claim 1, wherein the second rest time T₂ is in a range from about 5 days to about 12 days.

8. The method of claim 1, wherein the screening the plurality of lithium ion batteries comprises removing large self-discharge batteries from the plurality of lithium ion batteries, and wherein the large self-discharge batteries comprise a self-discharge voltage decay greater than 0.1 V.

9. The method of claim 1, wherein the open circuit voltage of the plurality of lithium ion batteries is about 3.15 V.

10. The method of claim 1, further comprising previously resting the plurality of lithium ion batteries for a predetermined time before the galvanostatic discharging the plurality of lithium ion batteries at the first constant current I₁ to have the plurality of lithium ion batteries in a 50% state of charge.

11. The method of claim 10, wherein the previously resting the plurality of lithium ion batteries for the predetermined time is at room temperature.