GAS DETECTION APPARATUS AND GAS DETECTION METHOD FOR CELL MODULE ASSEMBLIES

Abstract

A gas detection apparatus for cell module assemblies accurately and rapidly detects a damaged cell of a cell module assembly and the damaged position of the damaged cell. The gas detection apparatus includes a gas detection chamber configured to receive a cell module assembly; and a sliding die configured to be movable to the lower part of the gas detection chamber in the state in which the cell module assembly is disposed at the upper end thereof. The gas detection apparatus further includes a gas sensor provided in the gas detection chamber, the gas sensor including a plurality of gas sensors disposed so as to correspond to positions of cells of the cell module assembly. A gas detection method for cell module assemblies uses the gas detection apparatus for cell module assemblies.

Claims

1. A gas detection apparatus for cell module assemblies, the gas detection apparatus comprising: a gas detection chamber configured to receive a cell module assembly having a plurality of cells; a sliding die configured to be movable to a lower part of the gas detection chamber when the cell module assembly is disposed at an upper end of the sliding die; and a plurality of gas sensors disposed at positions corresponding to positions of the plurality of cells of the cell module assembly.

2. The gas detection apparatus according to claim 1, wherein the plurality of gas sensors is provided at an outer wall of the gas detection chamber so as to be spaced apart from each other by a predetermined distance.

3. The gas detection apparatus according to claim 1, further comprising a press provided in the gas detection chamber, the press being configured to press an upper part of the cell module assembly.

4. The gas detection apparatus according to claim 1, further comprising a gas circulator provided in the gas detection chamber.

5. The gas detection apparatus according to claim 4, wherein the gas circulator comprises at least one selected from among an air suction device, an air fan, and an air blower.

6. The gas detection apparatus according to claim 5, wherein the air suction device comprises a duct extending through a wall of the gas detection chamber.

7. The gas detection apparatus according to claim 5, wherein the air fan is disposed at an upper end wall of the gas detection chamber.

8. The gas detection apparatus according to claim 5, wherein the air blower extends through a side wall surface of the gas detection chamber at a predetermined position of the cell module assembly.

9. The gas detection apparatus according to claim 1, wherein the gas detection chamber is moved downwards so as to be physically coupled to the sliding die such that the gas detection chamber is partially sealed or completely sealed.

10. The gas detection apparatus according to claim 1, wherein the gas detection chamber is coupled to a stripper so as to be reciprocated upwards and downwards.

11. The gas detection apparatus according to claim 1, wherein the sliding die comprises a mounting die and a sliding frame.

12. A gas detection method for cell module assemblies, the gas detection method comprising: transferring a cell module assembly to a lower end of a gas detection chamber using a sliding die; moving the gas detection chamber downwards to receive the cell module assembly in the gas detection chamber; driving a gas circulator to circulate gas in the gas detection chamber; detecting the gas in the gas detection chamber using a gas sensor; moving the gas detection chamber upwards to open the gas detection chamber; and driving the gas circulator to purify the gas detection chamber.

13. The gas detection method according to claim 12, wherein, in moving the gas detection chamber, an upper part of the cell module assembly is pressed using a press provided in the gas detection chamber.

Description

DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is a front view of a gas detection apparatus for cell module assemblies according to an embodiment of the present invention.

[0034] FIG. 2 is a perspective view of the gas detection apparatus for cell module assemblies according to the embodiment of the present invention.

[0035] FIG. 3 is a perspective view of a gas detection chamber unit of the gas detection apparatus for cell module assemblies according to the embodiment of the present invention.

[0036] FIG. 4 is a view showing the internal structure of the gas detection chamber unit according to the embodiment of the present invention.

[0037] FIG. 5 is a front view showing the state in which a cell module assembly according to an embodiment of the present invention is disposed at the lower end of the gas detection chamber unit.

[0038] FIG. 6 is a perspective view of a cell module assembly having cracks formed therein according to an embodiment of the present invention.

[0039] FIG. 7 is a photograph of a cell module assembly having a crack formed therein according to an embodiment of the present invention.

[0040] FIG. 8 is a flowchart of a gas detection method for cell module assemblies according to an embodiment of the present invention.

[0041] FIGS. 9 to 14 show results of gas detection experiments on the cell module assembly according to examples of the present invention.

BEST MODE

[0042] In the present application, it should be understood that the terms “comprises,” “has,” “disposes,” “includes,” etc. specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0043] In addition, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. In the case in which one part is said to be connected to another part in the specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part. In addition, that a certain element is included does not mean that other elements are excluded, but means that such elements may be further included unless mentioned otherwise.

[0044] Hereinafter, the present invention will be described with reference to the accompanying drawings in order to assist in understanding the present invention.

[0045] FIG. 1 is a front view of a gas detection apparatus for cell module assemblies according to an embodiment of the present invention, and FIG. 2 is a perspective view of the gas detection apparatus for cell module assemblies according to the embodiment of the present invention.

[0046] Referring to FIGS. 1 and 2, the gas detection apparatus 10 for cell module assemblies includes a gas detection chamber unit 110, a sliding die unit 120, a gas sensor unit 130, a gas circulation unit 140, and a pressing unit 150. In addition, the sliding die unit 120 according to the embodiment of the present invention may include a mounting die 121 and a sliding frame 122, the gas sensor unit 130 may include a gas sensing portion 131 and a gas electrode portion 132, and the gas circulation unit 140 may include an air suction device 141, an air fan 142, and an air blower 143.

[0047] FIG. 3 is a perspective view of the gas detection chamber unit of the gas detection apparatus for cell module assemblies according to the embodiment of the present invention.

[0048] Referring to FIG. 3, the gas sensor unit 130 may be constituted by a plurality of gas sensors 130a and 130b provided at an outer wall of the gas detection chamber unit 110, and each of the plurality of gas sensors 130 may be a semiconductor type gas sensor. The gas sensing portion 131 is a portion that directly reacts with gas that leaks due to damage to a cell according to the present invention to indicate a change in resistance, and the gas electrode portion 132 is a portion that transmits an electrical signal from the gas sensing portion 131 to the outside. Each of the gas sensors 130 may be disposed at a corresponding one of cells constituting a cell module assembly 100, or may be disposed at a corresponding one of predetermined positions of the cells. The gas sensing portion 131 extends through the side wall of the gas detection chamber unit 110 such that one end of the gas sensing portion is disposed at the inner surface of the side wall of the gas detection chamber unit 110 so as to face an inner space of the gas detection chamber unit 110, and the other end of the gas sensing portion 131 is connected to the gas electrode portion 132. The gas sensing portion is connected to an external data logger (not shown), which realizes the kind and concentration value of a detected gas from the electrical signal from the gas sensing portion 131. The plurality of gas sensors 130 may be disposed respectively at the stacked cells of the cell module assembly 100 or at the predetermined positions of the cells so as to be spaced apart from each other by a predetermined distance, and the number of gas sensors is not particularly restricted. In addition, the plurality of gas sensors may be disposed respectively at outer surfaces of cases of the cells that face the outer wall of the gas detection chamber unit, or may be disposed respectively at the predetermined positions of the outer surfaces of the cases of the cells that face the outer wall of the gas detection chamber unit. Consequently, the gas sensors 130 are disposed at the cells included in the cell module assembly 100 or are disposed at the predetermined positions of the cells, whereby it is possible to check a cell having a damaged case, from among the cells of the cell module assembly, and/or the damaged position of the cell having the damaged case based on a detection result. In the cell module assembly production stage, therefore, it is possible to check a defect of a cell due to damage thereto in advance and to replace the damaged cell, whereby it is possible to reduce a cell module assembly defect rate.

[0049] The gas circulation unit 140 may include at least one selected from the group consisting of an air suction device 141, an air fan 142, and an air blower 143. However, the present invention is not limited thereto. The air suction device 141 may be constituted by a duct provided so as to extend through an upper wall surface of the gas detection chamber unit 110 and a suction pump (not shown) connected to the other end of the duct, and suctions air in the gas detection chamber unit 110 through driving of the suction pump. Preferably, one or more air suction devices 141 are provided. One or more air fans 142 may be provided in the gas detection chamber unit 110. Preferably, the air fan 142 may be disposed in a space defined between an inner upper end surface of the upper wall surface of the gas detection chamber unit 110 and an upper end surface of the cell module assembly received in the gas detection chamber unit 110, and one or more air fans 142 may be provided. The air blower 143 may be constituted by a nozzle (not shown) extending through the wall surface of the gas detection chamber unit 110 and an air hose (not shown) coupled to the nozzle. The air blower 143 may be disposed so as to extend through the upper wall surface or a side wall surface of the gas detection chamber unit 110. Preferably, the air blower is disposed spaced apart from the side wall surface of the gas detection chamber unit by a predetermined distance. One or more air blowers may be disposed depending on characteristics of the cell module assembly and other environments, and the number of air blowers is not particularly restricted.

[0050] FIG. 4 is a view showing the internal structure of the gas detection chamber unit according to the embodiment of the present invention.

[0051] Referring to FIG. 4, the air suction device 141 may be disposed so as to extend through the upper wall surface of the gas detection chamber unit 110, a central shaft 152 connected to a motor 151 disposed at an upper end wall of the gas detection chamber unit 110 may be disposed so as to extend through a central plate 153, and the pressing unit 150 may be coupled to an end of the central shaft 152 while being located at a lower end surface of the central plate 153. A receiving space 111 configured to receive the cell module assembly may be formed under the lower end of the pressing unit 150. In addition, the pressing unit 150 may press the upper end surface of the cell module assembly while pressing pressure thereof is adjusted using a method of controlling the lowering height of the pressing unit by driving of the motor 151.

[0052] FIG. 5 is a front view showing the state in which a cell module assembly according to an embodiment of the present invention is disposed at the lower end of the gas detection chamber unit.

[0053] Referring to FIG. 5, when the mounting die 121 disposed at the upper end of the cell module assembly 100 is located at the lower end of the gas detection chamber unit 110 along the sliding frame 122, the gas detection chamber unit 110 is moved downwards by downward operation of the stripper 160 mechanically coupled to the gas detection chamber unit 110, whereby the lower end surface of the side wall of the gas detection chamber unit 110 comes into tight contact with the upper surface of the mounting die 121 while the cell module assembly 100 is received in the receiving space in the gas detection chamber unit 110. Each of the gas detection chamber unit 110 and the mounting die 121 is provided with a fastening member (not shown), by which the inner space of the gas detection chamber unit 110 may be completely sealed. In addition, when gas detection is completed, the gas detection chamber unit 110 is moved upwards by upward operation of the stripper 160, whereby the cell module assembly 100 and the sliding die unit 120 are opened, and the sliding die unit 120 is moved to replace the cell module assembly with a cell module assembly to be inspected.

[0054] FIG. 6 is a perspective view of a cell module assembly having cracks formed therein according to an embodiment of the present invention.

[0055] Referring to FIG. 6, battery cells are stacked such that relatively wide surfaces of the battery cells face each other to constitute a cell module assembly, cracks p are formed in side surfaces of cases of the stacked battery cells 101 and in the upper surface of the uppermost battery cell that does not face the other battery cells or the lower part of the uppermost battery cell. The cracks may be distributed at various positions of the battery cells.

[0056] FIG. 7 is a photograph showing formation of a crack according to an embodiment of the present invention.

[0057] Referring to FIG. 7, a circular-hole-shaped crack is formed in the surface of the case of one of the stacked cells constituting the cell module assembly. The diameter of the crack is 0.65 mm.

[0058] FIG. 8 is a flowchart of a gas detection method for cell module assemblies according to an embodiment of the present invention.

[0059] Referring to FIG. 8, a method of detecting gas in a cell module assembly 100 using the gas detection apparatus for cell module assemblies includes a step of disposing the cell module assembly 100 at the upper end of the mounting die 121 of the sliding die unit 120 and transferring the cell module assembly 100 using the sliding die unit 120 such that the mounting die 121 is located at the lower end of the gas detection chamber unit 110 along the sliding frame 122; a step of moving the gas detection chamber unit 110 downwards through downward operation of the stripper 160 such that the lower surface of the gas detection chamber unit 110 comes into tight contact with the upper surface of the mounting die 121 in order to receive the cell module assembly 100 mounted at the upper part of the mounting die 121 in the gas detection chamber unit 110; a step of driving the gas circulation unit 140 to circulate gas in the gas detection chamber unit 110; a step of detecting the gas in the gas detection chamber unit 110 using the gas sensor unit 130; a step of moving the gas detection chamber unit 110 upwards through upward operation of the stripper 160 to separate the cell module assembly 100 and the sliding die unit 120 from the gas detection chamber unit; and a step of purifying the interior of the gas detection chamber unit 110 using the gas circulation unit 140.

[0060] Also, in the step of receiving the cell module assembly in the gas detection chamber unit 110, the lowering height of the stripper 160 may be adjusted, and the cell module assembly 100 may be pressed using the pressing unit 150.

[0061] FIGS. 9 to 14 show results of gas detection experiments on the cell module assembly according to examples of the present invention.

[0062] In the following examples of the present invention, the cell module assembly was disposed in the gas detection chamber unit 110 such that relatively long ones of the side surfaces of the stacked battery cells, excluding the stacked surfaces thereof, face the front wall surface and the rear wall surface of the gas detection chamber unit 110 and relatively short ones of the side surfaces of the stacked battery cells face the side wall surface of the gas detection chamber unit 110. In addition, a CO.sub.2 detection sensor was used as the gas sensor.

Example 1

[0063] Cracks were formed at positions p3 and p6 of the cell module assembly 100 shown in FIG. 6, and gas detection experiments were performed.

[0064] The cell module assembly 200 having cracks formed at positions p3 and p6 was disposed on the mounting die 121, the mounting die 121 was moved along the sliding frame 122 so as to be located at the lower end of the gas detection chamber unit 110, the stripper 160 was driven downwards such that the lower surface of the gas detection chamber unit 110 came into close contact with the upper surface of the mounting die 121, gas in the gas detection chamber unit 110 was detected using the gas sensor unit 130 while the gas circulation unit 140 was driven to circulate the gas in the gas detection chamber unit 110, result values were transmitted to the external data logger, and detected CO.sub.2 concentration values were collected.

[0065] Experiment times and CO.sub.2 concentration detection values according to Example 1 are shown in FIG. 9.

Example 2

[0066] Gas detection experiments were performed in the state in which the interior of the gas detection chamber unit 110 was completely sealed.

[0067] Gas detection experiments were performed in the same manner as in Example 1 except that the lower surface of the gas detection chamber unit 110 and the upper surface of the mounting die 121 were fastened to each other via a fastening member such that the interior of the gas detection chamber unit was completely sealed.

[0068] Experiment times and CO.sub.2 concentration detection values according to Example 1 are shown in FIG. 9.

Example 3

[0069] Gas detection experiments were performed in the state in which the cell module assembly 100 was not pressed in the gas detection chamber unit 110 that was partially sealed.

[0070] Cracks were formed at positions p1 and p4 of the cell module assembly 100 shown in FIG. 6, and gas detection experiments were performed.

[0071] The cell module assembly 100 having cracks formed at positions p1 and p4 was disposed on the mounting die 121, the mounting die 121 was moved along the sliding frame 122 so as to be located at the lower end of the gas detection chamber unit 110, the stripper 160 was driven downwards such that the lower surface of the gas detection chamber unit 110 came into close contact with the upper surface of the mounting die 121, gas in the gas detection chamber unit 110 was detected using the gas sensor unit 130 while the gas circulation unit 140 was driven to circulate the gas in the gas detection chamber unit 110, result values were transmitted to the external data logger, and detected CO.sub.2 concentration values were collected.

[0072] Experiment times and CO.sub.2 concentration detection values according to Example 3 are shown in FIG. 10.

Example 4

[0073] Gas detection experiments were performed in the state in which the cell module assembly 100 was pressed in the gas detection chamber unit 110 that was partially sealed.

[0074] Cracks were formed at positions p1 and p4 of the cell module assembly 100 shown in FIG. 6, and gas detection experiments were performed.

[0075] Gas detection experiments were performed in the same manner as in Example 3 except that a step of bringing the lower surface of the gas detection chamber unit 110 into close contact the upper surface of the mounting die 121 and further driving the stripper 160 downwards in the state in which the pressing unit 150 was disposed in contact with the upper end surface of the cell module assembly 100 in order to press the upper end surface of the cell module assembly 100 was added.

[0076] Experiment times and CO.sub.2 concentration detection values according to Example 4 are shown in FIG. 10.

Example 5

[0077] Experiments on a gas circulation effect depending on change in operation conditions of the gas circulation unit 140 were performed in the state in which the interior of the gas detection chamber unit 110 was partially sealed and the cell module assembly 100 was not pressed.

[0078] The cell module assembly 100 having cracks formed therein was disposed on the mounting die 121, the mounting die 121 was moved along the sliding frame 122 so as to be located at the lower end of the gas detection chamber unit 110, the stripper 160 was driven downwards such that the lower surface of the gas detection chamber unit 110 came into close contact with the upper surface of the mounting die 121, gas in the gas detection chamber unit 110 was detected using the gas sensor unit 130, and result values were transmitted to the external data logger. In the step of detecting the gas using the gas sensor unit, the air fan 142 and the air blower 143 were individually or simultaneously driven either for 2 seconds or continuously to perform gas detection experiments.

[0079] Experiment times and CO.sub.2 concentration detection values according to Example 5 are shown in FIG. 11.

Example 6

[0080] Experiments on an effect of purifying the gas detection chamber unit 110 depending on change in operation conditions of the gas circulation unit 140 were performed in the state in which the interior of the gas detection chamber unit 110 was partially sealed and the cell module assembly 100 was not pressed.

[0081] Gas detection experiments according to the present invention were performed using the cell module assembly 100 having cracks formed in the surfaces of the pouch cases of the cells, and experiments to purify the gas detection chamber unit 110 through driving of the gas circulation unit 140 were performed after gas detection.

[0082] It can be seen from the experiment results that the gas detection chamber unit was the most quickly purified when the air suction device 141, the air fan 142, and the air blower 143 were simultaneously driven.

[0083] Experiment times and CO.sub.2 concentration detection values according to Example 6 are shown in FIG. 12.

Example 7

[0084] Gas detection experiments were performed in the same manner as in Example 1 except that gas detection was performed at positions p1, p2, p3, p4, p5, p6, and p7 of the cell module assembly 100 shown in FIG. 6.

[0085] It can be seen from the gas detection experiment result for each crack position according to Example 7 that the position of the crack formed in the upper surface of the uppermost cell of the cell module assembly was detected. For this reason, the surfaces of the stacked cells that face each other, i.e. the upper surface and the lower surface of each unit cell, form stacked surfaces, whereby an effect similar to a taping effect is achieved, and therefore gas detection due to gas leakage within a short time may be difficult. Consequently, it can be seen that it may be difficult to rapidly detect the positions of cracks formed in the stacked surfaces using the gas detection apparatus for cell module assemblies according to the present invention.

[0086] The results of CO.sub.2 gas detection according to Example 7 are shown in FIG. 13.

Example 8

[0087] In Example 8, gas detection experiments were performed on a normal cell module assembly having no crack formed therein and a defective cell module assembly having a crack formed therein using the gas detection method according to the present invention. In this example, a defective cell module assembly having a crack formed at position P2 shown in FIG. 7 was used. Gas sensors were disposed at the front wall surface and the rear wall surface of the gas detection chamber unit 110 so as to be spaced apart from each other by a predetermined distance in a 3×3 matrix, and gas sensors were disposed at the side wall surface of the gas detection chamber unit so as to be spaced apart from each other by a predetermined distance in a 2×3 matrix. In addition, two gas sensors were also disposed at positions adjacent to the front of the upper wall surface of the gas detection chamber unit 110 so as to be spaced apart from each other by a predetermined distance. Experiments were performed through a step of transferring the cell module assembly using the sliding die unit 120; a step of moving the gas detection chamber unit 110 downwards through downward operation of the stripper 160 to receive the cell module assembly in the gas detection chamber unit 110; a step of driving the gas circulation unit 140 to circulate gas in the gas detection chamber unit 110; a step of detecting the gas in the gas detection chamber unit 110 using the gas sensor unit 130; a step of moving the gas detection chamber unit 110 upwards through upward operation of the stripper 160 to separate the gas detection chamber unit 110 and the sliding die unit 120 from each other; and a step of purifying the interior of the gas detection chamber unit 110 using the gas circulation unit 140.

[0088] The results of gas detection experiments according to Example 8 are shown in FIG. 14. In the result graph, the period from the start to 25 seconds of an x-axis, which indicates time, is a gas detection period, and the period from the 25 seconds to 40 seconds is a period during which the gas detection chamber unit 110 is purified after gas detection is completed. It can be seen from the result graph that gas was not detected as the result of gas detection experiments using the normal cell module assembly and that five gas sensors disposed at the crack position and the upper side, the lower side, the left side, and the right side of the crack position, among 34 gas sensors, detected CO.sub.2 gas as the result of gas detection experiments using the cell module assembly having the cracks formed therein. The detected CO.sub.2 concentration value was greater when the gas sensor was disposed closer to the crack position, and the average CO.sub.2 concentration value of the gas sensor disposed closest to the crack position was the greatest. Consequently, it can be seen that it is possible to determine whether the battery cell is damaged based on whether CO.sub.2 is detected by the gas sensor and that it is possible to determine a damaged cell and the damaged position of the cell based on comparison in CO.sub.2 concentration values detected by the gas sensors.

[0089] Although the specific details of the present invention have been described in detail, those skilled in the art will appreciate that the detailed description thereof discloses only preferred embodiments of the present invention and thus does not limit the scope of the present invention. Accordingly, those skilled in the art will appreciate that various changes and modifications are possible, without departing from the category and technical idea of the present invention, and it will be obvious that such changes and modifications fall within the scope of the appended claims.

DESCRIPTION OF REFERENCE SYMBOLS

[0090] 10: Gas detection apparatus for cell module assemblies

[0091] 100: Cell module assembly

[0092] 101: Cell

[0093] 110: Gas detection chamber unit

[0094] 111: Receiving space

[0095] 120: Sliding die unit

[0096] 121: Mounting die

[0097] 122: Sliding frame

[0098] 130, 130a, 130b: Gas sensor units

[0099] 131, 131a, 131b: Gas sensing portions

[0100] 132, 132a, 132b: Gas electrode portions

[0101] 140: Gas circulation unit

[0102] 141: Air suction device

[0103] 142: Air fan

[0104] 143: Air blower

[0105] 150: Pressing unit

[0106] 151: Motor

[0107] 152: Central shaft

[0108] 153: Central plate

[0109] 160: Stripper

[0110] p, p1, p2, p3, p4, p5, p6, p7: Gas sensor detection positions