Method for screening lithium ion battery

Patent metadata

Field	Value
Publication number	US-2017276732-A1
Application number	US-201715618078-A
Country	US
Kind code	A1
Filing date	Jun 8, 2017
Priority date	Dec 8, 2014
Publication date	Sep 28, 2017
Grant date	—

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 I 1 . The number of lithium ion batteries are rested for a first rest time T 1 to raise an open circuit voltage of the number of lithium ion batteries to U 1 . U 1 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 I 2 , in which I 2 <<I 1 . The number of lithium ion batteries are rested for a second rest time T 2 and the batteries are screened based on a self-discharge of the number of lithium ion batteries.

First claim

What is claimed is:

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 I 1 ; resting the plurality of lithium ion batteries for a first rest time Ti to raise an open circuit voltage of the plurality of lithium ion batteries to U 1 , wherein U 1 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 I 2 , wherein I 2 <<I 1 ; and resting the plurality of lithium ion batteries for a second rest time T 2 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 I 2 is in a range from about 0.5 C to about 1 C.

3 . The method of claim 1 , wherein the second constant current I 2 is less than or equal to one fifth of the first constant current I 1 .

4 . The method of claim 1 , wherein the second constant current I 1 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 I 2 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 T 1 is in a range from about 5 minutes to about 10 minutes.

7 . The method of claim 1 , wherein the second rest time T 2 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 galvanostatic discharging the plurality of lithium ion batteries at the first constant current I 1 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 a predetermined time is at room temperature.

Assignees

• Jiangsu Huadong Inst Of Li-Ion Battery Co Ltd
• Univ Tsinghua

Inventors

• Yang Yong
• Zhang hong-sheng
• He xiang-ming
• Li Jian-Jun
• Wang Li
• Li Guo-Hua
• Li Tuan-Wei
• Wang Shu-Hui

Classifications

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• G01R31/3627 Primary

  Physics · mapped topic

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• G01R31/3658

  Physics · mapped topic

• H01M10/441

  for several batteries or cells simultaneously or sequentially · CPC title