Cylindrical Battery Cell Including Pocket With the Identification Fluid

Abstract

The present invention relates to a cylindrical battery cell comprising a pocket portion containing an identification liquid, specifically comprising: a battery can (100) having an open top and accommodating an electrode assembly; a top cap (200) coupled to the top of the battery can (100); a safety vent (300) positioned at a predetermined distance from the bottom of the top cap (200); and a CID (400) having a portion in contact with the bottom of the safety vent (300); wherein a pocket portion (500) having a predetermined space is formed on the lower surface of the top cap (200).

Description

Technology Field

[0001] The present invention relates to a cylindrical battery cell comprising a pocket portion containing an identification liquid. Specifically, the invention relates to a cylindrical battery cell comprising a pocket portion containing an identification liquid, wherein the pocket portion is formed within the cylindrical battery cell and the identification liquid is embedded in the pocket portion, so that damage to the cylindrical battery cell due to an increase in internal pressure caused by the generation of venting gas, etc., can be confirmed from the outside. Background Technology

[0002] Recently, the demand for rechargeable batteries capable of storing generated electrical energy is increasing due to air pollution caused by the use of fossil fuels and the development of alternative energy sources resulting from energy depletion. Rechargeable rechargeable batteries are being closely utilized in daily life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0003] Rechargeable batteries, which serve as an indispensable energy source for various electronic devices in modern society, are seeing increased capacity requirements due to the growing usage and complexity of mobile devices and the development of electric vehicles. While multiple battery cells are arranged in small devices to meet user demand, vehicles utilize battery modules that electrically connect multiple battery cells, or battery packs equipped with multiple such modules.

[0004] Meanwhile, although secondary batteries have excellent electrical characteristics, under abnormal operating conditions such as overcharging, over-discharging, exposure to high temperatures, or electrical short circuits, decomposition reactions of the battery's components, such as active materials and electrolytes, are induced, generating heat and gas, and the secondary battery may be damaged due to increased internal pressure.

[0005] For example, in a cylindrical battery cell housed within such a secondary battery, venting gas may be generated when the temperature rises above a certain level due to an abnormal operating condition, and as a safety device for this, the CID is short-circuited to cut off the flow of current.

[0006] After such a short circuit occurs, the CID needs to be replaced and separated from the battery module; however, there is a problem in that it is difficult to determine whether the cylindrical battery cell is damaged because there is no visible difference in the cell.

[0007] FIG. 1 is a cross-sectional view showing a cylindrical battery cell according to the prior art. As shown in FIG. 1, the cylindrical battery cell according to the prior art comprises an electrode assembly (10) including an electrode and a separator, a battery can (20) that accommodates the electrode assembly, a top cap (30) located at the top of the battery can (20), a safety vent (40) located at the bottom of the top cap (30), and a CID filter (50) provided at the bottom of the safety vent (40).

[0008] In this way, according to the conventional cylindrical battery cell, the CID filter (50) is electrically connected to the electrode lead (11). When venting gas is generated inside the battery can (20), the pressure of the venting gas causes the CID filter (50) to be short-circuited with the electrode lead (11), thereby cutting off the current.

[0009] In such cases, it is necessary to check the cylindrical battery cell and perform replacement and removal work, but since the short circuit of the CID filter (50) cannot be visually checked from the outside, there is a problem that a lot of time and cost is consumed in the replacement and removal work. Prior art literature

[0010] Korean Patent Publication No. 2021-0044643 The problem to be solved

[0011] To solve the above-mentioned problems, the present invention aims to provide a cylindrical battery cell comprising a pocket portion containing an identification solution, wherein the presence of a CID short circuit can be visually confirmed after venting gas is generated inside the cylindrical battery cell.

[0012] In addition, the present invention aims to provide a cylindrical battery cell including a pocket portion containing an identification solution, which can verify whether a CID is short-circuited even when the cylindrical battery cell is mounted in a low-illumination area or in a situation where the illumination is low after the generation of venting gas. means of solving the problem

[0013] A cylindrical battery cell according to the present invention for achieving the above-mentioned purpose, comprising a battery can (100) having an open top and accommodating an electrode assembly, a top cap (200) coupled to the top of the battery can (100), a safety vent (300) positioned at a predetermined distance from the bottom of the top cap (200), and a CID (400) having a portion in contact with the bottom of the safety vent (300); wherein a pocket portion (500) having a predetermined space is formed on the lower surface of the top cap (200).

[0014] In addition, in the cylindrical battery cell according to the present invention, the pocket portion (500) is characterized by including a flat horizontal portion (510) and a vertical portion (520) that connects to a top cap (200) at the edge of the horizontal portion.

[0015] In addition, the cylindrical battery cell according to the present invention is characterized in that the pocket portion (500) has an identification liquid (530) built into it.

[0016] In addition, in the cylindrical battery cell according to the present invention, the identification liquid (530) is characterized by containing one or more of a colored material and a light-emitting material.

[0017] In addition, the cylindrical battery cell according to the present invention is characterized in that a first notch (511) with a predetermined depth is formed on the lower surface of the horizontal portion (510).

[0018] In addition, in the cylindrical battery cell according to the present invention, a projection (310) of a predetermined height is formed on the upper surface of the safety vent (300) at a position corresponding to the vertical line of the first notch (511).

[0019] In addition, in the cylindrical battery cell according to the present invention, the horizontal portion (510) and the vertical portion (520) are characterized by being made of a material having a certain degree of brittleness or greater.

[0020] In addition, in the cylindrical battery cell according to the present invention, the protrusion (310) is characterized by being made of a material that is stronger than the brittleness of the horizontal portion (510).

[0021] In addition, the cylindrical battery cell according to the present invention is characterized in that a second notch (521) is formed along the lower edge of the vertical portion (520) in a predetermined portion.

[0022] In addition, in the cylindrical battery cell according to the present invention, the height of the protrusion (310) is longer than the thickness of the horizontal portion (510).

[0023] In addition, in the cylindrical battery cell according to the present invention, the protrusion (310) is characterized by becoming narrower in width as it goes upward.

[0024] In addition, the present invention aims to provide a battery module including the aforementioned cylindrical battery cell. Effects of the invention

[0025] As described above, the cylindrical battery cell including a pocket portion containing an identification solution according to the present invention has the advantage of being able to quickly determine whether the CID is short-circuited without a separate sensing device by providing a pocket portion containing an identification solution.

[0026] In addition, according to the cylindrical battery cell comprising a pocket portion containing an identification solution according to the present invention, the identification solution contains a luminescent material, so there is an advantage in that the short circuit status of the CID can be easily detected even in places with low brightness, such as inside a car. Brief explanation of the drawing

[0027] FIG. 1 is a cross-sectional view showing a cylindrical battery cell according to the prior art. FIG. 2 is a cross-sectional view of a cylindrical battery cell according to a preferred first embodiment of the present invention. FIG. 3 is a cross-sectional view showing an enlarged upper portion of a cylindrical battery cell according to a preferred first embodiment of the present invention. FIG. 4 is a cross-sectional view showing an enlarged upper portion of a cylindrical battery cell according to a preferred second embodiment of the present invention. Specific details for implementing the invention

[0028] Embodiments that enable a person skilled in the art to easily implement the present invention are described in detail below with reference to the attached drawings. However, in describing the operating principles of preferred embodiments of the present invention in detail, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description is omitted.

[0029] In addition, the same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected, but also cases where they are indirectly connected with other elements in between. Furthermore, unless specifically stated otherwise, the inclusion of a certain component does not exclude other components but implies that additional components may be included.

[0030] Hereinafter, a cylindrical battery cell including a pocket portion containing an identification solution according to the present invention will be described with reference to the attached drawings.

[0031] FIG. 2 is a cross-sectional view of a cylindrical battery cell according to a preferred first embodiment of the present invention, and FIG. 3 is a cross-sectional view showing an enlarged upper portion of a cylindrical battery cell according to a preferred first embodiment of the present invention.

[0032] Referring to FIGS. 2 and 3, the cylindrical battery cell according to the present invention comprises a battery can (100), a top cap (200), a safety vent (300), a CID (400), and a pocket portion (500).

[0033] First, the battery can (100) may have a cylindrical shape with an open top, and houses an electrode assembly with a wound structure inside to protect the electrode assembly from the outside.

[0034] Here, the electrode assembly is manufactured by stacking the anode, cathode, and separator in sequence and winding them into a round shape.

[0035] A cylindrical center pin is inserted into a through-type winding core formed in the central part of the electrode assembly, and the center pin is generally made of a metal material to provide a certain strength. This center pin functions to fix and support the electrode assembly, as well as serving as a passage for releasing gases generated by internal reactions during charging, discharging, and operation.

[0036] The top cap (200) is positioned on the top of the battery can (100) to seal the internal space of the battery can (100), in which the electrode assembly is housed, from the outside.

[0037] In order to maintain a more effective seal through the top cap (200), a gasket (210) that surrounds the circumference of the top cap (200) may be provided on the upper side of the top cap (200).

[0038] At this time, the gasket (210) surrounds the top cap (200) as shown in the illustration, so that the top cap (200) can be fixed more firmly, and the lower part of the gasket (210) may have a shape bent toward the top cap (200), and through this shape, the top cap (200) can be supported more stably.

[0039] The safety vent (300) is positioned at a predetermined distance from the bottom of the top cap (200), and a projection (310) having a predetermined height is formed on the upper surface of the safety vent (300).

[0040] The protrusion (310) may have a pointed shape that narrows as it goes upward from the safety vent (300).

[0041] Additionally, the safety vent (300) may have a fracture section (320) having a relatively small thickness compared to other areas of the safety vent (300). When the internal pressure rises excessively due to venting gas or the like being generated in the electrode assembly housed inside the battery can (100), the fracture section (320) may break, allowing the venting gas inside the battery can (100) to be discharged to the outside.

[0042] The CID (400) is located at the bottom of the safety vent (300), and a portion of it is bent at a predetermined angle and is in close contact with the safety vent (300).

[0043] Additionally, the CID (400) is electrically connected to an electrode lead protruding from the electrode assembly so that current can flow under normal conditions, and when a pressure greater than a certain amount occurs inside the battery can (100), a certain part of the CID (400) can be separated, thereby separating it from the electrode lead and blocking the flow of current.

[0044] Such a CID (400) can be formed as a plurality of partially divided CIDs (400) rather than as a single unit.

[0045] Next, the pocket portion (500) is formed by including a horizontal portion (510), a vertical portion (520), and an identification liquid (530).

[0046] The horizontal portion (510) is flat in shape, and a first notch (511) is formed on the lower surface of the horizontal portion (510) with a predetermined depth.

[0047] As described above, the first notch (511) is formed with a shape that is recessed to a predetermined depth and is thinner than other parts in the horizontal section (510), so it can be more easily damaged by impact.

[0048] A protrusion (310) of the safety vent (300) is formed at a position corresponding to the vertical line of the first notch (511), and the internal pressure rises due to the generation of internal venting gas, etc., causing the CID (400) to rise, and as the CID (400) rises, the safety vent (300) rises and the protrusion (310) collides with the first notch (511) and damages the first notch (511).

[0049] Here, the height of the protrusion (310) may be longer than the thickness of the horizontal portion (510), which has the advantage of making it easier for the protrusion (310) to rise and break the first notch (511).

[0050] Although the first notch (511) and the projection (310) are each formed as one in FIG. 2 and FIG. 3, it is acceptable to form two or more if the first notch (511) and the projection (310) are formed at positions corresponding to each other on a vertical line.

[0051] The horizontal part (510) may be made of a material having a certain degree of brittleness or greater, for example, the horizontal part (510) may be made of a material with high brittleness, such as cast iron, plastic, or ceramic.

[0052] Here, the horizontal part (510) may be made of a brittle material that breaks and is damaged when pressure is applied. This is because if the brittleness of the horizontal part (510) is below a certain level, the first notch (511) is not damaged even if the protrusion (310) rises and collides with the first notch (511), and only shape changes such as elongation or bending occur, so the identification liquid (530) stored in the pocket part (500) does not leak, and thus an error may occur in determining whether the CID (400) is short-circuited.

[0053] At this time, the protrusion (310) may be made of a material that is stronger than the brittleness of the horizontal part (510), because if the brittleness of the protrusion (310) is less than that of the horizontal part (510), when the protrusion (310) and the first notch (511) collide, the first notch (511) will not be damaged but the protrusion (310) will be damaged, so the identification liquid (530) will not leak, and an error may occur in determining whether the CID (400) is short-circuited.

[0054] One side of the vertical section (520) is connected to the top cap (200), and the other side is connected to the edge of the horizontal section (510), so that a predetermined space can be formed.

[0055] The vertical part (520) may be made of a material having a certain degree of brittleness, such as the horizontal part (510) described above, and may be brittle to the extent that it breaks and breaks when pressure is applied. This is because if the brittleness of the vertical part (520) is below a certain brittleness coefficient, it will not be damaged by the pressure applied by the rise of the safety vent (300) due to the generation of venting gas, and only shape changes such as deformation or bending will occur, so the built-in identification liquid (530) will not leak, and an error may occur in determining whether the CID (400) is short-circuited.

[0056] Here, the vertical part (520) may be made of a material having a brittle modulus greater than a predetermined value, just like the horizontal part (510) described above, and may be, for example, cast iron, plastic, or ceramic material.

[0057] The identification liquid (530) is a liquid embedded in a predetermined space formed by the horizontal part (510) and the vertical part (520), and may be a liquid containing one or more of a colored material and a luminescent material.

[0058] The identification liquid (530) is normally contained within the pocket portion (500), but when a short circuit of the CID (400) occurs due to the generation of venting gas inside the cylindrical battery cell, causing the protrusion portion (310) of the safety vent (300) to rise and damage the horizontal portion (510), the identification liquid (530) leaks out of the pocket portion (500) and can be visually confirmed from outside the cylindrical battery cell.

[0059] At this time, the identification liquid (530) has the advantage of being easy to check visually as it has a color as described above, and if it contains a light-emitting material, it has the advantage of being able to more easily check whether the CID (400) is short-circuited even in a situation where the illumination of the part housing the cylindrical battery cell is low.

[0060] FIG. 4 is a cross-sectional view showing the upper portion of a cylindrical battery cell according to a preferred second embodiment of the present invention.

[0061] Referring to FIG. 4, the cylindrical battery cell according to the second preferred embodiment of the present invention is identical to the cylindrical battery cell according to the first embodiment described with reference to FIG. 2 and FIG. 3, except that a second notch (521) is formed in the vertical portion (520). Therefore, the description of the identical configuration will be omitted, and only the different configuration will be described.

[0062] In a cylindrical battery cell according to a preferred second embodiment of the present invention, a second notch (521) is formed in the vertical portion (520).

[0063] The second notch (521) is formed in a shape that is recessed to a predetermined depth along the edge of the part where the horizontal section (510) and the vertical section (520) meet, so that when pressure is applied due to the rise of the safety vent (300) caused by the generation of venting gas, the joint of the horizontal section (510) and the vertical section (520) can be damaged more easily, and thus the pocket section (500) is not damaged, which has the advantage of reducing errors in determining whether the CID (400) is short-circuited.

[0064] Here, although the second notch (521) in FIG. 4 is formed on the outer side of the vertical section (520), it may be formed on the inner side of the vertical section (520) or on both the inner and outer sides of the vertical section (520) so that the pocket section (500) can be more easily damaged when venting gas is generated.

[0065] Although the physical properties of the horizontal part (510) and the vertical part (520) in the present invention have been described as brittle, it is acceptable to describe the physical properties of the horizontal part (510) and the vertical part (520) using hardness, provided that breakage, bending, and elongation of the horizontal part (510) and the vertical part (520) can be explained.

[0066] The present invention may be a battery module housing the aforementioned cylindrical battery cell. Additionally, the battery module or the battery pack housing the battery module may be mounted on a device, for example, the device may be an electronic device containing a large-capacity battery, such as an electric vehicle, a hybrid vehicle, or a plug-in hybrid electric vehicle.

[0067] As specific parts of the present invention have been described in detail above, it is obvious to those skilled in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the invention, and that various changes and modifications are possible within the scope and spirit of the invention, and that such variations and modifications fall within the scope of the appended claims. Explanation of the symbols

[0068] 100 : Battery can 200 : Top Cap 210: Gasket 300: Safety vent 310 : Protrusion 320 : Fracture section 400 : CID 500 : Pocket section 510 : Horizontal section 511: 1st notch 520 : Vertical section 521 : 2nd notch 530 : Identification solution

Claims

Claim 1 A cylindrical battery cell comprising: a battery can having an open top and accommodating an electrode assembly; a top cap coupled to the top of the battery can; a safety vent positioned at a predetermined distance from the bottom of the top cap; and a CID having a portion in contact with the bottom of the safety vent; wherein a pocket portion having a predetermined space is formed on the lower surface of the top cap, and the pocket portion includes a flat horizontal portion and a vertical portion connecting to the top cap at the edge of the horizontal portion, and wherein an identification liquid is contained in the pocket portion. Claim 2 delete Claim 3 delete Claim 4 A cylindrical battery cell according to claim 1, characterized in that the identification solution contains one or more of a colored material and a luminescent material. Claim 5 A cylindrical battery cell according to claim 1, characterized in that a first notch with a predetermined depth is formed on the lower surface of the horizontal portion. Claim 6 A cylindrical battery cell according to claim 5, characterized in that a projection of a predetermined height is formed on the upper surface of the safety vent at a position corresponding to a vertical line with respect to the first notch. Claim 7 A cylindrical battery cell according to claim 6, characterized in that the horizontal and vertical portions are made of a material having a certain degree of brittleness or greater. Claim 8 A cylindrical battery cell according to claim 7, characterized in that the brittleness of the protrusion is stronger than the brittleness of the horizontal portion. Claim 9 A cylindrical battery cell according to claim 6, characterized in that a second notch is formed along the lower edge of the vertical portion in a predetermined portion. Claim 10 A cylindrical battery cell according to claim 6, characterized in that the height of the protrusion is longer than the thickness of the horizontal portion. Claim 11 A cylindrical battery cell according to claim 6, characterized in that the protrusion becomes narrower in width as it goes upward. Claim 12 A battery module comprising a cylindrical battery cell as described in any one of claims 1 and 4 through 11.

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