Battery pack

Abstract

This invention belongs to the field of battery technology and discloses a battery pack. The battery pack includes a battery, an adhesive layer, and a base plate. The adhesive layer is located between the battery and the base plate. The battery includes a battery casing and an insulating component covering the surface of the battery casing. The insulating component has a notch, which exposes at least a portion of the bottom surface of the battery casing facing the base plate. The adhesive layer is at least partially disposed at the notch and bonded to the base plate. An insulating layer is disposed between the base plate and the adhesive layer. The orthographic projection of the notch on the base plate falls within the orthographic projection of the insulating layer on the base plate. The ratio of the notch area S1 to the total area S2 of the battery casing surface covered by the insulating component is a, i.e., a = S1 / S2. The minimum distance between the battery casing at the notch and the base plate is h millimeters, and a and h satisfy the relationship: 0.01 ≤ a / h ≤ 0.13. The battery pack provided by this invention has high insulation performance, high bonding strength between the battery and the base plate, and high energy density.

Description

[0001] This application is a divisional application. The original application has the application number 2025105681125, the application date is April 30, 2025, and the invention title is "Battery Pack". Technical Field

[0002] This invention relates to the field of battery technology, and more particularly to a battery pack. Background Technology

[0003] A battery pack typically consists of a housing and multiple batteries housed within it. The bottom of the batteries is bonded to the base plate of the housing with adhesive to improve the overall strength of the battery pack and prevent damage to the battery pack under vibration conditions.

[0004] Currently, batteries are covered with insulating components. To ensure the bonding strength between the battery and the base plate of the casing, a metal shell is usually exposed on the side of the insulating component closest to the base plate for adhesive bonding to the base plate, thus improving the adhesion strength between the adhesive layer and the battery. However, this setup can lead to the risk of insulation failure between the battery and the casing. Summary of the Invention

[0005] The purpose of this invention is to provide a battery pack that solves the technical problem in the prior art of failing to balance insulation performance and bonding strength.

[0006] Based on the above concept, the technical solution adopted by this invention is as follows:

[0007] A battery pack includes a battery, an adhesive layer, and a base plate. The base plate supports the battery, and the adhesive layer is located between the battery and the base plate, serving to securely connect the base plate and the battery. The battery includes a battery casing body and an insulating member covering the surface of the battery casing body. The insulating member has a notch, which exposes at least a portion of the bottom surface of the battery casing body facing the base plate. The adhesive layer is at least partially disposed at the notch and adheres to the base plate. An insulating layer is disposed between the base plate and the adhesive layer, and the edge of the notch, when projected onto the base plate, falls within the projection of the insulating layer onto the base plate.

[0008] The ratio of the notch area S1 of the insulating component to the total area S2 of the battery case body surface covered by the insulating component is a, i.e., a = S1 / S2; the minimum distance between the battery case body at the notch and the bottom plate is h millimeters, and a and h satisfy the relationship: 0.1 ≤ a / h ≤ 0.13.

[0009] The above technical solution has at least the following beneficial effects:

[0010] By adding an insulating layer to the base plate, the insulation strength between the battery body and the base plate corresponding to the notch is improved. However, the insulating layer on the base plate increases the overall processing difficulty of the base plate and weakens the adhesion strength between the base plate and the battery. Therefore, by controlling the range of a / h to satisfy the above relationship, it is possible to ensure good adhesion strength between the battery and the base plate while preventing short circuits between the base plate and the battery, thus improving the overall structural strength and safety performance of the battery pack. If the a / h value is too large, the exposed area of ​​the metal battery casing will increase, increasing the risk of short circuits between the battery casing and the base plate, reducing the insulation performance between them, and potentially leading to short circuits between the battery and the base plate, affecting battery safety. If the a / h value is too small, the bonding area between the battery casing and the base plate, as well as the excessive distance between them, will result in weak adhesion strength, posing a risk of detachment under battery pack vibration conditions, affecting the overall strength and safety of the battery. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of a battery pack provided in an embodiment of the present invention;

[0013] Figure 2 This is a cross-sectional schematic diagram of a battery pack provided in an embodiment of the present invention;

[0014] Figure 3 This is provided by an embodiment of the present invention. Figure 2 The enlarged view of point A shown;

[0015] Figure 4 This is a schematic diagram of the structure of a battery provided in an embodiment of the present invention;

[0016] Figure 5 This is an exploded view of a battery provided in an embodiment of the present invention;

[0017] Figure 6 This is a bottom view of a battery provided in an embodiment of the present invention;

[0018] Figure 7 This is a bottom view of another battery provided in one embodiment of the present invention;

[0019] Figure 8 This is a bottom view of another battery provided in an embodiment of the present invention;

[0020] Figure 9 This is a bottom view of another type of battery provided in an embodiment of the present invention;

[0021] Figure 10 This is a partially enlarged cross-sectional view of a battery pack according to an embodiment of the present invention;

[0022] Figure 11 This is a perspective view of a battery provided in an embodiment of the present invention;

[0023] Figure 12 This is a front view of a battery provided in an embodiment of the present invention;

[0024] Figure 13 This is a partially enlarged cross-sectional view of another battery pack provided in an embodiment of the present invention.

[0025] In the picture:

[0026] 100. Battery; 110. Battery casing body; 111. Bottom surface; 112. Side surface; 113. Top surface; 120. Insulating component; 121. Notch; 122. First insulating part; 123. Second insulating part; 124. Opening; 130. Explosion-proof valve; 140. Terminal post; 150. Battery cell; 200. Adhesive layer; 300. Base plate; 400. Insulating layer; 500. Frame structure; 510. Frame; 520. Crossbeam; 530. Longitudinal beam; 10. Outer casing; 101. Battery compartment; X, First direction. Detailed Implementation

[0027] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0028] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. In the description of this embodiment, unless otherwise specified, "multiple" specifically refers to two or more.

[0032] In the description of this embodiment, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are based on the orientation or positional relationships shown in the accompanying drawings and are only for ease of description and simplification of operation. They 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 of the present invention. Furthermore, the terms "first" and "second" are merely used for distinction in description and have no special meaning.

[0033] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or it can be located in between the component.

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] This embodiment provides a battery pack that can balance the connection strength and insulation performance between the battery and the base plate.

[0036] For example, such as Figure 1As shown, the battery typically includes an outer casing 10 and multiple batteries 100 disposed within the outer casing 10, with the batteries 100 arranged in groups within the outer casing 10. The outer casing 10 typically includes a base plate 300, a frame structure 500, and a cover (not shown in the figure). The frame structure 500 includes a side frame 510, a crossbeam 520, and a longitudinal beam 530. The side frame 510 connects the base plate 300 and the cover to form a battery compartment. The crossbeams 520 and longitudinal beams 530 are intersected within the battery compartment, dividing it into multiple battery sub-compartments 101, each of which contains multiple batteries 100. Optionally, there may be only one or more crossbeams 520 and longitudinal beams 530; this embodiment does not limit this.

[0037] Optionally, the battery 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this embodiment is not limited to this. The battery 100 typically includes a battery casing 110, a cell assembly (not shown in the figure), and an electrolyte (not shown in the figure). The battery casing 110 is used to house the cell assembly and the electrolyte, and the battery casing 110 is provided with at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and separators.

[0038] The positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is directly or indirectly coated on the positive current collector. The positive current collector without the positive active material layer protrudes from the positive current collector with the positive active material layer. The positive current collector without the positive active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and form an electrical connection with the positive electrode post. For example, the multiple stacked positive electrode tabs can be directly soldered to the positive electrode post to form an electrical connection; or, the battery cell assembly can also include a positive electrode adapter piece. The multiple stacked positive electrode tabs are soldered to one end of the positive electrode adapter piece, and the other end of the positive electrode adapter piece is soldered to the positive electrode post, so that the positive electrode tabs and the positive electrode post form an electrical connection.

[0039] The negative electrode generally includes a negative current collector and a negative active material layer. The negative active material layer is directly or indirectly coated on the negative current collector. The negative current collector without the negative active material layer protrudes from the negative current collector with the negative active material layer. The negative current collector without the negative active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and form an electrical connection with the negative electrode post. For example, the stacked negative electrode tabs can be directly welded to the negative electrode post to form an electrical connection; alternatively, the battery cell assembly may also include a negative electrode adapter piece. The stacked negative electrode tabs are welded to one end of the negative electrode adapter piece, and the other end of the negative electrode adapter piece is welded to the negative electrode post, so that the negative electrode tabs and the negative electrode post form an electrical connection. The material of the separator is not limited; for example, it can be polypropylene or polyethylene.

[0040] Optionally, the outer casing can be assembled from a base plate 300 and side plates connected to the base plate, that is, as shown in the figure. Figure 2 and Figure 3 As shown, the battery pack also includes a base plate 300, which supports the battery 100. The battery 100 is fixedly bonded to the base plate 300 by an adhesive layer 200. Specifically, the adhesive layer 200 is located between the battery 100 and the base plate 300 and is used to fix the base plate 300 and the battery 100 together.

[0041] In this embodiment, the battery includes a battery casing body 110 and an insulating member 120 covering the surface of the battery casing body 110. The insulating member 120 is used to insulate the battery casing body 110 from the outside environment. It should be noted that the insulating member 120 and the battery casing body 110 are fixedly connected and integrated into one unit, so that the insulating member 120 will not move relative to the battery casing body 110.

[0042] Optionally, the insulating element 120 includes an insulating protective film and / or an insulating protective coating. That is, the insulating element 120 may only include an insulating protective film; or it may only include an insulating protective coating; or it may include both an insulating protective film and an insulating protective coating, in which case the insulating protective film and the insulating protective coating may be stacked; or a part of the structure of the insulating element 120 may be an insulating protective film and another part may be an insulating protective coating. The specific choice can be flexible, and this embodiment does not limit it.

[0043] It should be noted that the insulating protective film can be applied to the battery case body 110 by means of adhesion; the insulating protective coating can be applied to the battery case body 110 by means of coating, and this embodiment does not limit this.

[0044] For example, the material of the insulating protective film is polyethylene terephthalate, polyimide, polypropylene, etc. The material of the insulating protective coating is polyacrylate, silicone, polyurethane, epoxy resin, etc., and this embodiment is not limited to these. For example, the insulating protective film can be a blue film.

[0045] In this embodiment, the insulating member 120 is provided with a notch 121. Specifically, the notch 121 is provided on the portion of the insulating member 120 between the bottom surface 111 of the battery case body 110 facing the bottom plate 300 and the bottom plate 300, so that the notch 121 can expose at least a portion of the bottom surface 111 of the battery case body 110 facing the bottom plate 300. The adhesive layer 200 is at least partially disposed at the notch 121 and bonded to the bottom plate 300, thereby improving the bonding strength and reliability between the battery case body 110 and the bottom plate 300.

[0046] It should be noted that the insulating material covering the outer surface of the battery 100 (or battery case body 110) is the insulating component 120. That is, the insulating material covering the outer surface of the battery 100 (or battery case body 110) except for the opening facing the bottom plate 300 is the insulating component 120. In other words, all insulating materials covering the outer surface of the battery 100 (or battery case body 110) are insulating components 120.

[0047] In this embodiment, please continue to refer to Figure 2 and Figure 3 An insulating layer 400 is provided between the base plate 300 and the adhesive layer 200. The insulating layer 400 is used to improve the insulation performance between the battery case body 110 and the base plate 300. Specifically, the orthographic projection of the notch 121 on the base plate 300 falls within the orthographic projection of the insulating layer 400 on the base plate 300. That is, the orthographic projection of the notch 121 on the base plate 300 is completely within the orthographic projection of the insulating layer 400 on the base plate 300, and has no portion outside the insulating layer 400. Thus, the portion of the bottom surface 111 of the battery case body 110 exposed through the notch 121 faces the insulating layer 400 directly, rather than directly facing the base plate 300, thereby increasing the insulation performance between the battery case body 110 and the base plate 300 through the insulating layer 400.

[0048] In this embodiment, as Figure 5 As shown, the ratio of the area S1 of the notch 121 of the insulating member 120 to the total area S2 of the surface of the battery case body 110 covered by the insulating member 120 is a, i.e., a = S1 / S2. Therefore, in this embodiment, 'a' can be used to characterize the size of the battery case body 110. Figure 3As shown, the minimum distance between the battery casing body 110 located at the notch 121 and the base plate 300 is h millimeters. That is, the minimum distance between the portion of the bottom surface 111 of the battery casing body 110 opposite to the notch 121 and the base plate 300 is h millimeters. Wherein, a and h satisfy the relationship: 0.01≤a / h≤0.13.

[0049] It should be noted that a / h can be any value between 0.01 and 0.13, or a range between any two values; this embodiment does not limit this. For example, the value of a / h can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, etc.

[0050] In some optional embodiments, the ratio of the area S1 of the notch 121 of the insulating member 120 to the total area S2 of the surface of the battery casing body 110 covered by the insulating member 120 can also be understood as: the area S1 of the notch 121 of the insulating member 120 is divided by the area of ​​the entire insulating member 120. It should be noted that the units of S1 and S2 in this embodiment can be mm. 2 It can also be other common units, and this embodiment does not limit it.

[0051] In some optional embodiments, this embodiment provides a range of values ​​for 'a', for example, the range of values ​​for 'a' is 0.01-0.2. The value of 'a' can be 0.01, 0.05, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2, etc.

[0052] For example, this embodiment also provides a range of values ​​for h, such as 0.7-3.8. The value of h can be 0.7, 1, 1.2, 1.5, 1.8, 2, 2.5, 2.8, 3, 3.5, 3.8, etc.

[0053] In this embodiment, 'a' represents the ratio of the area S1 of the notch 121 in the insulating member 120 to the total area S2 of the surface of the battery case body 110 covered by the insulating member 120. Therefore, the size of 'a' determines the proportion of the area S1 of the notch 121 to the total area of ​​the insulating member 120 on the surface of the battery case body 110. This is used to confirm the overlap between the battery case body 110 and the base plate 300, so as to more accurately reflect the risk of insulation failure of the battery case body 110. It should be noted that the risk of insulation failure mentioned in this embodiment can be understood as: in addition to metal-to-metal overlap, there is also the possibility of insulation failure due to condensation or liquid conduction such as electrolyte on the surface of the battery case body 110.

[0054] By setting an insulating layer 400 on the base plate 300, the insulation strength between the part of the battery body 110 corresponding to the notch 121 and the base plate 300 is improved. However, the setting of the insulating layer 400 on the base plate 300 makes the overall processing difficulty of the base plate 300 and the bonding strength between the base plate 300 and the battery 100 weaker. Therefore, by controlling the range of a / h to meet 0.01≤a / h≤0.13, it is possible to ensure good bonding strength between the battery 100 and the base plate 300, and also to ensure that short circuits do not occur between the base plate 300 and the battery 100, thereby improving the overall structural strength and safety performance of the battery pack. If the a / h value is too high, the exposed area of ​​the metal battery casing 110 will increase, increasing the risk of short circuit between the battery casing 110 and the base plate 300. The insulation performance between the two will decrease, leading to a short circuit between the battery 100 and the base plate 300, affecting the safety performance of the battery 100 and the battery pack. If the a / h value is too low, the bonding area between the battery casing 110 and the base plate 300, as well as the excessive distance between them, will result in weak bonding strength between the battery 100 and the base plate 300. This poses a risk of detachment under vibration conditions, affecting the overall strength and safety of the battery.

[0055] Optionally, in this embodiment, the battery casing body 110 is used to accommodate the battery cell 150 and to isolate the battery cell 150 from the external environment. The battery casing body 110 may include an outer shell (not shown in the figure) and a cover plate (not shown in the figure). One end of the outer shell has an opening, and the cover plate is welded to the outer shell to seal the opening of the outer shell, thereby forming a relatively sealed accommodating space for accommodating the battery cell 150. The battery casing body 110 is made of metal materials such as aluminum or stainless steel, therefore an insulating structure needs to be provided between the battery casing body 110 and the base plate 300 to ensure insulation.

[0056] For example, the base plate 300 is made of a metal material, such as aluminum, stainless steel, aluminum alloy, iron, etc. This embodiment does not limit the material.

[0057] In one embodiment, the insulating layer 400 can be made of any one of polyethylene terephthalate, polyimide, mica, UV coating material, and epoxy resin. The insulating layer 400 can be sprayed onto the surface of the base plate 300 facing the battery 100, or it can be pasted onto the surface of the base plate 300 facing the battery 100. This embodiment does not limit this.

[0058] In some alternative embodiments, such as Figure 4As shown, the area of ​​the orthographic projection of the notch 121 onto the base plate 300 is smaller than the area of ​​the bottom surface 111 of the battery casing body 110. In this case, a and h satisfy the relationship: 0.05 ≤ a / h ≤ 0.13. It should be noted that since the area of ​​the orthographic projection of the notch 121 onto the base plate 300 is smaller than the area of ​​the bottom surface 111 of the battery casing body 110, the notch 121 does not completely expose the bottom surface 111 of the battery casing body 110, but only a portion of it. At this point, the bonding area between the battery 100 and the base plate 300 is small, and the fixing strength between the battery 100 and the base plate 300 is weak. Therefore, reducing the distance between the battery 100 and the base plate 300 can improve the connection strength between them.

[0059] When the area of ​​the orthographic projection of the notch 121 on the base plate 300 is smaller than the area of ​​the bottom surface 111 of the battery case body 110, the relative positional relationship between the notch 121 and the bottom surface 111 of the battery case body 110 can be varied. This embodiment provides the following three possible implementation methods.

[0060] In one possible implementation, such as Figure 6 As shown, the edge of one end of the notch 121 in the first direction coincides with the edge of one end of the bottom surface 111 of the battery case body 110 in the first direction. It should be noted that the coincidence of the edge of one end of the notch 121 in the first direction with the edge of one end of the bottom surface 111 of the battery case body 110 in the first direction can be understood as the orthographic projection of the edge of one end of the notch 121 in the first direction onto the base plate 300 coincides with or is collinear with the orthographic projection of the edge of one end of the bottom surface 111 of the battery case body 110 in the first direction onto the base plate 300.

[0061] It should also be noted that the first direction refers to the length or width direction of the battery casing body 110, but this embodiment does not limit this. In this embodiment... Figure 6 A schematic diagram is shown, with the first direction being the length direction of the battery casing body 110.

[0062] In another possible implementation, such as Figure 7 As shown, the edges of the notch 121 at both ends in the first direction correspond to the edges of the bottom surface 111 of the battery case body 110 at both ends in the first direction. It should be noted that the edges of the notch 121 at both ends in the first direction correspond one-to-one with the edges of the bottom surface 111 of the battery case body 110 at both ends in the first direction, and are flush with each other in the height direction of the battery case body 110.

[0063] In another possible implementation, such as Figure 8As shown, the edge of the notch 121 is spaced apart from the edge of the bottom surface 111 of the battery case body 110, meaning the edge of the notch 121 does not extend to the edge of the bottom surface 111 of the battery case body 110. Furthermore, the minimum distance b between the edge of the notch 121 and the edge of the bottom surface 111 of the battery case body 110 ranges from 2mm to 30mm. Thus, when the edge of the notch 121 of the insulating member 120 is spaced apart from the edge of the bottom surface 111 of the battery case body 110, the exposed area of ​​the bottom surface 111 of the battery case body 110 is small, reducing the risk of a short circuit between the battery case body 110 and the base plate 300.

[0064] For example, the minimum distance b between the edge of the notch 121 and the edge of the bottom surface 111 of the battery case body 110 can be any value between 2mm and 30mm, or any two values. This embodiment does not limit this. For example, the minimum distance b between the edge of the notch 121 and the edge of the bottom surface 111 of the battery case body 110 can be 2mm, 5mm, 8mm, 10mm, 12mm, 15mm, 18mm, 20mm, 22mm, 25mm, 28mm, 30mm, etc.

[0065] It should be noted that, in this embodiment, the notch 121 may be located at the center of the surface of the insulating member 120 facing the base plate 300.

[0066] All three possible implementations of the battery pack can meet the insulation performance requirements between the battery 100 and the base plate 300, the connection strength requirements between the battery 100 and the base plate 300, and the high energy density requirements of the battery pack.

[0067] In other alternative embodiments, such as Figure 9 As shown, the area of ​​the orthographic projection of the notch 121 onto the base plate 300 is equal to the area of ​​the bottom surface 111 of the battery case body 110, and a and h satisfy the relationship: 0.01≤a / h≤0.1. Wherein, the area of ​​the orthographic projection of the notch 121 onto the base plate 300 is equal to the area of ​​the bottom surface 111 of the battery case body 110, which can be understood as the part of the battery case body 110 facing the bottom surface 111 of the base plate 300 that is completely exposed and not covered by the insulating component 120. When the area of ​​the orthographic projection of the notch 121 onto the base plate 300 is equal to the area of ​​the bottom surface 111 of the battery case body 110, by controlling the range of a / h to satisfy 0.01≤a / h≤0.1, it is possible to ensure good bonding strength between the battery 100 and the base plate 300, and the increased creepage clearance between the battery case body 110 and the base plate 300 ensures that short circuits between the base plate 300 and the battery 100 will not occur, thus improving the overall structural strength and safety performance of the battery pack.

[0068] In some alternative embodiments, such as Figure 10As shown, the battery 100 also includes an explosion-proof valve 130, which can be located on the bottom surface 111 of the battery casing 110 facing the base plate 300. The explosion-proof valve 130 is used to release pressure from the gas inside the battery 100 when thermal runaway causes the internal pressure to reach a certain level, allowing the high-temperature gas inside the battery 100 to escape. The explosion-proof valve 130 is typically designed with grooves to act as a weak point in the battery casing 110, thus achieving pressure relief. A clearance hole (not shown in the figure) is provided on the adhesive layer 200 corresponding to the position of the explosion-proof valve 130 to prevent the explosion-proof valve 130 from bursting if pressure relief is not timely. The orthogonal projection of the explosion-proof valve 130 onto the adhesive layer 200 is located within the clearance hole, ensuring that the adhesive layer 200 does not affect the rupture and venting of the explosion-proof valve 130. In this embodiment, the orthographic projection of the explosion-proof valve 130 on the insulating member 120 is located within the notch 121, and a and h satisfy the relationship: 0.03≤a / h≤0.13. It should be noted that the orthographic projection of the explosion-proof valve 130 on the insulating member 120 specifically means that the orthographic projection of the explosion-proof valve 130 on the surface of the insulating member 120 facing the base plate 300 is located within the notch 121, that is, the explosion-proof valve 130 and the notch 121 are directly opposite each other.

[0069] In this embodiment, the explosion-proof valve 130 and the notch 121 are located on the same side of the battery 100, and the orthogonal projection of the explosion-proof valve 130 on the insulating member 120 is located within the notch 121. Since the explosion-proof valve 130 needs to promptly release the gas and pressure inside the battery casing body 110 in the event of thermal runaway of the battery 100, it cannot be blocked by the adhesive layer 200. By controlling the a / h ratio to satisfy the relationship 0.03≤a / h≤0.13, the bonding area and bonding strength between the adhesive layer 200 and the bottom of the battery casing body 110 can be ensured, while not affecting the insulation performance between the battery 100 and the base plate 300.

[0070] To ensure the bonding strength of the entire bottom surface 111 of the battery casing body 110 is not compromised due to an insufficient bonding area, thus preventing the risk of weak sides, it is necessary to control the distance between the explosion-proof valve 130 and the edge of the notch 121 in the direction perpendicular to the height of the battery casing body 110. For example, as... Figure 10 As shown, the minimum distance k between the edge of the explosion-proof valve 130 and the edge of the notch 121 in the direction perpendicular to the height of the battery housing body 110 (i.e., the length or width direction of the battery housing body 110) ranges from 0.2mm to 5mm. Thus, there is a gap between the edge of the explosion-proof valve 130 and the edge of the notch 121. This gap can be used to install the adhesive layer 200, thereby improving the bonding strength between the battery housing body 110 and the base plate 300, and the adhesive layer 200 does not affect the function of the explosion-proof valve 130.

[0071] For example, the minimum distance k between the edge of the explosion-proof valve 130 and the edge of the notch 121 in the direction perpendicular to the height of the battery housing body 110 is any value between 0.2 mm and 5 mm, or any two values. For example, the minimum distance k between the edge of the explosion-proof valve 130 and the edge of the notch 121 in the direction perpendicular to the height of the battery housing body 110 may be 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.2 mm, 2.5 mm, 3 mm, 3.8 mm, 4 mm, 4.5 mm, 4.8 mm, 5 mm, etc.

[0072] In one embodiment, the explosion-proof valve 130 and the battery housing body 110 are an integral structure. That is, the battery housing body 110 is provided with a weak area, the function of which is exactly the same as that of the explosion-proof valve 130. Therefore, the weak area can be considered as the explosion-proof valve 130. By making the explosion-proof valve 130 and the battery housing body 110 an integral structure, the manufacturing of the explosion-proof valve 130 is facilitated, the battery assembly steps are reduced, the battery assembly efficiency is improved, and the functionality of the battery housing body 110 is enriched.

[0073] It is understandable that the explosion-proof valve 130 may not be integrally formed with the battery housing body 110, but may be two independent components of the battery housing body 110. That is, the explosion-proof valve 130 is a split explosion-proof valve. In this case, the connection between the explosion-proof valve 130 and the battery housing body 110 may be welding or other methods. This embodiment does not limit this.

[0074] In one possible implementation, since the explosion-proof valve 130 is positioned directly opposite the notch 121, in order to further improve the insulation performance at the explosion-proof valve 130, an explosion-proof valve protection patch (not shown in the figure) can be provided on the side of the explosion-proof valve 130 away from the battery housing body 110. The explosion-proof valve protection patch is used to protect the explosion-proof valve 130 to prevent the explosion-proof valve 130 from breaking before the breaking condition is met, and also to prevent the explosion-proof valve 130 from breaking due to external forces from outside the battery 100, thereby improving the reliability of the explosion-proof valve 130.

[0075] Optionally, the explosion-proof valve protective patch has the same insulating function as the insulating member 120. Exemplarily, the explosion-proof valve protective patch is made of an insulating material, such as polytetrafluoroethylene, polyethylene terephthalate, polyethylene, polypropylene, or polyimide. In this case, the total area S2 of the battery casing body 110 surface covered by the insulating member 120 is equal to the area of ​​the insulating member 120 plus the area of ​​the explosion-proof valve protective patch. That is, the insulating member 120 includes the explosion-proof valve protective patch; in other words, a portion of the insulating member 120 forms the explosion-proof valve protective patch.

[0076] It is understandable that the explosion-proof valve 130 may not be located on the bottom surface 111 of the battery housing body 110 facing the base plate 300, but may be located on other surfaces. Specifically, such as... Figure 11 As shown, the explosion-proof valve 130 is disposed on the battery housing body 110, and the surface of the battery housing body 110 on which the explosion-proof valve 130 is disposed is different from the surface of the battery housing body 110 opposite to the notch 121. For example, the explosion-proof valve 130 is disposed on the top surface of the battery housing body 110 on the side away from the base plate 300. In this way, the explosion-proof valve 130 and the notch 121 are not on the same side of the battery 100, and the notch 121 will not cause a short circuit between the battery 100 and the base plate 300 due to the explosion of the explosion-proof valve 130, thereby improving the safety of the battery pack.

[0077] In one possible implementation, the insulating member 120 has a clearance portion (not shown) at the explosion-proof valve 130, and an explosion-proof valve protection patch is provided on the side of the explosion-proof valve 130 away from the battery casing body 110. The explosion-proof valve protection patch is used to protect the explosion-proof valve 130. The material of the explosion-proof valve protection patch is the same as that described above, so that the explosion-proof valve protection patch can be used for insulation between the battery 100 and the battery pack housing. At this time, the total area S2 of the surface of the battery casing body 110 covered by the insulating member 120 is equal to the sum of the area of ​​the insulating member 120 and the area of ​​the explosion-proof valve protection patch.

[0078] In other possible embodiments, the insulating component 120 is provided to cover the explosion-proof valve 130. This prevents a short circuit between the battery 100 and the outer casing of the battery pack due to the explosion-proof valve 130 rupturing and bursting, thus improving the safety of the battery pack.

[0079] Optionally, such as Figure 12 As shown, the surface of the battery case body 110 adjacent to the bottom surface 111 is called the side surface 112 of the battery case body 110. In this embodiment, the insulating member 120 covers the side surface 112 of the battery case body 110, and there is a gap between the insulating member 120 and the bottom surface 111 of the battery case body 110. The ratio of the length d1 of the gap in the height direction of the battery case body 110 to the height d2 of the battery case body 110 is in the range of 0.05-0.95, and a and h satisfy the relationship: 0.01≤a / h≤0.06.

[0080] It should be noted that the ratio of d1 to d2 should not be too large. An excessively large ratio would result in a larger exposed area of ​​the battery casing 110, which would affect the insulation performance of the battery 100. In this embodiment, the ratio of d1 to d2 can be any value between 0.05 and 0.95, or any range between any two values; this embodiment does not limit this. For example, the ratio of d1 to d2 can be 0.05, 0.1, 0.3, 0.5, 0.6, 0.8, 0.9, 0.95, etc.

[0081] In one embodiment, such as Figure 11 As shown, the surface of the battery case body 110 facing away from the base plate 300 can be referred to as the top surface 113 of the battery case body 110. The insulating member 120 has an opening 124 corresponding to the portion of the top surface 113 of the battery case body 110, and a and h satisfy the relationship: 0.03 ≤ a / h ≤ 0.13. Thus, the insulating member 120 does not completely cover the top surface 113 of the battery case body 110. In this case, the total area S2 of the insulating member 120 is relatively small, while the area S1 of the notch 121 on the bottom surface 111 of the insulating member 120 is relatively large. By controlling the range of a / h to satisfy 0.03 ≤ a / h ≤ 0.13, while ensuring good bonding strength between the battery 100 and the base plate 300, short circuits between the base plate 300 and the battery 100 will not occur, improving the structural strength and safety performance of the battery pack. Furthermore, when the insulating member 120 does not cover the top surface 113 of the battery case body 110, the efficiency of the battery case body 110 covering the insulating member 120 is improved, thereby increasing the assembly and packing speed of the battery 100.

[0082] In some alternative embodiments, the opening 124 fully exposes the top surface 113 of the battery case body 110, thereby further improving the packing and assembly rate of the battery 100.

[0083] In other embodiments, the insulating member 120 may also cover a portion of the top surface 113 of the battery case body 110; that is, the top surface 113 of the battery case body 110 is provided with the insulating member 120. In one possible embodiment, such as Figure 11 As shown, the insulating component 120 includes a first insulating portion 122 and a second insulating portion 123 that are interconnected. The first insulating portion 122 is disposed on the top surface 113 of the battery casing body 110; the second insulating portion 123 covers the side surface 112 of the battery casing body 110 adjacent to the bottom surface 111. By assembling the insulating component 120 into two insulating portions, assembly efficiency can be improved, and the insulation effect on the exposed surface of the battery casing body 110 can be enhanced, thereby improving the overall insulation performance of the battery 100.

[0084] Optionally, the first insulating portion 122 includes an insulating protective film and / or an insulating protective coating, which is not limited in this embodiment. The second insulating portion 123 includes an insulating protective film and / or an insulating protective coating. The materials of the insulating protective film and the insulating protective coating have been given above and will not be repeated here.

[0085] In one possible implementation, the materials of the first insulating part 122 and the second insulating part 123 may be the same or different, and this embodiment does not limit this.

[0086] It should be noted that in this embodiment, the second insulating part 123 also covers at least part of the bottom surface 111 of the battery case body 110, that is, the notch 121 is provided on the second insulating part 123.

[0087] In this embodiment, the first insulating part 122 and the second insulating part 123 may overlap or not overlap on the top surface 113 of the battery case body 110. This embodiment will describe these two situations in detail.

[0088] The positional relationship between the first insulating portion 122 and the second insulating portion 123 on the top surface 113 of the battery housing body 110 is as follows: the first insulating portion 122 does not completely cover the top surface 113 of the battery housing body 110, leaving an exposed portion of the top surface 113; the second insulating portion 123 is at least partially disposed on the top surface 113 of the battery housing body 110; the edge of the first insulating portion 122 abuts against the edge of the second insulating portion 123 on the top surface 113 of the battery housing body 110; and the first insulating portion 122 and the second insulating portion 123 cooperate to cover the top surface 113 of the battery housing body 110. Thus, the first insulating portion 122 and the second insulating portion 123 do not overlap on the top surface 113 of the battery housing body 110, ensuring that the insulating member 120 does not affect the heat dissipation performance of the top surface 113 of the battery housing body 110, and that the height of the battery 100 does not increase due to the overlap of the first insulating portion 122 and the second insulating portion 123, thus guaranteeing the energy density of the battery pack.

[0089] Another positional relationship between the first insulating portion 122 and the second insulating portion 123 on the top surface 113 of the battery casing body 110 is as follows: the second insulating portion 123 is at least partially disposed on the top surface 113 of the battery casing body 110, and the first insulating portion 122 and the second insulating portion 123 at least partially overlap. Thus, the overlapping portion of the first insulating portion 122 and the second insulating portion 123 can improve the insulation performance of the insulating member 120, thereby giving the battery 100 a higher insulation effect.

[0090] It should be noted that, assuming the area of ​​the first insulating part 122 is S3, the area of ​​the second insulating part 123 is S4, and the area of ​​the first insulating part 122 and the second insulating part 123 overlapping on the top surface 113 of the battery case body 110 is S5, then the total area of ​​the surface of the battery case body 110 covered by the insulating member 120 is S2 = S3 + S4 - S5. It can be seen that the size of a reflects the size of the battery case body 110.

[0091] In this embodiment, to improve the insulation effect of the insulating member 120 at the connection between the top surface 113 and the side surface 112 of the battery case body 110, the area of ​​the top surface 113 of the battery case body 110 covered by the first insulating part 122 is, for example, a ratio of 30% to 95% of the area of ​​the top surface 113 of the battery case body 110. Thus, the area of ​​the portion of the first insulating part 122 bent towards the top surface 113 of the battery case body 110 can be controlled, thereby ensuring the insulation performance of the insulating member 120 at the connection between the top surface 113 and the side surface 112 of the battery case body 110.

[0092] It should be noted that the proportion of the area of ​​the top surface 113 of the battery case body 110 covered by the first insulating part 122 to the area of ​​the top surface 113 of the battery case body 110 is any value or any two values ​​between 30% and 95%, and this embodiment does not limit this. For example, the proportion of the area of ​​the top surface 113 of the battery case body 110 covered by the first insulating part 122 to the area of ​​the top surface 113 of the battery case body 110 is 30%, 45%, 50%, 60%, 70%, 80%, 90%, 95%, etc.

[0093] In one embodiment, the second insulating portion 123 is an insulating film, and the thickness of the insulating film ranges from 80μm to 110μm. When the thickness of the insulating film is within this range, the insulating effect of the second insulating portion 123 is good, and it does not additionally increase the height of the battery 100. The thickness of the insulating film cannot be too large, as this would result in an excessively high battery 100 and would not significantly improve the insulation performance. The thickness of the insulating film also cannot be too small, as this would affect the insulation effect and lead to insulation failure. The thickness of the insulating film can be any value within the range of 80μm-110μm or any two values; this embodiment does not limit this. For example, the thickness of the insulating film can be 80μm, 90μm, 100μm, 110μm, etc.

[0094] In other embodiments, the second insulating portion 123 may not be an insulating film, but an insulating coating. That is, the second insulating portion 123 is an insulating coating disposed on the top surface 113 of the battery casing body 110, and the thickness of the insulating coating ranges from 130μm to 170μm. When the thickness of the insulating coating is within this range, the insulating effect of the second insulating portion 123 is good, and it does not additionally increase the height of the battery 100. The thickness of the insulating coating cannot be too large, as this would result in an excessively high battery 100, with little improvement in insulation performance, and reduced adhesion of the insulating coating, making it prone to peeling off. The thickness of the insulating coating also cannot be too small, as this would affect the insulation effect and lead to insulation failure. The thickness of the insulating coating can be any value or any two values ​​between 130μm and 170μm, and this embodiment does not limit this. For example, the thickness of the insulating coating can be 130μm, 140μm, 150μm, 160μm, or 170μm.

[0095] Optionally, the adhesive layer 200 is located between the bottom surface 111 of the battery case body 110 and the base plate 300, and the insulating member 120 overlaps with the adhesive layer 200 at least partially. Thus, the overlapping portion between the adhesive layer 200 and the insulating member 120 allows the adhesive layer 200 to bond not only to the portion of the battery case body 110 exposed through the notch 121, but also to the surface of the insulating member 120 facing the base plate 300. This results in a larger bonding area between the bottom of the battery 100 and the adhesive layer 200, improving the bonding strength between the battery 100 and the base plate 300.

[0096] In one possible implementation, the thickness of the adhesive layer 200 ranges from 0.5mm to 3.4mm. Thus, when the thickness of the adhesive layer 200 is within a certain range, the bonding strength between the battery 100 and the base plate 300 can be improved. Simultaneously, since the adhesive layer 200 is also insulating, the insulation performance between the battery 100 and the base plate 300 is improved to a certain extent.

[0097] It should be noted that the thickness of the adhesive layer 200 can be any value or any two values ​​between 0.5mm and 3.4mm, and this embodiment does not limit it. For example, the thickness of the adhesive layer 200 can be 0.5mm, 0.6mm, 0.8mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.4mm, etc.

[0098] For example, the dielectric constant of the adhesive layer 200 ranges from 2.4 F / m to 4.2 F / m. It should be noted that the dielectric constant of the adhesive layer 200 mentioned in this embodiment refers to the dielectric constant range of 2.4 F / m to 4.2 F / m at a frequency of 1 MHz. Thus, when the dielectric constant of the adhesive layer 200 is within a certain range, the adhesive layer 200 also possesses a certain insulating capability, thereby improving the insulation performance between the battery 100 and the base plate 300.

[0099] It should be noted that the dielectric constant of the adhesive layer 200 can be any value or any two values ​​between 2.4 F / m and 4.2 F / m, and this embodiment does not limit it. For example, the dielectric constant of the adhesive layer 200 can be 2.4 F / m, 3 F / m, 3.2 F / m, 3.4 F / m, 3.8 F / m, 4 F / m, 4.2 F / m, etc.

[0100] Optionally, the thickness of the insulating layer 400 ranges from 0.02mm to 0.3mm. Thus, when the thickness of the insulating layer 400 is within a certain range, the insulating effect of the insulating layer 400 is excellent, ensuring the insulation effect between the battery 100 and the base plate 300.

[0101] It should be noted that the thickness of the insulating layer 400 can be any value or any two values ​​between 0.02mm and 0.3mm, and this embodiment does not limit it. For example, the thickness of the insulating layer 400 can be 0.02mm, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, etc.

[0102] Optionally, the base plate 300 in this embodiment can be a heat exchange plate or a regular plate; this embodiment does not limit this. When the base plate 300 is a heat exchange plate, a and h satisfy the relationship: 0.05 ≤ a / h ≤ 0.13. Thus, when the base plate 300 is a heat exchange plate, the cooling effect on the battery can be improved. When the range of a / h satisfies 0.05 ≤ a / h ≤ 0.13, the connection strength between the battery 100 and the base plate 300 can be guaranteed, the insulation performance between the battery 100 and the base plate 300 can be improved, and the heat dissipation effect of the battery 100 can be improved, reducing the risk of thermal runaway of the battery 100.

[0103] In one embodiment, the roughness Ra of the base plate 300 ranges from 0.8 μm to 3.2 μm. Thus, when the roughness of the base plate 300 is within a certain range, the adhesion between the base plate 300 and the insulating layer 400 is better, the insulating layer 400 can adhere better to the base plate 300, the risk of it falling off the base plate 300 is lower, resulting in fewer weak insulation areas in the insulating layer 400. In other words, the connection strength between the base plate 300 and the battery casing body 110 is higher.

[0104] In one embodiment, the battery 100 further includes a terminal post 140, which can be located on the side 112 or the bottom 111 of the battery casing 110, and a and h satisfy the relationship: 0.01≤a / h≤0.10. When the terminal post 140 is located on the side 112 or the bottom 111 of the battery 100, it is necessary to prevent the terminal post 140 from conducting with the base plate 300, that is, to prevent the terminal post 140 from short-circuiting with the base plate 300. When the value range of a / h satisfies the relationship 0.01≤a / h≤0.10, the insulation performance between the battery 100 and the base plate 300 can be guaranteed, the conduction between the terminal post 140 and the base plate 300 can be avoided, and the overall safety and insulation performance of the battery 100 can be improved.

[0105] In other embodiments, when the battery includes terminals 140, such as Figure 11 As shown, the terminal 140 can also be located on the top surface 113 of the battery housing body 110. The top surface of the battery housing body 110 is positioned opposite to the bottom surface 111 of the battery housing body 110, and a and h satisfy the relationship: 0.03≤a / h≤0.13. In this way, the terminal 140 is far from the base plate 300. When the value range of a / h satisfies the relationship 0.01≤a / h≤0.10, the battery 100 and the base plate 300 can have a high connection strength while improving the insulation effect between them.

[0106] For example, such as Figure 13 As shown, the maximum distance d3 between the edge of the insulating layer 400 and the edge of the lower surface of the battery 100 projected onto the insulating layer 400 ranges from 0.5mm to 7mm. This improves the insulation effect at the notch 121 between the base plate 300 and the insulating component 120, ensuring that the insulating layer 400 completely covers the edge of the notch 121. Furthermore, while maintaining insulation effectiveness, the area of ​​the insulating layer 400 does not need to be excessively large, reducing insulation material loss and thus lowering the cost of the battery pack.

[0107] Optionally, the maximum distance d3 between the edge of the insulating layer 400 and the edge of the corresponding bottom surface of the battery 100 projected onto the insulating layer 400 can be any value between 0.5mm and 7mm, or any two values. This embodiment does not limit this. For example, the maximum distance d3 between the edge of the insulating layer 400 and the edge of the corresponding bottom surface of the battery 100 projected onto the insulating layer 400 can be 0.5mm, 1mm, 2mm, 3mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, etc.

[0108] It should be noted that the edge of the insulating layer 400 may extend beyond the edge of the bottom surface 111 of the battery case body 110, and the distance between the two satisfies the above-mentioned relationship. Alternatively, the edge of the insulating layer 400 may not extend beyond the edge of the bottom surface 111 of the battery case body 110. That is, the orthographic projection of the bottom surface 111 of the battery case body 110 onto the plane where the insulating layer 400 is located completely covers the insulating layer 400, and the distance between the two satisfies the above-mentioned relationship. This embodiment does not limit this.

[0109] Optionally, the battery pack typically includes multiple batteries 100, which are arranged in rows and / or columns at intervals on the base plate 300. In this embodiment, the insulating layer 400 at least completely covers the bottom surface 111 of one battery 100. Thus, the insulating layer 400 completely covers the bottom surface of the battery 100, satisfying the insulation requirements of that single battery 100's bottom surface. In some optional embodiments, the insulating layer 400 completely covers the bottom surface of each battery 100, thereby satisfying the insulation requirements of the bottom surfaces of multiple batteries 100.

[0110] In some alternative embodiments, the surface of the base plate 300 facing the battery 100 can be completely covered by the insulating layer 400, so that the bottom surface of each battery 100 can be covered by the insulating layer 400, thereby improving the insulation effect between the battery 100 and the base plate 300.

[0111] In some alternative embodiments, the bottom plate 300 has a plurality of insulating layers 400 on the surface facing the battery 100, and the plurality of insulating layers 400 correspond one-to-one with the plurality of batteries 100, and each insulating layer 400 can cover the bottom surface of the battery 100 to which it corresponds.

[0112] When multiple batteries 100 are spaced apart on the base plate 300, the insulating layer 400 completely covers the bottom surface of one battery 100, and the insulating layer 400 at least covers the bottom surface of adjacent batteries 100. In this way, when the insulating layer 400 covers the bottom surfaces of multiple batteries 100, the coating efficiency and insulation effect of the insulating layer 400 can be improved, thereby improving the packing effect of the batteries 100.

[0113] The battery pack provided in this embodiment has a notch 121 on the surface of the insulating member 120 of the battery 100 facing the base plate 300, which can improve the connection strength between the battery 100 and the base plate 300 and improve the heat dissipation performance of the battery 100. By controlling the ratio of the area S1 of the notch 121 to the total area S2 of the surface of the battery casing body 110 covered by the insulating member 120, and the relationship between the minimum distance h of the battery casing body 110 located at the notch 121 and the base plate 300, the insulation effect between the battery 100 and the base plate 300 can be guaranteed, and the energy density of the battery pack can also be high.

[0114] This embodiment also provides a method for testing insulation performance, which can test the insulation performance between the battery and the base plate.

[0115] During the testing process, different a / h values ​​were given, and the resistance between the battery and the base plate 300 was tested when the a / h values ​​were different. A / h values ​​between 0.01 and 0.13 were designated as examples, and this embodiment provides 23 examples. A / h values ​​outside the 0.01-0.13 range were designated as comparative examples, and this embodiment provides 4 comparative examples. For each example and each comparative example, 10 batteries of the same model were used, differing only in their a / h values; all other aspects were the same. A notch 121 was made on the surface of the insulating component 120 of the battery 100, and the notch 121 was cleaned with alcohol. After natural drying, adhesive was applied to the surface of the battery casing 110 facing the base plate (specifically, at the notch), resulting in an adhesive layer 200. The glued battery was then bonded to an aluminum alloy plate coated with an insulating layer 400 (used to simulate the base plate 300) and cured at 25°C for 24 hours. The ratio a of the area S1 of the notch 121 of the insulating component 120 to the total area S2 of the battery casing body 110 covered by the insulating component 120 in different embodiments and comparative examples, and the minimum distance h of the battery casing body 110 at the notch 121 from the aluminum alloy plate are shown in Table 1 below. All other conditions are the same. The resistance between the battery 100 and the aluminum alloy plate was tested using an insulation withstand voltage tester. One output terminal of the insulation withstand voltage tester was connected to the aluminum alloy plate, and the other end was connected to the exposed aluminum part on the battery surface. A DC voltage of 3000V was applied between the two output terminals, and the current was measured. The resistance between the battery 100 and the aluminum alloy plate was calculated according to formula (1). The resistance of 10 batteries in each embodiment and comparative example was measured and the average value was taken to obtain the test results. The specific results are shown in Table 1. If the obtained resistance is greater than or equal to 500MΩ, the insulation between battery 100 and aluminum alloy plate is qualified; if the obtained resistance is less than 500MΩ, the insulation between battery 100 and aluminum alloy plate is unqualified.

[0116] R = U / I (1)

[0117] This embodiment also provides a method for testing the pull-out force between the battery and the base plate.

[0118] Similarly, for different embodiments and comparative examples, 10 batteries of the same model were taken, with the only difference being the a / h value. A notch 121 was made on the surface of the insulating part 120 of the battery 100, and the notch 121 was cleaned with alcohol. After air drying, adhesive was applied to the surface of the battery casing body 110 facing the bottom plate (specifically, at the notch) to obtain an adhesive layer 200. The glued battery was then bonded to an aluminum alloy plate (used to simulate the base plate 300) coated with an insulating layer 400 and cured at 25°C for 24 hours. The ratio 'a' of the area S1 of the notch 121 of the insulating component 120 to the total area S2 of the battery casing body 110 covered by the insulating component 120, and the minimum distance h of the battery casing body 110 at the notch 121 from the aluminum alloy plate are shown in Table 1. All other parameters are the same. The peel force of the battery 100 from the aluminum alloy plate was tested using an electronic universal testing machine (ETM304C Shenzhen WanCe) at a rate of 5 mm / min. Ten tests were performed for each embodiment and comparative example, and the average value was taken. Specific results are shown in Table 1. If the tested peel force is greater than or equal to 10 MPa, the connection strength between the battery and the aluminum alloy plate is qualified; if the tested peel force is less than 10 MPa, the connection strength between the battery and the aluminum alloy plate is unqualified.

[0119] Table 1

[0120]

[0121]

[0122] A comparison of the actual data from Examples 1 to 14 and Comparative Examples 1 to 4 reveals that when a / h is within a certain range, the bonding strength between the battery 100 and the aluminum alloy sheet is good, and the insulation performance between them is good, eliminating the risk of short circuits. A comparison of the experimental data from Examples 1 to 14 and Examples 15 to 23 reveals that when a is too small, the coverage ratio of the insulating component 120 on the surface of the battery casing 110 is too large, resulting in poor heat dissipation. When a is too large, the heat transfer between adjacent batteries 100 becomes faster, making it impossible to effectively reduce heat transfer between adjacent batteries 100 when the battery 100 experiences thermal runaway. When h is too small, the heat exchange rate between the battery 100 and the base plate 300 is too fast, and thermal runaway of one battery 100 will affect other batteries 100. If h is too large, the heat dissipation of the bottom surface of the battery 100 is poor.

[0123] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A battery pack, comprising a battery (100), an adhesive layer (200), and a base plate (300), wherein the base plate (300) supports the battery (100), and the adhesive layer (200) is located between the battery (100) and the base plate (300) and is used to fix the base plate (300) and the battery (100); characterized in that, The battery includes a battery casing body (110) and an insulating member (120) covering the surface of the battery casing body (110); the insulating member (120) has a notch (121), the notch (121) exposes at least a portion of the bottom surface of the battery casing body (110) facing the base plate (300), the adhesive layer (200) is at least partially disposed at the notch (121) and bonded to the base plate (300); an insulating layer (400) is disposed between the base plate (300) and the adhesive layer (200), and the orthographic projection of the notch (121) on the base plate (300) falls within the orthographic projection of the insulating layer (400) on the base plate (300); The ratio of the area S1 of the notch (121) of the insulating element (120) to the total area S2 of the surface of the battery case body (110) covered by the insulating element (120) is a, i.e., a = S1 / S2; the minimum distance between the battery case body (110) located at the notch (121) and the bottom plate (300) is h millimeters; a and h satisfy the relationship: 0.01 ≤ a / h ≤ 0.13; The thickness of the adhesive layer (200) ranges from 0.5mm to 3.4mm; the base plate (300) is a heat exchange plate; The value of a ranges from 0.01 to 0.2; the value of h ranges from 0.7 to 3.

8.

2. The battery pack according to claim 1, characterized in that, The insulating member (120) covers the side of the battery case body (110) adjacent to the bottom surface of the battery case body (110), and there is a gap between the insulating member (120) and the bottom surface of the battery case body (110). The ratio of the length d1 of the gap in the height direction of the battery case body (110) to the height d2 of the battery case body (110) is in the range of 0.05-0.95, and a and h satisfy the relationship: 0.01≤a / h≤0.

06.

3. The battery pack according to claim 1, characterized in that, The insulating component (120) has an opening (124) on the top surface of the battery housing body (110) facing away from the bottom plate (300), and a and h satisfy the relationship: 0.03≤a / h≤0.

13.

4. The battery pack according to claim 1, characterized in that, The insulating component (120) includes a first insulating portion (122) and a second insulating portion (123); the first insulating portion (122) is disposed on the top surface of the battery housing body (110) on the side facing away from the bottom plate (300); the second insulating portion (123) covers the side surface of the battery housing body (110) adjacent to the bottom surface, and the second insulating portion (123) also covers at least a portion of the bottom surface of the battery housing body (110), and the notch (121) is disposed on the second insulating portion (123).

5. The battery pack according to claim 1, characterized in that, The adhesive layer (200) is located between the bottom surface of the battery case body (110) and the base plate (300), and the insulating member (120) at least partially overlaps with the adhesive layer (200).

6. The battery pack according to claim 1, characterized in that, The dielectric constant of the adhesive layer (200) ranges from 2.4 F / m to 4.2 F / m.

7. The battery pack according to claim 1, characterized in that, The battery pack includes a plurality of the batteries (100), and the insulating layer (400) completely covers the bottom surface of at least one of the batteries (100).

8. The battery pack according to claim 1, characterized in that, The maximum distance d3 between the edge of the insulating layer (400) and the edge of the bottom surface of the battery (100) projected onto the insulating layer (400) ranges from 0.5mm to 7mm.

9. The battery pack according to claim 1, characterized in that, The battery pack includes a plurality of batteries (100) spaced apart on the base plate (300); the insulating layer (400) completely covers the bottom surface of one of the batteries (100), and the insulating layer (400) at least partially covers the bottom surface of adjacent batteries (100).

10. The battery pack according to claim 1, characterized in that, The roughness Ra of the base plate (300) ranges from 0.8 μm to 3.2 μm.

11. The battery pack according to claim 1, characterized in that, The battery (100) also includes a terminal post, which is located on the side or bottom of the battery casing body (110), and a and h satisfy the relationship: 0.01≤a / h≤0.

10.

12. The battery pack according to claim 1, characterized in that, The battery (100) also includes a terminal post, which is located on the top surface of the battery housing body (110). The top surface of the battery housing body (110) is opposite to the bottom surface of the battery housing body (110), and a and h satisfy the relationship: 0.03≤a / h≤0.13.

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