Secondary battery including pouch containing gas adsorbent and manufacturing method thereof

Abstract

The present invention relates to a secondary battery including a pouch coated with a gas adsorbent and a manufacturing method thereof, and the configuration of the present invention includes a pouch case, a cell housed inside the pouch case, and a gas adsorbent interposed at the joint surface of the excess portion formed by folding the pouch case.

Description

[Technical field]

[0001] The present invention relates to a secondary battery including a pouch coated with a gas adsorbent and a method for manufacturing the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0139834 dated October 20, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0003] With the development of technologies for mobile devices such as mobile phones, smartphones, laptops, and video cameras, as well as transportation such as electric vehicles, the demand for secondary batteries that can be charged and discharged as a power supply source is rapidly increasing, and much research is being conducted to meet the needs for various technological developments of such secondary batteries.

[0004] In terms of shape, the demand for such secondary batteries is increasing, particularly for pouch-type secondary batteries and square-type secondary batteries that are thin and can be applied to products such as mobile phones.

[0005] Pouch-type secondary batteries have the advantages of low manufacturing costs, high energy density, and ease of configuring large-capacity battery packs by connecting them in series or parallel, and have recently been attracting attention as a power supply source for electric vehicles and hybrid vehicles.

[0006] FIG. 1 is a diagram showing a typical manufacturing process for a pouch-type secondary battery.

[0007] As shown in FIG. 1, the manufacturing process of a general pouch-type secondary battery includes a process (a) of forming an upper housing portion 11a and a lower housing portion 11b in a pouch case 10, a process (b) of inserting a cell 20 as an electrode assembly into the lower housing portion 11b of the pouch case 10, a process (c) of folding the pouch case 10 so that the upper housing portion 11a of the pouch case 10 covers the cell 20 housed in the lower housing portion 11b of the pouch case 10, and a process (d) of folding the side of the pouch case 10. The process comprises a step (d) of forming side seal portion 12 by heat fusing excess portion 10a formed in pouch case 10, a step (e) of injecting an electrolyte solution, which is a liquid electrolyte, into the inside of pouch case 10, removing gas through an activation process, and then heat fusing the upper and lower surfaces of pouch case 10 to form upper seal portion 13a and lower seal portion 13b, and a step (f) of cutting excess portion 10a of pouch case 10 excluding side seal portion 12.

[0008] In this way, immediately after an electrolyte solution, which is a liquid electrolyte, is injected into the pouch case 10, gas is generated by reaction with the electrolyte during charging, aging, and charging / discharging, and a gas pocket is formed to capture this gas, so that the surplus portion 10a is present longer than the length of the cell 20.

[0009] The excess part 10a is a part that is discarded during the process of manufacturing a secondary battery, and an increase in the area of ​​the excess part 10a increases the process cost of the secondary battery. In addition, the excess part 10a has a limitation in that the degassing efficiency after activation is not high enough because it collects only the amount of gas discharged due to the gas pressure inside the battery. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2021-0014345 [Patent Document 2] Korean Patent Publication No. 10-2008-0011477 Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the above-mentioned problems in the related art, and provides a secondary battery including a pouch coated with a gas adsorbent, and a method for manufacturing the same, by designing a pouch case such that, when the pouch case is folded, an excess portion includes a major axis surface that is provided along a side of the pouch case and a minor axis surface that is provided perpendicular to the major axis surface, and the minor axis surface has a length that is 10 to 90% of the width of the folded pouch case, and by interposing a gas adsorbent on a joint surface of the excess portion of the pouch case, it is possible to reduce the excess portion of the pouch case that is discarded in the process of manufacturing a secondary battery and to reduce the process cost of the secondary battery. [Means for solving the problem]

[0012] As a means to achieve the above objectives, In one embodiment, the present invention comprises: Pouch case and A cell contained inside the pouch case; and a gas adsorbent interposed between the bonding surface of the excess portion formed by folding the pouch case.

[0013] In this case, the excess portion includes a long axis surface provided along the side surface of the pouch case and a short axis surface provided perpendicular to the long axis surface, and the short axis surface may have a length that is 10 to 90% based on the width of the folded pouch case, specifically, a length that is 20 to 90%, 30 to 90%, 40 to 90%, or 50 to 90% based on the width.

[0014] In addition, the gas adsorbent may be applied to the bonding surface of the excess part in the form of a coating layer; may be applied to the bonding surface of the excess part in the form of a powder; or may be manufactured in a plate shape and attached to the bonding surface of the excess part.

[0015] The gas adsorbent may be present continuously or discontinuously along the major axis of the excess portion.

[0016] The gas adsorbent may also include azo-linked porous organic polymers (ALPs).

[0017] Also, a gas pocket portion for the gas adsorbent to be present may be further formed in the surplus portion.

[0018] In one embodiment, the present invention provides a method for producing a composition comprising: designing the pouch case such that when the pouch case is folded, the excess portion includes a major axis surface that is provided along a side surface of the pouch case, and a minor axis surface that is provided perpendicular to the major axis surface, and the minor axis surface has a length that is 10 to 90% of the width of the folded pouch case; inserting a cell as an electrode assembly into the pouch case; a gas adsorbent is interposed between the joint surface of the excess portion of the pouch case, and then the pouch case is folded; and forming a side seal portion by joining an excess portion formed on a side of the pouch case, and then removing gas using a gas adsorbent during an activation process.

[0019] Here, the gas adsorbent may be applied to the bonding surface of the excess part in the form of a coating layer, or may be applied to the bonding surface of the excess part in the form of a powder; or may be manufactured in a plate shape and attached to the bonding surface of the excess part.

[0020] The gas adsorbent may also include azo-linked porous organic polymers (ALPs).

[0021] In addition, the method for manufacturing a secondary battery may further include removing an excess portion of a side surface of the pouch case having the gas adsorbent interposed therein, after the step of removing the gas. Effect of the Invention

[0022] The secondary battery according to the present invention has an advantage that, by introducing a gas adsorbent into the bonding surface of the excess part provided on the pouch case during the assembly of the battery, it is possible to remove gas generated during activation of the secondary battery with high efficiency, as well as to reduce the excess part of the pouch case that is discarded during the manufacturing process of the secondary battery, thereby reducing the process cost of the secondary battery. [Brief description of the drawings]

[0023] [Figure 1] 1A to 1C are diagrams showing a manufacturing process of a general pouch-type secondary battery. [Diagram 2] 1A to 1C are diagrams illustrating a process for manufacturing a secondary battery including a pouch coated with a gas adsorbent according to a first embodiment of the present invention. [Diagram 3] FIG. 4 is a cross-sectional view of a secondary battery including a pouch coated with a gas adsorbent according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of a secondary battery including a pouch coated with a gas adsorbent according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the following, in order to explain the present invention in detail to the extent that a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The object, operation, effect, and other objects, features, and operational advantages of the present invention will become more apparent from the description of the preferred embodiment.

[0025] For reference, the embodiments disclosed herein are merely the most preferred embodiments selected and presented from among various possible examples to aid in the understanding of those skilled in the art, and the technical ideas of the present invention are not necessarily limited or restricted to only the presented embodiments, and various changes, additions, and modifications, including equivalents or substitutions, are possible within the scope that does not deviate from the technical ideas of the present invention.

[0026] In addition, the terms and expressions used in the specification and claims of this application are defined based on the principle that the inventor can appropriately define the concept of the term in order to best describe his / her invention, and should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that correspond to the technical ideas of the present invention. For example, singular expressions include plural expressions unless clearly different in the context, and directional expressions are set based on the positions shown in the drawings for convenience of explanation.

[0027] (First embodiment) FIG. 2 is a diagram showing a process for manufacturing a secondary battery including a pouch coated with a gas adsorbent according to the first embodiment of the present invention.

[0028] As shown in FIG. 2, the method for manufacturing a secondary battery including a pouch coated with a gas adsorbent according to the first embodiment of the present invention includes a step (g) of forming an upper receiving portion 31a and a lower receiving portion 31b in a pouch case 30 designed to include a major axis surface along a side surface of the pouch case 30 when the pouch case 30 is folded and a minor axis surface perpendicular to the major axis surface, the minor axis surface having a length of 10 to 90% based on the width of the folded pouch case; The method includes a process (h) of inserting a cell 40 as an electrode assembly into the lower storage portion 31b, a process (i) of interposing a gas adsorbent 50 on a part of the joint surface of the excess portion 30a of the pouch case 30 and then folding the pouch case 30 so that the upper storage portion 31a of the pouch case 30 covers the cell 40 stored in the lower storage portion 31b, and a process (j) of forming a side seal portion by heat-sealing the excess portion 30a formed on the side of the pouch case 30, and then removing the gas using the gas adsorbent 50 during an activation process.

[0029] The gas adsorbent 50 may be applied to the bonding surface of the excess portion 30a in the form of a coating layer.

[0030] The gas adsorbent 50 may be applied in powder form to a part of the joining surface of the excess portion 30a.

[0031] The gas adsorbent 50 may be manufactured in a plate shape and attached to a part of the joining surface of the excess portion 30a.

[0032] The gas adsorbent 50 may be applied discontinuously along the longitudinal direction of the excess portion 30a.

[0033] The gas adsorbent 50 can be manufactured by using azo-linked porous organic polymers (ALPs) and polymerizing one monomer selected from the group consisting of 1,3,5,7-tetrakis(4-aminophenyl)adamantine (TAPA), 2,6,12-triaminotriptycene (TAT), tetrakis(4-aminophenyl)methane (TAM), and 1,3,5-tris(4-aminophenyl)benzene (TAB).

[0034] In addition, after the gas removing step (j), the method further includes removing the excess side portion of the pouch case in which the gas adsorbent is interposed, thereby obtaining a secondary battery from which gas generated during activation has been removed.

[0035] Second embodiment FIG. 3 is a cross-sectional view of a secondary battery including a pouch coated with a gas adsorbent according to a second embodiment of the present invention.

[0036] As shown in FIG. 3, the secondary battery including a pouch coated with a gas adsorbent according to the second embodiment of the present invention includes a pouch case 30 having an upper accommodating portion 31a and a lower accommodating portion 31b formed therein, a cell 40 accommodated in a space formed by the upper accommodating portion 31a and the lower accommodating portion 31b, and a gas adsorbent 50 disposed inside an excess portion 30a formed by folding the pouch case 30.

[0037] The excess portion 30a includes a long axis surface provided along the side of the pouch case 30 and a short axis surface provided perpendicular to the long axis surface, and the short axis surface has a length of 10 to 90% based on the width of the folded pouch case 30.

[0038] The gas adsorbent 50 may be applied to the bonding surface of the excess portion 30a in the form of a coating layer.

[0039] The gas adsorbent 50 may be applied in powder form to the joining surface of the excess portion 30a.

[0040] The gas adsorbent 50 may be manufactured in a plate shape and attached to the bonding surface of the excess portion 30a.

[0041] The gas adsorbent 50 may be disposed continuously or discontinuously along the major axis surface of the excess portion 30a.

[0042] The gas adsorbent 50 can be manufactured by using azo-linked porous organic polymers (ALPs) and polymerizing one monomer selected from the group consisting of 1,3,5,7-tetrakis(4-aminophenyl)adamantine (TAPA), 2,6,12-triaminotriptycene (TAT), tetrakis(4-aminophenyl)methane (TAM), and 1,3,5-tris(4-aminophenyl)benzene (TAB).

[0043] Third embodiment FIG. 4 is a cross-sectional view of a secondary battery including a pouch coated with a gas adsorbent according to a third embodiment of the present invention.

[0044] As shown in FIG. 4, the secondary battery including a pouch coated with a gas adsorbent according to the third embodiment of the present invention includes a pouch case 30 having an upper accommodating portion 31a and a lower accommodating portion 31b formed therein, a cell 40 accommodated in a space formed by the upper accommodating portion 31a and the lower accommodating portion 31b, and a gas adsorbent 50 interposed inside a surplus portion 30a formed by folding the pouch case 30, and is configured in a structure in which a gas pocket portion 30b for interposing the gas adsorbent 50 is formed in the surplus portion 30a.

[0045] The excess portion 30a includes a long axis surface provided along the side of the pouch case 30 and a short axis surface provided perpendicular to the long axis surface, and the short axis surface has a length of 10 to 90% based on the width of the folded pouch case 30.

[0046] The gas adsorbent 50 may be applied to the bonding surface of the excess portion 30a in the form of a coating layer.

[0047] The gas adsorbent 50 may be applied in powder form to a part of the joining surface of the excess portion 30a.

[0048] The gas adsorbent 50 may be manufactured in a plate shape and attached to a part of the joining surface of the excess portion 30a.

[0049] The gas adsorbent 50 may be disposed continuously or discontinuously along the major axis surface of the excess portion 30a.

[0050] The gas adsorbent 50 can be manufactured by using azo-linked porous organic polymers (ALPs) and polymerizing one monomer selected from the group consisting of 1,3,5,7-tetrakis(4-aminophenyl)adamantine (TAPA), 2,6,12-triaminotriptycene (TAT), tetrakis(4-aminophenyl)methane (TAM), and 1,3,5-tris(4-aminophenyl)benzene (TAB).

[0051] The secondary battery including the pouch coated with the gas adsorbent according to the embodiment of the present invention and the method for manufacturing the same configured as above have the following functions.

[0052] First, as shown in FIG. 2(g), the upper storage portion 31a and the lower storage portion 31b are formed in the pouch case 30.

[0053] Next, as shown in FIG. 2(h), the cell 40 serving as the electrode assembly is placed in the lower housing portion 31b of the pouch case 30.

[0054] After the cell 40 as the electrode assembly is placed in the lower storage portion 31b of the pouch case 30, a gas adsorbent 50 is interposed between a part of the joint surface of the excess portion 30a of the pouch case 30 as shown in FIG. 2(i).

[0055] In this case, the gas adsorbent 50 may be applied to the bonding surface of the excess part 30a in the form of a coating layer, or the gas adsorbent 50 may be applied to the bonding surface of the excess part 30a in the form of a powder, or the gas adsorbent 50 may be manufactured in a plate shape and attached to the bonding surface of the excess part 30a.

[0056] Next, the gas adsorbent 50 may be interposed continuously or discontinuously along the major axis surface of the excess portion 30a.

[0057] After the gas adsorbent 50 is thus interposed between the joint surface of the excess portion 30a, the pouch case 30 is folded so that the upper storage portion 31a of the pouch case 30 covers the cells 40 stored in the lower storage portion 31b.

[0058] In this case, the excess portion 30a includes a long axis surface provided along the side of the pouch case 30 and a short axis surface provided perpendicular to the long axis surface, and the short axis surface is designed to have a length that is 10 to 90% of the width of the folded pouch case 30.

[0059] After folding the pouch case 30, the excess portion 30a formed on the side of the pouch case 30 is heat-sealed to form a side seal portion, and then gas is removed using a gas adsorbent 50 during the activation process. [Explanation of symbols]

[0060] 10, 30 pouch case 20, 40 cells 50 Gas Adsorbents

Claims

1. Pouch case and A cell contained inside the pouch case; an excess portion formed on a side surface of the pouch case after folding the pouch case; A gas adsorbent is interposed between the bonding surfaces of the excess portions, The gas adsorbent adsorbs and removes gas generated during activation, The excess portion includes a long axis surface provided along a side surface of the pouch case and a short axis surface provided perpendicular to the long axis surface, The short axis surface has a length of 10 to 90% based on the width of the folded pouch case.

2. The secondary battery according to claim 1 , wherein the gas adsorbent is provided on the bonding surface of the excess portion in the form of a coating layer.

3. The secondary battery according to claim 1 , wherein the gas adsorbent is provided in a powder form on the bonding surface of the excess portion.

4. The secondary battery according to claim 1 , wherein the gas adsorbent is plate-shaped and provided on a bonding surface of the excess portion.

5. The secondary battery according to claim 1 , wherein the gas adsorbent is continuously interposed along a major axis surface of the excess portion.

6. The secondary battery according to claim 1 , wherein the gas adsorbent is discontinuously interposed along a major axis surface of the excess portion.

7. The secondary battery according to claim 1 , wherein the gas adsorbent comprises an azo-linked porous organic polymer.

8. The secondary battery according to claim 1 , wherein the surplus portion further includes a gas pocket portion in which the gas adsorbent is interposed and which collects gas generated during activation.

9. designing the pouch case such that, when the pouch case is folded, an excess portion includes a major axis surface provided along a side surface of the pouch case and a minor axis surface provided perpendicular to the major axis surface, and the minor axis surface has a length of 10 to 90% based on a width of the folded pouch case; inserting a cell as an electrode assembly into the pouch case; interposing a gas adsorbent on a bonding surface of the excess portion of the pouch case, and then folding the pouch case; forming a side seal portion by joining the excess portion formed on the side of the pouch case, and then removing gas using the gas adsorbent during an activation process; A method for manufacturing a secondary battery comprising the steps of:

10. The method for manufacturing a secondary battery according to claim 9 , wherein the gas adsorbent is applied to the bonding surface of the excess portion in a form of forming a coating layer.

11. The method for manufacturing a secondary battery according to claim 9 , wherein the gas adsorbent is applied in a powder form to the bonding surface of the excess portion.

12. The method for manufacturing a secondary battery according to claim 9 , wherein the gas adsorbent is manufactured in a plate shape and attached to the joint surface of the excess portion.

13. The method for producing a secondary battery according to claim 9 , wherein the gas adsorbent comprises an azo-bonded porous organic polymer.

14. After the gas removing step, The method for manufacturing a secondary battery according to claim 9 , further comprising the step of removing an excess portion of a side surface of the pouch case in which the gas adsorbent is interposed.

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