Patent Application
20250192283
The present disclosure relates to a pouch battery cell including an electrode assembly, an electrode tab, an electrode lead, and a pouch.
A secondary battery, which has high applicability according to a product group and an electrical property such as high energy density, is widely applied to not only a portable device, but also an electric vehicle (EV) or a hybrid electric vehicle (HEV), which is driven by an electrical driving source.
Since the secondary battery has the primary advantage of remarkably reducing the use of fossil fuel, as well as the advantage of not generating by-products according to the use of energy at all, the secondary battery is attracting attention as a new energy source for eco-friendly and energy efficiency improvement.
Currently widely used secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. An operating voltage of a unit secondary battery cell, i.e., a unit battery cell, ranges from about 2.5 V to about 4.5 V. Accordingly, when a higher output voltage is required, a plurality of battery cells may be connected in series to configure a battery pack. In addition, according to a charge/discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to configure a battery pack. Accordingly, the number and electrical connection type of battery cells included in the battery pack may be variously set according to the required output voltage or charge/discharge capacity.
Meanwhile, in general, secondary batteries are classified into cylindrical batteries and prismatic batteries in which an electrode assembly is built in a cylindrical or prismatic metal can, and pouch-type batteries in which the electrode assembly is built in a pouch-type case of an aluminum laminate sheet depending on the shape of a battery case,, and the electrode assembly built in the battery case is formed in a structure including a positive electrode, a negative electrode, and a separator interposed between the positive and the negative electrodes, is a power generating element capable of charging and discharging, and is classified into a jelly-roll type electrode assembly wound with a separator interposed between a positive electrode and a negative electrode, which are long sheet-shaped and are coated with active materials, and a stack-type electrode assembly in which a plurality of positive electrodes and negative electrodes of a predetermined size are sequentially stacked while a separator is interposed therebetween.
Among these, the stack-type and pouch-type batteries are gradually increasing in use as the capacity of batteries increases and thus interest in a case that can be processed into a large area and a thin material increases.
Referring to
Referring to
The present disclosure is conceived in view of the aforementioned problem of the related art, and an object thereof is to provide an improved pouch cell capable of preventing conduction of heat by providing a thermal insulator instead of a welding tape on a metal layer inside a pouch to prevent adhesion between a metal portion and an inner insulating layer.
Another object of the present disclosure is to achieve prevention of damage to an inner surface of a pouch due to a bead of a welded portion, which is conventionally performed by a welding tape, with a thermal insulator.
Still another object of the present disclosure is to exhibit a thermal insulating effect as much as possible within a range in which interference between an electrode assembly or a lead film and a thermal insulator does not occur, by appropriately selecting the shape and range of the thermal insulator covering a metal portion.
Yet another object of the present disclosure is to provide a pouch cell having an improved structure, a battery pack including the same, and an electronic device including the battery pack.
Aspects according to the present disclosure are not limited to the above ones, and other aspects and advantages that are not mentioned above may be clearly understood from the following description and may be more clearly understood from the aspects set forth herein. Additionally, the aspects and advantages in the present disclosure may be realized via means and combinations thereof that are described in the appended claims.
In order to achieve the above-described objective, the present disclosure provides a pouch cell structure configured to cover a portion, which may come into contact with an inner insulating layer of a pouch, of a surface of a metal portion connected to an electrode assembly accommodated in the pouch with a thermal insulator, and a shape of the thermal insulator.
In addition, in order to achieve the above-described objective, the present disclosure defines a range in which the thermal insulator covers the metal portion.
These technical solutions may be applied to a pouch-type battery cell in which an electrode lead is connected to an electrode tab connected to an electrode assembly, and a pouch having an insulating layer accommodates a portion of the electrode lead, the electrode tab, and the electrode assembly to be sealed.
The electrode tab and the electrode lead may be connected to each other to form a metal portion.
The thermal insulator directly or indirectly covers at least a portion of a portion of the metal portion between the electrode assembly and the lead film.
The thermal insulator may cover not only the metal portion but also a welding tape attached to the metal portion or the like. That is, the present disclosure does not exclude the use of the welding tape. The thermal insulator may also perform the function of the welding tape, and in some cases, the welding tape may be used and the thermal insulator may be further used.
The thermal insulator may include any one material selected from the group consisting of foamed synthetic resin, glass fiber, rock wool, mica, perlite, vermiculite, and cellulose. However, the thermal insulator is not limited thereto and any material may be used as long as the thermal insulator can exhibit thermal insulation performance.
The thermal insulator may be a thermal insulating film.
The thermal insulator may be a thermal insulating film attached to both surfaces of the metal portion.
The thermal insulator may be a thermal insulating film having a width greater than a width of the metal portion and attached to the metal portion or to each other. (In this case, the width of each of the thermal insulator and the metal portion refers to a length in a direction parallel to the entire pouch cell and perpendicular to a length direction, when a direction from the electrode assembly to the electrode leads through the electrode tab is referred to as the length direction.)
The thermal insulator may be a thermal insulating film having a shape surrounding the metal portion with a length direction of the metal portion as an axis.
The thermal insulating film may be a thermal reflective film coated with a metal thin film by a sputtering method. However, the thermal insulating film is not limited thereto, and may be manufactured by any method and in any structure as long as it is capable of exhibiting thermal insulation performance.
The thermal insulator may cover 50% or more of a surface area of a portion between the electrode assembly and the lead film in order to achieve a sufficient thermal insulating effect.
The thermal insulator may be spaced apart from the electrode assembly by 2 mm or more to avoid interference with the electrode assembly.
The thermal insulator may be spaced apart from the lead film by 2 mm or more so that the lead film may be smoothly fused and to avoid interference with the lead film.
When the electrode tab and the electrode lead are connected through welding, the thermal insulator may cover the welded portion in order to prevent an inner surface of the pouch from being damaged from a sharp bead of the welded portion.
The thermal insulator may cover a connection portion of the electrode tab and the electrode lead to prevent any roughness that may be present at the connection portion from damaging the inner surface of the pouch.
In one aspect of the present disclosure, the metal portion may be provided with an electrode tab and an electrode lead connected by welding, the thermal insulator may have a width greater than a width of the metal portion, and the thermal insulator may be a thermal insulating film attached to both surfaces of the metal portion in a region covering the metal portion and attached thereto at a portion larger than the width of the metal portion, and covering 50% or more of an area of a portion of the metal portion between the electrode assembly and the lead film including a welded portion.
Meanwhile, the present disclosure provides a pouch-type secondary battery, a battery pack including the pouch-type secondary battery, and an electronic device including the battery pack as a power source.
The electronic device may be selected from, for example, a computer, a mobile phone, a wearable electronic device, a power tool, an electric vehicle (EV), a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric two-wheeled vehicle, an electric golf cart, or a power storage system.
The structures and manufacturing methods of the electronic devices are known in the art, and thus detailed descriptions thereof will be omitted herein.
According to the present disclosure, a phenomenon in which heat conducted to a metal portion through an electrode lead in a high temperature and high pressure sealing process is transferred to an inner surface of a pouch can be minimized by covering all or a portion of the metal portion with a thermal insulator. Accordingly, a phenomenon can be prevented in which insulating performance is reduced as an insulating layer inside the pouch is melted to be adhered to a metal layer or the corresponding insulating layer is destructed. That is, the present disclosure can provide a pouch cell with improved stability of insulating performance.
In addition, according to another aspect of the present disclosure, a welding tape that is attached to prevent damage to an inner surface of a pouch caused by a bead of a welded portion can be omitted, and a thermal insulator configured to cover a metal portion to prevent heat of the metal portion from being transferred to the inner surface of the pouch also performs a function the conventional welding tape, so that it is economical in a production process.
According to still another aspect of the present disclosure, a thermal insulating film is employed as the thermal insulator, so that it is economical to use the equipment for attaching the existing welding tape.
According to yet another aspect of the present disclosure, by providing a clearance dimension between a thermal insulator and an electrode assembly or a lead film, interference between the thermal insulator and the electrode assembly or the lead film can be excluded.
In addition to the above effects, various other effects may be produced according to the preset disclosure, and description of the effects is provided with reference to each aspect or description of effects predicted by one having ordinary skill in the art readily and the like are omitted.
Description of Reference Numerals used in the present disclosure are as follows:
The above-described aspects, features and advantages are specifically described hereafter with reference to the accompanying drawings such that one having ordinary skill in the art to which the present disclosure pertains can embody the technical spirit of the disclosure easily. In the disclosure, detailed description of known technologies in relation to the subject matter of disclosure is omitted if it is deemed to make the gist of the disclosure unnecessarily vague. Hereafter, preferred aspects according to the disclosure are specifically described with reference to the accompanying drawings. In the drawings, identical reference numerals can denote identical or similar components.
The terms “first”, “second” and the like are used herein only to distinguish one component from another component. Thus, the components should not be limited by the terms. Certainly, a first component can be a second component, unless stated to the contrary.
Throughout the disclosure, each component can be provided as a single one or a plurality of ones, unless explicitly stated to the contrary.
When any one component is described as being “in the upper portion (or lower portion)” or “on (or under)” another component, any one component can be directly on (or under) another component, but an additional component can be interposed between any one component and another component on (or under) any one component.
When any one component is described as being “connected”, “coupled”, or “connected” to another component, any one component can be directly connected or coupled to another component, but an additional component can be “interposed” between the two components or the two components can be “connected”, “coupled”, or “connected” by an additional component.
The singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless explicitly indicated otherwise. It is to be understood that the terms “comprise” or “include” and the like, set forth herein, are not interpreted as necessarily including all the stated components or steps but can be interpreted as excluding some of the stated components or steps or can be interpreted as including additional components or steps.
Throughout the disclosure, the phrase “A and/or B” as used herein can denote A, B or A and B, and the phrase “C to D” can denote C or greater and D or less, unless stated to the contrary.
For convenience of description, in the present specification, a direction extending from an electrode assembly to an electrode lead through an electrode tab is referred to as a length direction Y. In addition, a direction perpendicular to the length direction and parallel to the entire pouch cell in a lying-down state is referred to as a width direction X. In addition, a direction perpendicular to the entire pouch cell in the lying-down state is referred to as a height direction Z.
Hereinafter, exemplary aspect of the present disclosure will be described with reference to the accompanying drawings.
Referring to
The electrode assembly 11 has a structure in which an electrode plate (a positive electrode plate and a negative electrode plate) coated with an active material on one surface or both surfaces thereof is stacked multiple times with a separator interposed therebetween. The electrode tab 14 may include a positive electrode tab connected to the positive electrode plate and a negative electrode tab connected to the negative electrode plate.
The electrode tab 14 may be formed by a portion of the electrode plate, which is not coated with the active material and extends to protrude to the outside from the stacked structure of the electrode plate and the separator. Portions extending from the stacked plurality of electrode plates may overlap each other to form the electrode tabs 14.
Both the electrode tab 14 and the electrode lead 12 may be made of an electrically conductive metal material. Accordingly, the electrode tab 14 and the electrode lead 12 may be connected by stacking end portions thereof, which face each other, in the height direction so that some portions overlap in the length direction, and then welding those portions together.
There is a possibility that a weld bead may be generated at the welded portion, which may damage an inner surface of the pouch, which will be described below. Accordingly, welding tapes 15 may be attached to both surfaces of the welded portion as necessary. According to the present disclosure, a structure in which a thermal insulator 20 to be described below covers the metal portion 41 is provided, and thus the thermal insulator 20 may also perform the function of the welding tape 15. Accordingly, the welding tape 15 may be omitted.
Referring to
The insulating layer 30 may include a polypropylene (PP) material.
The pouch 10 may be made of a flexible material.
The pouch 10 is formed by folding the sheet to accommodate the electrode assembly 11 therein, and sealing and attaching edge portions of the sheet, which face each other due to folding of the sheet, by pressing and heating. The electrode lead 12 extends further out of the pouch through the sealingly attached portion of the edge of the pouch 10.
The lead film 13 is provided in a region in which the electrode lead 12 passes through the sealed portion of the edge of the pouch 10. A pair of lead films 13 are attached to an upper surface and a lower surface of the electrode lead 12, respectively, and are laminated on both sides of the electrode lead 12 and further extend laterally. An extension direction of the lead film 13 attached to the electrode lead 12 corresponds to an extension direction of the edge of the pouch.
When the two edge portions of the pouch are heated and pressed by a sealing tool in a state in which the electrode lead 12 and the lead film 13 are interposed, the lead film 13 and the edge portion of the pouch are fused and sealed.
Referring to
In this case, the insulating layer 30 adhered to the metal portion 41 may subsequently be disconnected when the metal portion 41 or the like is moved, thereby lowering the insulating performance of the pouch cell.
Accordingly, referring to
The thermal insulator 20 may be applied to the metal portion 41 before the electrode assembly 11 is accommodated in the pouch 10.
Hereinafter, the shape and range in which the thermal insulator 20 covers the metal portion 41 will be described.
The term “covers” described above includes a case in which heat of the metal portion 41 can be blocked from the inner insulating layer 30a of the pouch as in a case in which the thermal insulator 20 is in contact with the metal portion 41 by being directly attached to the metal portion 41, as well as a case in which the thermal insulator 20 indirectly covers the metal portion 41 by surrounding the metal portion 41 with an air layer or covering the welding tape 15 or the like directly attached to the metal portion 41 as shown in
Referring to
Referring again to
The thermal insulating film 20 may cover the metal portion 41 in a shape surrounding the metal portion 41 with the length direction (Y direction) of the metal portion 41 as an axis. At this time, the thermal insulating film 20 may surround the perimeter of the metal portion 41 one or more times, and may surround the perimeter of the metal portion 41 two or more times in order to increase the insulating function of the thermal insulating film 20.
The thermal insulator 20 may cover 50% or more of a surface area of a portion between the electrode assembly 11 and the lead film 13 in order to achieve a sufficient thermal insulating effect.
Referring to
Further, referring to
The thermal insulator 20 may cover a connection portion of the electrode tab 14 and the electrode lead 12 to prevent any roughness that may be present at the connection portion from damaging the inner surface of the pouch 10. In particular, when the electrode tab 14 and the electrode lead 12 are connected through welding, the thermal insulator 20 may be positioned to cover the welded portion in order to prevent the inner surface of the pouch 10 from being damaged from a sharp bead of the welded portion.
The thermal insulator 20 may include any one material selected from the group consisting of foamed synthetic resin, glass fiber, rock wool, mica, perlite, vermiculite, and cellulose. However, the thermal insulator 20 is not limited thereto and any material may be used as long as the thermal insulator can exhibit thermal insulation performance.
When the thermal insulator 20 is the thermal insulating film 20, the thermal insulating film 20 may be a thermal reflective film coated with a metal thin film by a sputtering method. However, the thermal insulating film 20 is not limited thereto, and may be manufactured by any method and in any structure as long as it is capable of exhibiting thermal insulation performance.
It should be understood that the described aspects are illustrative in all respects and not restrictive, and the scope of the present disclosure will be indicated by the following claims rather than the described detailed description. And the meaning and scope of the claims to be described later, as well as all changes and modifications derived from the equivalent concept should be interpreted as being included in the scope of the present disclosure.
The aspects are described above with reference to a number of illustrative aspects thereof. However, aspects are not limited to the aspects and drawings set forth herein, and numerous other modifications and aspects may be drawn by one skilled in the art within the technical scope of the disclosure. Further, the effects and predictable effects based on the configurations in the disclosure are to be included within the scope of the disclosure though not explicitly described in the description of the aspects.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0046974 | Apr 2022 | KR | national |
This application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2023/001277 filed Jan. 27, 2023, which claims the benefit of foreign priority to Korean Patent Application No. 10-2022-0046974, filed on Apr. 15, 2022 in the Republic of Korea, the disclosures of which are incorporated by reference herein in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/001277 | 1/27/2023 | WO |
