Battery cell shell, battery cell and battery pack
By filling the insulation layer or reinforcement layer in the sealing cavity of the battery cell shell, the safety problems of power lithium batteries in mechanical, electrical and thermal abuse are solved, and higher thermal insulation performance and structural strength are achieved, thereby improving the safety of the battery cell.
Patent Information
- Application Number
- CN202420454329.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-08
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-03-08
AI Technical Summary
The safety of existing power lithium batteries is affected by factors such as materials and structure, especially in the case of mechanical, electrical and thermal abuse, which can easily lead to failures and safety accidents.
A battery cell housing is designed to improve the thermal insulation performance and structural strength of the battery cell housing by forming a sealing cavity between the outer shell and the inner shell and filling the sealing cavity with a thermal insulation layer or reinforcement layer.
This design effectively reduces the thermal conductivity of the battery cell when thermal runaway, improves the puncture resistance and mechanical properties, reduces the risk of thermal runaway caused by external force puncture, and thus improves the safety of the battery cell.
Smart Images
Figure CN222601156U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of power batteries, and in particular to a battery cell shell. At the same time, the utility model also relates to a battery cell provided with the battery cell shell, and a battery pack provided with the battery cell. Background Art
[0002] With the explosive growth of new energy vehicles, the demand for power lithium-ion batteries is expanding rapidly. As the energy carrier of electric vehicles, the safety of lithium batteries cannot be ignored.
[0003] The factors that induce battery safety accidents vary slightly due to different battery materials, structures, etc., but can be roughly divided into two categories: one is instantaneous events or abuse conditions, such as mechanical abuse (such as collision, extrusion, puncture, etc.), electrical abuse (such as external short circuit, overcharge, over-discharge, etc.) and thermal abuse (fire, oven, etc.); the other is the battery itself, such as defects in the battery itself or design defects, such as metal impurities mixed in during the manufacturing process, misalignment of the current collector, low electrochemical window of the electrolyte, etc. These factors are very likely to evolve into failures as the battery is used, threatening battery safety.
[0004] Based on the above problems, common protection solutions can be divided into three categories: The first type of solution is passive protection, which is more typical in Kirin batteries. This protection method is based on the combination of dredging and blocking (heat dissipation + heat insulation) as the design center, and uses control to enhance heat dissipation and heat insulation as the main technical means to achieve thermal runaway of only a small number of cells in the battery pack and no open flames outside the entire pack.
[0005] The second type of solution is active protection, spray system and big data monitoring. The ingenious design of the battery system coolant pipeline can accurately inject a large amount of coolant at the moment of thermal runaway to achieve active directional fire extinguishing. Backstage big data mining makes full use of the battery system intelligent management and charging system to actively discover, actively protect, and discover batteries with safety risks as early as possible. The third type of solution is to improve the thermal stability of the material level to achieve intrinsic safety. By improving the thermal stability of materials such as positive and negative electrodes, diaphragms, electrolytes, and current collectors, currently known feasible technical routes include: mixed use of lithium manganese iron phosphate and ternary, composite current collectors, etc.
[0006] At present, common protection schemes will have more or less impact on battery energy density, cost, electrical performance, etc. For example, the design of adding heat dissipation channels to the battery pack will increase the free space and reduce the volume energy density of the battery pack. The use of a spray system requires the injection of a large amount of coolant, which increases the mass of the battery pack and reduces the weight energy density of the battery pack. The design of coating battery materials to improve thermal stability will increase the synthesis cost of the materials, and the presence of surface coatings will block the ion transmission channels, resulting in a decrease in electrical performance. Utility Model Content
[0007] In view of this, the utility model aims to provide a battery cell casing, so as to improve the safety of the battery cell while ensuring the energy density of the battery cell.
[0008] In order to achieve the above object, the technical solution of the utility model is implemented as follows:
[0009] A battery cell shell, comprising a shell body, the shell body comprising an inner shell with an open top, and an outer shell sleeved outside the inner shell, and a sealed cavity is formed between the outer shell and the inner shell at least along the outer periphery of the inner shell;
[0010] The sealed cavity is filled with a heat-insulating layer, and the heat-insulating layer is used to reduce the transfer of heat from the shell body to the outside; or, the sealed cavity is filled with a strengthening layer, and the strengthening layer is used to enhance the strength of the shell body.
[0011] Furthermore, the heat insulation layer is made of a heat insulation material, or the heat insulation layer is formed by air filled in the sealed cavity.
[0012] Furthermore, the reinforcement layer is made of non-Newtonian fluid or carbon fiber composite material.
[0013] Furthermore, the cross-section of the shell body is any one of rectangular, circular and polygonal; and / or the shell body is made of aluminum or steel.
[0014] Furthermore, the cross-section of the shell body is rectangular;
[0015] The length H of the housing body satisfies: 50 mm ≤ H ≤ 1200 mm;
[0016] The width W of the housing body satisfies: 50 mm ≤ W ≤ 200 mm;
[0017] The thickness T of the shell body satisfies: 50mm≤T≤200mm.
[0018] Furthermore, at least one of the thickness d1 of the inner shell, the thickness d2 of the sealed cavity, and the thickness d3 of the outer shell is in the range of 0.1 mm to 1.5 mm.
[0019] Compared with the prior art, the utility model has the following advantages:
[0020] The battery cell shell described in the utility model can improve the thermal insulation performance of the battery cell shell by filling a thermal insulation layer in the sealed cavity formed between the outer shell and the inner shell, thereby reducing the thermal conductivity performance of the battery cell shell, which is beneficial to reducing the impact on the surrounding area when the battery cell is in thermal runaway; by arranging a reinforcement layer in the sealed cavity, it is beneficial to improve the structural strength of the battery cell shell, thereby improving the puncture resistance of the battery cell and the mechanical properties of the battery cell, thereby reducing the risk of thermal runaway of the battery cell due to puncture by external force; by arranging the thermal insulation layer or the reinforcement layer in the sealed cavity, it is also beneficial to increase the corrosion resistance of the battery cell shell and reduce the risk of leakage, thereby reducing the risk of arcing ignition, and thus improving the safety of the battery cell.
[0021] In addition, the heat insulation layer is made of heat insulation material, or is formed by air filled in a sealed cavity, which is convenient for arrangement and implementation, and has good heat insulation effect, and is also conducive to the lightweight of the battery cell shell. The reinforcement layer is made of non-Newtonian fluid or carbon fiber composite material, which is not only conducive to improving the structural strength of the battery cell shell, but also conducive to the lightweight of the battery cell shell. The setting of the cross-sectional shape of the shell body is conducive to application on batteries of different specifications, and has good flexibility of use; the shell body is made of aluminum or steel, which is easy to implement and has good use effect. Setting the cross-section of the shell body to a rectangle, as well as the setting of the relationship and range of the length, width and thickness of the shell body, is conducive to meeting the use requirements of batteries of different specifications, and has good versatility.
[0022] In addition, another object of the present invention is to provide a battery cell, comprising the battery cell shell as described above, a pole group arranged in the battery cell shell, and a cover plate for sealing the opening.
[0023] The battery cell of the utility model is provided with the battery cell shell as described above, which is beneficial to improving the safety of the battery cell.
[0024] In addition, the utility model also provides a battery pack, on which the battery pack is provided with the battery cell as described above.
[0025] The battery pack described in the present invention has the same beneficial effects as the above-mentioned battery cell, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:
[0027] Figure 1 This is a schematic diagram of the structure of the battery cell housing according to an embodiment of the utility model;
[0028] Figure 2This is a structural schematic diagram of a cross section of a battery cell housing according to an embodiment of the utility model;
[0029] Figure 3 for Figure 2 Enlarged view of part A in .
[0030] Description of reference numerals:
[0031] 1. Shell body; 100. Sealed cavity; 101. Outer shell; 102. Inner shell. DETAILED DESCRIPTION
[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.
[0033] In the description of the present invention, it should be noted that if there are terms indicating orientation or positional relationship such as "upper", "lower", "inner", "back", etc., they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if there are terms such as "first", "second", etc., they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0034] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.
[0035] Embodiment 1
[0036] The present embodiment relates to a battery cell casing, which aims to improve the safety of the battery cell while ensuring the energy density of the battery cell by optimizing its own structure.
[0037] In terms of overall structure, the battery cell shell includes a shell body 1, which includes an inner shell 102 with an open top, and an outer shell 101 sleeved outside the inner shell 102, and a sealed cavity 100 is formed between the outer shell 101 and the inner shell 102 at least along the outer periphery of the inner shell 102, and the sealed cavity 100 is filled with a heat insulation layer, which is used to reduce the transfer of heat from the shell body 1 to the outside; or, the sealed cavity is filled with a reinforcement layer, which is used to enhance the strength of the shell body 1.
[0038] The cell shell described in this embodiment can improve the thermal insulation performance of the cell shell by filling a heat insulation layer in the sealed cavity 100 formed between the outer shell 101 and the inner shell 102, thereby reducing the thermal conductivity of the cell shell, which is conducive to reducing the impact on the surrounding area when the cell is in thermal runaway. By providing a strengthening layer in the sealed cavity 100, it is conducive to improving the structural strength of the cell shell, thereby improving the puncture resistance of the cell and the mechanical properties of the cell, thereby reducing the risk of thermal runaway caused by external force puncture of the cell.
[0039] At the same time, by providing a heat insulating layer or a strengthening layer in the sealed cavity 100, it is also beneficial to increase the corrosion resistance of the shell body 1 and reduce the risk of liquid leakage, thereby reducing the risk of arc ignition. When the battery cell shell is applied to the battery cell, it does not simultaneously have the three elements of corrosion (electronic conduction, ion conduction, and corrosion potential), which is beneficial to enhance the corrosion and liquid leakage resistance of the battery cell shell, thereby improving the safety performance of the battery cell.
[0040] Based on the above overall introduction, an exemplary structure of the battery cell housing in this embodiment is as follows: Figure 1 to Figure 2 As shown in . The tops of the inner shell 102 and the outer shell 101 are both open, and the top edges of the two are connected to block the sealed cavity 100 formed between the two. The opening on the inner shell 102 is conducive to the installation of the pole group in the inner shell 102, and the opening on the outer shell 101 is conducive to the installation of the inner shell 102 in the outer shell 101 and the formation of the sealed cavity 100, and the structures of the inner shell 102 and the outer shell 101 are simple.
[0041] As a preferred embodiment, still refer to Figure 1 and Figure 2 As shown in the figure, the cross section of the housing body 1 is rectangular, that is, the cross sections of the inner housing 102 and the outer housing 101 are both rectangular. The outer housing 101 is sleeved outside the inner housing 102, and is spaced from the outer periphery and the bottom of the inner housing 102, so that the sealed cavity 100 is not only located between the outer peripheries of the inner housing 102 and the outer housing 101, but also located at the bottoms of the inner housing 102 and the outer housing 101. Of course, it is also feasible to form the sealed cavity 100 only on the outer periphery of the inner housing 102.
[0042] Specifically, the cross-section of the shell body 1 is rectangular. Figure 1 As shown in , the length H of the shell body 1 satisfies: 50mm≤H≤1200mm, the width W of the shell body 1 satisfies: 50mm≤W≤200mm; and the thickness T of the shell body 1 satisfies: 50mm≤T≤200mm.
[0043] For example, the length H of the housing body 1 may be 50 mm, 100 mm, 300 mm, 500 mm, 600 mm, 800 mm, 1000 mm or 1200 mm, etc. The width W of the housing body 1 may be 50 mm, 60 mm, 80 mm, 100 mm, 120 mm, 140 mm, 160 mm, 180 mm or 200 mm, etc. The thickness T of the housing body 1 may be 50 mm, 60 mm, 80 mm, 100 mm, 120 mm, 140 mm, 160 mm, 180 mm or 200 mm, etc.
[0044] The battery cell shell in this embodiment can be applied to square batteries of different specifications by setting the above-mentioned length, width and thickness ranges, and has a good application range and small application limitations. In specific implementation, the length, width and thickness ranges of the shell body 1 can be adjusted according to the use requirements.
[0045] In addition, it should be noted that in this embodiment, the cross section of the housing body 1 is not only Figure 1 In addition to the rectangular shape shown in the figure, it can also be any of a circle and a polygon. In this case, the battery cell shell is applied to a cylindrical battery cell and a prismatic battery cell, which is conducive to meeting the use requirements of square batteries under different specifications and has good versatility.
[0046] As a preferred embodiment of the heat insulation layer, the heat insulation layer in this embodiment is made of a heat insulation material, or the heat insulation layer is formed by air filled in the sealed cavity 100. Such a setting is conducive to the arrangement and implementation of the heat insulation layer, and has a good heat insulation effect. Specifically, the heat insulation material can be aerogel, glass fiber, asbestos, rock wool, silicate, etc. Among them, aerogel is preferred, which is conducive to the lightweight of the battery cell shell.
[0047] As a preferred embodiment of the strengthening layer, the strengthening layer is made of non-Newtonian fluid or carbon fiber composite material. This is not only conducive to improving the structural strength of the battery cell shell, but also conducive to layout and implementation. Specifically, the strengthening layer can be made of polyethylene, polyacrylamide, polyvinyl chloride, nylon V6, rubber solution, chemical fiber melt, starch solution, etc.
[0048] The carbon fiber composite material can be a carbon fiber composite ceramic or a carbon fiber composite resin. At this time, the carbon fiber composite material has the characteristic of high structural strength. The reinforcing layer is used to improve the structural strength of the battery shell, so that the shell body 1 has better breakdown resistance.
[0049] As a preferred implementation, in this embodiment, in order to improve the application range of the battery cell housing, as Figure 3As shown in , at least one of the thickness d1 of the inner shell 102 , the thickness d2 of the sealed cavity 100 , and the thickness d3 of the outer shell 101 is in the range of 0.1 mm to 1.5 mm.
[0050] Here, the thickness d1 of the inner shell 102, the thickness d2 of the sealed cavity 100, and the thickness d3 of the outer shell 101 are all in the range of 0.1mm to 1.5mm. For example, the ranges of d1, d2, and d3 can all be 0.1mm, 0.5mm, 0.8mm, 1mm, 1.2mm, or 1.5mm, etc. The setting of the ranges of d1, d2, and d3 here is conducive to reducing the overall weight while meeting the molding and use requirements of the shell body 1, so as to further facilitate the lightweight setting of the battery cell shell. Of course, in the specific implementation, the values of d1, d2, and d3 can also be determined according to the use requirements of the battery cell shell.
[0051] The shell body 1 in this embodiment is made of aluminum or steel. The density of the heat insulation layer and the strengthening layer does not exceed the density of the shell body 1, which is conducive to reducing the weight of the battery cell shell.
[0052] The battery cell shell in this embodiment is beneficial to improving the safety of the battery cell by providing a heat insulation layer or a reinforcement layer, and has good promotion significance.
[0053] Embodiment 2
[0054] This embodiment relates to a battery cell, comprising the battery cell shell as described above, a pole group arranged in the battery cell shell, and a cover plate for sealing the opening, wherein the pole column is arranged on the cover plate, and the pole ear is located at the end of the pole group.
[0055] The battery cell of this embodiment is provided with the battery cell housing as described above, which helps to improve the safety of the battery cell.
[0056] In addition, the present embodiment also relates to a battery pack, on which the battery cell as described above is provided.
[0057] The battery pack of this embodiment has the same beneficial effects as the above-mentioned battery cell, which will not be described in detail here.
[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A battery cell casing, characterized in that: The housing body comprises an inner housing with an open top and an outer housing sleeved outside the inner housing, and a sealed cavity is formed between the outer housing and the inner housing at least along the outer periphery of the inner housing; The sealed cavity is filled with a heat-insulating layer, and the heat-insulating layer is used to reduce the transfer of heat from the shell body to the outside; or, the sealed cavity is filled with a strengthening layer, and the strengthening layer is used to enhance the strength of the shell body.
2. The battery cell casing according to claim 1, characterized in that: The heat insulation layer is made of a heat insulation material, or the heat insulation layer is formed by air filled in the sealed cavity.
3. The battery cell casing according to claim 1, characterized in that: The strengthening layer is made of non-Newtonian fluid or carbon fiber composite material.
4. The battery cell casing according to claim 1, characterized in that: The cross section of the housing body is circular or polygonal; and / or, The shell body is made of aluminum or steel.
5. The battery cell casing according to claim 4, characterized in that: The cross section of the shell body is rectangular; The length H of the housing body satisfies: 50 mm ≤ H ≤ 1200 mm; The width W of the housing body satisfies: 50 mm ≤ W ≤ 200 mm; The thickness T of the shell body satisfies: 50mm≤T≤200mm.
6. The battery cell casing according to claim 1, characterized in that: At least one of the thickness d1 of the inner shell, the thickness d2 of the sealed cavity, and the thickness d3 of the outer shell is in the range of 0.1 mm to 1.5 mm.
7. A battery cell, characterized in that: The invention comprises a battery cell shell according to any one of claims 1 to 6, a pole group arranged in the battery cell shell, and a cover plate for sealing the opening.
8. A battery pack, characterized in that: The battery pack is provided with the battery cell described in claim 7.