Defective porous sheet detection system and detection method

Patent metadata

Field	Value
Publication number	US-2023138842-A1
Application number	US-202117918438-A
Country	US
Kind code	A1
Filing date	Jul 8, 2021
Priority date	Jul 8, 2020
Publication date	May 4, 2023
Grant date	—

Abstract

The present disclosure relates to a system for detecting a defective porous sheet. The system 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

1 . A system for detecting a defective porous sheet, comprising:
an air permeability-determining unit 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 is 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 is introduced; a heating unit heating the first jig or the second jig; a temperature sensor measuring temperature of the first jig or the second jig; a controlling unit controlling the heating unit and the temperature sensor; and a judging unit determining whether the porous sheet is defective or not, wherein the controlling unit calculates 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 vale) of the porous sheet determined by the air permeability-determining unit, and the judging unit determines 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.

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 is interposed 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 displaying the temperature in X axis as the function of time and the air permeability (Gurley value) of the porous sheet in Y axis as the function of time.

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 recording the shut-down temperature of the porous sheet calculated by the controlling unit.

9 . The system for detecting a defective porous sheet according to claim 1 , further comprising a display unit displaying the shut-down temperature of the porous sheet calculated by the controlling unit.

10 . A method for detecting a defective porous sheet, 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 air permeability-determining unit passes through 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 the 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.

11 . The method for detecting a defective porous sheet according to claim 10 , 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 the function of time.

12 . The method for detecting a defective porous sheet according to claim 10 , wherein the determining comprises determining a porous sheet having a shut-down temperature higher than the reference value by 0.5° C. or more as a defective porous sheet.

Assignees

• Lg Energy Solution Ltd

Inventors

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

Classifications

• H01M50/414

  Synthetic resins, e.g. thermoplastics or thermosetting resins · CPC title

• H01M10/0525

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

• H01M10/4285

  Testing apparatus · 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

• G01K5/58

  the solid body being constrained at more than one point, e.g. rod, plate, diaphragm (G01K5/62 takes precedence) · CPC title