Battery pack

Abstract

This invention belongs to the field of battery technology and discloses a battery pack, including a battery, a base plate, and an adhesive layer. The battery is fixed to the base plate by the adhesive layer. The battery includes a shell, an insulating component, and a cell. The cell is disposed within the shell and includes multiple electrode plates. The insulating component covers the outer surface of the shell, and the surface of the shell facing the base plate is the bottom surface of the shell. The insulating component has an opening that exposes at least part of the bottom surface of the shell. The portion of the bottom surface of the shell exposed by the opening is bonded to the adhesive layer. The minimum distance between the electrode plates and the bottom surface of the shell is 'a' mm, and the minimum distance between the opening of the insulating component and the base plate is 'b' mm. The product of 'a' and 'b' ranges from 1 to 18. The battery pack provided by this invention has high energy density, good insulation performance, and good heat dissipation performance.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery pack. Background Technology

[0002] A battery pack typically includes a housing and multiple batteries housed within the housing. The bottom of the batteries is bonded to the bottom plate of the housing with an adhesive layer to improve the overall strength of the battery pack and prevent damage to the battery pack under vibration conditions.

[0003] In existing technologies, the surface of a battery is typically covered with an insulating component. To ensure the fixing strength between the battery and the base plate of the enclosure, the metal casing of the battery usually needs to be exposed on the side of the insulating component closest to the base plate for adhesive bonding, thereby satisfying the adhesion strength of the adhesive layer between the battery and the base plate. However, this arrangement carries the risk of insulation failure between the battery and the enclosure. Summary of the Invention

[0004] The purpose of this invention is to provide a battery pack that solves the technical problem in the prior art that cannot simultaneously achieve insulation performance and bonding strength.

[0005] Based on the above concept, the technical solution adopted by this invention is as follows:

[0006] A battery pack includes a battery, a base plate, and an adhesive layer. The base plate supports the battery, and the battery is fixedly mounted on the base plate by the adhesive layer. The battery includes a housing, an insulating component, and a battery cell. The battery cell is disposed inside the housing and includes multiple stacked electrode plates. The insulating component covers the outer surface of the housing, and the surface of the housing facing the base plate is the bottom surface of the housing. The insulating component has an opening that exposes at least part of the bottom surface of the housing, and the portion of the bottom surface of the housing exposed by the opening is bonded to the adhesive layer.

[0007] The minimum distance between the electrode and the bottom surface of the housing is a mm, and the minimum distance between the opening of the insulating component and the base plate is b mm. The product of a and b ranges from 1 to 18.

[0008] The beneficial effects that the above technical solution can achieve are:

[0009] By controlling the range of a*b to satisfy the above relationship, both good bonding strength between the battery and the base plate can be ensured, and short circuits between the base plate and the battery can be prevented, thus improving the overall structural strength and safety performance of the battery pack. If the value of a*b is too large, the bonding area between the casing and the base plate, as well as the excessive distance between them, will result in weak bonding strength between the battery and the base plate, posing a risk of detachment under vibration conditions, affecting the overall strength and safety of the battery. If the value of a*b is too small, the distance between the internal electrode plates and the base plate will decrease, increasing the risk of short circuits between the cells and the base plate, reducing the insulation performance between them, and potentially leading to short circuits between the battery and the base plate, thus affecting the safety performance of the battery pack. Attached Figure Description

[0010] 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.

[0011] Figure 1 This is a schematic diagram of the structure of a battery pack provided in an embodiment of the present invention;

[0012] Figure 2 This is a cross-sectional view of a battery pack provided in an embodiment of the present invention;

[0013] Figure 3 This is provided by an embodiment of the present invention. Figure 2 The enlarged view at point A is shown below;

[0014] Figure 4 This is a schematic diagram of the first structure of a battery provided in an embodiment of the present invention;

[0015] Figure 5 This is a partially enlarged cross-sectional view of a first type of battery pack provided in an embodiment of the present invention;

[0016] Figure 6 This is a schematic diagram showing the positions of the battery, base plate, insulating support plate, and opening provided in an embodiment of the present invention;

[0017] Figure 7 This is a schematic diagram showing the positions of the base plate, insulating support plate, and opening provided in an embodiment of the present invention;

[0018] Figure 8 This is a partially enlarged cross-sectional view of a second type of battery pack provided in an embodiment of the present invention;

[0019] Figure 9This is a partially enlarged cross-sectional view of a third type of battery pack provided in an embodiment of the present invention;

[0020] Figure 10 This is a first partial enlarged view of a cross-sectional view of a fourth type of battery pack provided in an embodiment of the present invention;

[0021] Figure 11 This is a second partial enlarged view of a cross-sectional view of a fourth type of battery pack provided in an embodiment of the present invention;

[0022] Figure 12 This is a partially enlarged cross-sectional view of a fifth type of battery pack provided in an embodiment of the present invention;

[0023] Figure 13 This is a schematic diagram showing the positions of the battery, the second insulating coating, and the base plate according to an embodiment of the present invention;

[0024] Figure 14 This is a schematic diagram of the second structure of a battery provided in an embodiment of the present invention.

[0025] In the picture:

[0026] 100. Battery; 110. Casing; 111. Casing bottom; 120. Insulator; 121. Opening; 130. Cell; 131. Electrode; 1311. Positive electrode; 1312. Negative electrode; 132. Separator; 140. Insulating support plate; 141. Through hole; 150. Insulating film; 160. Terminal post; 170. Explosion-proof valve; 200. Base plate; 300. Adhesive layer; 400. Second insulating coating; 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 1 As 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 200, 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 200 and the cover to form a battery compartment. The crossbeams 520 and longitudinal beams 530 are intersected within the battery compartment, dividing the battery compartment 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 casing 110, a cell 130, and an electrolyte (not shown in the figure). The casing 110 is used to house the cell 130 and the electrolyte, and the casing 110 is provided with at least one positive electrode post and at least one negative electrode post. The cell 130 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] For example, such as Figure 2 As shown, the battery pack includes a battery 100, a base plate 200, and an adhesive layer 300. The base plate 200 supports the battery 100. Specifically, the battery 100 is fixedly mounted on the base plate 200 via the adhesive layer 300; that is, the battery 100 is bonded to the base plate 200 via the adhesive layer 300. It is also understood that the battery pack includes a frame, which is fixedly connected to the base plate 200 to form an accommodating space, within which the battery 100 is located.

[0041] For example, such as Figure 2 As shown, the battery includes a casing 110, an insulator 120, and a battery cell 130. The battery cell 130 is disposed within the casing 110 and includes multiple electrode plates 131. The insulator 120 covers the outer surface of the casing 110 to insulate the casing 110 from the external environment. Furthermore, the surface of the casing 110 facing the base plate 200 is the bottom surface 111 of the casing; that is, the bottom surface 111 is the surface of the casing 110 closest to the base plate 200. Figure 4 As shown, the insulating member 120 is provided with an opening 121 that exposes at least part of the bottom surface 111 of the housing. That is, the opening 121 exposes at least part of the bottom surface 111 of the housing. The adhesive layer 300 is at least partially disposed at the opening 121 and bonded to the base plate 200, thereby bonding the exposed portion of the bottom surface 111 of the housing with the adhesive layer 300, and thus bonding the housing 110 to the base plate 200 through the adhesive layer 300, improving the connection strength between the battery 100 and the base plate 200.

[0042] It should be noted that the insulating material covering the outer surface of the battery 100 (or the casing 110) is the insulating component 120. That is, the insulating material covering the outer surface of the battery 100 (or the casing 110) except for the notch facing the bottom plate 200 is the insulating component 120. In other words, all insulating materials covering the outer surface of the battery 100 (or the casing 110) are insulating components 120.

[0043] In this embodiment, as Figure 3 As shown, the minimum distance between the electrode 131 and the bottom surface 111 of the housing is a mm, and the minimum distance between the opening 121 of the insulating member 120 and the base plate 200 is b mm. The product of a and b ranges from 1 to 18.

[0044] It should be noted that the product of a and b can be any value between 1 and 18, or any two values ​​within that range. This embodiment does not limit this. For example, the product of a and b can be 1, 1.50, 1.71, 2.38, 3.35, 4.69, 6.28, 7.49, 8.09, 8.54, 9.04, 9.07, 8.43, 8.22, 8.05, 7.14, 6.18, 5.53, 4.96, 10.66, 12.10, 13.59, 14.10, 1.95, 1.85, 5.20, 7.72, 3.98, 3.57, 2.99, 2.77, 2.01, 4.02, 16.00, 17, 18, etc.

[0045] Optionally, the value of 'a' ranges from 0.6 to 8.0. The value of 'a' can be any value between 0.6 and 8.0, or a range between any two values. For example, the values ​​of 'a' are 0.6, 0.63, 0.69, 0.98, 1.46, 2.04, 2.61, 3.04, 3.53, 4.11, 4.65, 5.02, 5.48, 6.01, 6.55, 7.02, 7.57, 8, 5.03, 6.11, 6.32, 7.23, 7.94, 0.5, and 0.49.

[0046] In one possible implementation, the value of b ranges from 0.6 to 3.8. The value of b is any value between 0.6 and 3.8 or a range between any two values, for example, the values ​​of b are 0.6, 3.78, 2.48, 3.42, 3.21, 3.08, 2.87, 2.66, 2.42, 2.2, 1.95, 1.68, 1.5, 1.34, 1.09, 0.88, etc.

[0047] It should be noted that the minimum distance between the electrode 131 and the bottom surface 111 of the housing is specifically the minimum distance between the surface of the electrode 131 closest to the bottom surface 111 of the housing and the bottom surface 111 of the housing. The minimum distance between the opening 121 of the insulating member 120 and the base plate 200 can be understood as the distance between the surface of the insulating member 120 facing away from the housing 110 along a direction perpendicular to the base plate 200 and the surface of the base plate 200 facing the battery 100.

[0048] The battery pack provided in this embodiment, by controlling the range of a*b (i.e., the product of a and b) to be between 1 and 18, can ensure good bonding strength between the battery 100 and the base plate 200, and also ensure that short circuits between the base plate 200 and the battery 100 will not occur, thus improving the overall structural strength and safety performance of the battery pack. If the a*b value is too large, the bonding area between the shell 110 and the base plate 200, as well as the excessive distance between the shell 110 and the base plate 200, will result in weak bonding strength between the battery 100 and the base plate 200, posing a risk of detachment under vibration conditions, affecting the overall strength and safety of the battery. If the a*b value is too small, the distance between the internal electrode 131 of the battery 100 and the base plate 200 will decrease, increasing the risk of short circuits between the cell 130 and the base plate 200, reducing the insulation performance between them, and ultimately causing short circuits between the battery 100 and the base plate 200, affecting the safety performance of the battery pack.

[0049] Optionally, in this embodiment, the housing 110 is used to accommodate the battery cell 130 and to isolate the battery cell 130 from the external environment. The housing 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 130. The housing 110 is made of metal materials such as aluminum or stainless steel, therefore an insulating structure needs to be provided between the housing 110 and the base plate 200 to ensure insulation.

[0050] For example, the base plate 200 is made of a metal material, such as aluminum, stainless steel, aluminum alloy, iron, etc. This embodiment does not limit the material.

[0051] 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.

[0052] It should be noted that the insulating protective film can be adhered to the housing 110; the insulating protective coating can be applied to the housing 110 as a coating, and this embodiment does not limit this. For example, the insulating protective film can be a blue film.

[0053] 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 does not limit the choice.

[0054] In one embodiment, such as Figure 3 As shown, no other components are disposed between the battery cell 130 and the bottom surface 111 of the casing.

[0055] In other embodiments, such as Figure 5 As shown, the battery 100 also includes an insulating support plate 140, which is disposed between the cell 130 and the bottom surface 111 of the casing, and is used to isolate the cell 130 from the bottom surface 111 of the casing. When the insulating support plate 140 exists between the cell 130 and the bottom surface 111 of the casing, the product of a and b ranges from 1 to 14.5.

[0056] By setting an insulating support plate 140 between the cell 130 and the bottom surface 111 of the casing, on the one hand, the insulation reliability between the cell 130 and the bottom surface 111 of the casing 110 is increased, which indirectly increases the insulation reliability between the cell 130 and the base plate 200, further ensuring that there will be no short circuit between the cell 130 and the base plate 200, thereby further improving the safety performance of the battery pack; on the other hand, by setting the insulating support plate 140, insulation protection is added between the cell 130 and the base plate 200. On this basis, it can also have a good insulation effect within the range where the a*b value is reduced, and the energy density of the battery pack can be appropriately increased while taking insulation performance into account.

[0057] For example, the insulating support plate 140 is used to prevent the cell 130 from contacting the housing 110, thereby preventing the risk of a short circuit. Optionally, the insulating support plate 140 can be made of polypropylene, polyethylene, or polyethylene terephthalate. Of course, it is understood that the insulating support plate 140 can also be made of other insulating materials, and this embodiment is not limited to this.

[0058] For example, the thickness d1 of the insulating support plate 140 affects the insulation effect between the cell 130 and the bottom surface 111 of the housing 110. Optionally, such as Figure 5 As shown, the thickness d1 of the insulating support plate 140 ranges from 0.1mm to 3mm. When the thickness of the insulating support plate 140 is within this range, the insulating support plate 140 can have a good insulation effect, and the setting of the insulating support plate 140 has little impact on the energy density of the battery pack.

[0059] In this embodiment, the thickness d1 of the insulating support plate 140 is any value within the range of 0.1mm-3mm or any two values, and this embodiment does not limit it. For example, the thickness d1 of the insulating support plate 140 can be 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc. The thickness d1 of the insulating support plate 140 cannot be too large, otherwise it will occupy a large space inside the casing 110, which is not conducive to improving the energy density of the battery 100. The thickness d1 of the insulating support plate 140 cannot be too small either, as this will result in weak insulation performance.

[0060] It should be noted that, as Figure 5 As shown, the casing 110 of the battery 100 typically has a rounded corner (R-angle). Specifically, the R-angle is the corner of the casing 110. Due to the presence of the R-angle, after the battery cell 130 is placed inside the casing 110, it may not directly contact the bottom surface 111 of the casing 110, and therefore will not be directly supported by the bottom wall of the casing 110. This can cause the battery cell 130 to wobble inside the casing 110, making it susceptible to damage. In this embodiment, an insulating support plate 140 is provided between the battery cell 130 and the bottom wall of the casing 110, and the thickness d1 of the insulating support plate 140 is in the range of 0.1mm-3.0mm, allowing the battery cell 130 to be directly supported on the insulating support plate 140.

[0061] Optionally, the insulating support plate 140 can be fixedly connected to the housing 110 to prevent the insulating support plate 140 from shaking relative to the housing 110, thereby improving the overall integrity of the insulating support plate 140 and the housing 110.

[0062] In some alternative embodiments, such as Figure 6 As shown, the projected area of ​​the insulating support plate 140 along the first direction X on the base plate 200 is S1, and the area of ​​the surface of the battery cell 130 near the bottom surface 111 of the housing is S2, wherein the value of S1 / S2 ranges from 20% to 95%. It should be noted that in this embodiment, the first direction X is perpendicular to the base plate 200. It should also be noted that the surface of the battery cell 130 near the bottom surface 111 of the housing can be understood as the area of ​​the surface of the battery cell 130 facing the bottom surface 111 of the housing.

[0063] In this embodiment, when S1 / S2 is within the above range, the insulating support plate 140 has a good insulation effect between the bottom wall of the battery cell 130 and the housing 110, as well as between the battery cell 130 and the base plate 200, so as to ensure that there is no risk of breakdown and short circuit between the battery cell 130 and the base plate 200.

[0064] In this embodiment, the value of S1 / S2 is any value between 20% and 95% or any two values, and this embodiment does not limit it. For example, the value of S1 / S2 is 20%, 30%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, 95%, etc.

[0065] In one possible implementation, such as Figure 6 As shown, the projected area of ​​the insulating support plate 140 along the first direction X on the base plate 200 is S1, and the projected area of ​​the opening 121 along the first direction X on the base plate 200 is S3, where S1 ≥ S3. Thus, the size of the insulating support plate 140 is larger than the size of the opening 121, increasing the probability that the projection of the insulating support plate 140 along the first direction X on the base plate 200 coincides with the projection of the opening 121 along the first direction X on the base plate 200. This further ensures that the battery cell 130 will not experience a short circuit through the opening 121 with the base plate 200, thus further improving the safety of the battery pack.

[0066] Further, optional, please continue to see Figure 6 The insulating support plate 140 completely covers the opening 121 in the first direction X (i.e., the direction perpendicular to the base plate 200). This arrangement ensures that the portion of the bottom wall of the housing 110 not covered by the insulating member 120 has an insulating support plate 140 between it and the battery cell 130, thereby optimizing the insulation effect of the insulating support plate 140. This improves the insulation effect between the portion of the bottom wall of the housing 110 not covered by the insulating member 120 and the battery cell 130, further ensuring that the base plate 200 and the battery cell 130 will not short-circuit.

[0067] In other embodiments, S1 may not be greater than or equal to S3. For example, as shown... Figure 7 As shown, the area of ​​the insulating support plate 140 projected onto the base plate 200 in a direction perpendicular to the base plate 200 is S1, and the area of ​​the opening 121 projected onto the base plate 200 in a direction perpendicular to the base plate 200 is S3, where S1 < S3. Thus, the size of the insulating support plate 140 is smaller than the size of the opening 121, and a gap exists between the insulating support plate 140 and the inner wall of the housing 110. This gap allows for the placement of electrolyte, resulting in a larger amount of electrolyte within the housing 110. Therefore, the wetting efficiency and effect of the battery cell 130 after electrolyte injection can be improved. Optionally, when the insulating support plate 140 is parallel to the base plate 200, the area of ​​the insulating support plate 140 is smaller than the area of ​​the region where the opening 121 is located on the insulating member 120. It should be noted that in this embodiment, the insulating support plate 140 can be centered with the opening 121.

[0068] In one possible implementation, such as Figure 8As shown, the insulating support plate 140 is provided with a plurality of through holes 141, each of which penetrates the insulating support plate 140 along a first direction X. In this embodiment, the thickness direction of the insulating support plate 140 is the same as the first direction X. The area of ​​the projection of the insulating support plate 140 along the first direction X onto the base plate 200 is S1, and the sum of the areas of the plurality of through holes 141 is S4. The ratio of S4 / S1 is in the range of 5%-60%. It should be noted that the sum of the areas of the plurality of through holes 141 specifically refers to the sum of the opening areas of the plurality of through holes 141.

[0069] By providing through holes 141 on the insulating support plate 140, during electrolyte injection, after the electrolyte enters the housing 110, it enters the space between the insulating support plate 140 and the bottom wall of the housing 110 through the through holes 141, achieving pre-filling. This ensures that after the battery 100 experiences vibration or other events, no additional electrolyte is needed in the gap between the insulating support plate 140 and the housing 110. Therefore, the amount of electrolyte used to wet the cell 130 will not decrease. Furthermore, electrolyte will be stored in the through holes 141 and the gap, thereby increasing the amount of electrolyte used to wet the cell 130, improving the wetting efficiency of the cell 130 after electrolyte injection, and thus ensuring the performance of the battery 100.

[0070] It should be noted that the through hole 141 in this embodiment can be a structure with a constant aperture, that is, the through hole 141 is a straight through hole 141. The sum of the areas of the above-mentioned multiple through holes 141 can be the sum of the opening areas of the multiple through holes 141, or it can be the sum of the cross-sectional areas of the multiple through holes 141 in the first direction X. This embodiment does not limit this. Of course, it can be understood that the through hole 141 can also be a structure with a variable aperture. This embodiment does not limit this.

[0071] It should also be noted that the value of S4 / S1 can be any value within the range of 5%-60% or any two values, and this embodiment does not limit this. For example, the value of S4 / S1 can be 5%, 10%, 12%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 55%, 58%, or 60%. The value of S4 / S1 should not be too large, as this will affect the insulation effect of the insulating support plate 140 on the bottom wall of the battery cell 130 and the housing 110. The value of S4 / S1 should not be too small, as this will reduce the amount of electrolyte adsorbed, resulting in a less significant improvement in the wetting effect of the battery cell 130 on the electrolyte.

[0072] In some alternative embodiments, exemplarily, such as Figure 9As shown, the battery 100 also includes an insulating film 150. The insulating film 150 is at least partially located between the bottom of the cell 130 and the bottom surface 111 of the casing, and the product of a and b ranges from 1 to 16.2. By providing the insulating film 150, the insulation performance between the cell 130 and the bottom wall of the casing 110 is enhanced, indirectly increasing the insulation reliability between the cell 130 and the base plate 200, further ensuring that short circuits will not occur between the cell 130 and the base plate 200, thereby further improving the safety performance of the battery pack. Furthermore, by providing the insulating film 150, insulation assurance is added between the cell 130 and the base plate 200. Based on this, a good insulation effect can be achieved even within the reduced range of a*b values, allowing for an appropriate increase in the energy density of the battery pack while maintaining insulation performance.

[0073] Optionally, the insulating film 150 may be made of polyethylene terephthalate, polyphenylene sulfide, polytetrafluoroethylene, polyethylene, polyimide, polypropylene, acrylic adhesive, etc., but this embodiment does not limit the material.

[0074] In one embodiment, only an insulating film 150 or only an insulating support plate 140 may be provided between the battery cell 130 and the bottom surface 111 of the housing 110. In other embodiments, such as Figure 9 As shown, an insulating film 150 or an insulating support plate 140 may be provided between the battery cell 130 and the housing 110. This embodiment does not limit this.

[0075] Optionally, when both an insulating support plate 140 and an insulating film 150 are provided inside the housing 110, the insulating support plate 140 can be located between the insulating film 150 and the bottom surface 111 of the housing. That is, the insulating film 150 is closer to the battery cell 130 than the insulating support plate 140. With this arrangement, the insulating support plate 140 can be fixed to the housing 110, and the insulating film 150 can be fixed to the insulating support plate 140. The connection between the insulating support plate 140 and the housing 110 is easier than the connection between the insulating film 150 and the housing 110, thus facilitating the fixation of the insulating support plate 140 and the insulating film 150 inside the housing 110.

[0076] In some optional embodiments, when both the insulating support plate 140 and the insulating film 150 are provided inside the housing 110, the insulating support plate 140 and the insulating film 150 are fixedly connected. This prevents the insulating film 150 from shifting relative to the insulating support plate 140, improves the overall integrity of the insulating support plate 140 and the insulating film 150, and allows both to be assembled into the housing 110 in a single assembly process, improving the assembly efficiency of the battery pack and reducing the assembly difficulty.

[0077] In one embodiment, to further improve the wetting effect of the battery cell 130, the insulating film 150 may have a certain porosity. For example, the porosity of the insulating film 150 ranges from 10% to 40%. When the porosity of the insulating film 150 is within this range, the electrolyte can be adsorbed onto the insulating film 150, increasing the amount of electrolyte within the housing 110, thereby improving the wetting efficiency of the battery cell 130 with the electrolyte. This allows the insulating film 150 to simultaneously provide insulation and improve the wetting effect of the battery cell 130. The porosity of the insulating film 150 cannot be too large, as this would result in lower insulation properties of the insulating film 150 itself, contributing less to the insulation between the battery cell 130 and the base plate 200. Conversely, the porosity of the insulating film 150 cannot be too small, as this would reduce the amount of electrolyte adsorbed, resulting in a less significant improvement in the wetting effect of the battery cell 130 with the electrolyte.

[0078] It should be noted that the porosity of the insulating film 150 is any value or a range between any two values ​​from 10% to 40%. For example, the porosity of the insulating film 150 is 10%, 20%, 25%, 30%, 35%, 40%, etc.

[0079] In one possible implementation, such as Figure 9 As shown, the thickness d0 of the insulating film 150 ranges from 1.5 μm to 20 μm. By controlling the thickness d0 of the insulating film 150 within a certain range, on the one hand, the insulating film 150 provides better coverage of the bottom of the cell 130, improving the insulation between the cell 130 and the casing 110; on the other hand, the thickness d0 of the insulating film 150 does not occupy too much space inside the casing 110, ensuring the energy density of the battery 100. The thickness d0 of the insulating film 150 cannot be too large, as this would occupy too much internal space of the casing 110, which is detrimental to improving the energy density of the battery 100. The thickness d0 of the insulating film 150 cannot be too small, as this would affect the coverage and insulation effect on the cell 130. It should be noted that the thickness of the insulating film 150 is its dimension in the first direction X.

[0080] It should be noted that the thickness d0 of the insulating film 150 is any value or any two values ​​between 1.5μm and 20μm. For example, the thickness d0 of the insulating film 150 is 1.5μm, 2μm, 3μm, 1.5μm, 5μm, 8μm, 10μm, 12μm, 15μm, 18μm, 20μm, etc.

[0081] Optionally, the insulation performance of the insulating film 150 is also affected by its dielectric constant. In this embodiment, the dielectric constant of the insulating film 150 ranges from 1.2 F / m to 4.0 F / m. When the dielectric constant of the insulating film 150 is within a certain range, the insulating effect of the insulating film 150 is better, thereby ensuring the insulation between the bottom of the battery cell 130 and the bottom wall of the housing 110. It should be noted that the dielectric constant of the insulating film 150 is the dielectric constant at a frequency of 1 kHz.

[0082] It should be noted that the dielectric constant of the insulating film 150 is any value or any two values ​​between 1.2 F / m and 4.0 F / m. For example, the dielectric constant of the insulating film 150 is 1.2 F / m, 1.5 F / m, 2 F / m, 2.5 F / m, 3 F / m, 3.5 F / m, 4 F / m, etc.

[0083] In one embodiment, the insulating film 150 may be disposed only on the surface of the cell 130 facing the bottom surface 111 of the housing. For example, the insulating film 150 may cover part or all of the surface of the cell 130 facing the bottom surface 111 of the housing. In other embodiments, the insulating film 150 may cover not only the surface of the cell 130 facing the bottom surface 111 of the housing, but also the side surface of the cell 130, thereby achieving the wrapping of the cell 130 and preventing the side surface of the cell 130 from short-circuiting with the housing 110.

[0084] For example, such as Figure 10 As shown, the battery cell 130 also includes a separator 132. A separator 132 is provided between each of the electrodes 131, which insulates the electrodes 131 from each other, improving the battery's performance and safety. This embodiment does not impose any particular limitation on the type of separator 132; any known porous structure separator 132 with good chemical and mechanical stability can be selected. As an example, the main material of the separator 132 can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator 132 can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator 132 is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0085] Please continue reading Figure 10The distance d2 between the diaphragm 132 and the bottom surface 111 of the housing 110 is less than the minimum distance d3 between the electrode 131 and the bottom surface 111 of the housing. With this arrangement, the diaphragm 132 is closer to the bottom surface 111 of the housing than the electrode 131. Since the diaphragm 132 has an electronic isolation function, that is, an insulating function, it can provide insulation protection for the electrode 131, reducing the risk of short circuit between the electrode 131 and the bottom surface 111 of the housing. Therefore, it can further ensure that there will be no short circuit between the cell 130 and the bottom surface 111 of the housing, and between the cell 130 and the base plate 200.

[0086] In an optional embodiment, the thickness d4 of the separator 132 ranges from 9 μm to 50 μm. When the thickness of the separator 132 is within this range, it provides better support for the cell 130. Furthermore, the electrode 131 is farther from the bottom surface 111 of the housing than the separator 132. With the better support of the separator 132, the electrode 131 can be kept at a position farther from the bottom surface 111 of the housing. Therefore, the insulation effect between the electrode 131 and the bottom surface 111 of the housing is better.

[0087] It should be noted that the thickness d4 of the diaphragm 132 is any value or any two values ​​between 9μm and 50μm. For example, the thickness d4 of the diaphragm 132 is 9μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, etc.

[0088] In one embodiment, such as Figure 10 or Figure 11 As shown, the multiple electrodes 131 of the cell 130 include multiple positive electrode plates 1311 and multiple negative electrode plates 1312. The number of positive electrode plates 1311 and negative electrode plates 1312 can be the same or different. The multiple positive electrode plates 1311 and multiple negative electrode plates 1312 are stacked, and the positive electrode plates 1311 and negative electrode plates 1312 are alternately arranged in the stacking direction. That is, the battery 100 in this embodiment is a stacked battery. The separator 132 is located between adjacent positive electrode plates 1311 and negative electrode plates 1312 in the stacking direction to play the role of electronic isolation and ion conduction. In this embodiment, the distance between the separator 132 and the bottom surface 111 of the casing is less than the minimum distance between the electrode plate 131 and the bottom surface 111 of the casing. Of course, it can be understood that the battery in this embodiment can also be a wound battery, and this embodiment does not limit it.

[0089] Optionally, in order to make full use of the positive electrode material on the positive electrode 1311, the area of ​​the negative electrode 1312 is usually larger than the area of ​​the positive electrode 1311. In order to achieve electronic isolation between the positive electrode 1311 and the negative electrode 1312, the area of ​​the portion of the separator 132 located between the positive electrode 1311 and the negative electrode 1312 is larger than the area of ​​the negative electrode 1312.

[0090] For example, please see Figure 11 The distance d31 between the negative electrode 1312 and the bottom surface 111 of the casing is less than the distance d31 between the positive electrode 1311 and the bottom surface 111 of the casing. Thus, the negative electrode 1312 is closer to the bottom surface 111 of the casing than the positive electrode 1311. Because the negative electrode 1312 has better hardness, it provides better support for the battery cell 130. This allows the negative electrode 1312 and the separator 132 to work together to support the battery cell 130, reducing the risk of the battery cell 130 shaking along the first direction X within the casing 110. This also reduces the amplitude of the battery cell 130's movement within the casing 110, thereby reducing the risk of material falling off the battery cell 130. In other words, it reduces the risk of the coatings on the positive electrode 1311 and the negative electrode 1312 falling off, thus preventing short circuits between the electrode 131 and the casing 110 caused by coatings falling onto the bottom surface 111 of the casing.

[0091] It should be noted that when both the positive electrode 1311 and the negative electrode 1312 are present, in this embodiment, the minimum distance a between the electrode 131 and the bottom surface 111 of the shell is equal to the distance d31 between the negative electrode 1312 and the bottom surface 111 of the shell.

[0092] In one embodiment, a first insulating coating (not shown) is provided on the side of the bottom surface 111 of the housing facing the cell 130. By providing the first insulating coating on the surface of the bottom wall of the housing 110 facing the cell 130, an insulating barrier is added between the bottom wall of the housing 110 and the cell 130, making the insulation performance between the housing 110 and the cell 130 more excellent. Furthermore, the first insulating coating can be formed by coating, spraying, or pasting, which facilitates the formation of the first insulating coating and thus improves the assembly efficiency of the battery 100.

[0093] Optionally, the first insulating coating can be formed on the bottom surface 111 of the housing by spraying, pasting, or other methods. The material of the first insulating coating is an insulating material. The material of the first insulating coating can be any one of polyethylene terephthalate, polyimide, mica, UV coating material, and epoxy resin, and this embodiment does not limit it.

[0094] In some alternative embodiments, at least one of the first insulating coating, the insulating support plate 140, and the insulating film 150 may be present, or none of the three may be present; this embodiment does not limit this.

[0095] For example, the thickness of the first insulating coating ranges from 90 μm to 200 μm. Within this thickness range, the probability of weak areas in the first insulating coating is low, and it exhibits good insulation performance while having minimal impact on the energy density of the battery 100. The thickness of the first insulating coating cannot be too large, as this would occupy excessive space within the casing 110, hindering the improvement of the battery 100's energy density. Conversely, the thickness of the insulating coating cannot be too small, as this would create weak insulation areas, thereby affecting the insulation performance.

[0096] Optionally, the thickness of the first insulating coating is any value between 90 μm and 200 μm, or a range between any two values. For example, the thickness of the first insulating coating is 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 150 μm, 170 μm, 200 μm, etc.

[0097] In one possible implementation, such as Figure 12 As shown, the battery pack may further include a second insulating coating 400, which serves to insulate the bottom wall of the housing 110 from the base plate 200. The second insulating coating 400 is at least partially disposed between the adhesive layer 300 corresponding to the opening 121 and the base plate 200. This arrangement ensures that at least a portion of the second insulating coating 400 is positioned opposite the opening 121, allowing the portion of the bottom wall of the housing 110 exposed through the opening 121 to directly face the second insulating coating 400. This enables the second insulating coating 400 to insulate the base plate 200 from the housing 110, thereby also insulating the base plate 200 from the battery cell 130. Furthermore, by providing the second insulating coating 400, insulation is added between the battery cell 130 and the base plate 200. This also allows for better insulation even within a narrowed a*b value range, enabling a suitable increase in the battery pack's energy density while maintaining insulation performance. It should be noted that the minimum distance b between the opening 121 of the insulating component 120 and the base plate 200 is greater than or equal to the thickness of the second insulating coating 400.

[0098] Optionally, the second insulating coating 400 can be formed on the base plate 200 by spraying, pasting, or other methods. The material of the second insulating coating 400 is an insulating material. The material of the second insulating coating 400 can be any one of polyethylene terephthalate, polyimide, mica, UV coating material, and epoxy resin, and this embodiment does not limit it.

[0099] Alternatively, the projection of the second insulating coating 400 in the first direction X completely covers the opening 121. Thus, either an insulating element 120 or a second insulating coating 400 exists between the bottom wall of the housing 110 and the base plate 200, or both an insulating element 120 and a second insulating coating 400 exist, resulting in better insulation between the battery 100 and the base plate 200 and preventing weak insulation areas.

[0100] 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 200 facing the battery 100, or it can be pasted onto the surface of the base plate 200 facing the battery 100. This embodiment does not limit this.

[0101] In some alternative embodiments, such as Figure 13 As shown, the battery pack includes multiple batteries 100 arranged on a base plate 200. In this embodiment, the arrangement of the multiple batteries 100 on the base plate 200 can be along the length direction of the base plate 200, or along the width direction of the base plate 200, or several batteries can be arranged along the length direction of the base plate 200 and several batteries can be arranged along the width direction of the base plate 200. This embodiment does not limit this arrangement.

[0102] In this embodiment, as Figure 13 As shown, the orthographic projection of the second insulating coating 400 in the first direction X covers at least a portion of the adjacent battery 100. Thus, the projection of the insulating coating in the first direction X not only covers the bottom surface of one battery 100, but can also cover part or all of the batteries 100 adjacent to that battery 100. When forming the second insulating coating 400, it is not necessary to form a second insulating coating 400 for each battery 100 individually; instead, multiple batteries 100 can correspond to one second insulating coating 400, thereby improving the overall grouping efficiency of the multiple batteries 100 and thus improving the assembly efficiency of the battery pack.

[0103] In this embodiment, as Figure 2 As shown, the thickness d5 of the adhesive layer 300 ranges from 0.5μm to 3.4μm. When the thickness of the adhesive layer 300 is within a certain range, it can ensure the bonding strength between the battery 100 and the base plate 200, while also enhancing the insulation effect between the battery 100's casing 110 and the base plate 200. The thickness of the adhesive layer 300 cannot be too large, as this would result in a higher battery pack height and a lower energy density. Conversely, the thickness of the adhesive layer 300 cannot be too small, as this would affect the bonding strength between the battery 100 and the base plate 200.

[0104] It should be noted that the thickness of the adhesive layer 300 is any value or any two values ​​between 0.5μm and 3.4μm. For example, the thickness of the adhesive layer 300 can be 0.5μm, 1μm, 1.5μm, 1.8μm, 2μm, 2.5μm, 3μm, 3.4μm, etc.

[0105] In some embodiments, the dielectric constant of the adhesive layer 300 ranges from 2.4 F / m to 4.2 F / m. The dielectric constant of the adhesive layer 300 reflects its insulating properties. It should be noted that the dielectric constant of the adhesive layer 300 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. When the dielectric constant of the adhesive layer 300 is within the above range, the adhesive layer 300 has good insulating properties, thus further enhancing the insulating properties between the battery 100 and the base plate 200 while ensuring the bonding strength between the base plate 200 and the battery 100.

[0106] For example, the base plate 200 in this embodiment can be a heat exchange plate to dissipate heat from the battery 100. In this case, the product of a and b ranges from 1 to 12.8. When a*b satisfies this range, it can not only ensure the connection strength between the battery 100 and the base plate 200 and improve the insulation performance between the battery 100 and the base plate 200, but also improve the heat dissipation effect of the battery 100 and reduce the risk of thermal runaway of the battery 100.

[0107] It should be noted that, in this embodiment, the heat exchange plate refers to the battery 100 being cooled by the heat exchange plate. Therefore, the heat exchange plate can also be called a cooling plate. The heat exchange plate may have cooling channels, and the cooling channels may contain a cooling medium. This embodiment does not limit this.

[0108] In one embodiment, such as Figure 14 As shown, the battery includes terminals 160, which are mounted on the housing 110 and connected to the cell 130 for the input and output of electrical energy from the battery 100. The surface of the housing 110 where the terminals 160 are located can be positioned opposite the surface of the housing 110 facing the opening 121; that is, the terminals 160 are mounted on the surface of the housing 110 opposite to the bottom surface 111 of the housing. In this case, the product of a and b ranges from 1 to 11. Thus, the terminals 160 are relatively far from the base plate 200, thereby ensuring the insulation performance between the terminals 160 and the base plate 200 and improving the safety performance of the battery pack.

[0109] In other embodiments, the terminal post can also be disposed on the side of the housing 110 adjacent to the bottom surface 111 of the housing, and the product of a and b is in the range of 3.5-18. Thus, disposing the terminal post on the side of the housing 110 can improve the grouping efficiency of multiple batteries 100 in the battery pack and the space utilization of the battery pack, thereby increasing the energy density of the battery pack. The product of a and b satisfying the above range can prevent short circuits between the terminal post 160 and the base plate 200, further improving the safety of the battery pack.

[0110] In one embodiment, such as Figure 14 As shown, the battery 100 also includes an explosion-proof valve 170. The explosion-proof valve 170 can be disposed on the surface of the housing 110 opposite to the bottom surface 111 of the housing, with the explosion-proof valve 170 positioned at a distance from the housing bottom surface 111. The explosion-proof valve 170 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 170 is generally formed by creating grooves, serving as a weak point in the housing 110 to achieve pressure relief. The explosion-proof valve 170 and the housing 110 can be an integrally formed structure, or it can be an independent structure separate from the housing 110; this embodiment does not limit this.

[0111] In other embodiments, the explosion-proof valve 170 may also be disposed on the bottom surface 111 of the housing 110, that is, the explosion-proof valve 170 and the opening 121 are located on the same side of the battery 100. When the explosion-proof valve 170 is disposed on the bottom surface 111 of the housing, in order to improve the insulation performance at the explosion-proof valve 170, an explosion-proof valve protection patch (not shown in the figure) may be disposed on the side of the explosion-proof valve 170 away from the housing 110. The explosion-proof valve protection patch is used for the explosion-proof valve 170 to prevent the explosion-proof valve 170 from breaking before the breaking condition is reached, and also to prevent the explosion-proof valve 170 from breaking due to external forces from outside the battery 100, thereby improving the reliability of the explosion-proof valve 170.

[0112] 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, polyimide, etc. Exemplarily, 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.

[0113] In other embodiments, the explosion-proof valve 170 may also be disposed on the side of the housing 110 adjacent to the bottom surface 111 of the housing, but this embodiment does not limit this.

[0114] The battery pack provided in this embodiment has an opening 121 on the insulating member 120 on the outer surface of the housing 110. This allows the portion of the housing 110 exposed through the opening 121 to be directly bonded to the base plate 200 via the adhesive layer 300, thereby improving the bonding strength between the battery 100 and the base plate 200, as well as the heat dissipation performance of the battery 100. The product of the minimum distance 'a' between the electrode 131 and the bottom surface 111 of the housing and the minimum distance 'b' between the opening 121 of the insulating member and the base plate 200 is within the range of 1-18. This results in a low risk of breakdown and short circuit between the electrode 131 of the cell 130 and the bottom wall of the housing 110, as well as between the bottom wall of the housing 110 and the base plate 200, thus providing high reliability and safety.

[0115] This embodiment also provides a method for testing insulation performance, which can test the insulation performance between the battery and the base plate.

[0116] During the testing process, different a*b values ​​were given, and the resistance between battery 100 and base plate 200 was tested when the a*b values ​​were different. Those with a*b values ​​between 1 and 18 were called embodiments, and this embodiment provides 32 embodiments; those with a*b values ​​outside the 1-18 range were called comparative examples, and this embodiment provides 6 comparative examples. For each embodiment and each comparative example, 10 batteries of the same model were used, differing only in their a*b values; everything else was the same. A notch 121 was made on the surface of the insulating component 120 of battery 100, and the notch 121 was cleaned with alcohol. After air drying, adhesive was applied to the surface of the casing 110 facing the base plate 200 (specifically, at the notch), resulting in an adhesive layer 300. Then, the glued battery 100 was bonded to an aluminum alloy plate (used to simulate the base plate 200) and cured at 25°C for 24 hours. The minimum distance 'a' between the electrode 131 and the bottom surface 111 of the casing, and the minimum distance 'b' between the opening 121 of the insulating part 120 and the base plate 200 in different embodiments and comparative examples are shown in Table 1 below. All other aspects 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 surface of the battery. 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.

[0117] R = U / I (1)

[0118] This embodiment also provides a method for testing the pull-out force between the battery and the base plate.

[0119] Similarly, for different embodiments and comparative examples, 10 batteries of the same model were used, with the only difference being the a*b value; all other aspects were the same. 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 casing 110 facing the base plate (specifically, the notch), resulting in an adhesive layer 300. The glued battery 100 was then bonded to an aluminum alloy plate (used to simulate the base plate 200) and cured at 25°C for 24 hours. The minimum distance 'a' between the electrode 131 and the bottom surface 111 of the casing, and the minimum distance 'b' between the opening 121 of the insulating part 120 and the base plate 200 in different embodiments and comparative examples are shown in Table 1 below. All other aspects were 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. The specific results are shown in Table 1. If the 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 peel force is less than 10 MPa, the connection strength between the battery and the aluminum alloy plate is unqualified.

[0120] Table 1

[0121]

[0122]

[0123] A comparison of the experimental data from Examples 1-22 and Comparative Examples 1-6 reveals that when a and b satisfy the relationship, the battery 100 and the aluminum alloy sheet have good bonding strength and good insulation performance. A comparison of the experimental data from Examples 23 to 32 reveals that when a is not within the preferred range (i.e., 0.6-8.0), but the formula is within the preferred range, an excessively large a will affect the space utilization rate inside the casing 110 of the battery 100, reducing the energy density of the battery 100; an excessively small a will prevent the battery 100 from effectively releasing expansion force during cycling, thus affecting the lifespan of the battery 100. When b is not within the preferred range (i.e., 0.6-3.8), but the formula is within the preferred range, an excessively large b will cause the heat dissipation of the corresponding opening 121 area of ​​the battery 100 to be too slow, affecting the heat dissipation effect of the battery 100; an excessively small b will cause the heat dissipation of the opening 121 area of ​​the battery 100 to be too fast, and in the event of thermal runaway, the heat will be quickly transferred to other batteries, affecting the safety of the battery pack.

[0124] 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), a base plate (200), and an adhesive layer (300), wherein the base plate (200) supports the battery (100), and the battery (100) is fixedly disposed on the base plate (200) by the adhesive layer (300), characterized in that, The battery (100) includes a housing (110), an insulating member (120), and a battery cell (130). The battery cell (130) is disposed inside the housing (110) and includes multiple electrode plates (131). The insulating member (120) covers the outer surface of the housing (110). The surface of the housing (110) facing the base plate (200) is the bottom surface (111) of the housing. The insulating member (120) is provided with an opening (121) that exposes at least part of the bottom surface (111) of the housing. The adhesive layer (300) is at least partially disposed at the opening (121) and bonded to the base plate (200). The minimum distance between the electrode (131) and the bottom surface (111) of the housing is a mm, and the minimum distance between the opening (121) of the insulating member (120) and the base plate (200) is b mm. The product of a and b ranges from 1 to 18; the value of a ranges from 0.6 to 8.0; and the value of b ranges from 0.6 to 3.

8. The battery (100) also includes an insulating support plate (140), which is disposed between the battery cell (130) and the bottom surface (111) of the casing; The battery pack also includes a second insulating coating (400), which is at least partially disposed between the adhesive layer (300) corresponding to the opening (121) and the base plate (200).

2. The battery pack according to claim 1, characterized in that, When the battery (100) includes the insulating support plate (140), the product of a and b ranges from 1 to 14.

5.

3. The battery pack according to claim 2, characterized in that, The thickness d1 of the insulating support plate (140) ranges from 0.1 mm to 3.0 mm.

4. The battery pack according to claim 2, characterized in that, Along the direction perpendicular to the base plate (200), the projected area of ​​the insulating support plate (140) on the base plate (200) is S1, and the area of ​​the surface of the cell (130) near the bottom surface (111) of the housing is S2. The value of S1 / S2 ranges from 20% to 95%.

5. The battery pack according to claim 2, characterized in that, The projected area of ​​the insulating support plate (140) on the base plate (200) in a direction perpendicular to the base plate (200) is S1, and the projected area of ​​the opening (121) on the base plate (200) in a direction perpendicular to the base plate (200) is S3, where S1 ≥ S3.

6. The battery pack according to claim 5, characterized in that, The insulating support plate (140) completely covers the opening (121) in a direction perpendicular to the base plate (200).

7. The battery pack according to claim 2, characterized in that, Along the direction perpendicular to the base plate (200), the projected area of ​​the insulating support plate (140) on the base plate (200) is S1, and the projected area of ​​the opening (121) on the base plate (200) is S3, where S1 < S3.

8. The battery pack according to claim 2, characterized in that, The insulating support plate (140) is provided with a plurality of through holes (141), the through holes (141) penetrate the insulating support plate (140) along a first direction (X), the projected area of ​​the insulating support plate (140) on the base plate (200) along the first direction (X) is S1, the sum of the areas of the plurality of through holes (141) is S4, and the range of S4 / S1 is 5%-60%; the first direction (X) is a direction perpendicular to the base plate (200).

9. The battery pack according to claim 1, characterized in that, The battery (100) further includes an insulating film (150), which is at least partially located between the bottom of the cell (130) and the bottom surface (111) of the casing, and the product of a and b is in the range of 1-16.

2.

10. The battery pack according to claim 9, characterized in that, The porosity of the insulating film (150) ranges from 10% to 40%.

11. The battery pack according to claim 9, characterized in that, The thickness d0 of the insulating film (150) ranges from 1.5 μm to 20 μm.

12. The battery pack according to claim 9, characterized in that, The dielectric constant of the insulating film (150) ranges from 1.2 F / m to 4.0 F / m.

13. The battery pack according to claim 9, characterized in that, The battery (100) also includes an insulating support plate (140), which is disposed between the insulating film (150) and the bottom surface (111) of the housing.

14. The battery pack according to claim 13, characterized in that, The insulating support plate (140) is fixedly connected to the insulating film (150).

15. The battery pack according to claim 1, characterized in that, The cell (130) also includes a separator (132), the distance d2 of which is from the bottom surface (111) of the housing is less than the minimum distance d3 of which is from the electrode (131) to the bottom surface (111) of the housing.

16. The battery pack according to claim 15, characterized in that, The thickness d4 of the diaphragm (132) ranges from 9 μm to 50 μm.

17. The battery pack according to claim 1, characterized in that, The plurality of electrode plates (131) include a plurality of positive electrode plates (1311) and a plurality of negative electrode plates (1312), the positive electrode plates (1311) and the negative electrode plates (1312) are stacked, and the distance d31 of the negative electrode plate (1312) from the bottom surface (111) of the housing is less than the distance d32 of the positive electrode plate (1311) from the bottom surface (111) of the housing.

18. The battery pack according to claim 1, characterized in that, The bottom surface (111) of the housing is provided with a first insulating coating on the side facing the battery cell (130).

19. The battery pack according to claim 18, characterized in that, The thickness of the first insulating coating ranges from 90μm to 200μm.

20. The battery pack according to claim 1, characterized in that, The thickness d5 of the adhesive layer (300) ranges from 0.5μm to 3.4μm.

21. The battery pack according to claim 1, characterized in that, The dielectric constant of the adhesive layer (300) ranges from 2.4 F / m to 4.2 F / m.

22. The battery pack according to claim 1, characterized in that, The projection of the second insulating coating (400) onto the insulating member (120) along the first direction (X) completely covers the opening (121), the first direction (X) being perpendicular to the base plate (200).

23. The battery pack according to claim 1, characterized in that, The battery pack includes a plurality of batteries (100), and the second insulating coating (400) covers at least a portion of the adjacent batteries (100) in a direction perpendicular to the base plate (200).

24. The battery pack according to claim 1, characterized in that, The base plate (200) is a heat exchange plate, and the product of a and b ranges from 1 to 12.

8.

25. The battery pack according to claim 1, characterized in that, The battery (100) includes a terminal (160), which is mounted on the housing (110) and connected to the cell (130). The terminal (160) is mounted on the surface of the housing (110) opposite to the bottom surface (111) of the housing, and the product of a and b is in the range of 1-11.

26. The battery pack according to claim 1, characterized in that, The battery (100) includes a terminal (160), which is mounted on the housing (110) and connected to the cell (130). The terminal (160) is disposed on the side of the housing adjacent to the bottom surface (111) of the housing, and the product of a and b is in the range of 3.5-18.

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