Battery cell leak inspection device and battery cell leak inspection method

1. An apparatus for inspecting a battery cell for battery cell leaks, comprising:

a vacuum chamber including an upper chamber and a lower chamber and configured to set a receiving space to a controlled pressure different from a first pressure, the upper chamber and the lower chamber being arranged to face each other with the receiving space for a battery cell therebetween and providing sealing for the receiving space;

a vacuum pipe valve fluidly connected to the receiving space for the battery cell to set the receiving space to a second pressure less than the first pressure; and

a thickness measuring sensor configured to measure a before-vacuum thickness of the battery cell under the first pressure and measure an after-vacuum thickness of the battery cell under the second pressure; and

a destroy pipe valve configured to set the receiving space for the battery cell to a third pressure higher than the second pressure.

2. The apparatus of claim 1 , further comprising a controller configured to determine whether the battery cell leaks based on a thickness difference between the before-vacuum thickness and the after-vacuum thickness.

3. The apparatus of claim 2 , wherein the controller compares the before-vacuum thickness with the after-vacuum thickness and determines that a leak occurs in a battery cell in which swelling occurs.

4. The apparatus of claim 2 , wherein the controller compares a reference value set in advance with the thickness difference and determines that a leak occurs in a battery cell in which the thickness difference exceeding the reference value is measured.

5. The apparatus of claim 1 , further comprising

a total volatile organic compound (TVOC) pipe valve configured to suck an internal gas from an inside of the receiving space for the battery cell; and

a total volatile organic compound (TVOC) sensor arranged on a sucking flow path of the internal gas to measure a concentration of total volatile organic compound from the internal gas.

6. The apparatus of claim 5 , further comprising a controller configured to synthesize information regarding the before-vacuum thickness and the after-vacuum thickness transmitted from the thickness measuring sensor and information regarding the concentration of the total volatile organic compound transmitted from the TVOC sensor to determine whether a battery cell leaks.

7. The apparatus of claim 5 , wherein the TVOC pipe valve provides a negative pressure lower than the third pressure to forcibly suck the internal gas from the inside of the receiving space set to the third pressure.

8. The apparatus of claim 7 , wherein

the receiving space is included in plurality of receiving spaces, and

the vacuum pipe valve, the TVOC pipe valve, and the destroy pipe valve are arranged in a position of the upper chamber between the plurality of receiving spaces, fluidly connected to the plurality of receiving spaces, and set a pressure shared by the plurality of receiving spaces.

9. The apparatus of claim 1 , wherein the thickness measuring sensor is provided at a position of the upper chamber that faces the receiving space and arranged to face a battery cell inside the receiving space.

10. The apparatus of claim 1 , wherein the thickness measuring sensor is a non-contact type eddy current sensor,

wherein an insulating block is assembled in the upper chamber, the insulating block surrounding and insulating the thickness measuring sensor.

11. The apparatus of claim 1 , wherein the thickness measuring sensor is provided in plural to correspond to the receiving space and a second receiving space, respectively.

12. The apparatus of claim 1 , wherein the first pressure corresponds to an atmospheric pressure.

13. The apparatus of claim 1 , wherein a seat jig is assembled in the lower chamber, a plurality of receiving spaces being provided in the seat jig, the plurality of receiving spaces including the receiving space.

14. The apparatus of claim 13 , wherein the apparatus performs inspection of the battery cell in the receiving space, and further performs inspection of a second battery cell in a second receiving space of the plurality of receiving spaces.

15. A method of inspecting a battery cell leak using an inspection apparatus including a vacuum chamber and a vacuum pipe valve for controlling a pressure of an inside of the vacuum chamber, the vacuum chamber including an upper chamber and a lower chamber, the method comprising:

placing a battery cell to an inspection position such that an inspection stage is provided, in which the upper chamber and the lower chamber are arranged to face each other with a receiving space for the battery cell therebetween;

sealing the receiving space by lowering the upper chamber toward the lower chamber;

maintaining the vacuum pipe valve in an off-state to maintain the receiving space of the battery cell at a first pressure which is the same pressure as before the sealing of the vacuum chamber and measuring a before-vacuum thickness of the battery cell under the first pressure;

switching the vacuum pipe valve to an on-state to set the receiving space of the battery cell to a second pressure lower than the first pressure;

measuring an after-vacuum thickness of the battery cell under the second pressure; and

switching a destroy pipe valve fluidly connected to the receiving space for the battery cell to an on-state to set the receiving space to a third pressure higher than the second pressure.

16. The method of claim 15 , further comprising determining whether the battery cell leaks based on a thickness difference between the before-vacuum thickness and the after-vacuum thickness.

17. The method of claim 16 , wherein the determining of whether the battery cell leaks includes comparing the before-vacuum thickness with the after-vacuum thickness and determining that a leak occurs in the battery cell in which swelling occurs.

18. The method of claim 15 , further comprising:

forcibly sucking an internal gas from an inside of the receiving space set to the third pressure and measuring a concentration of total volatile organic compound from the sucked internal gas.

19. The method of claim 18 , further comprising synthesizing a thickness difference between the before-vacuum thickness and the after-vacuum thickness, and the concentration of the total volatile organic compound to determine whether the battery cell leaks.

20. The method of claim 15 , wherein the placing of the battery cell to the inspection position includes

assembling a seat jig in the lower chamber, receiving spaces for a plurality of battery cells being provided in the seat jig; and

moving the lower chamber receiving the plurality of battery cells to a waiting position of the upper chamber.

21. The method of claim 15 , further comprising raising the upper chamber in a direction away from the lower chamber to discharge an inspection-completed battery cell.