Battery pack and electric device

Abstract

The invention discloses a battery pack and a power utilization device, and belongs to the technical field of batteries, the battery pack comprises a plurality of single batteries and a liquid cooling assembly, the plurality of single batteries are arranged along a first direction, each single battery comprises a shell and an insulating layer, the shell is provided with a first surface intersected with the first direction and a second surface connected with the first surface, the insulating layer covers the shell, and the liquid cooling assembly is arranged on the first surface. The insulating layer is provided with a first end and a second end, the first end and the second end are in lap joint to form an overlapping area, and the overlapping area covers the first surface; the liquid cooling assembly covers the second surface. In this way, the liquid cooling assembly is arranged on the second surface and staggered with the overlapping area of the insulating layer. If the liquid cooling assembly leaks liquid, cooling liquid needs to reach the first surface through the gap between the liquid cooling assembly and the shell and then penetrate through the double-layer overlapping area of the insulating layer, the permeation path is remarkably prolonged, the possibility that the liquid permeates into the shell can be effectively reduced, the risks of shell corrosion and insulation failure are further reduced, and the service life of the shell is prolonged. And the safety performance of the single battery is improved.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a battery pack and an electrical device. Background Art

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power sources, power energy storage sources, new energy storage power sources, and aerospace and military industries due to their advantages of large capacity, high working voltage, strong charge retention ability, and long cycle life. The structure of a lithium-ion battery includes: a cover plate, a housing, a pole group, electrolyte, blue insulating tape, etc. Among them, the cover plate and the housing are fixed by welding to form a sealed space for protecting the pole group; the blue insulating tape is mainly coated on the outside of the housing to achieve external insulation of the housing. When the liquid cooling component in the battery pack leaks, it may penetrate into the housing through the blue insulating tape, resulting in housing corrosion or insulation failure, affecting the safety performance of the battery. Summary of the Invention

[0003] Object of the Invention: The embodiments of this application provide a battery pack and an electrical device, aiming to solve the technical problem that the housing is corroded or the insulation fails due to the leakage of the liquid cooling component.

[0004] Technical Solution: The embodiments of this application provide a battery pack, including:

[0005] A plurality of single cells arranged along a first direction. Each single cell includes a housing and an insulating layer. The housing has a first surface intersecting the first direction and a second surface connected to the first surface. The insulating layer coats the housing. The insulating layer has a first end and a second end, and the first end and the second end overlap to form an overlapping area, and the overlapping area covers the first surface;

[0006] A liquid cooling component that covers the second surface.

[0007] In some embodiments, the surface area of the housing is S, and the area of the overlapping area is S1, satisfying: 0.01 ≤ S1 / S ≤ 0.05.

[0008] In some embodiments, the dimension of the overlapping area in a second direction is L, satisfying: 5 mm ≤ L ≤ 10 mm, and the second direction intersects the first direction.

[0009] In some embodiments, the housing has a receiving cavity. The single cell includes a cover plate assembly. The cover plate assembly is connected to the housing and seals the receiving cavity. The insulating layer includes a connected body portion and a flanging portion. The body portion coats the housing, and the flanging portion covers at least part of the cover plate assembly.

[0010] In some embodiments, the cover plate assembly includes a cover plate body and a pole column. The cover plate body is connected to the housing and seals the accommodation cavity. The cover plate body has a pole column hole, and the pole column passes through the pole column hole and is connected to the cover plate body. The flanging portion covers at least a part of the cover plate body and is spaced apart from the pole column.

[0011] In some embodiments, the flanging portion includes a first folding ear, and the first folding ear is connected to the body portion and extends along a first direction.

[0012] In some embodiments, the dimension of the first folding ear in the first direction is M1, satisfying: 3 mm ≤ M1 ≤ 5 mm.

[0013] In some embodiments, the flanging portion includes a second folding ear, and the second folding ear is connected to the body portion and extends along a second direction, and the second direction intersects with the first direction.

[0014] In some embodiments, the dimension of the second folding ear in the second direction is M2, satisfying: 3 mm ≤ M2 ≤ 5 mm.

[0015] Correspondingly, an embodiment of the present application provides an electrical device, including the above-mentioned battery pack.

[0016] Beneficial effects: The battery pack of the embodiment of the present application includes a plurality of single cells and a liquid cooling component. The plurality of single cells are arranged along a first direction. The single cell includes a housing and an insulating layer. The housing has a first surface intersecting with the first direction and a second surface connecting the first surface. The insulating layer covers the housing. The insulating layer has a first end and a second end, and the first end and the second end overlap to form an overlapping area, and the overlapping area covers the first surface; the liquid cooling component covers the second surface. With such an arrangement, the liquid cooling component is arranged on the second surface and is misaligned with the overlapping area of the insulating layer. If the liquid cooling component leaks, the coolant needs to first pass through the gap between the liquid cooling component and the housing to reach the first surface, and then penetrate through the double-layer overlapping area of the insulating layer, significantly extending the penetration path, which can effectively reduce the possibility of liquid penetrating into the housing, thereby reducing the risks of housing corrosion and insulation failure, and improving the safety performance of the single cell.

[0017] The electrical device of the embodiment of the present application includes the above-mentioned battery pack. Therefore, the electrical device can have all the technical features and beneficial effects of the above-mentioned battery pack, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0019] Figure 1It is a schematic structural diagram of a battery pack according to an embodiment of the present application;

[0020] Figure 2 It is a schematic structural diagram of the first type of single battery according to an embodiment of the present application;

[0021] Figure 3 It is a schematic structural diagram of the second type of single battery according to an embodiment of the present application;

[0022] Figure 4 It is a schematic structural diagram of the third type of single battery according to an embodiment of the present application;

[0023] Figure 5 is Figure 4 an enlarged view of part A of

[0024] Explanation of reference numerals: 1, single battery; 2, liquid cooling component; 10, housing; 11, insulating layer; 12, cover plate assembly; 100, first surface; 101, second surface; 110, first end; 111, second end; 112, overlapping area; 113, body part; 114, flanging part; 120, cover plate body; 121, pole column; 1140, first folding ear; 1141, second folding ear; X, first direction; Y, second direction; Z, third direction. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0026] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application 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. Therefore, it should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality of" means two or more, and at least one means one, two or more, unless otherwise specifically defined. In the description of the present application, "vertical" means completely vertical at 90° or almost completely vertical. For example, within the range of an included angle of 80° to 100°, it is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel. For example, within a range of 10° of complete parallelism, it is considered parallel.

[0027] The applicant has noticed that due to its advantages such as large capacity, high working voltage, strong charge retention ability, and long cycle life, lithium-ion batteries are currently widely used in various fields such as transportation power sources, power energy storage power sources, new energy storage power sources, and aerospace and military industries. The structure of a lithium-ion battery includes: a cover plate, a housing 10, a pole group, electrolyte, an insulating sheet, a blue insulating tape, etc. Among them, the cover plate and the housing 10 are fixed by welding to form a sealed space for protecting the pole group; the pole group is coated with an insulating sheet to protect the pole group and prevent the pole group from contacting the housing 10 and causing an internal short circuit; the blue insulating tape is mainly coated on the outside of the housing 10 to achieve external insulation of the housing 10. Usually, when the blue insulating tape is lapped at the small surface of the housing 10 in a circumferential wrapping manner, in the battery pack, the lapping part of the blue insulating tape faces upward and is directly below the cold plate. When the liquid cooling component 2 in the battery pack leaks, the coolant may penetrate into the housing 10 through the blue insulating tape, resulting in corrosion or insulation failure of the housing 10 and affecting the safety performance of the battery.

[0028] In view of this, an embodiment of the present application provides a battery pack and an electrical device, including a plurality of single cells 1 and a liquid cooling component 2. The plurality of single cells 1 are arranged along a first direction X. The single cell 1 includes a housing 10 and an insulating layer 11. The housing 10 has a first surface 100 intersecting with the first direction X and a second surface 101 connecting the first surface 100. The insulating layer 11 covers the housing 10. The insulating layer 11 has a first end 110 and a second end 111. An overlapping area 112 is formed by the overlapping of the first end 110 and the second end 111, and the overlapping area 112 covers the first surface 100. The liquid cooling component 2 covers the second surface 101. With such an arrangement, the liquid cooling component 2 is arranged on the second surface 101 and is offset from the overlapping area 112 of the insulating layer 11. If the liquid cooling component 2 leaks, the coolant needs to first reach the first surface 100 through the gap between the liquid cooling component 2 and the housing 10, and then penetrate through the double-layer overlapping area 112 of the insulating layer 11, significantly extending the penetration path, effectively reducing the possibility of liquid penetrating into the housing 10, thereby reducing the risk of corrosion of the housing 10 and insulation failure, and improving the safety performance of the single cell 1.

[0029] The battery pack and the electrical device of the present application will be described in detail below with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0030] Figure 1 is a schematic structural diagram of a battery pack according to an embodiment of the present application; Figure 2 is a schematic structural diagram of the first type of single cell 1 according to an embodiment of the present application; Figure 3 is a schematic structural diagram of the second type of single cell 1 according to an embodiment of the present application; Figure 4 is a schematic structural diagram of the third type of single cell 1 according to an embodiment of the present application; Figure 5 is Figure 4 an enlarged view of part A of

[0031] Refer to Figures 1 to 5, an embodiment of the present application provides a battery pack, including a plurality of single cells 1 and a liquid cooling component 2. The plurality of single cells 1 are arranged along the first direction X. The single cell 1 includes a housing 10 and an insulating layer 11. The housing 10 has a first surface 100 intersecting the first direction X and a second surface 101 connecting the first surface 100. The insulating layer 11 covers the housing 10. The insulating layer 11 has a first end 110 and a second end 111. The first end 110 and the second end 111 overlap to form an overlapping area 112, and the overlapping area 112 covers the first surface 100; the liquid cooling component 2 covers the second surface 101. The surface area of the first surface 100 is larger than the surface area of the second surface 101. With such a setting, the liquid cooling component 2 is arranged on the second surface 101, forming a dislocation with the overlapping area 112 of the insulating layer 11. If the liquid cooling component 2 leaks, the coolant needs to first reach the first surface 100 through the gap between the liquid cooling component 2 and the housing 10, and then penetrate the overlapping area 112 of the insulating layer 11, significantly extending the penetration path, effectively reducing the possibility of liquid penetrating into the housing 10, thereby reducing the risk of corrosion of the housing 10 and insulation failure, and improving the safety performance of the single cell 1.

[0032] In some embodiments, the surface area of the housing 10 is S, and the area of the overlapping area 112 is S1, satisfying: 0.01 ≤ S1 / S ≤ 0.05. Refer to Figure 2 , the dimension of the housing 10 in the first direction X is A, the dimension of the housing 10 in the second direction Y is B, the dimension of the housing 10 in the third direction Z is A, the first direction X, the second direction Y and the third direction Z are perpendicular to each other pairwise, and the surface area S of the housing 10 = 2C*(A + B). The dimension of the overlapping area 112 in the second direction Y is L, and the area S1 of the overlapping area 112 = L*C. By limiting the ratio range of the area S1 of the overlapping area 112 to the surface area S of the housing 10, on the one hand, it avoids material waste and reduced production efficiency caused by a relatively large area S1 of the overlapping area 112. On the other hand, it avoids insufficient bonding strength of the overlapping area 112 and easy warping problems caused by a relatively small area S1 of the overlapping area 112, thereby reducing the insulation performance of the insulating layer 11. With such a setting, while reducing material costs and improving production efficiency, it can ensure that the insulating layer 11 is not easily warped after wrapping and has sufficient insulation protection.

[0033] In some embodiments, refer to Figure 3, the dimension L of the overlapping region 112 in the second direction Y satisfies: 5 mm ≤ L ≤ 10 mm. Exemplarily, the dimension L of the overlapping region 112 in the second direction Y can be any value among 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm or a range value between any two values. By limiting the dimension L of the overlapping region 112 in the second direction Y in the embodiments of the present application, the insulation performance of the insulating layer 11 and the material utilization rate can be effectively balanced. On the one hand, a too small L value will lead to a shortened penetration path of the coolant, which may affect the insulation effect of the insulating layer 11, and will also result in insufficient bonding strength of the overlapping region 112, prone to warping problems, and further lead to a reduction in the insulation performance of the insulating layer 11. On the other hand, a too large L value will lead to material waste and a reduction in production efficiency. Such a setting can reduce the risk of liquid penetrating into the interior of the housing 10 and improve the safety performance of the single cell 1; at the same time, it is convenient for the processing and assembly of the insulating layer 11 and improves production efficiency.

[0034] In some embodiments, by setting insulating layers 11 with different sizes of S, L, and S1 and conducting verification, the verification results are shown in Table 1.

[0035] Table 1:

[0036]

[0037]

[0038]

[0039]

[0040] Referring to Embodiment 1 to Embodiment 12, when the insulating layer 11 satisfies 0.01 ≤ S1 / S ≤ 0.05 and 5 mm ≤ L ≤ 10 mm, the verification result is that there are no obvious appearance defects such as misalignment, wrinkles, and warping in the overlapping region 112, and the insulating layer 11 is easy to tear off during rework. It can be understood that by reasonably designing the insulating layer 11 in the embodiments of the present application, on the one hand, material waste and production efficiency reduction caused by a relatively large overlapping region 112 are avoided, and on the other hand, insufficient bonding strength of the overlapping region 112 caused by a relatively small overlapping region 112 is avoided, which is prone to warping problems, and further leads to a reduction in the insulation performance of the insulating layer 11. Such a setting can ensure that the insulating layer 11 is not easy to warp after being wrapped and has sufficient insulation protection while reducing material costs and improving production efficiency.

[0041] Referring to Reference Example 13 and Example 14, when the insulating layer 11 does not satisfy 0.01 ≤ S1 / S ≤ 0.05 and 5 mm ≤ L ≤ 10 mm, the verification result shows that the area of the overlapping region 112 is insufficient, the bonding strength is insufficient, and there is a problem of warping. It can be understood that when the L value and the S1 value are relatively small, the bonding strength of the overlapping region 112 will be insufficient, prone to warping problems, and further lead to a decrease in the insulation performance of the insulating layer 11.

[0042] Referring to Reference Example 15 to Example 17, when the insulating layer 11 satisfies 5 mm ≤ L ≤ 10 mm but does not satisfy 0.01 ≤ S1 / S ≤ 0.05, the verification result shows that the area of the overlapping region 112 is relatively large. When there are defects after encapsulation and rework is required, it is not easy to tear off. When the S1 value is relatively large, even if a larger overlapping region 112 can provide better insulation protection, it will cause material waste and increase costs. At the same time, a larger overlapping region 112 is not easy to adhere. If there are appearance defects during encapsulation, there are problems such as not being easy to tear off and difficult rework, thereby reducing production efficiency.

[0043] In some embodiments, referring to Figure 4 and Figure 5 , the housing 10 has a receiving cavity, the single battery 1 includes a cover plate assembly 12, the cover plate assembly 12 is connected to the housing 10 and seals the receiving cavity, the insulating layer 11 includes a connected body portion 113 and a flanging portion 114, the body portion 113 covers the housing 10, and the flanging portion 114 covers at least part of the cover plate assembly 12. The body portion 113 completely covers the outer wall of the housing 10, and the flanging portion 114 covers at least part of the cover plate assembly 12. By extending the flanging portion 114 of the insulating layer 11 to the cover plate assembly 12, it not only effectively prevents liquid from penetrating at the connection between the cover plate and the housing 10, but also enhances the sealing performance of the entire single battery 1.

[0044] In some embodiments, referring to Figure 4 and Figure 5 , the cover plate assembly 12 includes a cover plate body 120 and a terminal post 121. The cover plate body 120 is connected to the housing 10 and seals the receiving cavity. The cover plate body 120 has a terminal post 121 hole, the terminal post 121 passes through the terminal post 121 hole and is connected to the cover plate body 120, and the flanging portion 114 covers at least part of the cover plate body 120 and is spaced from the terminal post 121. The cover plate body 120 is usually provided with an insulating patch. The flanging portion 114 extends to the cover plate body 120 and is connected to at least part of the insulating patch, which can avoid problems such as warping and falling off of the flanging portion 114 or the insulating patch, and reduce the risk of insulation failure.

[0045] In some embodiments, referring to Figure 5, the flanging part 114 includes a first folding ear 1140, and the first folding ear 1140 is connected to the body part 113 and extends along the first direction X. The dimension of the first folding ear 1140 in the first direction X is M1, satisfying: 3mm ≤ M1 ≤ 5mm. Exemplarily, the dimension M1 of the first folding ear 1140 in the first direction X can be any value among 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5mm or a range value between any two values. With such a setting, by reasonably designing the dimension of the first folding ear 1140, it is ensured that no current leakage or short circuit occurs when the single cell 1 is working, improving the sealing performance and insulation performance of the single cell 1. In addition, the existence of the first folding ear 1140 also provides an additional support point for the installation and fixation of the insulating layer 11, enabling it to fit more firmly on the surface of the housing 10 during the production process, reducing the risk of insulation failure caused by installation errors, and improving the production efficiency and product quality.

[0046] In some embodiments, referring to Figure 5 , the flanging part 114 includes a second folding ear 1141, and the second folding ear 1141 is connected to the body part 113 and extends along the second direction Y, and the second direction Y intersects with the first direction X. The dimension of the second folding ear 1141 in the second direction Y is M2, satisfying: 3mm ≤ M2 ≤ 5mm. Exemplarily, the dimension M2 of the second folding ear 1141 in the second direction Y can be any value among 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5mm or a range value between any two values. With such a setting, by reasonably designing the dimension of the second folding ear 1141, it is ensured that no current leakage or short circuit occurs when the single cell 1 is working, improving the sealing performance and insulation performance of the single cell 1. In addition, the existence of the second folding ear 1141 also provides an additional support point for the installation and fixation of the insulating layer 11, enabling it to fit more firmly on the surface of the housing 10 during the production process, reducing the risk of insulation failure caused by installation errors, and improving the production efficiency and product quality.

[0047] In some embodiments, the insulating layer 11 includes a PET (polyester) film and a pressure-sensitive adhesive, and is produced by coating the pressure-sensitive adhesive on the PET film. The PET film is a polyester film with good insulation performance. The pressure-sensitive adhesive is an adhesive with viscosity, which is used to fix the PET film on the cover body 120 and the housing 10.

[0048] Correspondingly, an embodiment of the present application provides an electrical device, including the above battery pack. Therefore, it can have all the technical features and technical effects of the above battery pack, which will not be elaborated here. The electrical device can be a mobile phone, a portable device, a laptop computer, a battery car, an electric vehicle, a ship, a spacecraft, an electric toy, an electric tool, etc. For example, spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc.

[0049] In the above embodiments, the descriptions of the respective embodiments have their own focuses. For parts not elaborated in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0050] The above has introduced in detail a battery pack and an electrical device provided by an embodiment of the present application, and specific examples have been used to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack, characterized in that: include: A plurality of single cells are arranged along a first direction, the single cells comprising a shell and an insulating layer, the shell having a first surface intersecting the first direction and a second surface connected to the first surface, the insulating layer covering the shell, the insulating layer having a first end and a second end, the first end and the second end overlap to form an overlapping area, and the overlapping area covers the first surface; A liquid cooling component covers the second surface.

2. The battery pack according to claim 1, characterized in that: The surface area of ​​the shell is S, and the area of ​​the overlapping region is S1, which satisfies: 0.01≤S1 / S≤0.

05.

3. The battery pack according to claim 1, characterized in that: The size of the overlapping area in the second direction is L, which satisfies: 5 mm ≤ L ≤ 10 mm, and the second direction intersects with the first direction.

4. The battery pack according to claim 1, characterized in that: The shell has a accommodating cavity, the single cell includes a cover assembly, the cover assembly is connected to the shell and covers the accommodating cavity, the insulating layer includes a main body and a flange portion connected to each other, the main body covers the shell, and the flange portion covers at least part of the cover assembly.

5. The battery pack according to claim 4, characterized in that: The cover plate assembly includes a cover plate body and a pole, wherein the cover plate body is connected to the shell and covers the accommodating cavity, the cover plate body has a pole hole, the pole is passed through the pole hole and connected to the cover plate body, and the flange portion covers at least part of the cover plate body and is spaced apart from the pole.

6. The battery pack according to claim 4, characterized in that: The flange portion includes a first folded ear, which is connected to the main body portion and extends along the first direction.

7. The battery pack according to claim 6, characterized in that: The dimension of the first folded ear in the first direction is M1, which satisfies: 3mm≤M1≤5mm.

8. The battery pack according to claim 4, characterized in that: The flange portion includes a second folded ear, the second folded ear is connected to the main body portion and extends along a second direction, and the second direction intersects with the first direction.

9. The battery pack according to claim 8, characterized in that: The dimension of the second folded ear in the second direction is M2, which satisfies: 3mm≤M2≤5mm.

10. An electrical device, characterized in that: A battery pack comprising the battery pack as claimed in any one of claims 1 to 9.

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