Patent Application
20250149687
The present disclosure relates to a battery cell and a battery module including the same, and particularly relates to a battery cell for increasing a sealing level, and a battery module including the same.
As technical developments and demands on mobile devices are increasing, demands on secondary batteries as energy sources are abruptly increasing. Hence, research on the rechargeable batteries for satisfying various kinds of demands are in progress.
The currently commercially available rechargeable batteries include a nickel cadmium battery, a nickel metal hydride battery, a nickel zinc alloy battery, and a lithium secondary battery. The lithium secondary battery has merits of free charging and discharging, low self-discharging rates, and high energy density and is being paid high attention to.
The rechargeable battery is classified into a cylindrical battery and a square-type battery of which the electrode assembly is installed in a cylindrical or square-type metal can, and a pouch-type battery of which the electrode assembly is installed in a pouch-type case of an aluminum laminate sheet, depending on a shape of the battery case.
Such rechargeable batteries are classified depending on a structure of an electrode assembly in which a positive electrode, a negative electrode, and a separating membrane interposed between the positive electrode and the negative electrode are stacked. Representative examples thereof may include a jelly-roll type (wound type) of electrode assembly in which a positive electrode and a negative electrode having a long sheet-like shape are wound with a separating membrane interposed therebetween, a stacked type of electrode assembly in which a plurality of positive electrodes and negative electrodes that are cut in a predetermined size unit are sequentially stacked with separating membranes interposed therebetween, and the like. Recently, a stack/folding type of electrode assembly, a combined form of the jelly-roll type and the stack type, has been developed in order to solve problems of the jelly-roll type of electrode assemblies and the stack-type electrode assemblies. From among them, particularly uses of the pouch-type battery with a structure in which the stack-type or stack/folding-type electrode assembly is installed in the pouch-type battery case of a laminate sheet is gradually increasing because of low manufacturing costs, light weight, and easy transformation.
Referring to
As the sealing portion 16 of the battery cell 10 is generally bonded by thermal fusion, deviation of rigidity per position may be great, and the sealing portion 16 may be easily ruptured when an internal pressure of the battery cell 10 increases. When the sealing portion 16 of the battery cell 10 or a peripheral area thereof is opened and gas in the battery cell 10 is discharged, a fire may be generated to the battery cell 10, and the fire may be spread to an adjacent battery cell 10.
As energy density of the battery cell recently increases, the amount of gas generated in the battery cell also increases, and this problem is further worsened.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
The present invention has been made in an effort to provide a battery cell for removing deviation of rigidity of a sealing portion, and a battery module including the same.
However, tasks to be solved by embodiments of the present invention may not be limited to the above-described task and may be extended in various ways within a range of technical scopes included in the present invention.
An embodiment of the present invention provides a battery cell including: an electrode assembly including a positive electrode, a negative electrode, and a separating membrane disposed between the positive electrode and the negative electrode; a cell case for receiving the electrode assembly; and an electrode lead connected to the electrode assembly and protruding from one end of the cell case, wherein the cell case includes a receiving portion for receiving the electrode assembly and a sealing portion formed on an edge of the cell case and sealing the electrode assembly, and a reinforcing member is positioned on an external side of the cell case combined by the sealing portion.
The reinforcing member may be disposed at a position that corresponds to the sealing portion.
The reinforcing member may be disposed at a position that corresponds to the electrode lead in the cell case.
The reinforcing member may have a length and a width.
The reinforcing member may include a bending portion that is bent to have a curvature, an extension extending from the bending portion, and a connector connected to respective ends of the extension.
A bent unit may be formed between the bending portion and the extension.
The extension may include a first extension and a second extension extending from respective ends of the bending portion, and a gap between the first extension and second extension may have a value that is less than a maximum diameter of the bending portion.
The connector may extend to the second extension from the first extension, and a hook may be formed on a portion contacting the second extension on the connector.
The connector may be formed by entangling portions extending from first extension and the second extension with each other.
A reinforcing tape may be provided to an external side of the cell case combined by the sealing portion.
Another embodiment of the present invention provides a battery module including at least the one battery cell.
According to the embodiments, the present disclosure provides an additional member around the sealing portion of the battery cell, thereby removing the deviation of rigidity of the sealing portion, and minimizing gas discharge of the battery cell.
The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
The drawings and description are to be regarded as illustrative in nature and not restrictive, and like reference numerals designate like elements throughout the specification.
The size and thickness of each configuration shown in the drawings are arbitrarily shown for better understanding and ease of description, but the present invention is not limited thereto. The thicknesses of layers, films, panels, regions, etc., are enlarged for clarity. For better understanding and ease of description, the thicknesses of some layers and areas are exaggerated.
It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. The word “on” or “above” means positioned on or below the object portion, and does not necessarily mean positioned on the upper side of the object portion based on a gravitational direction. On the other hand, as in explaining that it is “on” or “above” another part, explaining being “below” or “under” another part may also be understood with reference to the above description.
Unless explicitly described to the contrary, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
Further, in the specification, the phrase “on a plane” means when an object portion is viewed from above, and the phrase “on a cross-section” means when a cross-section taken by vertically cutting an object portion is viewed from the side.
A battery cell according to an embodiment will now be described.
Referring to
The cell case 114 may include a receiving portion 115 for receiving the electrode assembly and a sealing portion 116 formed on the edge of the cell case 114 and sealing the electrode assembly. The cell case 114 may have a laminate structure of a resin layer/a metal thin-film layer/a resin layer.
The cell case 114 may be provided in a form in which the laminate sheet is folded and corners thereof contacting each other are sealed. In this instance, an internal space formed by folding the sheet may be the receiving portion 115 for receiving the electrode assembly, and the three opened corners of the folded sheet are sealed to form the sealing portion 116.
Here, the sealing portion 116 is illustrated to be formed on respective ends 114a and 114b of the cell case 114 and the one side 114c for connecting them, and without being limited thereto, the sealing portion 116 may be formed on the entire corners of the cell case 114.
The electrode leads 111 and 112 may pass through the sealing portion 116 and may protrude in an outward direction of the cell case 114. In detail, first ends of the respective electrode leads 111 and 112 are positioned inside the battery cell 110 and are electrically connected to a positive electrode tab or a negative electrode tab of the electrode assembly, and second ends of the electrode leads 111 and 112 are provided outside the battery cell 110 so they may be electrically connected to an additional member, for example, a bus bar.
The lead film 118 may be positioned on top surfaces or bottom surfaces of the electrode leads 111 and 112 corresponding to the sealing portion 116. The lead film 118 may prevent the electrode leads 111 and 112 from being short-circuited when the sealing portion 116 undergoes thermal fusion or press fusion. The lead film 118 may be positioned between the sealing portion 116 and the electrode leads 111 and 112 and may increase the sealing property between the sealing portion 116 and the electrode leads 111 and 112.
The lead film 118 may have a greater width than the electrode leads 111 and 112. The lead film 118 may be longer than the sealing portion 116 in the direction in which the electrode leads 111 and 112 protrude, and it may be shorter than the electrode leads 111 and 112. Accordingly, the lead film 118 may not hinder the electrical connection of the electrode leads 111 and 112 and may prevent lateral sides of the electrode leads 111 and 112 from being exposed to the outside.
Referring to
Here, the vulnerable region 120 according to the present disclosure given with the drawings and descriptions may be described with reference to one end of the battery cell, but it is not limited thereto, and other ends of the battery cell may also be described in an identical or similar way.
As shown in
A reinforcing tape 210 and a reinforcing member 220 according to the present disclosure for reinforcing rigidity of the vulnerable region 120 will now be described.
Referring to
The reinforcing tape 210 shown in
An adhesive may be applied to one side of the reinforcing tape 210. By including the adhesive, the reinforcing tape 210 may be easily attached to the cell case 114. The reinforcing tape 210 may be easily crafted. A size of the reinforcing tape 210 may be easily adjusted by cutting so a designer may easily adjust the size according to intention when it is applied to the cell case 114. The reinforcing tape 210 may be a material with more than a predetermined level of toughness. For example, the reinforcing tape 210 may be a PET tape, a silicon tape, or an aluminum (AL) tape.
Referring to
When a substantial pressure works in the battery cell 110 as the gas pocket is formed to be somewhat large, rigidity of the reinforcing tape 210 may be insufficient to minimize the shearing force applied to the sealing portion 116. Therefore, hereinafter, the reinforcing member 220 having greater rigidity than the reinforcing tape 210 will be described.
Referring to
The reinforcing member 220 may be generated by forming a long member so that its respective ends in a length direction may contact each other and connecting the respective ends. The reinforcing member 220 may have a folded shape. The reinforcing member 220 may have a width as shown in
The reinforcing member 220 may be a material that is very rigid and is also ductile. For example, the reinforcing member 220 may be manufactured of a metal, plastic, or other substances.
The reinforcing member 220 may include a bending portion 222, an extension 224, and a connector 226. Here, the bending portion 222 may represent a portion that is bent so that the reinforcing member 220 may be formed thereon, the connector 226 may indicate a portion where respective ends of the member are connected to each other, and the extension 224 may indicate a portion covering from the bending portion 222 to the connector 226. For ease of description, two portions of the reinforcing member 220 that are bent by the bending portion 222 and face each other, that is, two portions of the extension 224 extending from respective ends of the bending portion 222, may be referred to as a first extension 224a and a second extension 224b.
Two sides of the cell case 114 may be inserted between the bending portion 222 and the connector 226 so that the reinforcing member 220 may fix a gap between the two sides. The reinforcing member 220 may be provided to correspond to the sealing portion 116 formed on the respective ends 114a and 114b of the cell case 114. The reinforcing member 220 may be provided to correspond to a portion where the electrode leads 111 and 112 are positioned or a portion where the lead film 118 is positioned in the cell case 114.
The reinforcing member 220 may have a gap for inserting the two sides of the cell case 114 that is the end of the battery cell 110 between the first extension 224a and the second extension 224b. In this instance, the gap may be wide enough so that the end of the battery cell 110 may be inserted into it, and the gap may be narrow enough so that the inserted end of the battery cell 110 may not leave it. The gap between the first extension 224a and the second extension 224b may be preferably constant according to its position. This is for the reinforcing member 220 to evenly support the two sides of the cell case 114.
A bent unit 223 may be formed between the bending portion 222 and the extension 224. The bent unit 223 may be bent toward the inside of the reinforcing member 220 between the bending portion 222 and the extension 224. The bending portion 222 has a round shape with curvature so when the extension 224 is connected from the bending portion 222 without the bent unit 223, a maximum diameter of the bending portion 222 may become a gap size between the first extension 224a and the second extension 224b. However, when the bent unit 223 is formed between the bending portion 222 and the extension 224, the maximum diameter of the bending portion 222 may be different from the gap size between the first extension 224a and the second extension 224b, thereby allowing freer design. Here, the maximum diameter may represent an interior diameter of the bending portion 222. When the bending portion 222 does not completely form a circle or a semicircle, the maximum distance spaced toward the second extension 224b from the first extension 224a may be considered to be the above-described maximum diameter on the bending portion 222.
When the above-described gap is slightly less than the thickness of the battery cell 110, the space between the first extension 224a and the second extension 224b may be increased, and in this instance, the bending portion 222 may receive a tension and its curvature may be reduced, and hence, the space between the first extension 224a and the second extension 224b is increased and the connector 226 positioned at the end of the extension 224 may receive an excessive amount of pressure. However, when the bent unit 223 is formed on the reinforcing member 220 and when a curvature value of the bending portion 222 is reduced, the bent unit 223 is deformed, and the gap between the first extension 224a and the second extension 224b is increased, thereby minimizing the above-noted problem.
The connector 226 may connect ends of the first extension 224a and the second extension 224b. The reinforcing member 220 may maintain the shape and may stably support the end of the battery cell 110 through the connector 226.
The connector 226 may have various shapes.
For example, as shown in
For another example, as shown in
The shape of the connector 226 is not to be limited to the above-described examples and the drawings, and the connector 226 may have various shapes.
Referring to
The above-described battery cell 110 may be included in the battery module or the battery pack. The battery pack may be formed by packaging at least one battery module in the pack case. The battery module may be made by forming at least one battery cell 110 into a module. However, the battery cells 110 included in the battery pack may not be packaged into an additional frame that is like the battery module but may be mounted in the pack case of the battery pack. The battery pack may additionally include a battery management system (BMS) and a cooling device for managing temperatures or voltages of the battery.
The battery module including the above-described battery cell 110 and the battery pack including the same are applicable to various types of devices. The devices include transport means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto, and it may be applied to various devices that use the battery module and the battery pack including the same, which also belongs to the scope of the present invention.
While this invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0116869 | Sep 2021 | KR | national |
This application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2022/012663 filed on Aug. 24, 2022, which claims priority to and the benefit of Korean Patent Application No. 10-2021-0116869 filed in the Korean Intellectual Property Office on Sep. 2, 2021, the entire contents of both of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/012663 | 8/24/2022 | WO |
