Battery pack

Abstract

The invention belongs to the technical field of batteries, and discloses a battery pack which comprises a battery, an adhesive layer and a bottom plate, and the adhesive layer is located between the battery and the bottom plate; the battery comprises a battery shell body and an insulating part coated on the surface of the battery shell body; the insulating part is provided with a notch, the notch exposes at least partial area of the bottom surface, facing one side of the bottom plate, of the battery shell body, the adhesive layer is at least partially arranged at the notch and is bonded and connected with the bottom plate, an insulating layer is arranged between the bottom plate and the adhesive layer, and the orthographic projection of the notch on the bottom plate falls into the orthographic projection of the insulating layer on the bottom plate; the ratio of the notch area S1 of the insulating part to the total area S2 of the surface of the battery shell body wrapped by the insulating part is a, namely a = S1 / S2; the minimum distance between the battery shell body located at the notch and the bottom plate is h mm, and a and h meet the relational expression that a / h is larger than or equal to 0.01 and smaller than or equal to 0.13. The battery pack provided by the invention can have relatively high insulating property, the bonding strength of the battery and the bottom plate is relatively high, and the energy density of the battery pack is relatively large.

Description

[0001] This application is a divisional application. The application number of the original application is 2025105681125, the application date is April 30, 2025, and the name of the invention is “Battery Pack”. Technical Field

[0002] The present invention relates to the technical field of batteries, and in particular to a battery pack. Background Art

[0003] A battery pack typically includes a box and multiple batteries housed within it. The bottom of the batteries are bonded to the bottom plate of the box using a colloid to increase the overall strength of the battery pack and prevent damage to the battery pack under vibration conditions.

[0004] Currently, batteries are covered with an insulating member. To ensure the secure connection between the battery and the bottom plate of the housing, a metal shell is typically left exposed near the bottom plate of the insulating member for gluing and securing the battery to the bottom plate. This ensures the adhesive layer maintains a strong bond between the battery and the housing. However, this arrangement can lead to the risk of insulation failure between the battery and the housing. Summary of the Invention

[0005] The object of the present invention is to provide a battery pack to solve the technical problem in the prior art that both insulation performance and bonding strength cannot be taken into account.

[0006] As conceived above, the technical solution adopted by the present invention is:

[0007] A battery pack, comprising a battery, an adhesive layer, and a base plate, wherein the base plate is used to support the battery, the adhesive layer is located between the battery and the base plate and is used to fixedly connect the base plate and the battery; the battery comprises a battery shell body and an insulating member covering the surface of the battery shell body; the insulating member is provided with a notch, the notch exposing at least a portion of the bottom surface of the battery shell body facing the base plate; the adhesive layer is at least partially disposed in the notch and is adhesively connected to the base plate; an insulating layer is provided between the base plate and the adhesive layer, and the orthographic projection of the edge of the notch on the base plate falls within the orthographic projection of the insulating layer on the base plate;

[0008] The ratio of the notch area S1 of the insulating member to the total area S2 of the surface of the battery shell body covered by the insulating member is a, that is, a=S1 / S2; the minimum distance between the battery shell body located at the notch and the bottom plate is h mm, 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 providing an insulating layer on the bottom plate, the insulation strength between the portion of the battery body corresponding to the notch and the bottom plate is improved. However, the provision of the insulating layer on the bottom plate makes the overall processing difficulty of the bottom plate and the bonding strength between the bottom plate and the battery weakened. Therefore, by controlling the range of a / h to meet the above relationship, it is possible to ensure that the bonding strength between the battery and the bottom plate is good and that the bottom plate and the battery are not short-circuited, thereby 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 shell body will increase, the risk of short-circuiting between the battery shell body and the bottom plate will increase, and the insulation performance between the two will decrease, resulting in the problem of short-circuiting between the battery and the bottom plate, affecting the safety performance of the battery. If the a / h value is too small, the bonding area between the battery shell body and the bottom plate and the distance between the battery shell body and the bottom plate are too far, resulting in weak bonding strength between the battery and the bottom plate. There is a risk of falling off under vibration conditions of the battery pack, affecting the overall strength and safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0012] Figure 1 is a schematic structural diagram of a battery pack provided by one embodiment of the present invention;

[0013] Figure 2 is a schematic cross-sectional view of a battery pack provided by one embodiment of the present invention;

[0014] Figure 3 An embodiment of the present invention provides Figure 2 An enlarged view of point A is shown;

[0015] Figure 4 1 is a schematic structural diagram of a battery provided by one embodiment of the present invention;

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

[0017] Figure 6 is a bottom view of a battery provided by one embodiment of the present invention;

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

[0019] Figure 8 is a bottom view of another battery provided by one embodiment of the present invention;

[0020] Figure 9 is a bottom view of another battery provided by one embodiment of the present invention;

[0021] Figure 10 is a partially enlarged view of a cross-sectional view of a battery pack provided by one embodiment of the present invention;

[0022] Figure 11 is a three-dimensional diagram of a battery provided in one embodiment of the present invention;

[0023] Figure 12 is a front view of a battery provided by one embodiment of the present invention;

[0024] Figure 13 It is a partially enlarged cross-sectional view of another battery pack provided by one embodiment of the present invention.

[0025] In the picture:

[0026] 100. Battery; 110. Battery shell body; 111. Bottom; 112. Side; 113. Top; 120. Insulator; 121. Notch; 122. First insulating portion; 123. Second insulating portion; 124. Opening; 130. Explosion-proof valve; 140. Post; 150. Cell; 200. Glue layer; 300. Bottom plate; 400. Insulating layer; 500. Frame structure; 510. Frame; 520. Crossbeam; 530. Longitudinal beam; 10. Outer box; 101. Battery sub-compartment; X, first direction. DETAILED DESCRIPTION

[0027] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the drawings only show portions relevant to the present invention, not all of them.

[0028] It should be understood that references throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present invention. Therefore, appearances of "in one embodiment" or "in an embodiment" throughout this specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0030] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0031] In the present invention, unless otherwise clearly stipulated and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is at a lower 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, terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate description and simplify operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used only to distinguish in the description and have no special meaning.

[0033] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or there may be an element located in the middle.

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

[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, Figure 1As shown, the battery generally includes an outer box body 10 and a plurality of batteries 100 arranged in the outer box body 10, and the batteries 100 are arranged in groups in the outer box body 10. The outer box body 10 generally includes a bottom plate 300, a frame structure 500 and a box cover (not shown in the figure). The frame structure 500 includes a frame 510, a crossbeam 520 and a longitudinal beam 530. The frame 510 is connected between the bottom plate 300 and the box cover to form a battery compartment, and the crossbeam 520 and the longitudinal beam 530 are cross-connected in the battery compartment and divide the battery compartment into a plurality of battery sub-compartments 101, and each battery sub-compartment 101 is provided with a plurality of batteries 100. Optionally, only one or more crossbeams 520 and longitudinal beams 530 can be provided, and this embodiment is not limited to this.

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

[0038] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the stacked multiple positive electrode tabs can be directly welded to the positive electrode column to form an electrical connection. Alternatively, the battery cell assembly may further include a positive electrode adapter. The stacked multiple positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode column to form an electrical connection between the positive electrode tab and the positive electrode column.

[0039] The negative electrode sheet can generally include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tabs can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter. The multiple stacked negative electrode tabs are welded to one end of the negative electrode adapter, and the other end of the negative electrode adapter is welded to the negative electrode column to form an electrical connection between the negative electrode tab and the negative electrode column. The material of the separator is not limited, and can be, for example, polypropylene or polyethylene.

[0040] Optionally, the outer box body can be formed by assembling the bottom plate 300 and the side plates connected to the bottom plate, that is, Figure 2 and Figure 3 As shown, the battery pack further includes a bottom plate 300, which is used to support the battery 100. The battery 100 is fixedly bonded to the bottom plate 300 through the adhesive layer 200. Specifically, the adhesive layer 200 is located between the battery 100 and the bottom plate 300 and is used to fix the bottom plate 300 and the battery 100.

[0041] The battery in this embodiment includes a battery shell body 110 and an insulating member 120 covering the surface of the battery shell body 110. The insulating member 120 is used to insulate the battery shell body 110 from the outside world. It should be noted that the insulating member 120 and the battery shell body 110 are fixedly connected and connected as a whole, so that the insulating member 120 does not move relative to the battery shell body 110.

[0042] Optionally, the insulating part 120 includes an insulating protective film and / or an insulating protective coating, that is, the insulating part 120 may include only an insulating protective film; or only an insulating protective coating; or 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 part of the structure of the insulating part 120 may be an insulating protective film, and the other part of the structure may be an insulating protective coating; the specific selection may be flexible, and this embodiment does not limit this.

[0043] It should be noted that the insulating protective film can be coated on the battery shell body 110 in an adhesive manner; the insulating protective coating can be coated on the battery shell body 110 in a coating manner, which is not limited in this embodiment.

[0044] Exemplarily, the insulating protective film is made of polyethylene terephthalate, polyimide, polypropylene, etc. The insulating protective coating is made of polyacrylate, silicone, polyurethane, epoxy resin, etc., which are not limited in this embodiment. 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 a portion of the insulating member 120 between the bottom surface 111 of the battery shell body 110 on the side 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 shell body 110 on the side facing the bottom plate 300. The adhesive layer 200 is at least partially provided at the notch 121 and bonded to the bottom plate 300, thereby improving the bonding strength and reliability of the battery shell 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 the battery shell body 110) is the insulating member 120. That is, the insulating material covering the outer surface of the battery 100 (or the battery shell body 110) except for the opening facing the bottom plate 300 is the insulating member 120. In other words, as long as the insulating material covering the outer surface of the battery 100 (or the battery shell body 110) is the insulating member 120.

[0047] In this embodiment, please continue to refer to Figure 2 and Figure 3 An insulating layer 400 is provided between the bottom plate 300 and the adhesive layer 200. The insulating layer 400 is used to improve the insulation performance between the battery shell body 110 and the bottom plate 300. The orthographic projection of the notch 121 on the bottom plate 300 falls within the orthographic projection of the insulating layer 400 on the bottom plate 300. In other words, the orthographic projection of the notch 121 on the bottom plate 300 is completely located within the orthographic projection of the insulating layer 400 on the bottom plate 300. In other words, the orthographic projection of the notch 121 on the insulating layer 400 is completely located on the insulating layer 400, without having a portion located outside the insulating layer 400. In this way, the portion of the bottom surface 111 of the battery shell body 110 exposed through the notch 121 is directly opposite to the insulating layer 400, rather than directly opposite to the bottom plate 300, so that the insulation performance with the bottom plate 300 can be improved through the insulating layer 400.

[0048] In this embodiment, if 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 battery shell body 110 covered by the insulating member 120 is a, that is, a=S1 / S2. It can be seen that a in this embodiment can be used to represent the size of the battery shell body 110. Figure 3As shown, the minimum distance between the battery case body 110 located at the notch 121 and the bottom plate 300 is h mm. That is, the minimum distance between the portion of the bottom surface 111 of the battery case body 110 opposite the notch 121 and the bottom plate 300 is h mm. Where 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, which is not limited in this embodiment. 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 shell 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 to 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 , or other common units, which is not limited in this embodiment.

[0051] In some optional embodiments, this embodiment provides a value range of a, for example, the value range of 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 further provides a value range of h, for example, the value range of h is 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 is 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 shell body 110 covered by the insulating member 120. Therefore, the size of a determines the ratio of the area S1 of the notch 121 to the total area of ​​the entire insulating member 120 on the surface of the battery shell body 110. This is used to confirm the overlap between the battery shell body 110 and the bottom plate 300, so as to more accurately reflect the risk of insulation failure of the battery shell body 110. It should be noted that the insulation failure risk mentioned in this embodiment can be understood as follows: in addition to metal-to-metal overlap, there is also the possibility of insulation failure due to condensation on the surface of the battery body 110 or liquid conduction such as electrolyte.

[0054] By providing an insulating layer 400 on the bottom plate 300, the insulation strength between the portion of the battery body 110 corresponding to the notch 121 and the bottom plate 300 is improved. However, the provision of the insulating layer 400 on the bottom plate 300 reduces the overall processing difficulty of the bottom plate 300 and the bonding strength between the bottom plate 300 and the battery 100. Therefore, by controlling the range of a / h to satisfy 0.01≤a / h≤0.13, it is possible to ensure good bonding strength between the battery 100 and the bottom plate 300, and also to ensure that short circuiting between the bottom plate 300 and the battery 100 does not occur, thereby 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 shell body 110 will increase, the risk of short circuit between the battery shell body 110 and the bottom plate 300 will increase, and the insulation performance between the two will decrease, which will lead to the problem of short circuit between the battery 100 and the bottom plate 300, affecting the safety performance of the battery 100 and the battery pack; if the a / h value is too small, the bonding area between the battery shell body 110 and the bottom plate 300 and the distance between the battery shell body 110 and the bottom plate 300 are too far, resulting in weak bonding strength between the battery 100 and the bottom plate 300, and there is a risk of falling off under vibration conditions of the battery pack, affecting the overall strength and safety of the battery.

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

[0056] Illustratively, the material of the bottom plate 300 is a metal material. For example, the material of the bottom plate 300 can be aluminum, stainless steel, aluminum alloy, iron, etc., which is not limited in this embodiment.

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

[0058] In some optional embodiments, such as Figure 4As shown, the area of ​​the orthographic projection of the notch 121 on the bottom plate 300 is smaller than the area of ​​the bottom surface 111 of the battery case body 110. In this case, a and h satisfy the relationship: 0.05≤a / h≤0.13. It should be noted that the area of ​​the orthographic projection of the notch 121 on the bottom plate 300 is smaller than the area of ​​the bottom surface 111 of the battery case body 110. In other words, the notch 121 does not completely expose the bottom surface 111 of the battery case body 110, but only partially. In this case, the bonding area between the battery 100 and the bottom plate 300 is small, and the fixing strength between the battery 100 and the bottom plate 300 is weak. Therefore, by reducing the distance between the battery 100 and the bottom plate 300, the connection strength between the two is improved.

[0059] When the area of ​​the orthographic projection of the notch 121 on the bottom plate 300 is smaller than the area of ​​the bottom surface 111 of the battery shell body 110, the relative positional relationship between the notch 121 and the bottom surface 111 of the battery shell body 110 has various situations. This embodiment exemplarily provides the following three possible implementation methods.

[0060] In one embodiment, 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 shell body 110 in the first direction. It should be noted that 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 shell body 110 in the first direction. It can be understood that the orthographic projection of the edge of one end of the notch 121 in the first direction on the bottom 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 shell body 110 in the first direction on the bottom plate 300.

[0061] It should also be noted that the first direction is the length direction or width direction of the battery shell body 110, which is not limited in this embodiment. Figure 6 The schematic diagram shows that the first direction is the length direction of the battery case body 110 .

[0062] In another possible embodiment, Figure 7 As shown, the edges of the notch 121 at both ends in the first direction coincide with 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 embodiment, Figure 8As shown, the edge of the notch 121 is spaced apart from the edge of the bottom surface 111 of the battery shell body 110, that is, the edge of the notch 121 does not extend to the edge of the bottom surface 111 of the battery shell body 110. In addition, the minimum value b of the spacing distance between the edge of the notch 121 and the edge of the bottom surface 111 of the battery shell body 110 is in the range of 2mm-30mm. In this way, 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 shell body 110, the exposed area of ​​the bottom surface 111 of the battery shell body 110 is smaller, so that the risk of short circuit between the battery shell body 110 and the bottom plate 300 is reduced.

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

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

[0066] The battery packs in the above three possible implementation modes can all meet the insulation performance requirements of the battery 100 and the base plate 300, the connection strength requirements of the battery 100 and the base plate 300, and the high energy density requirements of the battery pack.

[0067] In other optional embodiments, such as Figure 9 As shown, the area of ​​the orthographic projection of the notch 121 on the bottom 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. The orthographic projection of the notch 121 on the bottom plate 300 is equal to the area of ​​the bottom surface 111 of the battery case body 110, which can be understood as the portion of the battery case body 110 that is completely exposed toward the bottom surface 111 of the bottom plate 300 and not covered by the insulating member 120. When the orthographic projection of the notch 121 on the bottom 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, the bonding strength between the battery 100 and the bottom plate 300 is improved, and the creepage clearance between the battery case body 110 and the bottom plate 300 is increased, thereby preventing short circuits between the bottom plate 300 and the battery 100, thereby improving the overall structural strength and safety of the battery pack.

[0068] In some optional embodiments, such as Figure 10As shown, the battery 100 also includes an explosion-proof valve 130, which can be provided on the bottom surface 111 of the battery shell body 110 facing the bottom plate 300. The explosion-proof valve 130 is used to release the gas inside the battery 100 from the explosion-proof valve 130 when the battery 100 experiences thermal runaway and reaches a certain pressure inside, so that the high-temperature gas inside the battery 100 can be discharged. The explosion-proof valve 130 generally achieves pressure relief by forming a notch as a weak part of the battery shell body 110. The adhesive layer 200 is provided with an avoidance hole (not shown in the figure) at the position corresponding to the explosion-proof valve 130 to prevent the explosion-proof valve 130 from bursting due to untimely pressure relief of the explosion-proof valve 130. The orthographic projection of the explosion-proof valve 130 on the adhesive layer 200 is located in the avoidance hole, so that the setting of the adhesive layer 200 will not affect the rupture and exhaust 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 refers to the orthographic projection of the explosion-proof valve 130 on the surface of the insulating member 120 facing the base plate 300 being located within the notch 121. In other words, the explosion-proof valve 130 is disposed directly opposite the notch 121.

[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 orthographic 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 discharge gas and pressure within the battery case 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 of the adhesive layer 200 to the bottom of the battery case body 110 can be ensured without affecting the insulation performance between the battery 100 and the bottom plate 300.

[0070] In order to ensure that the bonding strength of the entire bottom surface 111 of the battery shell body 110 does not cause the risk of a weak side due to a small bonding area, it is necessary to control the distance between the explosion-proof valve 130 and the edge of the notch 121 in a direction perpendicular to the height direction of the battery shell body 110. For example, 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 a direction perpendicular to the height of the battery case body 110 (i.e., the length or width of the battery case body 110) ranges from 0.2 mm to 5 mm. This allows for a gap between the edge of the explosion-proof valve 130 and the edge of the notch 121. This gap allows for the adhesive layer 200 to be positioned, thereby improving the bonding strength between the battery case body 110 and the bottom plate 300. 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 a direction perpendicular to the height direction of the battery case body 110 is any value between 0.2 mm and 5 mm, or a range between 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 a direction perpendicular to the height direction of the battery case body 110 is 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 shell body 110 are integrally formed, that is, the battery shell body 110 is provided with a weak area, and the function of the weak area is exactly the same as that of the explosion-proof valve 130, so the weak area can be considered as the explosion-proof valve 130. By providing the explosion-proof valve 130 and the battery shell body 110 as an integral structure, the processing and manufacturing of the explosion-proof valve 130 can be facilitated, the assembly steps of the battery are reduced, the assembly efficiency of the battery is improved, and the functions of the battery shell body 110 are enriched.

[0073] Of course, it is understandable that the explosion-proof valve 130 may not be integrally formed with the battery shell body 110, but may be two independent components of the battery shell body 110, that is, the explosion-proof valve 130 is a split explosion-proof valve. In this case, the connection method between the explosion-proof valve 130 and the battery shell body 110 may be welding fixation, etc., which is not limited in this embodiment.

[0074] In one embodiment, since the explosion-proof valve 130 is arranged 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 shell body 110. The explosion-proof valve protection patch is used to protect the explosion-proof valve 130 to avoid the explosion-proof valve 130 from rupturing before the rupture conditions are met, and also prevent the explosion-proof valve 130 from rupturing 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 protection patch has the same insulating function as the insulating member 120. Exemplarily, the explosion-proof valve protection patch is made of an insulating material, such as polytetrafluoroethylene, polyethylene terephthalate, polyethylene, polypropylene, polyimide, or the like. In this case, the total area S2 of the battery case 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 protection patch. In other words, the insulating member 120 includes the explosion-proof valve protection patch. In other words, a portion of the insulating member 120 forms the explosion-proof valve protection patch.

[0076] Of course, it is understandable that the explosion-proof valve 130 may not be arranged on the bottom surface 111 of the battery shell body 110 facing the bottom plate 300, but may be arranged on other surfaces. Figure 11 As shown, the explosion-proof valve 130 is disposed on the battery case body 110, and the surface of the battery case body 110 on which the explosion-proof valve 130 is disposed is different from the surface of the battery case body 110 opposite the notch 121. For example, the explosion-proof valve 130 is disposed on the top surface of the battery case body 110 on the side facing away from the bottom 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 short-circuit the battery 100 and the bottom plate 300 due to the explosion of the explosion-proof valve 130, thereby improving the safety of the battery pack.

[0077] In one embodiment, the insulating member 120 is provided with an avoidance portion (not shown in the figure) 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 shell 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 box. At this time, the total area S2 of the surface of the battery shell 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 embodiments, the insulating member 120 is provided to cover the explosion-proof valve 130. In this way, the explosion-proof valve 130 can be prevented from rupturing and bursting, thereby preventing the battery 100 from being short-circuited with the outer box of the battery pack, thereby improving the safety of the battery pack.

[0079] Alternatively, as Figure 12 As shown, the surface of the battery shell body 110 adjacent to the bottom surface 111 is called the side surface 112 of the battery shell body 110. In this embodiment, the insulating member 120 covers the side surface 112 of the battery shell body 110, and there is a gap between the insulating member 120 and the bottom surface 111 of the battery shell body 110. The ratio of the length d1 of the gap in the height direction of the battery shell body 110 to the height d2 of the battery shell 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 cannot be too large. If it is too large, the area of ​​the battery case body 110 exposed will be larger, which will affect the insulation performance of the battery 100. In this embodiment, the ratio of d1 to d2 is any value between 0.05 and 0.95 or a range between any two values, and this embodiment is not limited to this. For example, the ratio of d1 to d2 is 0.05, 0.1, 0.3, 0.5, 0.6, 0.8, 0.9, 0.95, etc.

[0081] In one embodiment, Figure 11 As shown, the surface of the battery shell body 110 facing away from the bottom plate 300 can be called the top surface 113 of the battery shell body 110. The insulating member 120 is provided with an opening 124 on the portion of the top surface 113 of the battery shell body 110 corresponding to the top surface 113, and a and h satisfy the relationship: 0.03≤a / h≤0.13. In this way, the insulating member 120 does not completely cover the top surface 113 of the battery shell body 110. At this time, the total area S2 of the insulating member 120 is small, and the area S1 of the notch 121 on the bottom surface 111 of the insulating member 120 accounts for a large proportion. By controlling the range of a / h to meet 0.03≤a / h≤0.13, while ensuring good bonding strength between the battery 100 and the bottom plate 300, the bottom plate 300 and the battery 100 will not be short-circuited, thereby 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 grouping and assembly speed of the battery 100 .

[0082] In some optional embodiments, the opening 124 completely exposes the top surface 113 of the battery case body 110 , thereby further improving the grouping and assembly speed 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 housing body 110, that is, the top surface 113 of the battery housing body 110 is provided with the insulating member 120. Figure 11 As shown, the insulating member 120 includes a first insulating portion 122 and a second insulating portion 123 connected to each other. The first insulating portion 122 is disposed on the top surface 113 of the battery housing body 110; the second insulating portion 123 covers the side surface 112 of the battery housing body 110 adjacent to the bottom surface 111. By assembling the insulating member 120 in two insulating portions, assembly efficiency is improved while also enhancing the insulation effect on the exposed surface of the battery housing body 110, 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 for the insulating protective film and the insulating protective coating have been described above and will not be repeated here.

[0085] In one embodiment, the materials of the first insulating portion 122 and the second insulating portion 123 may be the same or different, which is not limited in this embodiment.

[0086] It should be noted that, in this embodiment, the second insulating portion 123 further covers at least a portion of the bottom surface 111 of the battery housing body 110 . That is, the notch 121 is disposed on the second insulating portion 123 .

[0087] In this embodiment, the first insulating portion 122 and the second insulating portion 123 may overlap or not overlap on the top surface 113 of the battery shell body 110 . This embodiment provides detailed descriptions of these two situations.

[0088] One positional relationship between the first insulating portion 122 and the second insulating portion 123 on the top surface 113 of the battery shell body 110 is as follows: the first insulating portion 122 does not completely cover the top surface 113 of the battery shell body 110, leaving a portion of the top surface 113 exposed; the second insulating portion 123 is at least partially disposed on the top surface 113 of the battery shell body 110; the edge of the first insulating portion 122 abuts the edge of the second insulating portion 123 located on the top surface 113 of the battery shell body 110; and the first insulating portion 122 and the second insulating portion 123 cooperate to cover the top surface 113 of the battery shell body 110. In this manner, the first insulating portion 122 and the second insulating portion 123 do not overlap on the top surface 113 of the battery shell body 110, ensuring that the provision of the insulating member 120 does not affect the heat dissipation performance of the top surface 113 of the battery shell body 110. Furthermore, the height of the battery 100 is not increased due to the overlap between the first insulating portion 122 and the second insulating portion 123, thereby ensuring 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 case body 110 is as follows: the second insulating portion 123 is at least partially disposed on the top surface 113 of the battery case body 110, and the first insulating portion 122 and the second insulating portion 123 at least partially overlap. In this manner, the overlapping portion between the first insulating portion 122 and the second insulating portion 123 can improve the insulation performance of the insulating member 120, thereby providing the battery 100 with a higher insulation effect.

[0090] It should be noted that, assuming that the area of ​​the first insulating portion 122 is S3, the area of ​​the second insulating portion 123 is S4, and the overlapping area of ​​the first insulating portion 122 and the second insulating portion 123 on the top surface 113 of the battery shell body 110 is S5, at this time, the total area of ​​the surface of the battery shell 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 shell body 110.

[0091] In this embodiment, in order to improve the insulation effect of the insulating member 120 at the connection between the top surface 113 of the battery shell body 110 and the side surface 112 of the battery shell body 110, illustratively, the ratio of the area of ​​the top surface 113 of the battery shell body 110 covered by the first insulating portion 122 to the area of ​​the top surface 113 of the battery shell body 110 is in a range of 30% to 95%. In this way, the area of ​​the portion of the first insulating portion 122 bent toward the top surface 113 of the battery shell body 110 can be controlled, thereby ensuring the insulation performance of the insulating member 120 at the connection between the top surface 113 of the battery shell body 110 and the side surface 112 of the battery shell body 110.

[0092] It should be noted that the ratio of the area of ​​the top surface 113 of the battery shell body 110 covered by the first insulating portion 122 to the area of ​​the top surface 113 of the battery shell body 110 is any value between 30% and 95%, or a range between any two values, and this embodiment is not limited to this. For example, the ratio of the area of ​​the top surface 113 of the battery shell body 110 covered by the first insulating portion 122 to the area of ​​the top surface 113 of the battery shell 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 is in the range of 80 μm to 110 μm. When the thickness of the insulating film is within this thickness range, the insulating effect of the second insulating portion 123 is better, and the height of the battery 100 is not increased. The thickness of the insulating film cannot be too large, otherwise the height of the battery 100 will be too high, and the improvement in insulation performance will not be obvious. The thickness of the insulating film cannot be too small either, otherwise it will affect the insulation effect and cause insulation failure. The thickness of the insulating film is any value between 80 μm and 110 μm or a range between any two values, and this embodiment does not limit this. For example, the thickness of the insulating film is 80 μm, 90 μm, 100 μm, 110 μm, etc.

[0094] In other embodiments, the second insulating portion 123 may not be an insulating film, but rather an insulating coating. Specifically, the second insulating portion 123 is an insulating coating disposed on the top surface 113 of the battery case body 110, and the thickness of the insulating coating ranges from 130 μm to 170 μm. When the insulating coating thickness falls within this range, the second insulating portion 123 provides good insulation without increasing the height of the battery 100. The insulating coating thickness should not be too large, as this will result in an excessively high height of the battery 100, with minimal improvement in insulation performance, reduced adhesion, and easy detachment. The insulating coating thickness should also not be too small, as this will compromise insulation performance and lead to insulation failure. The insulating coating thickness can be any value between 130 μm and 170 μm, or within a range between any two values, and this is not limited in this embodiment. For example, the insulating coating thickness can be 130 μm, 140 μm, 150 μm, 160 μm, or 170 μm.

[0095] Optionally, the adhesive layer 200 is located between the bottom surface 111 of the battery case body 110 and the bottom plate 300, and the insulating member 120 at least partially overlaps the adhesive layer 200. In this way, the adhesive layer 200 and the insulating member 120 have overlapping portions, so that the adhesive layer 200 not only adheres to the portion of the battery case body 110 exposed by the notch 121, but also adheres to the surface of the insulating member 120 facing the bottom plate 300. This increases the bonding area between the bottom of the battery 100 and the adhesive layer 200, thereby improving the bonding strength between the battery 100 and the bottom plate 300.

[0096] In one embodiment, the thickness of the adhesive layer 200 ranges from 0.5 mm to 3.4 mm. 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. Furthermore, since the adhesive layer 200 is also insulating, the insulation performance between the battery 100 and the base plate 300 is also improved.

[0097] It should be noted that the thickness of the adhesive layer 200 is any value between 0.5 mm and 3.4 mm or a range between any two values, which is not limited in this embodiment. For example, the thickness of the adhesive layer 200 is 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.4 mm, etc.

[0098] For example, the dielectric constant of the adhesive layer 200 ranges from 2.4F / m to 4.2F / m. It should be noted that the dielectric constant of the adhesive layer 200 mentioned in this embodiment is within a range of 2.4F / m to 4.2F / m at a frequency of 1MHz. Thus, when the dielectric constant of the adhesive layer 200 is within a certain range, the adhesive layer 200 also has a certain insulation 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 is any value between 2.4 F / m and 4.2 F / m, or a range between any two values, and this embodiment is not limited thereto. For example, the dielectric constant of the adhesive layer 200 is 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 0.02 mm to 0.3 mm. Thus, when the thickness of the insulating layer 400 is within a certain range, the insulating effect of the insulating layer 400 is excellent, thereby ensuring the insulation effect between the battery 100 and the bottom plate 300 .

[0101] It should be noted that the thickness of the insulating layer 400 is any value between 0.02 mm and 0.3 mm or a range between any two values, which is not limited in this embodiment. For example, the thickness of the insulating layer 400 is 0.02 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, etc.

[0102] Optionally, the bottom plate 300 in this embodiment can be a heat exchange plate or an ordinary plate, which is not limited in this embodiment. When the bottom plate 300 is a heat exchange plate, a and h satisfy the relationship: 0.05≤a / h≤0.13. In this way, when the bottom plate 300 is a heat exchange plate, the cooling effect on the battery can be improved, so that when the range of a / h satisfies 0.05≤a / h≤0.13, it can not only ensure the connection strength between the battery 100 and the bottom plate 300, improve the insulation performance of the battery 100 and the bottom plate 300, but also improve the heat dissipation effect of the battery 100 and reduce the risk of thermal runaway of the battery 100.

[0103] In one embodiment, the roughness Ra of the bottom plate 300 is in the range of 0.8 μm to 3.2 μm. Thus, when the roughness of the bottom plate 300 is within a certain range, the bonding effect between the bottom plate 300 and the insulating layer 400 is better, the insulating layer 400 can be better attached to the bottom plate 300, and the risk of falling off the bottom plate 300 is reduced, resulting in fewer weak insulation areas in the insulating layer 400. In other words, the connection strength between the bottom plate 300 and the battery case body 110 is higher.

[0104] In one embodiment, the battery 100 further includes a terminal 140, which can be located on the side 112 or bottom 111 of the battery shell body 110, and a and h satisfy the relationship: 0.01≤a / h≤0.10. When the terminal 140 is located on the side 112 or bottom 111 of the battery 100, it is necessary to prevent conduction between the terminal 140 and the bottom plate 300, that is, it is necessary to prevent the problem of short circuit between the terminal 140 and the bottom 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 bottom plate 300 can be guaranteed, conduction between the terminal 140 and the bottom 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 a terminal 140, such as Figure 11 As shown, the terminal 140 can also be located on the top surface 113 of the battery shell body 110. The top surface of the battery shell body 110 is arranged opposite the bottom surface 111 of the battery shell body 110, and a and h satisfy the relationship: 0.03≤a / h≤0.13. In this way, the terminal 140 is far away from the bottom plate 300. When the value range of a / h satisfies the relationship 0.01≤a / h≤0.10, the battery 100 and the bottom plate 300 can have a higher connection strength while improving the insulation effect between the battery 100 and the bottom plate 300.

[0106] For example, Figure 13 As shown, the maximum distance d3 between the edge of the insulating layer 400 and the edge of the orthographic projection of the lower surface of the battery 100 on the insulating layer 400 ranges from 0.5 mm to 7 mm. This improves the insulation between the bottom plate 300 and the notch 121 of the insulating member 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, in turn, 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 orthographic projection of the bottom surface of the corresponding battery 100 on the insulating layer 400 is any value between 0.5 mm and 7 mm, or a range between any two values, and this embodiment is not limited thereto. For example, the maximum distance d3 between the edge of the insulating layer 400 and the edge of the orthographic projection of the bottom surface of the corresponding battery 100 on the insulating layer 400 is 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, etc.

[0108] It should be noted that the edge of the insulating layer 400 may be set beyond the edge of the bottom surface 111 of the battery shell body 110, and the distance between the two satisfies the above relationship. Alternatively, the edge of the insulating layer 400 may not exceed the edge of the bottom surface 111 of the battery shell body 110, that is, the orthographic projection of the bottom surface 111 of the battery shell body 110 on the plane where the insulating layer 400 is located completely covers the insulating layer 400, and the distance between the two satisfies the above relationship. This embodiment is not limited to this.

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

[0110] In some optional embodiments, the surface of the base plate 300 facing the battery 100 can be completely covered with the insulating layer 400. In this way, 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 other optional embodiments, a plurality of insulating layers 400 are provided on the surface of the bottom plate 300 facing the battery 100 , and the plurality of insulating layers 400 correspond one-to-one to the plurality of batteries 100 , and each insulating layer 400 can cover the bottom surface of the corresponding battery 100 .

[0112] When multiple batteries 100 are spaced apart on the bottom plate 300, the insulating layer 400 completely covers the bottom surface of one battery 100, and the insulating layer 400 at least partially covers the bottom surface of an adjacent battery 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 grouping effect of the batteries 100.

[0113] The battery pack provided in this embodiment is provided with a notch 121 on the surface of the insulating member 120 of the battery 100 facing the bottom plate 300, thereby improving the connection strength between the battery 100 and the bottom plate 300 and improving 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 shell body 110 covered by the insulating member 120, as well as the relationship between the minimum distance h between the battery shell body 110 located at the notch 121 and the bottom plate 300, the insulation effect between the battery 100 and the bottom plate 300 can be ensured, 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 test, 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. The a / h values ​​between 0.01-0.13 were called embodiments, and 23 embodiments were given in this embodiment; the a / h values ​​outside the range of 0.01-0.13 were called comparative examples, and 4 comparative examples were given in this embodiment. For each embodiment and each comparative example, 10 batteries of the same model were taken, the only difference being the a / h values, and the others being the same. A notch 121 was opened on the surface of the insulating part 120 of the battery 100, and the notch 121 was cleaned with alcohol. After drying naturally, glue was applied to the surface of the battery shell body 110 facing the base plate (specifically, the notch) to obtain a glue layer 200. The glue-coated battery is then bonded to an aluminum alloy plate (used to simulate the bottom 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 member 120 to the total area S2 of the battery shell body 110 surface covered by the insulating member 120, and the minimum distance h between the battery shell body 110 at the notch 121 and the aluminum alloy plate in different embodiments and comparative examples are shown in Table 1 below. Other than that, all other values ​​are the same. An insulation withstand voltage tester is used to test the resistance between the battery 100 and the aluminum alloy plate. One output terminal of the insulation withstand voltage tester is connected to the aluminum alloy plate, and the other terminal is connected to the aluminum-leaking part of the battery surface. A DC voltage of 3000V is applied between the two output terminals, the current is measured, and the resistance between the battery 100 and the aluminum alloy plate is calculated according to formula (1). The resistance of 10 batteries in each embodiment and comparative example is measured and the average value is taken to obtain the test result. The specific results are shown in Table 1. If the obtained resistance is greater than or equal to 500 MΩ, the insulation between the battery 100 and the aluminum alloy plate is qualified; if the obtained resistance is less than 500 MΩ, the insulation between the battery 100 and the aluminum alloy plate is unqualified.

[0116] R=U / I (1)

[0117] This embodiment also provides a pull-out force method, which can test 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 from each example, differing only in the a / h value, with all other characteristics being the same. A notch 121 was formed on the surface of the insulating member 120 of the battery 100, and the notch 121 was cleaned with alcohol. After naturally drying, glue was applied to the surface of the battery case body 110 facing the bottom plate (specifically, the notch) to form a glue layer 200. The glue-coated battery was then bonded to an aluminum alloy plate (used to simulate the bottom 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 member 120 to the total area S2 of the battery shell body 110 surface covered by the insulating member 120, and the minimum distance h between the battery shell body 110 at the notch 121 and the aluminum alloy plate in different embodiments and comparative examples are shown in Table 1 below. Other than that, the peeling 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. Each embodiment and comparative example was tested 10 times, and the average value was taken. The specific results are shown in Table 1. If the tested peeling 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 peeling 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] Comparison of the actual data of Examples 1 to 14 and Comparative Examples 1 to 4 shows that when a / h is within the range, the bonding strength between the battery 100 and the aluminum alloy plate is good, and the insulation performance between the two is good, and there is no risk of short circuit. Comparison of the experimental data of Examples 1 to 14 and Examples 15 to 23 shows that when a is too small, the surface of the battery shell body 110 is covered by the insulating member 120 to a large extent, resulting in poor heat dissipation of the battery. When a is too large, the heat transfer between adjacent batteries 100 becomes faster, resulting in the inability to effectively reduce the heat transfer between adjacent batteries 100 when the battery 100 thermally runs away. When h is too small, the heat exchange rate between the battery 100 and the bottom plate 300 is too fast, and the thermal runaway of one battery 100 will affect other batteries 100. If h is too large, the bottom surface of the battery 100 does not dissipate heat well.

[0123] Note that the above are only preferred embodiments 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 that various obvious changes, readjustments, and substitutions can be made by those skilled in the art 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 the present invention is determined by the scope of the appended claims.

Claims

1. A battery pack, comprising a battery (100), an adhesive layer (200) and a bottom plate (300), wherein the bottom plate (300) is used to support the battery (100), and the adhesive layer (200) is located between the battery (100) and the bottom plate (300) and is used to fix the bottom plate (300) and the battery (100); characterized in that: The battery comprises a battery shell body (110) and an insulating member (120) coated on the surface of the battery shell body (110); the insulating member (120) is provided with a notch (121), the notch (121) exposing at least a portion of the bottom surface of the battery shell body (110) on the side facing the bottom plate (300); the adhesive layer (200) is at least partially disposed at the notch (121) and is adhesively connected to the bottom plate (300); an insulating layer (400) is disposed between the bottom plate (300) and the adhesive layer (200), and the orthographic projection of the notch (121) on the bottom plate (300) falls within the orthographic projection of the insulating layer (400) on the bottom plate (300); 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 shell body (110) covered by the insulating member (120) is a, that is, a=S1 / S2; the minimum distance between the battery shell body (110) located at the notch (121) and the bottom plate (300) is h mm; a and h satisfy the relationship: 0.01≤a / h≤0.13; The battery (100) further includes an explosion-proof valve (130), the explosion-proof valve (130) being arranged on the bottom surface of the battery shell body (110) facing the bottom plate (300), the adhesive layer (200) being provided with an escape hole at a position corresponding to the explosion-proof valve (130), and the orthographic projection of the explosion-proof valve (130) on the insulating member (120) being located within the notch (121); The thickness of the insulating layer (400) ranges from 0.02 mm to 0.3 mm.

2. The battery pack according to claim 1, wherein: The area of ​​the orthographic projection of the notch (121) on the bottom plate (300) is equal to the area of ​​the bottom surface of the battery shell body (110), and a and h satisfy the relationship: 0.01≤a / h≤0.

1.

3. The battery pack according to claim 1, wherein: The area of ​​the orthographic projection of the notch (121) on the bottom plate (300) is smaller than the area of ​​the bottom surface of the battery shell body (110), and a and h satisfy the relationship: 0.05≤a / h≤0.

13.

4. The battery pack according to claim 1, wherein: The minimum distance k between the edge of the explosion-proof valve (130) and the edge of the notch (121) in a direction perpendicular to the height direction of the battery shell body (110) ranges from 0.2 mm to 5 mm.

5. The battery pack according to claim 1, wherein: The explosion-proof valve (130) and the battery shell body (110) are an integrated structure.

6. The battery pack according to claim 1, wherein: The adhesive layer (200) is located between the bottom surface of the battery shell body (110) and the bottom plate (300), and the insulating member (120) at least partially overlaps with the adhesive layer (200).

7. The battery pack according to claim 1, wherein: The thickness of the adhesive layer (200) ranges from 0.5 mm to 3.4 mm.

8. The battery pack according to claim 1, wherein: The value range of a is 0.01-0.2; and / or the value range of h is 0.7-3.

8.

9. The battery pack according to claim 1, wherein: The battery (100) further includes a pole, which is located on the side or bottom of the battery shell body (110), and a and h satisfy the relationship: 0.01≤a / h≤0.

10.

10. The battery pack according to claim 1, wherein: The battery (100) further includes a pole, which is located on the top surface of the battery shell body (110). The top surface of the battery shell body (110) is arranged opposite to the bottom surface of the battery shell body (110), and a and h satisfy the relationship: 0.03≤a / h≤0.13.

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