Method of manufacturing a lithium-ion secondary battery

Patent metadata

Field	Value
Publication number	US-2022271327-A1
Application number	US-202217736723-A
Country	US
Kind code	A1
Filing date	May 4, 2022
Priority date	Jul 1, 2015
Publication date	Aug 25, 2022
Grant date	—

Abstract

A method of manufacturing a lithium-ion secondary battery of the present invention includes at least four steps as follows: an initial charging step of charging the lithium-ion secondary battery, which has not been subjected to initial charging, under a temperature environment ranging of equal to or higher than −20° C. and equal to or lower than 15° C.; an aging step of leaving the lithium-ion secondary battery under a temperature environment ranging of equal to or higher than 30° C. and equal to or lower than 80° C. after the initial charging step; a short circuit detecting step of detecting the presence or absence of a short circuit of the lithium-ion secondary battery by measuring a voltage drop quantity of the lithium-ion secondary battery and comparing the voltage drop quantity with a reference value; and a sorting step of sorting out a lithium-ion secondary battery in which no short circuit is detected.

First claim

1 . A method of manufacturing a lithium-ion secondary battery comprising:
an initial charging step of charging the lithium-ion secondary battery, which has not been subjected to initial charging, under a condition in which a viscosity of an electrolytic solution is equal to or higher than 6.0 mPa·s; an aging step of leaving the lithium-ion secondary battery subjected to the initial charging step under a condition in which the viscosity of the electrolytic solution is equal to or lower than 4.5 mPa·s after the initial charging step; a short circuit detecting step of detecting the presence or absence of a short circuit of the lithium-ion secondary battery subjected to the initial charging step by measuring a voltage drop quantity of the lithium-ion secondary battery and comparing the voltage drop quantity with a predetermined reference value; and a sorting step of sorting out a lithium-ion secondary battery in which no short circuit is detected.

2 . The method of manufacturing a lithium-ion secondary battery according to claim 1 ,
wherein the aging step is performed without carrying out charging and discharging even once after the initial charging step.

3 . The method of manufacturing a lithium-ion secondary battery according to claim 1 ,
wherein a voltage of the lithium-ion secondary battery when the aging step starts is equal to or higher than 3.80 V.

4 . The method of manufacturing a lithium-ion secondary battery according to claim 1 ,
wherein in the aging step, the lithium-ion secondary battery is left for equal to or longer than two days.

5 . The method of manufacturing a lithium-ion secondary battery according to claim 1 ,
wherein the lithium-ion secondary battery is subjected to discharging after the aging step, and a voltage of the lithium-ion secondary battery in the short circuit detecting step is set to a range of equal to or higher than 2.5 V and equal to or lower than 3.8 V.

6 . The method of manufacturing a lithium-ion secondary battery according to claim 1 ,
wherein a temperature environment in the lithium-ion secondary battery in the initial charging step is set to a range of equal to or higher than −20° C. and equal to or lower than 15° C.

7 . The method of manufacturing a lithium-ion secondary battery according to claim 1 ,
wherein a temperature environment in the lithium-ion secondary battery in the aging step is set to a range of equal to or higher than 30° C. and equal to or lower than 80° C.

8 . A method of determining whether a lithium-ion secondary battery is a quality product or a defective unit, the method comprising:
an initial charging step of charging the lithium-ion secondary battery, which has not been subjected to initial charging, under a condition in which a viscosity of an electrolytic solution is equal to or higher than 6.0 mPa·s; an aging step of leaving the lithium-ion secondary battery subjected to the initial charging step under a condition in which the viscosity of the electrolytic solution is equal to or lower than 4.5 mPa·s after the initial charging step; a short circuit detecting step of detecting for a short circuit in the lithium-ion secondary battery subjected to the aging step by measuring a voltage drop quantity of the lithium-ion secondary battery and comparing the voltage drop quantity with a predetermined reference value; and a determining step of determining that the lithium-ion secondary battery subjected to said short circuit detecting step is the quality product when the short circuit in the lithium-ion secondary battery is not detected, and determining that the lithium-ion secondary battery subjected to said short circuit detecting step is the defective unit when the short circuit in the lithium-ion secondary battery is detected.

9 . The method of determining whether a lithium-ion secondary battery is a quality product or a defective unit according to claim 8 ,
wherein the aging step is performed without carrying out charging and discharging even once after the initial charging step.

10 . The method of determining whether a lithium-ion secondary battery is a quality product or a defective unit according to claim 8 ,
wherein a voltage of the lithium-ion secondary battery when the aging step starts is equal to or higher than 3.80 V.

11 . The method of determining whether a lithium-ion secondary battery is a quality product or a defective unit according to claim 8 ,
wherein in the aging step, the lithium-ion secondary battery is left for equal to or longer than two days.

12 . The method of determining whether a lithium-ion secondary battery is a quality product or a defective unit according to claim 8 ,
wherein the lithium-ion secondary battery is subjected to discharging after the aging step, and a voltage of the lithium-ion secondary battery in the short circuit detecting step is set to a range of equal to or higher than 2.5 V and equal to or lower than 3.8 V.

13 . The method of determining whether a lithium-ion secondary battery is a quality product or a defective unit according to claim 8 ,
wherein a temperature environment in the lithium-ion secondary battery in the initial charging step is set to a range of equal to or higher than −20° C. and equal to or lower than 15° C.

14 . The method of determining whether a lithium-ion secondary battery is a quality product or a defective unit according to claim 8 ,
wherein a temperature environment in the lithium-ion secondary battery in the aging step is set to a range of equal to or higher than 30° C. and equal to or lower than 80° C.

Assignees

• Envision Aesc Japan Ltd

Inventors

• Ichikawa Tomoyuki
• Enomoto Shinsuke
• Iwata Naoyuki

Classifications

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/058 Primary

  Construction or manufacture · CPC title

• H01M4/0447

  of complete cells or cells stacks · CPC title

• G01R31/3865

  related to manufacture, e.g. testing after manufacture · CPC title

• H01M10/0566

  Liquid materials · CPC title