Battery device

Abstract

The utility model relates to the technical field of batteries, and discloses a battery device. The battery device comprises a cylindrical battery and a heat exchange plate, the number of the cylindrical batteries is at least two, each cylindrical battery comprises a battery shell, each battery shell comprises a metal shell and an insulating shell which are arranged in a stacked mode, and the metal shells and the insulating shells are of an integrally-formed structure; the heat exchange plate is bonded between two adjacent cylindrical batteries, the connection strength between the metal shell and the insulating shell is M1, the connection strength between the heat exchange plate and the battery shell is M2, and the ratio of M1 to M2 is greater than or equal to 1 and less than or equal to 5. According to the battery device, the heat exchange effect of the heat exchange plate on the cylindrical battery is ensured; moreover, after the heat exchange plate and the cylindrical battery are fixed, the heat exchange plate is relatively easy to disassemble, and the heat exchange plate can move slightly under the condition that the heat exchange plate is slightly deviated, so that the assembly yield is relatively high; the strength of the battery shell can support and protect the battery cell, so that the safety of the cylindrical battery and the battery device is ensured.

Description

Technical Field

[0001] The present disclosure relates to the field of battery technology, and in particular to a battery device. Background Art

[0002] The battery box of the existing battery device is provided with cylindrical batteries and heat exchange plates arranged between adjacent cylindrical batteries. The bonding area between the cylindrical batteries and the heat exchange plates is large, resulting in a high bonding strength. Moreover, the battery casing of the cylindrical batteries includes a stacked metal shell and an insulating shell, resulting in a low strength of the battery casing. At present, the connection strength between the heat exchange plate and the battery casing is not properly set, which can easily affect the heat exchange effect, or make the cylindrical batteries difficult to disassemble and have a low yield.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0004] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned related technologies and provide a battery device.

[0005] According to one aspect of the present disclosure, there is provided a battery device, comprising:

[0006] A cylindrical battery, provided in at least two, the cylindrical battery comprises a battery housing, the battery housing comprises a metal shell and an insulating shell which are stacked, the metal shell and the insulating shell being an integrally formed structure;

[0007] The heat exchange plate is bonded between two adjacent cylindrical batteries. The connection strength between the metal shell and the insulating shell is M1, the connection strength between the heat exchange plate and the battery shell is M2, and the ratio of M1 to M2 is greater than or equal to 1 and less than or equal to 5.

[0008] In the battery device disclosed in the present invention, the ratio of the connection strength M1 between the metal shell and the insulating shell to the connection strength M2 between the heat exchange plate and the battery shell is greater than or equal to 1 and less than or equal to 5, which not only ensures that the heat exchange plate and the battery shell are not easily peeled off, thereby ensuring the heat exchange effect of the heat exchange plate on the cylindrical battery; but also, after the heat exchange plate and the cylindrical battery are fixed, it is relatively easy to disassemble. In the case of a slight deviation of the heat exchange plate, the heat exchange plate can be moved slightly, thereby making the assembly yield higher; the metal shell and the insulating shell are also not easily peeled off, so as to ensure that the strength of the battery shell can support and protect the battery cell, thereby ensuring the safety of the cylindrical battery and the battery device.

[0009] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0011] Figure 1 FIG. 1 is a schematic structural diagram of an exemplary embodiment of a battery device disclosed herein.

[0012] Figure 2 for Figure 1 A schematic structural diagram of an exemplary embodiment of the cooperation between a cylindrical battery and a heat exchange plate.

[0013] Figure 3 for Figure 1 A schematic structural diagram of another exemplary embodiment of the cooperation between a mid-cylindrical battery and a heat exchange plate.

[0014] Description of reference numerals:

[0015] 1. Battery box; 11. Side frame; 12. Bottom plate;

[0016] 2. Cylindrical battery; 21. Battery shell; 211. Metal shell; 212. Insulation shell; 22. Side plate; 23. Bottom wall plate; 24. Cover plate; 25. Battery cell; 251. Main body; 252. First pole ear; 253. Second pole ear; 26. Battery pole;

[0017] 3. Heat exchange plate; 31. Heat exchange channel;

[0018] 4. Adhesive layer;

[0019] Z, height direction. DETAILED DESCRIPTION

[0020] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0021] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0022] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0023] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. "And / or" is just a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0024] The present disclosure provides a battery device according to an exemplary embodiment. Figure 1-Figure 3 As shown, the battery device may include a cylindrical battery 2 and a heat exchange plate 3; the cylindrical battery 2 is arranged in at least two, the cylindrical battery 2 may include a battery shell 21, the battery shell 21 may include a stacked metal shell 211 and an insulating shell 212, the metal shell 211 and the insulating shell 212 are an integrally formed structure; the heat exchange plate 3 is bonded between two adjacent cylindrical batteries 2, the connection strength between the metal shell 211 and the insulating shell 212 is M1, the connection strength between the heat exchange plate 3 and the battery shell 21 is M2, and the ratio of M1 to M2 is greater than or equal to 1 and less than or equal to 5.

[0025] The battery device disclosed in the present invention not only ensures that the heat exchange plate 3 and the battery casing 21 are not easily peeled off, thereby ensuring the heat exchange effect of the heat exchange plate 3 on the cylindrical battery 2; moreover, after the heat exchange plate 3 and the cylindrical battery 2 are fixed, it is relatively easy to disassemble. In the case of a slight deviation of the heat exchange plate 3, the heat exchange plate 3 can be moved slightly, thereby making the assembly yield higher; the metal shell 211 and the insulating shell 212 are also not easily peeled off, so as to ensure that the strength of the battery casing 21 can support and protect the battery cell 25, thereby ensuring the safety of the cylindrical battery 2 and the battery device.

[0026] In this example implementation, refer to Figure 1 As shown, the battery device may include a battery box 1, and the battery box 1 may include a bottom plate 12, a side frame 11, and a protective cover (not shown in the figure); the bottom plate 12 and the protective cover may be set as rectangular plates, and the side frame 11 is connected between the bottom plate 12 and the protective cover, and the side frame 11 is set as a rectangular frame. The bottom plate 12, the protective cover, and the side frame 11 surround and form a storage space for the battery box 1. At least two cylindrical batteries 2 are arranged in the battery box 1.

[0027] In this example implementation, refer to Figure 1-Figure 3 As shown, the battery cell can be a cylindrical battery 2, and therefore, the battery housing 21 can be set as a cylinder, that is, the battery housing 21 can include a bottom wall plate 23 and a side plate 22, the bottom wall plate 23 is set as a circle, and the side plate 22 is set as a cylinder. The bottom wall plate 23 is connected to one end of the side plate 22, so that the other end of the battery housing 21 forms an opening, that is, the battery housing 21 has an opening. The bottom wall plate 23 and the side plate 22 surround and form a accommodating cavity for the battery cell. A cover plate 24 is connected to the other side of the side plate 22, that is, the cover plate 24 covers the opening, and the opening of the battery housing 21 is sealed by the cover plate 24.

[0028] Reference Figure 2 and Figure 3 As shown, the battery housing 21 may include a metal shell 211 and an insulating shell 212 that are stacked, so that the bottom wall plate 23 and the side plate 22 of the battery housing 21 are both laminated structures including two layers of a metal layer and an insulating layer.

[0029] The metal shell 211 and the insulating shell 212 are an integrally formed structure, that is, the metal shell 211 and the insulating shell 212 are formed by an integrally formed process. For example, a layer of insulating film can be formed on a metal plate by bonding, coating, hot melting and other processes, and then the insulating film and the metal plate are simultaneously subjected to a stamping process or a stretching process, so that the insulating film and the metal plate form a battery housing 21 with a accommodating cavity, that is, the metal plate forms the metal shell 211, and the insulating film forms the insulating shell 212. The integrally formed structure is not to first perform a stamping process or a stretching process on the metal plate to form a metal shell 211 with a accommodating cavity, and then form the insulating shell 212 on the metal shell 211 by bonding, coating, hot melting and other processes. The integrally formed structure makes the connection between the metal shell 211 and the insulating shell 212 tighter, and there is almost no gap between the metal shell 211 and the insulating shell 212. Moreover, the preparation process is relatively simple, which is conducive to improving efficiency.

[0030] The material of the metal shell 211 can be stainless steel (SUS304), cold-rolled carbon steel (SPCC / SPCE), copper, titanium, nickel, chromium, aluminum or aluminum alloy, etc. Of course, it can also be other materials, which are not described here one by one.

[0031] The material of the insulating shell 212 can be a polymer or a resin. For example, the material of the insulating shell 212 can be polyethylene (PE), polytetrafluoroethylene (PTFE), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), LCP plastic material (LIQUID CRYSTAL POLYMER, also known as liquid crystal polymer), soluble polytetrafluoroethylene (PFA), acrylonitrile-butadiene-styrene copolymer (ABS), polyphenylene sulfide (PPS), etc.

[0032] The material of the insulating shell 212 may also be an inorganic non-metallic material, for example, the material of the insulating shell 212 may also be Al2O3, SiC, SiO2, etc.

[0033] In order to ensure the space utilization and energy density of the cylindrical battery 2, the wall thickness of the battery shell 21 including the metal shell 211 and the insulating shell 212 is basically the same as the wall thickness of the battery shell 21 including only the metal layer, that is, the sum of the wall thickness of the metal shell 211 and the wall thickness of the insulating shell 212 is generally a fixed value; and the strength of the insulating shell 212 is much lower than that of the metal shell 211, therefore, the strength of the battery shell 21 including the metal shell 211 and the insulating shell 212 is lower.

[0034] In this example implementation, refer to Figure 1-Figure 3As shown, a plurality of cylindrical batteries 2 are arranged in the battery box 1, and the plurality of cylindrical batteries 2 are arranged in sequence along a first direction to form a plurality of battery columns, and the cylindrical batteries 2 between two adjacent battery columns are staggered so that a portion of the cylindrical batteries 2 in one column is embedded in the gap formed between two adjacent cylindrical batteries 2 in another column, so as to improve the utilization rate of the space in the battery box 1, thereby improving the energy density of the battery device.

[0035] A heat exchange plate 3 is bonded between two adjacent cylindrical batteries 2. For example, two adjacent columns of batteries may be grouped together, and a heat exchange plate 3 is provided between two adjacent columns of batteries in the same group, while no heat exchange plate 3 is provided between two adjacent groups. The heat exchange plate 3 is provided as a corrugated plate adapted to the side plate 22 of the cylindrical battery 2 to increase the fitting area between the heat exchange plate 3 and the side plate 22 of the cylindrical battery 2, thereby increasing the heat exchange efficiency of the heat exchange plate 3 to the cylindrical battery 2.

[0036] A heat exchange channel 31 is provided in the heat exchange plate 3. When the cylindrical battery 2 needs to be heated, a heat exchange medium with a higher temperature can be introduced into the heat exchange channel 31, and the heat of the heat exchange medium is transferred to the cylindrical battery 2 to achieve heating of the cylindrical battery 2; when the cylindrical battery 2 needs to be cooled, a heat exchange medium with a lower temperature can be introduced into the heat exchange channel 31, and the heat of the cylindrical battery 2 is transferred to the heat exchange medium to achieve cooling of the cylindrical battery 2.

[0037] The connection strength between the metal shell 211 and the insulating shell 212 is M1, and the connection strength between the heat exchange plate 3 and the battery shell 21 is M2. Since the heat exchange plate 3 and the battery shell 21 are adhesively connected, the connection strength between the heat exchange plate 3 and the battery shell 21 can also be said to be the bonding strength between the heat exchange plate 3 and the battery shell 21. The ratio of M1 to M2 is greater than or equal to 1 and less than or equal to 5, that is, the ratio of the connection strength M1 between the metal shell 211 and the insulating shell 212 to the connection strength M2 between the heat exchange plate 3 and the battery shell 21 is greater than or equal to 1 and less than or equal to 5. For example, the ratio of M1 to M2 can be 1.3, 1.5, 1.8, 2, 2.2, 2.5, 2.7, 3, 3.3, 3.5, 3.8, 4, 4.2, 4.5, 4.7, and so on.

[0038] If the ratio of M1 to M2 is too large, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 is too small, and the heat exchange plate 3 and the battery housing 21 are easily peeled off. After the heat exchange plate 3 and the battery housing 21 are peeled off, the heat exchange plate 3 and the battery housing 21 cannot be in close contact with each other, which affects the heat exchange effect of the heat exchange plate 3 on the cylindrical battery 2.

[0039] If the ratio of M1 to M2 is too small, the connection strength M2 between the heat exchange plate 3 and the battery casing 21 is too large, which makes it difficult to disassemble the heat exchange plate 3 after it is fixed to the cylindrical battery 2. Moreover, during the installation process, after the heat exchange plate 3 is bonded to the cylindrical battery 2, due to the excessive bonding strength between the heat exchange plate 3 and the cylindrical battery 2 casing, if the heat exchange plate 3 has a slight deviation, it is difficult to move the heat exchange plate 3, resulting in poor yield; or, the connection strength M1 between the metal shell 211 and the insulating shell 212 is too small, and the metal shell 211 and the insulating shell 212 are easily peeled off, resulting in a significant reduction in the strength of the battery casing 21, and the battery cell 25 cannot be supported and protected, so that the overall safety performance of the cylindrical battery 2 is poor, causing the risk of safety failure of the cylindrical battery 2.

[0040] The above numerical range not only ensures that the heat exchange plate 3 and the battery casing 21 are not easily peeled off, thereby ensuring the heat exchange effect of the heat exchange plate 3 on the cylindrical battery 2; but also, after the heat exchange plate 3 and the cylindrical battery 2 are fixed, it is relatively easy to disassemble. In the case of a slight deviation of the heat exchange plate 3, the heat exchange plate 3 can move slightly, thereby making the assembly yield higher; the metal shell 211 and the insulating shell 212 are also not easily peeled off, so as to ensure that the strength of the battery casing 21 can support and protect the battery cell 25, thereby ensuring the safety of the cylindrical battery 2 and the battery device.

[0041] It should be noted that the connection strength M1 between the metal shell 211 and the insulating shell 212 can be measured according to the measurement method provided in the national standard GB / T39289-2020 (Measurement of Adhesive Bond Strength Metal and Plastic). In the case where the insulating shell 212 is provided on the outer surface of the metal shell 211, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can also be measured according to the measurement method provided in the national standard GB / T 39289-2020. Specifically, the floating roller method for measuring the peel strength of high-strength adhesives can be used for measurement, and this measurement method has a dedicated measurement equipment.

[0042] When the metal shell 211 is arranged on the outer surface of the insulating shell 212, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be measured according to the measurement method provided in GB-T 7124-1986 (Method for determination of tensile shear strength of adhesives - metal to metal). The specific testing machine and test conditions are not repeated here. The tensile shear strength of the adhesive of the metal overlap is calculated according to the following formula: τ is calculated according to the following formula, where τ is the tensile shear strength of the adhesive, unit: MPa; P is the maximum load of the sample shear failure, unit: N; B is the width of the sample overlap surface, unit: mm; L is the length of the sample overlap surface, unit: mm.

[0043] In some example embodiments of the present disclosure, reference is made to Figure 2As shown, the metal shell 211 is disposed on the outer surface of the insulating shell 212, that is, the insulating shell 212 is disposed closer to the battery cell 25 than the metal shell 211. The insulating shell 212 can insulate and isolate the metal shell 211 and the battery cell 25, thereby ensuring the insulation effect between the metal shell 211 and the battery cell 25.

[0044] When the metal shell 211 is the outer surface layer of the battery housing 21 , the bonding effect between the metal shell 211 and the heat exchange plate 3 is good.

[0045] The connection strength M2 between the heat exchange plate 3 and the battery housing 21 is less than or equal to 10 MPa. For example, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, 5 MPa, 5.5 MPa, 6 MPa, 6.5 MPa, 7 MPa, 7.5 MPa, 8 MPa, 8.5 MPa, 9 MPa, 9.5 MPa, etc.

[0046] Setting the connection strength M2 between the heat exchange plate 3 and the battery housing 21 to be relatively small can avoid peeling between the metal shell 211 and the insulating shell 212, so as to ensure that the strength of the battery housing 21 is sufficient to support and protect the battery cell 25, thereby ensuring the safety of the cylindrical battery 2 and the battery device.

[0047] For example, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be reduced by reducing the amount of adhesive used, that is, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be reduced by reducing the thickness of the adhesive layer 4.

[0048] Moreover, in this case, the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 is greater than or equal to 0.2 and less than or equal to 5. For example, the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 can be 0.5, 0.7, 1, 1.3, 1.5, 1.8, 2, 2.2, 2.5, 2.7, 3, 3.3, 3.5, 3.8, 4, 4.2, 4.5, 4.7, etc.

[0049] If the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 is too large, the wall thickness H2 of the insulating shell 212 will be too small, resulting in low strength of the insulating shell 212, and the insulating shell 212 will be easily damaged, thereby affecting the insulating effect of the insulating shell 212 and causing poor insulation of the battery.

[0050] If the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 is too small, the wall thickness H1 of the metal shell 211 is too small, resulting in the metal shell 211 being too weak in strength and unable to meet the strength requirements of the battery, and unable to support and protect the battery cells 25 therein.

[0051] The above numerical range not only ensures that the insulating shell 212 is not easily damaged to ensure the insulation effect of the battery, but also ensures that the strength of the metal shell 211 can meet the requirements and can support and protect the battery cell 25 therein.

[0052] In some other exemplary embodiments of the present disclosure, referring to Figure 3 As shown, the insulating shell 212 is disposed on the outer surface of the metal shell 211, that is, the insulating shell 212 is disposed farther away from the battery core 25 than the metal shell 211. The insulating shell 212 can increase the insulation effect between the battery housing 21 and other external components.

[0053] When the insulating shell 212 is the outer surface layer of the battery housing 21 , the bonding effect between the insulating shell 212 and the heat exchange plate 3 is poor.

[0054] The connection strength M2 between the heat exchange plate 3 and the battery housing 21 is greater than or equal to 0.2 MPa. For example, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be 0.5 MPa, 0.7 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, 5 MPa, 5.5 MPa, 6 MPa, 6.5 MPa, 7 MPa, 7.5 MPa, 8 MPa, 8.5 MPa, 9 MPa, 9.5 MPa, etc.

[0055] Setting the connection strength M2 between the heat exchange plate 3 and the battery housing 21 relatively large can ensure the bonding effect between the heat exchange plate 3 and the battery housing 21 and ensure that the heat exchange plate 3 and the battery housing 21 are not easily peeled off, thereby ensuring the heat exchange effect of the heat exchange plate 3 on the cylindrical battery 2.

[0056] For example, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be enhanced by increasing the amount of adhesive used, that is, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 can be enhanced by increasing the thickness of the adhesive layer 4.

[0057] Moreover, the thermal conductivity of the insulating shell 212 is less than or equal to 0.01 W / (m·K). For example, the thermal conductivity of the insulating shell 212 may be 0.001 W / (m·K), 0.002 W / (m·K), 0.003 W / (m·K), 0.004 W / (m·K), 0.005 W / (m·K), 0.006 W / (m·K), 0.007 W / (m·K), 0.008 W / (m·K), 0.009 W / (m·K), and the like.

[0058] Since the thermal conductivity of the insulating shell 212 is too small, when the cylindrical battery 2 is at high temperature, the heat accumulated in the insulating shell 212 cannot be quickly dissipated, and the insulating shell 212 is easily separated from the metal shell 211 due to the heat; especially the side of the cylindrical battery 2 with a larger area, the bulging degree is larger, and the risk of separation between the insulating shell 212 and the metal shell 211 is greater, thereby affecting the overall strength of the battery shell 21. The ratio of M1 to M2 is set to ≥1.2, that is, the ratio of the connection strength M1 between the metal shell 211 and the insulating shell 212 to the connection strength M2 between the heat exchange plate 3 and the battery shell 21 is ≥1.2, thereby increasing the connection strength between the metal shell 211 and the insulating shell 212, and ensuring the overall strength of the battery shell 21.

[0059] In this case, the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 is greater than or equal to 0.2 and less than or equal to 3. For example, the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 can be 0.5, 0.7, 1, 1.3, 1.5, 1.8, 2, 2.2, 2.5, 2.7, etc.

[0060] If the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 is too large, the wall thickness of the insulating shell 212 is too small. After the heat exchange plate 3 and the cylindrical battery 2 are fixed, once they are disassembled, the insulating shell 212 will be damaged, causing the cylindrical battery 2 to be scrapped.

[0061] If the ratio of the wall thickness H1 of the metal shell 211 to the wall thickness H2 of the insulating shell 212 is too small, the wall thickness H2 of the insulating shell 212 is too large, and the thermal conductivity of the insulating shell 212 is not as good as that of the metal shell 211, resulting in low thermal conductivity between the battery housing 21 and the heat exchange plate 3, which is not conducive to timely dissipating the heat generated by the cylindrical battery 2.

[0062] The above numerical range not only ensures that the insulating shell 212 is not easily damaged during the disassembly process of the heat exchange plate 3 and the cylindrical battery 2, but also ensures the thermal conductivity between the battery housing 21 and the heat exchange plate 3, so that the heat generated by the cylindrical battery 2 can be discharged in time.

[0063] In this example embodiment, the bonding area between the heat exchange plate 3 and a cylindrical battery 2 is S1, the area of ​​the outer peripheral surface of the cylindrical battery 2 is S2, and the ratio of S1 to S2 is greater than or equal to 20%. For example, the ratio of S1 to S2 can be 23%, 25%, 28%, 30%, 32%, 35%, 37%, 40%, etc. The bonding area between the heat exchange plate 3 and a cylindrical battery 2 is set larger to ensure the heat exchange effect of the heat exchange plate 3 on the cylindrical battery 2, and to avoid overheating of the cylindrical battery 2 and the battery device to cause safety accidents. Moreover, the connection strength M2 between the heat exchange plate 3 and the battery housing 21 is ≤8MPa.

[0064] It should be noted that the outer peripheral surface of the cylindrical battery 2 refers to the area of ​​the side plate 22 of the battery shell 21 away from the battery cell 25 , that is, the area of ​​the cylindrical outer surface of the battery shell 21 .

[0065] In this example implementation, refer to Figure 2 and Figure 3 As shown, the ratio of the wall thickness H3 of the battery housing 21 to the thickness H4 of the heat exchange plate 3 is greater than or equal to 0.05 and less than or equal to 0.1. For example, the ratio of the wall thickness H3 of the battery housing 21 to the thickness H4 of the heat exchange plate 3 can be 0.06, 0.07, 0.08, 0.09, etc.

[0066] If the ratio of the wall thickness H3 of the battery housing 21 to the thickness H4 of the heat exchange plate 3 is too small, the wall thickness H3 of the battery housing 21 is too small, resulting in the battery housing 21 having too low strength and a greater risk of deformation, and failing to support and protect the battery cell 25 .

[0067] If the ratio of the wall thickness H3 of the battery housing 21 to the thickness H4 of the heat exchange plate 3 is too large, the thickness H4 of the heat exchange plate 3 is too small, resulting in a small amount of heat exchange medium in the heat exchange plate 3 and a low overall heat exchange efficiency of the heat exchange plate 3 for the cylindrical battery 2.

[0068] The above numerical range can not only ensure that the strength of the battery housing 21 is sufficient to support and protect the battery core 25 , but also ensure that the heat exchange plate 3 has a high thermal efficiency for the cylindrical battery 2 .

[0069] In this example implementation, refer to Figure 2 and Figure 3 As shown, the large surface of the heat exchange plate 3 is perpendicular to the bottom plate 12. In the height direction Z, the ratio of the height K1 of the heat exchange plate 3 to the height K2 of the cylindrical battery 2 is greater than or equal to 0.5 and less than or equal to 1.2. For example, the ratio of the height K1 of the heat exchange plate 3 to the height K2 of the cylindrical battery 2 can be 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, and the like.

[0070] If the ratio of the height K1 of the heat exchange plate 3 to the height K2 of the cylindrical battery 2 is too small, the height K1 of the heat exchange plate 3 is too small, and the contact area between the heat exchange plate 3 and the cylindrical battery 2 is too small, resulting in low heat exchange efficiency of the heat exchange plate 3 to the cylindrical battery 2.

[0071] If the ratio of the height K1 of the heat exchange plate 3 to the height K2 of the cylindrical battery 2 is too large, the height K1 of the heat exchange plate 3 is too large, the bonding area between the heat exchange plate 3 and the cylindrical battery 2 is too large, and the bonding strength between the heat exchange plate 3 and the cylindrical battery 2 is too large, resulting in the heat exchange plate 3 being difficult to disassemble after being fixed to the cylindrical battery 2. Moreover, after the heat exchange plate 3 and the cylindrical battery 2 are bonded, if the heat exchange plate 3 has a slight deviation, the heat exchange plate 3 is difficult to move, resulting in poor yield.

[0072] The above numerical range ensures that the bonding area between the heat exchange plate 3 and the cylindrical battery 2 is relatively appropriate, so as to ensure the heat exchange efficiency and bonding strength of the heat exchange plate 3 to the cylindrical battery 2; and after the heat exchange plate 3 and the cylindrical battery 2 are fixed, the difficulty of disassembly is reduced; after the heat exchange plate 3 and the cylindrical battery 2 are bonded, and the heat exchange plate 3 has a slight deviation, the heat exchange plate 3 can be slightly moved, so as to ensure the assembly yield.

[0073] It should be noted that the large surface of the heat exchange plate 3 refers to the side with the largest area of ​​the heat exchange plate 3, or it can be said that the two opposite sides where the heat exchange plate 3 and the cylindrical battery 2 are bonded are both the large surfaces of the heat exchange plate 3. The height direction Z is perpendicular to the side where the cylindrical battery 2 is set on the bottom plate 12, that is, the height direction Z is parallel to the large surface of the heat exchange plate 3. The height K2 of the cylindrical battery 2 refers to the height excluding the battery pole 26. For example, the height K2 of the cylindrical battery 2 can be the sum of the height of the battery shell 21 and the thickness of the cover plate 24.

[0074] In this exemplary embodiment, the thermal conductivity of the adhesive layer 4 between the heat exchange plate 3 and the battery case 21 is greater than or equal to 0.1 W / (m·K). That is, the heat exchange plate 3 and the battery housing 21 are bonded together by the adhesive layer 4, and the thermal conductivity of the adhesive layer 4 is greater than or equal to 0.1W / (m·K). For example, the thermal conductivity of the adhesive layer 4 can be 0.5W / (m·K), 0.1W / (m·K), 0.15W / (m·K), 0.2W / (m·K), 0.25W / (m·K), 0.3W / (m·K), 0.35W / (m·K), 0.4W / (m·K), 0.45W / (m·K), 0.5W / (m·K), 0.55W / (m·K), 0.6W / (m·K), 0.65W / (m·K), 0.7W / (m·K), 0.75W / (m·K), 0.8W / (m·K), and the like. The thermal conductivity of the adhesive layer 4 is set to be relatively large, so that the adhesive layer 4 can perform better heat transfer between the battery housing 21 and the heat exchange plate 3, so as to improve the heat transfer efficiency and avoid overheating of the cylindrical battery 2. That is, the adhesive layer 4 not only plays the role of bonding the battery housing 21 and the heat exchange plate 3, but also plays the role of heat transfer between the battery housing 21 and the heat exchange plate 3.

[0075] In this example implementation, refer to Figure 2 and Figure 3 As shown, a battery cell 25 is arranged in the accommodating cavity of the battery housing 21 . The battery cell 25 is arranged as a cylinder adapted to the battery housing 21 . The battery cell 25 is the smallest unit for charging and discharging a single battery.

[0076] The battery cell 25 may include a body portion 251 and a pole ear portion; the body portion 251 may include a first pole piece, a separator and a second pole piece (not shown in the figure) arranged in a stacked manner, and the battery cell 25 may also be a wound type, where the stacked structure formed by the first pole piece, the separator and the second pole piece is wound to form the wound type battery cell 25. Different active materials are coated on the first pole piece and the second pole piece.

[0077] The polarity of the first electrode is opposite to the polarity of the second electrode. For example, the first electrode can be a positive electrode and the second electrode can be a negative electrode. Of course, the first electrode can also be a negative electrode and the second electrode can be a positive electrode. The following description is based on the example that the first electrode is a positive electrode and the second electrode is a negative electrode.

[0078] The tab portion may include a first tab 252 and a second tab 253. The first tab 252 and the second tab 253 may be led out from the same side of the body portion 251, for example, the first tab 252 and the second tab 253 may be led out from a first end surface of the body portion 251.

[0079] Specifically, the first pole ear 252 is connected to the first pole piece, and the first pole ear 252 is located on the side of the first end face away from the main body 251; a part of the first pole piece may extend out of the main body 251 and be bent to the side of the first end face away from the main body 251 to form the first pole ear 252.

[0080] The second pole ear 253 is connected to the second pole piece and is located on the side of the first end surface away from the main body 251 . The second pole ear 253 may be formed by a portion of the second pole piece extending out of the main body 251 and being bent to the side of the first end surface away from the main body 251 .

[0081] It should be noted that the first pole tab 252 and the second pole tab 253 are conductive foil areas without active material coating, that is, no active material coating is coated on the first pole tab 252 and the second pole tab 253 , and they are current collecting layers for transmitting current.

[0082] The first pole ear 252 can be connected to the battery pole 26 so that the battery pole 26 forms the positive electrode of the cylindrical battery 2 ; the second pole ear 253 can be connected to the battery shell 21 so that the battery shell 21 forms the negative electrode of the cylindrical battery 2 .

[0083] The "parallel" and "perpendicular" mentioned in this application can not only be completely parallel or perpendicular, but also can have a certain error; for example, if the angle between the two is greater than or equal to 0° and less than or equal to 5°, the two are considered to be parallel to each other; if the angle between the two is greater than or equal to 85° and less than or equal to 95°, the two are considered to be perpendicular to each other.

[0084] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A battery device, characterized in that: include: A cylindrical battery, provided in at least two, the cylindrical battery comprising a battery housing, the battery housing comprising a metal shell and an insulating shell stacked, the metal shell and the insulating shell being an integrally formed structure; The heat exchange plate is bonded between two adjacent cylindrical batteries, the connection strength between the metal shell and the insulating shell is M1, the connection strength between the heat exchange plate and the battery shell is M2, and the ratio of M1 to M2 is greater than or equal to 1 and less than or equal to 5.

2. The battery device according to claim 1, characterized in that: The metal shell is arranged on the outer surface of the insulating shell, and the connection strength M2 between the heat exchange plate and the battery housing is less than or equal to 10 MPa.

3. The battery device according to claim 2, characterized in that: The ratio of the wall thickness of the metal shell to the wall thickness of the insulating shell is greater than or equal to 0.2 and less than or equal to 5.

4. The battery device according to claim 1, characterized in that: The insulating shell is disposed on the outer surface of the metal shell, and the connection strength M2 between the heat exchange plate and the battery housing is greater than or equal to 0.2 MPa.

5. The battery device according to claim 4, characterized in that: The thermal conductivity of the insulating shell is less than or equal to 0.01 W / (m·K), and the ratio of M1 to M2 is ≥1.

2.

6. The battery device according to claim 4, characterized in that: The ratio of the wall thickness of the metal shell to the wall thickness of the insulating shell is greater than or equal to 0.2 and less than or equal to 3.

7. The battery device according to any one of claims 1 to 6, characterized in that: The bonding area between the heat exchange plate and one of the cylindrical batteries is S1, the area of ​​the outer peripheral surface of the cylindrical battery is S2, the ratio of S1 to S2 is greater than or equal to 20%, and the connection strength between the heat exchange plate and the battery housing is M2≤8MPa.

8. The battery device according to any one of claims 1 to 6, characterized in that: The ratio of the wall thickness of the battery housing to the thickness of the heat exchange plate is greater than or equal to 0.05 and less than or equal to 0.

1.

9. The battery device according to any one of claims 1 to 6, characterized in that: The battery device further comprises: A battery box comprises a bottom plate, wherein the large surface of the heat exchange plate is perpendicular to the bottom plate, and in the height direction, the ratio of the height of the heat exchange plate to the height of the cylindrical battery is greater than or equal to 0.5 and less than or equal to 1.2, and the height direction is perpendicular to the bottom plate and a side of the cylindrical battery is arranged.

10. The battery device according to any one of claims 1 to 6, characterized in that: The thermal conductivity of the adhesive layer between the heat exchange plate and the battery housing is greater than or equal to 0.1 W / (m·K).

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