Defective porous sheet detection system and detection method

Patent metadata

Field	Value
Publication number	US-12379298-B2
Application number	US-202117918438-A
Country	US
Kind code	B2
Filing date	Jul 8, 2021
Priority date	Jul 8, 2020
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A system for detecting a defective porous sheet includes a jig having a through-hole, a heating unit, a temperature sensor, a controlling unit, an air permeability-determining unit and a judging unit. In this manner, it is possible to provide a novel system for detecting a porous sheet, which may be a defective separator after being coated with a porous coating layer, beforehand by using the air permeability and shut-down temperature of the porous sheet itself.

First claim

What is claimed is:

1. A system for detecting a defective porous sheet, comprising:
an air permeability-determining unit capable of determining air permeability (Gurley value) of porous sheet;
a first jig arranged on one side of the porous sheet and having a first through-hole through which air discharged from the air permeability-determining unit can be introduced;
a second jig arranged on other side of the porous sheet which is an opposite surface of the one side of the porous sheet, and having a second through-hole through which air passing through the first through-hole and pores in the porous sheet can be introduced;
a heating unit capable of heating the first jig or the second jig;
a temperature sensor capable of measuring temperature of the first jig or the second jig;
a controlling unit capable of controlling the heating unit and the temperature sensor, wherein the controlling unit is capable of calculating shut-down temperature of the porous sheet by using the temperature measured by the temperature sensor as a function of time and the air permeability (Gurley value) of the porous sheet determined by the air permeability-determining unit;
a display unit capable of displaying the shut-down temperature of the porous sheet calculated by the controlling unit; and
a judging unit capable of determining whether the porous sheet is defective or not,
wherein the judging unit is capable of determining the porous sheet as a defective porous sheet, when the shut-down temperature of the porous sheet calculated by the controlling unit is higher than a predetermined reference value by 0.5° C. or more, and
the first through-hole is a first hole that goes through an entire thickness of the first jig, and
the second through-hole is a second hole that goes through an entire thickness of the second jig, and
the porous sheet to be determined is not coated with a porous coating layer.

2. The system for detecting a defective porous sheet according to claim 1 , wherein the air permeability-determining unit is linked to the first jig, and the controlling unit is linked to the first jig and the second jig.

3. The system for detecting a defective porous sheet according to claim 1 , wherein the heating unit and the temperature sensor are linked to at least one of the first jig or the second jig.

4. The system for detecting a defective porous sheet according to claim 1 , wherein the porous sheet can be interposed during operation between the first jig and the second jig.

5. The system for detecting a defective porous sheet according to claim 1 , further comprising a display unit capable of displaying the temperature in an X axis as and the air permeability (Gurley value) of the porous sheet in a Y axis.

6. The system for detecting a defective porous sheet according to claim 1 , wherein the shut-down temperature is a temperature corresponding to the air permeability (Gurley value) of 100,000 sec/100 cc, when the temperature is increased as a function of time.

7. The system for detecting a defective porous sheet according to claim 1 , wherein the first through-hole and the second through-hole have an average diameter of 2-15 mm.

8. The system for detecting a defective porous sheet according to claim 1 , further comprising a storage unit capable of recording the shut-down temperature of the porous sheet calculated by the controlling unit.

9. A method for detecting a defective porous sheet, using the system according to claim 1 , comprising:
interposing a porous sheet between a first jig and a second jig facing each other;
determining air permeability of the porous sheet, while air discharged from an air permeability-determining unit passes through a first through-hole in the first jig, pores in the porous sheet and second through-hole in the second jig sequentially;
acquiring temperature as a function of time from the heating unit heating the first jig or the second jig and temperature sensor measuring temperature of the first jig or the second jig;
calculating shut-down temperature of the porous sheet by a controlling unit using the temperature acquired from the temperature sensor as a function of time and the air permeability of the porous sheet acquired from the air permeability-determining unit; and
determining the porous sheet as a defective porous sheet by a judging unit, when the shut-down temperature of the porous sheet calculated by the controlling unit is higher than a predetermined reference value by 0.5° C. or more,
wherein the porous sheet is determined as a defective before the porous sheet is coated with a porous coating layer.

10. The method for detecting a defective porous sheet according to claim 9 , wherein the shut-down temperature is a temperature corresponding to the air permeability (Gurley value) of 100,000 sec/100 cc, when the temperature is increased as a function of time.

Assignees

• Lg Energy Solution Ltd

Inventors

• Bae Won-Sik
• Kwak Sang-Min
• Lee Joo-Sung

Classifications

• G01N2015/084

  Testing filters · CPC title

• H01M50/471

  Spacing elements inside cells other than separators, membranes or diaphragms (for preventing incorrect contact inside or outside batteries H01M50/584); Manufacturing processes thereof · CPC title

• G01N2015/086

  of films, membranes or pellicules · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• G01K5/70

  specially adapted for indicating or recording · CPC title