Secondary battery evaluation apparatus

Patent metadata

Field	Value
Publication number	US-10845181-B2
Application number	US-201816080619-A
Country	US
Kind code	B2
Filing date	Jan 23, 2018
Priority date	Jan 24, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

Disclosed is an apparatus capable of effectively and accurately predicting a deformation characteristic in relation to swelling of a secondary battery. The secondary battery evaluation apparatus includes a fixed jig configured to hold a first secondary battery and restrict swelling of the held first secondary battery, the fixed jig measuring a change in a first reaction force of the first secondary battery according to charging and discharging cycles; a variable jig configured to hold a second secondary battery and allow swelling of the held second secondary battery, the variable jig measuring a second reaction force and a first thickness change amount of the second secondary battery according to charging and discharging cycles; and a deriving unit configured to derive a relationship between the first reaction force measured by the fixed jig and the second reaction force and the first thickness change amount measured by the variable jig.

First claim

What is claimed is:

1. A secondary battery evaluation apparatus, comprising:
a fixed jig configured to hold a first secondary battery and restrict swelling of the first secondary battery, the fixed jig measuring a change in a first reaction force of the first secondary battery according to charging and discharging cycles;
a variable jig configured to hold a second secondary battery and allow swelling of the second secondary battery, the variable jig measuring a second reaction force and a first thickness change amount of the second secondary battery according to charging and discharging cycles; and
a deriving unit configured to derive a relationship between the first reaction force measured by the fixed jig and the second reaction force and the first thickness change amount measured by the variable jig.

2. The secondary battery evaluation apparatus according to claim 1 , wherein the deriving unit derives a graph of the second reaction force according to the first thickness change amount of the second secondary battery.

3. The secondary battery evaluation apparatus according to claim 1 , wherein the fixed jig includes:
a fixed upper jig configured to have a fixed position;
a fixed lower jig located below the fixed upper jig and spaced apart from the fixed upper jig by a predetermined distance to form a retention space for the first secondary battery;
a fixed base member located below the fixed lower jig and spaced apart from the fixed lower jig by a predetermined distance; and
a fixed measurement member interposed between the fixed base member and the fixed lower jig to measure a first reaction force according to swelling of the first secondary battery when the first secondary battery is charged and discharged.

4. The secondary battery evaluation apparatus according to claim 1 , wherein the deriving unit derives the relationship between the first reaction force measured by the fixed jig and the second reaction force and the first thickness change amount measured by the variable jig, based on the on a same charging and discharging cycle point.

5. The secondary battery evaluation apparatus according to claim 4 , wherein the deriving unit derives the relationship between the first reaction force measured by the fixed jig, the first thickness change amount and the second reaction force of the second secondary battery, based on a time point when the first reaction force measured by the fixed jig is maximized.

6. The secondary battery evaluation apparatus according to claim 1 , wherein the variable jig includes:
a variable upper jig configured to be movable in a vertical direction;
a variable lower jig located below the variable upper jig and spaced apart from the variable upper jig by a predetermined distance to form a retention space for the second secondary battery;
a variable base member located below the variable lower jig and spaced apart from the variable lower jig by a predetermined distance;
a variable measurement member interposed between the variable base member and the variable lower jig to measure a second reaction force according to swelling of the second secondary battery when the second secondary battery is charged and discharged; and
an elastic member coupled to the variable upper jig to give a restoring force in a direction opposite to the movement of the variable upper jig.

7. The secondary battery evaluation apparatus according to claim 6 , wherein a plurality of elastic members are provided to the variable jig and spaced apart from each other in a horizontal direction at an upper portion of the variable upper jig.

8. The secondary battery evaluation apparatus according to claim 6 , wherein the variable upper jig is configured so that the elastic member is exchangeable.

9. The secondary battery evaluation apparatus according to claim 8 , wherein the variable jig measures a reaction force and a thickness change amount of a plurality of secondary batteries according to charging and discharging cycles for each of the plurality of secondary batteries where a plurality of elastic members having different spring constants are coupled for each of the plurality of secondary batteries, respectively, and
wherein the deriving unit derives the relationship between the thickness change amounts and the reaction forces of the plurality of secondary batteries by using the reaction forces and the thickness change amounts for the plurality of elastic members, measured by the variable jig.

10. The secondary battery evaluation apparatus according to claim 6 , wherein the elastic member is located above the variable upper jig so that a bottom end thereof comes into contact with the variable upper jig and a top end thereof is coupled and fixed to the variable base member.

11. The secondary battery evaluation apparatus according to claim 10 , wherein the variable jig includes at least one bolt, and the bolt is configured to penetrate through the variable base member, the variable lower jig, the variable upper jig and the elastic member in order in an upper direction.

12. The secondary battery evaluation apparatus according to claim 11 , wherein the elastic member includes:
a lower plate having a lower surface that comes into contact with an upper surface of the variable upper jig, the bolt penetrating through the lower plate;
a spring located above the lower plate and having a hollow through which the bolt penetrates; and
an upper plate located above the spring and coupled and fixed to the bolt.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Dong-Yeon
• Kong Jin-Hak
• Choi Yong-Seok
• Seo Sung-Won
• Lee Yoon-Koo
• Kang Dal-Mo
• Mun Jeong-O

Classifications

• H01M10/48 Primary

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title

• G01R31/3648

  comprising digital calculation means, e.g. for performing an algorithm · CPC title

• H01M10/4285 Primary

  Testing apparatus · CPC title

• G01R31/392

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01B5/02

  for measuring length, width or thickness (G01B5/004, G01B5/08 take precedence) · CPC title