Battery case, battery cell, and battery pack

Abstract

This application relates to the field of battery technology and provides a battery casing, a battery cell, and a battery pack. The battery casing of this application includes an outer casing and an inner casing disposed within the outer casing. The inner casing includes an inner frame corresponding to the sidewall of the outer casing and an insulating pad corresponding to the bottom wall of the outer casing. The inner frame and the insulating pad are connected together and form a receiving groove for accommodating the electrode assembly. The inner frame is made of a heat-resistant insulating material, and the insulating pad has several through-holes arranged in a continuous manner. This battery casing not only improves battery safety but also enables liquid absorption and retention through the through-holes, facilitating rapid infiltration of the electrolyte from the bottom of the electrode assembly into the interior of the electrode assembly, thereby improving battery manufacturing efficiency.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery casing, a battery cell, and a battery pack. Background Technology

[0002] In the current market, lithium-ion batteries generally use aluminum casings to house the electrode assembly. However, for high-energy ternary lithium batteries, when thermal runaway occurs, the aluminum casing on the side of the battery will be impacted by the flames from the internal thermal runaway reaction, which will melt through and cause flames to erupt from various surfaces of the battery, increasing the risk of thermal runaway propagation throughout the pack and hindering the improvement of battery and battery pack safety. Utility Model Content

[0003] In view of this, this application aims to provide a battery casing that can improve battery safety and also improve battery manufacturing efficiency.

[0004] To achieve the above objectives, the technical solution of this application is implemented as follows: A battery casing includes an outer casing and an inner casing disposed within the outer casing; The inner housing includes an inner frame corresponding to the side wall of the outer housing and an insulating pad corresponding to the bottom wall of the outer housing. The inner frame and the insulating pad are connected together and form a receiving groove for accommodating the electrode assembly. The inner frame is made of heat-resistant insulating material, and the insulating pad has several through holes arranged in a continuous manner.

[0005] Furthermore, the diameter D of the through hole satisfies: 0.5≤D≤2mm; and / or, the number N of the through holes satisfies: N>100, and N is an integer.

[0006] Furthermore, the thickness t of the insulating pad satisfies: 2≤t≤5mm.

[0007] Furthermore, the inner housing is detachably disposed within the outer housing.

[0008] Furthermore, the assembly gap δ between the inner shell and the outer shell satisfies: 0.2≤δ≤0.5mm.

[0009] Furthermore, the heat-resistant insulating material is mica, alumina ceramic, aluminum nitride ceramic, or hexagonal boron nitride.

[0010] Furthermore, the insulating pad is made of foam, ceramic, fiber, or polymer.

[0011] Furthermore, the outer shell is made of metal and / or the inner shell and the insulating pad are connected by an adhesive layer.

[0012] Compared with related technologies, this application has the following advantages: (1) The battery casing described in this application, by setting an inner casing and the inner frame of the inner casing being made of heat-resistant insulating material, in conjunction with the insulating pad, can block the impact of the thermal runaway flame on the outer casing during thermal runaway, and prevent the flame from rushing out after the outer casing melts through, so as to improve the safety of the battery, and thus improve the safety of the battery pack made of the battery. At the same time, the insulating pad is provided with several through holes, which can not only achieve a certain degree of insulation between the electrode group and the bottom wall of the outer casing, but also achieve liquid absorption and liquid retention through each through hole, which helps the electrolyte to quickly wet from the bottom of the electrode group into the inside of the electrode group, thereby improving the battery manufacturing efficiency.

[0013] (2) The diameter D of the through hole satisfies: 0.5≤D≤2mm. At the same time, the number of through holes N satisfies: N>100 and N is an integer, which can make the insulating pad have better liquid absorption and liquid retention effects.

[0014] (3) The thickness t of the insulating pad satisfies: 2≤t≤5mm, which can ensure that the insulating pad has sufficient insulation protection performance and further enhance the liquid absorption and liquid retention functions.

[0015] (4) The inner shell is detachably located inside the outer shell, which can improve the ease of disassembly and assembly between the inner shell and the outer shell.

[0016] (5) The assembly gap δ between the inner shell and the outer shell satisfies: 0.2≤δ≤0.5mm, which can help improve the ease of disassembly and assembly of the inner shell and the outer shell.

[0017] (6) The heat-resistant insulating material is mica, alumina ceramic, aluminum nitride ceramic or hexagonal boron nitride, which makes the preparation materials and processes of the inner frame mature, which is conducive to cost reduction and preparation.

[0018] (7) The insulating pad is made of foam, ceramic material, fiber material or polymer material, which can not only have good insulation performance, but also achieve good liquid absorption and liquid retention function.

[0019] (8) The outer shell is made of metal, which can meet the overall structural strength and protection requirements of the battery casing. At the same time, the inner shell and the insulating pad are connected by an adhesive layer, which is simple in structure and easy to implement.

[0020] This application also proposes a battery cell, which includes a battery housing as described above, and an electrode assembly disposed in the receiving groove of the battery housing; The distance S1 between the electrode group and the inner wall of the inner frame, and the distance S2 between the electrode group and the insulating pad, satisfy: S1=S2≥5mm.

[0021] This application also proposes a battery pack, wherein the battery pack contains the aforementioned battery cells.

[0022] The battery cells and battery packs described in this application are equipped with the aforementioned battery casing, which has the same beneficial effects as conventional technologies, and will not be elaborated further here. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the battery casing structure described in an embodiment of this application; Figure 2 for Figure 1 A cross-sectional view of the structure shown; Figure 3 for Figure 1 Top view of the structure shown; Figure 4 for Figure 3 Enlarged view of point A in the middle; Explanation of reference numerals in the attached figures: 100. Outer shell; 101. Side wall; 102. Bottom wall; 200. Inner shell; 201. Inner frame; 202. Insulating pad; 2021. Through hole; 203. Receiving groove; δ, the assembly clearance between the inner shell and the outer shell. Detailed Implementation

[0024] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0026] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0028] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions 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 suitable manner in one or more embodiments or examples.

[0029] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0030] An embodiment of the first aspect of this application provides a battery casing that not only improves battery safety but also facilitates the improvement of battery manufacturing efficiency.

[0031] In related technologies, for high-energy ternary lithium batteries, when thermal runaway occurs, the aluminum casing on the side of the battery is subjected to flame impact from the internal thermal runaway reaction, which melts through and causes flames to erupt from various large surfaces of the battery, increasing the risk of thermal runaway propagation throughout the battery pack. Furthermore, because the bottom of the electrode assembly is not encased in a Mylar film (a high-molecular film made of polyethylene terephthalate with high strength, temperature resistance, and insulation), the electrolyte gradually seeps into the electrode assembly from the bottom after internal electrolyte injection, resulting in a slow wetting rate and a long process cycle.

[0032] In view of this, in order to overcome the shortcomings of the related technology, the battery casing of this embodiment incorporates... Figures 1 to 4 As shown, the overall design includes an outer shell 100 and an inner shell 200 disposed within the outer shell 100.

[0033] The inner housing 200 includes an inner frame 201 corresponding to the side wall 101 of the outer housing 100, and an insulating pad 202 corresponding to the bottom wall 102 of the outer housing 100. The inner frame 201 and the insulating pad 202 are connected together and form a receiving groove 203 for accommodating the electrode assembly. Furthermore, the inner frame 201 is made of heat-resistant insulating material, and the insulating pad 202 has a plurality of through holes 2021 arranged through it.

[0034] Therefore, by setting an inner shell 200, and the inner frame 201 of the inner shell 200 being made of heat-resistant insulating material, in conjunction with the insulating pad 202, the impact of the thermal runaway flame on the outer shell 100 can be blocked during thermal runaway, preventing the flame from rushing outward after the outer shell 100 melts through, thereby improving the safety of the battery and, in turn, the safety of the battery pack constructed using this battery. At the same time, the insulating pad 202 is provided with several through holes 2021, which not only achieve a certain degree of insulation between the electrode assembly and the bottom wall 102 of the outer shell 100, but also achieve the functions of liquid absorption and liquid retention through the through holes 2021, which helps the electrolyte to quickly wet from the bottom of the electrode assembly into the interior of the electrode assembly, thereby improving the battery manufacturing efficiency.

[0035] Based on the above general introduction, specifically, the battery casing of this embodiment is particularly suitable for prismatic batteries. That is, for each structure not mentioned in the battery casing of this embodiment, refer to the casing of prismatic batteries well known to those skilled in the art, and will not be described in detail here.

[0036] Continue to combine Figures 1 to 4 As shown, in some exemplary embodiments, the aperture D of the through-hole 2021 satisfies: 0.5 ≤ D ≤ 2 mm, and can specifically take values ​​of 0.5 mm, 1 mm, 1.5 mm, or 2 mm, etc. Simultaneously, in some exemplary embodiments, the number N of the through-holes 2021 satisfies: N > 100, and N is an integer. This configuration, based on the limitation of the aperture D and the number N of the through-holes 2021, allows the insulating pad 202 to have better liquid absorption and retention properties. Specifically, the number N of the through-holes 2021 can specifically take values ​​of 110, 120, 150, or 200, etc.

[0037] Meanwhile, in some exemplary embodiments, the thickness t of the insulating pad 202 satisfies: 2≤t≤5mm, and can specifically be 2mm, 3mm, 4mm or 5mm, etc., thereby ensuring that the insulating pad 202 has sufficient insulation protection performance and further improving the liquid absorption and liquid retention functions.

[0038] Furthermore, in some exemplary embodiments, the insulating pad 202 of this embodiment is made of foam, ceramic, fiber, or polymer. The main advantage of this design is that it not only provides good insulation performance but also achieves good liquid absorption and retention capabilities.

[0039] Furthermore, in some exemplary embodiments, the inner housing is detachably disposed within the outer housing to facilitate easier assembly and disassembly between the inner and outer housings.

[0040] Continue to combine Figures 3 to 4 As shown, in some exemplary embodiments, the assembly gap δ between the inner housing 200 and the outer housing 100 satisfies: 0.2≤δ≤0.5mm, and can specifically take values ​​of 0.2mm, 0.3mm, 0.4mm or 0.5mm, etc., which can help improve the ease of assembly and disassembly of the inner housing 200 in the outer housing 100.

[0041] It should be mentioned that, Figures 1 to 4 The assembly gap δ shown is mainly to clearly show the gap between the inner housing 200 and the outer housing 100, and to indicate that the inner housing 200 is easy to place in the outer housing 100. In practice, because the assembly gap δ is small, the assembly gap δ may not be obvious when the inner housing 200 is placed in the outer housing 100, and the inner housing 100 basically does not shake.

[0042] In addition, in some exemplary embodiments, the heat-resistant insulating material is mica, alumina ceramic, aluminum nitride ceramic, or hexagonal boron nitride. This not only gives the inner frame 201 better heat resistance, insulation, and stability, but also ensures that the materials and processes for preparing the inner frame 201 are mature, facilitating cost reduction and manufacturing.

[0043] Furthermore, in some exemplary embodiments, the outer casing 100 is made of a metallic material, such as aluminum or copper, to meet the overall structural strength and protection requirements of the battery casing.

[0044] Meanwhile, in some exemplary embodiments, the inner shell and the insulating pad are connected by an adhesive layer, resulting in a simple and easy-to-implement structure. Specifically, the adhesive layer can be made of epoxy resin to ensure sufficient bonding strength while also improving the corrosion resistance, aging resistance, and insulation performance at the connection between the inner shell and the insulating pad.

[0045] It is worth noting that, regarding the battery casing of this embodiment, based on the above exemplary embodiments, in specific implementation, as a preferred embodiment, it is still made of... Figures 1 to 4 As shown, the battery housing includes an outer shell 100 and an inner shell 200 disposed within the outer shell 100.

[0046] The inner housing 200 includes an inner frame 201 corresponding to the side wall 101 of the outer housing 100, and an insulating pad 202 corresponding to the bottom wall 102 of the outer housing 100. The inner frame 201 and the insulating pad 202 are connected together and form a receiving groove 203 for accommodating the electrode assembly. Furthermore, the inner frame 201 is made of heat-resistant insulating material, and the insulating pad 202 has a plurality of through holes 2021 arranged through it.

[0047] Among them, the diameter D of the through hole 2021 satisfies: 0.5≤D≤2mm, and the number N of the through holes 2021 satisfies: N>100, and N is an integer.

[0048] The thickness t of the insulating pad 202 satisfies: 2≤t≤5mm.

[0049] The assembly gap δ between the inner shell 200 and the outer shell 100 satisfies: 0.2≤δ≤0.5mm.

[0050] Among them, the heat-resistant insulating materials are mica, alumina ceramics, aluminum nitride ceramics, or hexagonal boron nitride.

[0051] The insulating pad 202 is made of foam, ceramic material, fiber material or polymer material.

[0052] The outer shell 100 is made of metal.

[0053] In the preferred embodiment of the battery casing described above, the specific configuration and arrangement of the outer casing 100, inner frame 201, insulating pad 202, through hole 2021, etc., can still be referred to the descriptions in the above exemplary embodiments. Furthermore, in this preferred embodiment, the beneficial effects brought about by the design of the outer casing 100, inner frame 201, insulating pad 202, through hole 2021, etc., can also be referred to the descriptions in the above exemplary embodiments.

[0054] In this embodiment, the battery casing adopts the above design. By using an inner frame 201 made of heat-resistant insulating material in conjunction with an insulating pad 202, it can block the impact of thermal runaway flames on the outer casing 100 during thermal runaway, preventing the flames from rushing outward after the outer casing 100 melts through, thereby improving the safety of the battery and the battery pack constructed using this battery. At the same time, the insulating pad 202 is provided with several through holes 2021. In addition to achieving a certain degree of insulation between the electrode assembly and the bottom wall 102 of the outer casing 100, the through holes 2021 can also achieve liquid absorption and retention, which helps the electrolyte to quickly penetrate from the bottom of the electrode assembly into the interior of the electrode assembly, improving the battery manufacturing efficiency.

[0055] Moreover, the insulating pad 202, which has several through holes 2021 and is made of foam, can not only absorb and retain liquid, but also help the electrolyte to quickly penetrate from the bottom of the electrode assembly into the interior of the electrode assembly, thus improving the battery manufacturing efficiency. At the same time, it can also release the electrolyte in the pores of the insulating pad 202 after the electrolyte inside the battery is consumed, effectively alleviating the problem of electrolyte loss during battery cycling, thereby effectively improving the cycle life of the battery.

[0056] An embodiment of the second aspect of this application provides a battery cell, which includes the battery casing described above.

[0057] In some exemplary embodiments, the battery cell of this embodiment further includes an electrode assembly disposed in a receiving groove 203 of the battery casing. The distance S1 between the electrode assembly and the inner wall of the inner frame 201, and the distance S2 between the electrode assembly and the insulating pad 202 satisfy: S1=S2≥5mm, and can specifically be 5mm, 6mm, 7mm or 8mm, etc., to ensure that the receiving groove 203 can completely accommodate the electrode assembly. Any structures not mentioned in this battery cell can be referred to as relevant structural parts in battery products well known to those skilled in the art, such as prismatic batteries. That is, the battery cell may have the aforementioned battery casing, an electrode assembly disposed in the battery casing, and a cover plate disposed on the battery casing for sealing the electrode assembly in the receiving cavity, etc., which will not be elaborated further here.

[0058] An embodiment of the third aspect of this application provides a battery pack, which includes the aforementioned battery cells.

[0059] The battery pack of this embodiment, by setting the above-mentioned battery cells, can reduce the risk of melt-through during battery thermal runaway and improve the safety of the battery pack. On the other hand, it can increase the speed at which the internal electrode assembly is wetted with electrolyte, improve the battery manufacturing efficiency, and utilize the insulating pad 202 to release the electrolyte in the pores of the insulating pad 202 after electrolyte consumption occurs inside the battery, effectively alleviating the problem of electrolyte loss during battery cycling, thereby effectively improving the cycle life of the battery, which can help improve the quality of the battery pack.

[0060] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A battery casing, characterized in that: It includes an outer shell and an inner shell disposed within the outer shell; The inner housing includes an inner frame corresponding to the side wall of the outer housing and an insulating pad corresponding to the bottom wall of the outer housing. The inner frame and the insulating pad are connected together and form a receiving groove for accommodating the electrode assembly. The inner frame is made of heat-resistant insulating material, and the insulating pad has several through holes arranged in a continuous manner.

2. The battery casing according to claim 1, characterized in that: The diameter D of the through hole satisfies: 0.5 ≤ D ≤ 2 mm; and / or, The number N of the through holes satisfies: N > 100, and N is an integer.

3. The battery casing according to claim 1, characterized in that: The thickness t of the insulating pad satisfies: 2≤t≤5mm.

4. The battery casing according to claim 1, characterized in that: The inner housing is detachably disposed within the outer housing.

5. The battery casing according to claim 4, characterized in that: The assembly gap δ between the inner shell and the outer shell satisfies: 0.2≤δ≤0.5mm.

6. The battery casing according to claim 1, characterized in that: The heat-resistant insulating material is mica, alumina ceramic, aluminum nitride ceramic, or hexagonal boron nitride.

7. The battery casing according to claim 1, characterized in that: The insulating pad is made of foam, ceramic, fiber, or polymer.

8. The battery casing according to any one of claims 1 to 6, characterized in that: The outer casing is made of a metallic material; and / or, The inner shell and the insulating pad are connected by an adhesive layer.

9. A single battery cell, characterized in that: The battery cell includes a battery housing as described in any one of claims 1 to 8, and an electrode assembly disposed in the receiving groove of the battery housing; The distance S1 between the electrode group and the inner wall of the inner frame, and the distance S2 between the electrode group and the insulating pad, satisfy: S1=S2≥5mm.

10. A battery pack, characterized in that: The battery pack includes the battery cells as described in claim 8 or 9.

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