Partition plate, battery cell and battery pack

Abstract

The utility model provides a partition plate, a battery cell and a battery pack, and relates to the technical field of batteries. The partition plate comprises a shell and a phase change substance. The shell is provided with an inner cavity; the phase change material is arranged in the inner cavity. According to the invention, the partition plate is provided with the inner cavity, and the phase change substance is arranged in the inner cavity, so that the partition plate has a function of insulating and isolating the core package, and also has a cooling effect of absorbing heat of the core package through heat absorption and phase change of the phase change substance, and the partition plate integrates multiple functions.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a separator, a battery cell and a battery pack. Background Art

[0002] In the related art, the battery cell includes a shell and a core package arranged in the shell. The core package is formed by stacking or winding pole pieces and diaphragms in sequence. In order to improve the energy density of the battery cell and meet high-voltage applications, multiple core packages are usually arranged in the shell. At the same time, in order to avoid short circuits caused by contact between two adjacent core packages, a partition is arranged between the core packages to insulate and isolate the core packages from each other through the partition.

[0003] However, the existing separators have a single function and can only meet the insulation isolation requirements of the battery core package. Utility Model Content

[0004] The embodiments of the present application provide a partition, a battery cell and a battery pack, which can improve the problem of the single function of the partition.

[0005] In a first aspect, an embodiment of the present application provides a partition, the partition comprising a shell and a phase change material. The shell has an inner cavity; the phase change material is disposed in the inner cavity.

[0006] In one embodiment, the shell is elastic, and the phase change material becomes a fluid after absorbing heat.

[0007] In one embodiment, the inner cavity includes a first inner cavity and a second inner cavity which are independent of each other, the phase change material is arranged in the first inner cavity, and the first inner cavity and the second inner cavity are arranged in sequence from the center of the partition to the periphery of the partition.

[0008] In one embodiment, the second inner cavity is filled with an inert gas, and / or the second inner cavity is an annular cavity arranged around the first inner cavity.

[0009] In one embodiment, the shell includes a first shell wall and a second shell wall arranged opposite to each other, the first shell wall and the second shell wall are connected to each other to form an inner cavity, and the opposite surfaces of the first shell wall and the second shell wall are connected to each other to divide the inner cavity into a first inner cavity and a second inner cavity.

[0010] In one embodiment, a thermoforming part is disposed on the shell, and the thermoforming part divides the inner cavity into a first inner cavity and a second inner cavity.

[0011] In one embodiment, the phase change substance includes a solid-liquid phase change material.

[0012] In one embodiment, the housing is an air bag.

[0013] In a second aspect, an embodiment of the present application provides a battery cell, which includes a shell, a core package and the aforementioned partition; the shell has a accommodating cavity; there are multiple core packages, and the multiple core packages are arranged in sequence in the accommodating cavity; wherein a partition is arranged between two adjacent core packages; a pair of opposite side walls of the shell are respectively in contact with the two adjacent core packages, and / or a partition is arranged between the core package and the shell.

[0014] In a third aspect, an embodiment of the present application further provides a battery pack, which includes the aforementioned battery cell.

[0015] Beneficial effects of the embodiments of the present application:

[0016] In the embodiments of the present application, an inner cavity is provided on the partition, and a phase change material is provided in the inner cavity, so that the partition not only has the function of insulating the core package, but also has a cooling effect by absorbing the heat of the core package through the endothermic phase change of the phase change material, thereby making the partition integrate multiple functions into one. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a front view of a partition provided in an embodiment of the present application;

[0019] Figure 2 is along Figure 1 Sectional view of AA in the middle;

[0020] Figure 3 is a side view of a partition provided in an embodiment of the present application;

[0021] Figure 4 yes Figure 3 Cross-sectional view of the middle BB;

[0022] Figure 5 It is a schematic diagram of the positions of the partitions and core packs provided in the embodiments of the present application.

[0023] Reference numerals:

[0024] 001-partition;

[0025] 011-housing; 111-thermoforming part;

[0026] 012-inner cavity; 121-first inner cavity; 122-second inner cavity;

[0027] 013-Phase change material;

[0028] 002-Core package. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0030] In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0031] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0034] See also Figure 1 , Figure 1 001 is a front view of a partition 001 provided in an embodiment of the present application. The embodiment of the present application provides a partition 001. The partition 001 includes a shell 011 and a phase change material 013. The shell 011 has an inner cavity 012. The phase change material 013 is disposed in the inner cavity 012.

[0035] It can be understood that the phase change material 013 is also called phase change energy storage material, which is a material that changes from one state to another state through temperature change, and is accompanied by heat absorption or heat release. In addition, the shell 011 is an insulating material.

[0036] Exemplarily, the phase change material 013 includes one or more of the following phase change materials: solid-solid phase change material, solid-liquid phase change material, liquid-liquid phase change material, liquid-gas phase change material, solid-gas phase change material. Optionally, the phase change material 013 includes a solid-liquid phase change material. Specifically, the solid-liquid phase change material includes an organic solid-liquid phase change material and an inorganic solid-liquid phase change material. Among them, the solid-liquid phase change material can be selected from water-containing compounds, such as lithium nitrate trihydrate, calcium chloride crystal water compound, sodium sulfate crystal water compound, sodium carbonate crystal water compound, etc.; aliphatic hydrocarbons, polyols, polyenols and other organic solid-liquid phase change materials, such as paraffin, can also be used; it can also be polyols, polymers and other organic solid-solid phase change materials, such as pentaerythritol and neopentyl glycol. Highly thermally conductive materials, such as one or more of graphite, carbon fiber, foamed metal, nano-aluminum oxide, nano-scale metal particles, nano-scale metal oxide particles, and metal chips, may also be added to the phase change material to increase the thermal conductivity of the phase change material 013, thereby improving the overall heating uniformity of the phase change material 013, and further improving the phase change uniformity of the phase change material 013. Thus, the force uniformity of the surface of the core package on both sides of the partition 001 in contact with the partition 001 can be improved.

[0037] In addition, the doping ratio of each substance in the phase change material 013 can be adjusted according to the heating conditions of different battery cells and the use environment to achieve gradient heat dissipation at different states of normal temperature and high temperature, so as to meet the heat dissipation requirements of the battery cells while achieving a balance between the heat dissipation effect of the partition 001 on the battery cells and the cost, thereby avoiding the high cost of the partition 001. For example, if the normal operating temperature of a battery cell is 35-40°C and the maximum operating temperature of the battery cell is 60°C, the phase change temperature of the phase change material 013 can be set at 35-40°C and 50-55°C, and more substances undergo phase change at 55°C.

[0038] In this embodiment, by providing an inner cavity 012 on the partition 001 and providing a phase change material 013 in the inner cavity 012, the partition 001 has the function of insulating and isolating the core package, and also has the cooling effect of absorbing the heat of the core package through the heat absorption of the phase change material 013, so that the partition integrates multiple functions into one. In this way, under the premise that the space occupied by the partition is inconvenient, it can not only insulate and isolate the core package, but also improve the heat dissipation efficiency of the core package, thereby improving the reliability of the battery cell, and has no effect on the energy density of the battery cell.

[0039] In one embodiment, the shell 011 is elastic, and the phase change material 013 becomes a fluid after absorbing heat.

[0040] It can be understood that when the battery cell is working, the core package will generate heat and expand, thereby squeezing the partition 001.

[0041] Based on this, in this embodiment, through the above arrangement, when the core package expands and squeezes the partition 001, the phase change material 013 can flow from the area of ​​the partition 001 that is most severely squeezed by the core package to other areas, so that the partition 001 can provide a buffer for the expansion of the core package and provide space for the expansion of the core package. Therefore, on the one hand, the core package can be prevented from being damaged when the expansion force is large and the expansion space is small, and on the other hand, the stress state of the partition 001 can be improved, thereby improving the reliability of the partition 001.

[0042] See also Figure 2 , Figure 2 is along Figure 1 In one embodiment, the inner cavity 012 includes a first inner cavity 121 and a second inner cavity 122 which are independent of each other. The phase change material 013 is disposed in the first inner cavity 121. From the center of the partition 001 to the periphery of the partition 001, the first inner cavity 121 and the second inner cavity 122 are disposed in sequence.

[0043] It can be understood that a partition structure is provided between the first inner cavity 121 and the second inner cavity 122 to separate the inner cavity 012 into the first inner cavity 121 and the second inner cavity 122 which are independent of each other. The lowest strength of the outer surface of the partition plate 001 is greater than the strength of the partition structure between the first inner cavity 121 and the second inner cavity 122.

[0044] When the core package expands, the core package squeezes the partition 001 so that the partition 001 is under great pressure, which may easily cause the inner cavity 012 to be squeezed and ruptured, causing the phase change material 013 to flow out of the shell 011 and contaminate the electrolyte.

[0045] Based on this, in this embodiment, by setting the inner cavity 012 as a first inner cavity 121 and a second inner cavity 122 that are independent of each other, when the first inner cavity 121 is under great pressure, the partition structure between the first inner cavity 121 and the second inner cavity 122 can be broken, and the phase change material 013 flows from the first inner cavity 121 into the second inner cavity 122. In this way, it can be avoided that the partition 001 is directly squeezed and the phase change material 013 flows out of the partition 001 and contaminates the electrolyte.

[0046] In one embodiment, the second inner cavity 122 is filled with an inert gas, such as helium or argon.

[0047] Since the partition 001 needs to have a certain thickness to insulate and isolate two adjacent core packages, in this embodiment, the second inner cavity 122 is filled with an inert gas, so that when the thickness of the wall of the partition 001 used to form the second inner cavity 122 is relatively small, the partition 001 can have a certain thickness dimension at the second inner cavity 122 based on the inert gas. In this way, the distance between two adjacent battery cells at the second inner cavity 122 can be avoided to be too small, thereby improving the reliability of the battery cells.

[0048] In addition, when the partition 001 is compressed so that the partition structure between the first inner cavity 121 and the second inner cavity 122 is broken, the inert gas can also buffer the phase change material 013 rushing into the second inner cavity 122, thereby reducing the impact force on the second inner cavity 122 and improving the reliability of the partition 001.

[0049] See also Figure 3 and Figure 4 , Figure 3 is a side view of the partition 001 provided in the embodiment of the present application, Figure 4 yes Figure 3 In one embodiment, the second inner cavity 122 is an annular cavity arranged around the first inner cavity 121.

[0050] In this embodiment, through the above arrangement, the circumference of the first inner cavity 121 is wrapped by the second inner cavity 122, so that the phase change material 013 can flow from any position of the circumference of the first inner cavity 121 into the second inner cavity 122, so that the layout structure of the first inner cavity 121 and the second inner cavity 122 is adapted to the situation where the pressure position of the partition 001 is uncertain and the flow direction of the phase change material is uncertain. In this way, the adaptability of the partition 001 to various expansion states of the core package can be improved.

[0051] See also Figure 2 In one embodiment, the housing 011 includes a first housing wall and a second housing wall. The first housing wall and the second housing wall are connected to each other to form an inner cavity 012, and the first housing wall and the second housing wall are connected to each other at opposite surfaces to separate the inner cavity 012 into a first inner cavity 121 and a second inner cavity 122.

[0052] Exemplarily, the first shell wall is glued to the second shell wall. Specifically, the first shell wall is connected to the second shell wall by ultrasonic hot pressing process to form a hot pressing forming part 111 on the shell 011. The hot pressing forming part 111 separates the inner cavity 012 into a first inner cavity 121 and a second inner cavity 122.

[0053] It can be understood that the hot pressing forming portion 111 is a pressing edge that separates the inner cavity 012 into the first inner cavity 121 and the second inner cavity 122 that are independent of each other.

[0054] In this embodiment, the first inner cavity 121 and the second inner cavity 122 are formed in the above manner, so that the partition 001 has a simple structure and is easy to form, thereby improving the production efficiency of the partition 001 and reducing the manufacturing cost of the partition 001.

[0055] In one embodiment, the shell 011 is an airbag, and the material of the airbag is a thermoplastic polymer material, specifically an insulating and puncture-resistant thermoplastic polymer film, such as polypropylene, phenolic resin, etc. and modified substances thereof.

[0056] In this embodiment, the shell 011 is configured as an air bag, which can reduce the space occupied by the shell 011 on the partition 001 of limited size, thereby increasing the amount of phase change material 013 and further improving the heat dissipation effect of the partition 001 on the core package.

[0057] In addition, the use of thermoplastic polymer material as the shell 011 can meet the strength requirements and deformation requirements of the partition 001 when the battery pack expands multiple times, so that it can be reused.

[0058] The forming method of the partition 001 mainly includes the following contents: a film is made into a capsule, and a hot pressing forming part 111 is formed on the shell 011 by an ultrasonic hot pressing process, and the hot pressing forming part 111 separates the inner cavity 012 of the capsule into a first inner cavity 121 and a second inner cavity 122. A first through hole connected to the first inner cavity 121 and a second through hole connected to the second inner cavity 122 are provided on the outer wall of the capsule. The phase change material 013 is filled into the first inner cavity 121 through the first through hole. After filling, the first through hole is closed by hot melting or hot pressing. The second inner cavity 122 is filled with an inert gas through the second through hole, and the second through hole is closed in an environment with a certain pressure and filled with an inert gas.

[0059] Accordingly, an embodiment of the present application provides a battery cell, wherein the battery cell package 002 includes a shell, a core package 002 and the aforementioned partition 001. The shell has a receiving cavity. There are multiple core packages 002. Multiple core packages 002 are sequentially arranged in the receiving cavity. Partitions 001 are provided between two adjacent core packages 002. A pair of opposite side walls of the shell 011 are in contact with two adjacent core packages 002, respectively.

[0060] It can be understood that the large surface of the core package 002 is in contact with the partition 001. Figure 4 As stated, Figure 4 It is a schematic diagram of the positions of the partition 001 and the core package 002 provided in the embodiment of the present application.

[0061] In this embodiment, by adopting the aforementioned partition 001, on the one hand, two adjacent core packages 002 can be insulated and isolated; on the other hand, the heat of the core package 002 can be absorbed by the endothermic phase change property of the phase change material 013 in the partition 001, thereby improving the heat dissipation efficiency of the battery cell and further improving the reliability of the battery cell.

[0062] Among them, multiple core packages 002 are arranged in sequence along the first direction. In one direction, the thickness of the partition 001 is d, and the thickness of the battery cell is D, satisfying 1.5% D≤d≤2.5% D. It can be understood that d includes but is not limited to 1.5% D, 1.6% D, 1.8% D, 2.0% D, 2.1% D, 2.4% D, and 2.5% D. If the thickness of the partition 001 is too small, the insulation isolation effect of the partition 001 on the core package 002 will be poor. If the thickness of the partition 001 is too large, it will have an adverse effect on the energy density of the battery cell.

[0063] In one embodiment, a partition 001 is provided between the core package 002 and the outer shell.

[0064] It can be understood that the partition can bind multiple core packages 002 together, or can be directly fixed on the core package 002, or can be set on the inner wall of the shell.

[0065] In this embodiment, through the above arrangement, the core package 002 can be insulated and isolated from the shell through the partition 001, and the core package 002 can be supported, and the heat dissipation performance of the battery cell can be improved.

[0066] Correspondingly, an embodiment of the present application also provides a battery pack, which includes the aforementioned battery cell.

[0067] It can be understood that the battery pack also includes components such as a box, a collection component, a battery management system, and a liquid cooling plate. Among them, the battery cells, the collection component, the battery management system, and the liquid cooling plate are arranged in the box. And multiple battery cells are connected in series or in parallel through the collection component.

[0068] In this embodiment, by adopting the aforementioned battery cell, the heat of the core pack 002 can be absorbed by the endothermic phase change property of the phase change material 013 in the partition 001, thereby improving the heat dissipation efficiency of the battery pack and further enhancing the reliability of the battery pack.

[0069] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A partition, characterized in that: include: a housing having an inner cavity; A phase change material is disposed in the inner cavity; Wherein, the shell is elastic, and the phase change material becomes a fluid after absorbing heat; The inner cavity includes a first inner cavity and a second inner cavity which are independent of each other. The phase change material is arranged in the first inner cavity. From the center of the partition to the periphery of the partition, the first inner cavity and the second inner cavity are arranged in sequence.

2. The separator according to claim 1, characterized in that The second inner cavity is filled with an inert gas, and / or the second inner cavity is an annular cavity arranged around the first inner cavity.

3. The separator according to claim 1, characterized in that The shell includes a first shell wall and a second shell wall; the first shell wall and the second shell wall are connected to each other to form the inner cavity, and the parts of the first shell wall and the second shell wall facing each other are connected to each other to separate the inner cavity into the first inner cavity and the second inner cavity.

4. The separator according to claim 1, characterized in that The shell is provided with a hot pressing forming part, and the hot pressing forming part divides the inner cavity into the first inner cavity and the second inner cavity.

5. The separator according to any one of claims 1 to 4, characterized in that: The phase change material includes a solid-liquid phase change material.

6. The separator according to any one of claims 1 to 4, characterized in that: The shell is an air bag.

7. A battery cell, characterized in that: include: A housing having a receiving cavity; A plurality of core packages are sequentially and spaced apart in the accommodating cavity; The partition according to any one of claims 1 to 6; The partition is disposed between two adjacent core packages, a pair of opposite side walls of the shell are in contact with the two adjacent core packages respectively, and / or the partition is disposed between the core package and the shell.

8. A battery pack, characterized in that: Comprising the battery cell as claimed in claim 7.

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