Battery cell and battery pack with same
By filling the phase change medium in the membrane module of the battery cell, the problem of thermal runaway from the extreme group is solved, and the safety of the battery cell is improved. By absorbing heat and cooling and providing expansion space, the safe use of the battery cell is ensured. .
Patent Information
- Application Number
- CN202420923883.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-29
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-04-29
AI Technical Summary
The existing battery cells are difficult to cool down in time when the electrode assembly is thermally out of control, which affects the safety of use.
The membrane module is filled with a phase change medium, and uses its characteristics of absorbing heat or cooling when the temperature changes, absorbing heat generated by the electrode group, and alleviating the expansion force of the electrode group through the expansion space, thereby improving the safety of the battery cell.
Effectively reduce the cooling to prevent heat loss, alleviate the expansion force of the electrode group, and improve the safety of battery cells.
Smart Images
Figure CN222214271U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of battery pack manufacturing, in particular to a battery monomer and a battery pack having the same. Background Art
[0002] In the existing solution, when the battery cell is running, the electrode group will generate a lot of heat. When the electrode group cannot be cooled down in time, thermal runaway of the electrode group will occur, which will affect the safety of the battery cell. Utility Model Content
[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a battery cell, which can improve the safety of the battery cell.
[0004] The utility model also provides a battery pack having the battery monomer.
[0005] According to the battery cell of the embodiment of the utility model, it includes: a shell; a pole group, the pole group is arranged in the shell; a membrane assembly, the membrane assembly is arranged between the pole group and the shell, a receiving cavity is formed in the membrane assembly, the receiving cavity is filled with a phase change medium, the phase change medium has a first state and a second state, and the phase change medium can be converted between the first state and the second state.
[0006] According to the battery cell of the utility model, a phase change medium is arranged in the membrane assembly, which can cool the electrode group, thereby improving the use safety of the battery cell, and at the same time, can alleviate the expansion force of the electrode group, thereby further ensuring the use safety of the battery cell.
[0007] According to some embodiments of the present invention, two ends of the membrane assembly are provided with folding sections, the folding sections are folded along the thickness direction of the membrane assembly, and the folding sections seal the accommodating cavity.
[0008] According to some optional embodiments of the present invention, the folding directions of the folding sections at both ends of the membrane assembly are opposite.
[0009] According to some embodiments of the present invention, the membrane assembly includes: a first membrane and a second membrane, the first membrane and the second membrane are stacked, and the accommodating cavity is defined between the first membrane and the second membrane.
[0010] According to some optional embodiments of the present invention, both the first film and the second film are elastic bodies, and at least parts of the first film and the second film are structural weak areas.
[0011] According to some embodiments of the present invention, the accommodating cavity includes a first cavity and a second cavity, the phase change medium is removably arranged in the first cavity, and the second cavity is filled with air.
[0012] According to some optional embodiments of the present invention, the volume ratio of the first cavity to the second cavity is 1:9.
[0013] According to some embodiments of the present invention, the resistivity of the phase change medium is greater than or equal to 10 6 Ω / cm.
[0014] According to some embodiments of the present invention, the thickness of the membrane assembly is greater than or equal to 3 mm.
[0015] A battery pack according to an embodiment of the second aspect of the utility model includes a battery cell according to the first aspect of the utility model.
[0016] According to the battery pack of the utility model, by providing the battery cell of the first embodiment and providing the phase change medium in the membrane assembly, the electrode group can be cooled, thereby improving the safety of the battery cell. At the same time, the expansion force of the electrode group can be alleviated, thereby further ensuring the safety of the battery cell.
[0017] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is an exploded view of a battery cell according to an embodiment of the first aspect of the utility model at one angle;
[0019] Figure 2 yes Figure 1 An exploded view of the battery cell from another angle shown in FIG.
[0020] Figure 3 yes Figure 2 Schematic diagram of the membrane module shown in;
[0021] Figure 4 yes Figure 3 A partial enlarged view of the middle A;
[0022] Figure 5 yes Figure 3 A partial enlarged view of point B in the middle.
[0023] Reference numerals:
[0024] 100. Battery cell;
[0025] 10. Shell;
[0026] 20. Pole group;
[0027] 30. Membrane assembly; 31. First membrane; 32. Second membrane; 33. Folding section; 34. Accommodating cavity. DETAILED DESCRIPTION
[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0029] Please refer to the following Figure 1-5 A battery cell 100 according to an embodiment of the present invention is described.
[0030] Reference Figure 1 , Figure 2 and Figure 3 According to an embodiment of the present invention, a battery cell 100 includes: a housing 10 , an electrode group 20 and a membrane assembly 30 .
[0031] Specifically, the pole group 20 is arranged in the shell 10; the membrane assembly 30 is arranged between the pole group 20 and the shell 10, and a receiving cavity 34 is formed in the membrane assembly 30. The receiving cavity 34 is filled with a phase change medium. The phase change medium has a first state and a second state, and the phase change medium can be converted between the first state and the second state.
[0032] For example, Figure 1 , Figure 2 and Figure 3 As shown, the phase change medium is in the first state at room temperature, the first state is solid, the phase change medium is in the second state after being heated, the second state is liquid, the phase change medium can absorb heat from the first state and melt to the second state, and the phase change medium can also cool down and solidify from the second state to the first state. Preferably, the phase change medium is paraffin, which can ensure that the phase change medium can normally switch between the first state and the second state when the pole group 20 is thermally runaway.
[0033] When the electrode group 20 in the battery cell 100 is in thermal runaway, the temperature of the electrode group 20 rises, and the phase change medium gradually changes from the first state to the second state after absorbing heat, so that the phase change medium can absorb the heat of the electrode group 20 to prevent the thermal runaway of the electrode group 20 from further aggravation.
[0034] The battery cell 100 of the present invention is provided with a phase change medium in the membrane assembly 30. The phase change medium can absorb heat from a first state to a second state, so that the electrode group 20 can be cooled, thereby preventing the thermal runaway of the electrode group 20 from being further aggravated, thereby improving the safety of the battery cell 100. At the same time, when the state of the phase change medium changes, expansion space can be provided for the electrode group 20, thereby alleviating the expansion force of the electrode group 20, thereby further ensuring the safety of the battery cell 100.
[0035] According to the battery cell 100 of the embodiment of the present invention, a phase change medium is arranged in the membrane assembly 30, which can cool the electrode group 20, thereby improving the safety of the battery cell 100. At the same time, the expansion force of the electrode group 20 can be alleviated, thereby further ensuring the safety of the battery cell 100.
[0036] Furthermore, if Figure 1 , Figure 2 and Figure 3 As shown, when the phase change medium is at 45°C to 85°C, the phase change medium absorbs heat and melts from the first state to the second state. Therefore, when the electrode group 20 thermally runs away, the phase change medium can be guaranteed to be able to transform from the first state to the second state, thereby ensuring the safety of the battery cell 100.
[0037] According to some embodiments of the present invention, referring to Figure 3 , Figure 4 and Figure 5 , both ends of the membrane assembly 30 (such as Figure 3 The upper and lower ends of the membrane assembly 30 shown in FIG. 1 are provided with folding sections 33, and the folding sections 33 are arranged along the thickness direction of the membrane assembly 30 (such as Figure 3 The folded section 33 is folded in the front-to-back direction (shown in the figure), and the folded section 33 seals the receiving cavity 34. Thus, the folded section 33 seals the receiving cavity 34, which can effectively prevent the phase change medium from flowing out of the receiving cavity 34, thereby ensuring the normal use of the membrane assembly 30. At the same time, the folding direction of the folded section 33 is reasonable, which can ensure the sealing effect.
[0038] According to some embodiments of the present invention, referring to Figure 3 , Figure 4 and Figure 5 , both ends of the membrane assembly 30 (such as Figure 3 The folding directions of the folding sections 33 at the upper and lower ends of the membrane assembly 30 shown are opposite. Therefore, this folding form is reasonable, and the membrane assembly 30 can bear the expansion force of the phase change medium to the greatest extent, thereby effectively preventing the phase change medium from flowing out of the membrane assembly 30.
[0039] For example, Figure 3 , Figure 4 and Figure 5As shown, the folding section 33 at the upper end of the membrane assembly 30 is folded to the left, and the folding section 33 is parallel to the membrane assembly 30 after being folded, and the folding section 33 at the lower end of the membrane assembly 30 is folded to the right, and the folding section 33 is parallel to the membrane assembly 30 after being folded, so that the membrane assembly 30 can bear the expansion force of the phase change medium to the greatest extent.
[0040] According to some embodiments of the present invention, referring to Figure 3 The membrane assembly 30 includes: a first membrane 31 and a second membrane 32, which are stacked and define a receiving cavity 34 between the first membrane 31 and the second membrane 32. Thus, the first membrane 31 and the second membrane 32 cooperate to form the membrane assembly 30. This structure is simple and convenient for processing. At the same time, the receiving cavity 34 is defined between the first membrane 31 and the second membrane 32, and there is no need to set up an additional receiving cavity 34, thereby reducing processing steps and reducing production costs.
[0041] Preferably, the ends of the first film 31 and the second film 32 are packaged by a heat-pressing sealing process, so that the sealing effect of the first film 31 and the second film 32 can be ensured.
[0042] According to some optional embodiments of the present invention, referring to Figure 4 and Figure 5 The first film 31 and the second film 32 are both elastic bodies, and at least parts of the first film 31 and the second film 32 are structurally weak areas. That is to say, parts of the first film 31 and the second film 32 may be structurally weak areas, or both the first film 31 and the second film 32 may be structurally weak areas.
[0043] In this way, when the electrode group 20 expands due to thermal runaway, the electrode group 20 will squeeze the first film 31 and the second film 32. The elastomer is elastic, so that the electrode group 20 can release the expansion force easily, thereby ensuring the safety of the battery cell 100. At the same time, the first film 31 and the second film 32 have structural weak areas. When the first film 31 and the second film 32 are damaged, the phase change medium can flow out of the accommodating cavity 34. The phase change medium mixes with the electrolyte, which can prevent the electrode group 20 from burning, thereby suppressing the thermal runaway of the battery cell 100.
[0044] Preferably, the first film 31 and the second film 32 are made of polyester, polyethylene, and polypropylene as raw materials, and a certain amount of organic solvent is added. In this way, the first film 31 and the second film 32 can have good insulation pressure resistance, electrolyte resistance, and ductility. At the same time, the first film 31 and the second film 32 can have good thermal conductivity, thereby ensuring that the phase change medium can be converted from the first state to the second state.
[0045] According to some embodiments of the present invention, referring to Figure 3The receiving cavity 34 includes a first cavity and a second cavity, wherein the first cavity is provided with a phase change medium, and the second cavity is filled with air. Thus, the receiving cavity 34 is filled with air, so that the volume expansion of the phase change medium when the state changes can avoid damaging the first membrane 31 and the second membrane 32, thereby ensuring the service life of the membrane assembly 30.
[0046] According to some optional embodiments of the present invention, referring to Figure 3 The volume ratio of the first cavity to the second cavity is greater than or equal to 1:9. Thus, it is possible to avoid the first cavity volume being too small to affect the storage of the phase change medium, and at the same time, it is possible to avoid the second cavity volume being too small to prevent the phase change medium from expanding and damaging the first film 31 and the second film 32. For example, Figure 3 As shown, the volume ratio of the first cavity and the second cavity can be: 1:9, 1:8, 1:7, 1:6 or 1:5.
[0047] According to some embodiments of the present invention, referring to Figure 1 , the resistivity of the phase change medium is greater than or equal to 106Ω / cm. Thus, the flame retardant effect of the phase change medium can be ensured, thereby effectively preventing the thermal runaway of the battery cell 100 from being aggravated.
[0048] According to some embodiments of the present invention, referring to Figure 3 , the thickness of the membrane assembly 30 is greater than or equal to 3 mm. Thus, the thickness of the membrane assembly 30 can be guaranteed and damage to the membrane assembly 30 can be avoided. For example, Figure 3 As shown, the thickness of the membrane assembly 30 can be: 3 mm, 4 mm, 5 mm, 6 mm, 7 mm or 8 mm.
[0049] According to the battery pack of the second embodiment of the utility model, refer to Figure 1 , including the battery cell 100 of the first aspect of this embodiment.
[0050] According to the battery pack of the embodiment of the utility model, by setting the battery cell 100 of the first embodiment mentioned above and setting the phase change medium in the membrane assembly 30, the electrode group 20 can be cooled, thereby improving the safety of the battery cell 100. At the same time, the expansion force of the electrode group 20 can be alleviated, thereby further ensuring the safety of the battery cell 100.
[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0053] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0055] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.
Claims
1. A battery cell, characterized in that: include: case; A pole group, the pole group is arranged in the shell; A membrane assembly is provided between the pole group and the shell, a receiving cavity is formed in the membrane assembly, the receiving cavity is filled with a phase change medium, the phase change medium has a first state and a second state, and the phase change medium can be switched between the first state and the second state.
2. The battery cell according to claim 1, characterized in that: Both ends of the membrane assembly are provided with folding sections, the folding sections are folded along the thickness direction of the membrane assembly, and the folding sections seal the accommodating cavity.
3. The battery cell according to claim 2, characterized in that: The folding directions of the folding sections at both ends of the membrane assembly are opposite.
4. The battery cell according to claim 1, characterized in that: The membrane assembly includes: a first membrane and a second membrane, the first membrane and the second membrane are stacked, and the accommodating cavity is defined between the first membrane and the second membrane.
5. The battery cell according to claim 4, characterized in that: The first film and the second film are both elastic bodies, and at least parts of the first film and the second film are structurally weak areas.
6. The battery cell according to claim 4, characterized in that: The accommodating cavity comprises a first cavity and a second cavity, the first cavity is provided with the phase change medium, and the second cavity is filled with air.
7. The battery cell according to claim 6, characterized in that: The volume ratio of the first cavity to the second cavity is 1:
9.
8. The battery cell according to claim 1, characterized in that: The phase change medium resistivity is greater than or equal to 10 6 Ω / cm.
9. The battery cell according to claim 1, characterized in that: The thickness of the membrane assembly is greater than or equal to 3 mm.
10. A battery pack, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 9.