Battery packs and electrical devices

Abstract

This utility model relates to the field of battery technology and discloses a battery pack and an electrical device. The battery pack includes: a housing; multiple battery cells, which are bonded side by side to the housing along the X direction of the housing using structural adhesive; each battery cell includes a cell shell and an insulating film wrapped around the outer surface of the cell shell; the surface of the insulating film facing the structural adhesive is wavy; the structural adhesive includes a first structural adhesive layer and a second structural adhesive layer; the bottom surface area of ​​the battery cell is S1, and the bonding surface area between the first structural adhesive layer and the bottom surface of any battery cell is Sa, where Sa and S1 satisfy: 50% ≤ Sa / S1 ≤ 85%; along the X direction of the housing, the sum of the surface areas of the opposite sides of the battery cell is S2, and the sum of the bonding surface areas between the second structural adhesive layer and the opposite sides of the battery cell is Sb, where Sb and S2 satisfy: 1.5% ≤ Sb / S2 ≤ 4%. By reasonably limiting the ratio of Sa to S1 and the ratio of Sb to S2, sufficient adhesive force can be achieved between the insulating film and the structural adhesive.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery pack and an electrical device. Background Technology

[0002] New energy batteries are widely used in various fields such as transportation power supply, power storage power supply, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high working voltage, strong charge retention capacity and long cycle life.

[0003] A battery pack typically consists of multiple battery cells, which are fixed inside the pack's casing. A battery cell generally includes a cover, casing, electrode assembly, electrode assembly end plates, bare cell insulating sheets, insulating film (such as blue film), and a cover plate top patch. The cover is welded to the casing and forms a sealed space protecting the electrode assembly. The bare cell insulating sheets cover the electrode assembly to protect it and prevent short circuits caused by contact between the electrode assembly and the casing. The electrode assembly end plates secure the tabs and provide space for their protection. The insulating film mainly covers the outside of the casing, providing external insulation.

[0004] In general, in order to securely assemble multiple cells inside the battery pack, structural adhesive is usually applied between two adjacent cells and between multiple cells and the inner wall of the battery pack, so as to bond and fix the cells inside the battery pack.

[0005] However, during the use of the battery pack, the bonding between the insulating film and the structural adhesive may fail due to insufficient adhesion, thus affecting the long-term reliability of the battery cells. Utility Model Content

[0006] In view of this, the present invention provides a battery pack and power supply device to solve the problem of bonding failure of the insulating film and structural adhesive on the outside of conventional battery cells due to insufficient adhesion.

[0007] In a first aspect, this utility model provides a battery pack, comprising:

[0008] Box;

[0009] Multiple battery cells are bonded side-by-side inside the housing along the X direction of the housing using structural adhesive; each battery cell includes a battery cell housing and an insulating film wrapped around the outer surface of the battery cell housing; the surface of the insulating film facing the structural adhesive is wavy.

[0010] The structural adhesive includes a first structural adhesive layer and a second structural adhesive layer. The first structural adhesive layer is located between the bottom surface of the plurality of battery cells and the bottom surface of the housing. The second structural adhesive layer is located between two adjacent battery cells and between the battery cells at both ends and the corresponding inner sidewalls of the housing.

[0011] The bottom surface area of ​​the battery cell is S1, and the bonding surface area between the first structural adhesive layer and any bottom surface of the battery cell is Sa. The relationship between Sa and S1 is: 50% ≤ Sa / S1 ≤ 85%. Along the X direction of the housing, the sum of the surface areas of the opposite sides of the battery cell is S2, and the bonding surface area between the second structural adhesive layer and the corresponding side of the battery cell is Sb. The relationship between Sb and S2 is: 1.5% ≤ Sb / S2 ≤ 4%.

[0012] Beneficial Effects: This invention features a wavy surface on the side of the insulating film facing the structural adhesive, increasing the contact area between the insulating film and the structural adhesive and enhancing their adhesion. Limiting the ratio of S1 and Sa to between 50% and 85% ensures a stable bond between the battery cell and the bottom of the casing, effectively preventing the battery cell from shaking or shifting inside the casing, guaranteeing the stability and safety of the battery cell during operation. It also avoids material waste and difficulties in disassembly during subsequent maintenance due to an excessively large bonding surface area. Limiting the ratio of S2 and Sb to between 1.5% and 4% ensures a reliable connection between the battery cell and the casing through a reasonable bonding surface area, effectively limiting the shaking of the battery cell in the arrangement direction and enhancing the stability of the battery cell within the casing. It also avoids increased material costs and disassembly difficulty due to an excessively large bonding surface area, while not excessively occupying the side space of the battery cell, ensuring that the battery cell's heat dissipation and other performance characteristics are not affected.

[0013] In one optional embodiment, the battery cell is a blade battery cell, and the relationship between Sa and S1 satisfies: 50% ≤ Sa / S1 ≤ 75%; the relationship between Sb and S2 satisfies: 1.5% ≤ Sb / S2 ≤ 3%.

[0014] Beneficial effects: By limiting the ratio of Sa to S1 to 50% ≤ Sa / S1 ≤ 75% and the ratio of Sb to S2 to 1.5% ≤ Sb / S2 ≤ 3%, this invention not only adapts to the structural characteristics of the blade battery cell and ensures a stable bond between the battery cell and the bottom and inner wall of the housing, effectively preventing it from shaking or shifting during use or movement, but also avoids material waste and inconvenience of disassembly caused by excessive bonding. At the same time, the reasonable bonding surface area will not affect the heat dissipation performance of the blade battery cell.

[0015] In one optional embodiment, S1 = W0 * L0 * K, Sa = W0 * L * K, where W0 is the width of the bottom surface of the battery cell in the X direction of the housing, and the value of W0 is in the range of 14mm ≤ W0 ≤ 25mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is in the range of 380mm ≤ L0 ≤ 600mm; L is the length of the bonding part between the first structural adhesive layer and the battery cell in the Y direction of the housing, and the value of L is in the range of 220mm ≤ L ≤ 400mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive side to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.6.

[0016] Beneficial Effects: For blade-shaped battery cells, this invention quantifies the bonding surface area between the structural adhesive and the battery cell by specifying the exact calculation methods for S1 and Sa. This provides a basis for the rational placement and dosage control of the structural adhesive, ensuring that the bonding of the structural adhesive at different parts of the battery cell better conforms to the cell's shape characteristics. Furthermore, by limiting the specific value ranges of W0, L0, and L, the calculation of the bonding surface area can be made more closely aligned with the actual size characteristics of the blade-shaped battery cell. This ensures sufficient bonding surface area between the structural adhesive layer and the battery cell to provide stable adhesion, preventing insufficient area from causing the battery cell to be poorly fixed. It also prevents excessive bonding surface area from leading to excessive structural adhesive usage, increasing the weight and cost of the battery pack. Simultaneously, standardized dimensional parameters help improve the consistency of battery pack assembly and production efficiency, further optimizing the overall performance of the battery pack.

[0017] In one optional embodiment, Sb = 2 * H * L * K, S2 = 2 * H0 * L0 * K, where H is the height of the second structural adhesive layer in the Z direction of the housing, and the value of H is in the range of 2mm ≤ H ≤ 5mm; L is the length of the bonding part between the second structural adhesive layer and the battery cell in the Y direction of the housing, and the value of L is in the range of 220mm ≤ L ≤ 400mm; H0 is the height of the battery cell in the Z direction of the housing, and the value of H0 is in the range of 85mm ≤ H0 ≤ 135mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is in the range of 380mm ≤ L0 ≤ 600mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive side to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.6.

[0018] Beneficial effects: This invention quantifies the bonding surface area between the second structural adhesive layer and the battery cell, as well as the corresponding area on the side of the battery cell, by clearly defining the calculation methods for Sb and S2 and limiting the value ranges of H, L, H0, and L0. This ensures that the second structural adhesive layer has appropriate height and length in the Z and Y directions, providing sufficient bonding surface area to enhance the stability of the battery cell, while also avoiding increased cost and weight due to excessive use of structural adhesive or excessively large area by standardizing dimensional parameters.

[0019] In one optional embodiment, the battery cell is a square battery cell, S1 = W0 * L0 * K, Sa = W0 * L * K, where W0 is the width of the bottom surface of the battery cell in the X direction of the housing, and the value of W0 is in the range of 25mm ≤ W0 ≤ 55mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is in the range of 150mm ≤ L0 ≤ 300mm; L is the length of the bonding part between the first structural adhesive layer and the battery cell in the Y direction of the housing, and the value of L is in the range of 110mm ≤ L ≤ 250mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive side to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.6.

[0020] Beneficial Effects: For prismatic battery cells, this invention quantifies the bonding surface area between the structural adhesive and the cell by specifying the exact calculation methods for S1 and Sa. This provides a basis for the rational placement and dosage control of the structural adhesive, ensuring that the bonding of the structural adhesive at different parts of the cell better conforms to the cell's shape characteristics. Furthermore, by limiting the specific value ranges of W0, L0, and L, the calculation of the bonding surface area can be made more closely aligned with the actual size characteristics of the prismatic battery cell. This ensures sufficient bonding surface area between the structural adhesive layer and the cell to provide stable adhesion, preventing the cell from being poorly fixed due to insufficient area. It also prevents excessive use of structural adhesive due to an excessively large bonding surface area, which would increase the weight and cost of the battery pack. Simultaneously, standardized dimensional parameters help improve the consistency of battery pack assembly and production efficiency, further optimizing the overall performance of the battery pack.

[0021] In one optional embodiment, Sb = 2 * H * L * K, S2 = 2 * H0 * L0 * K, where H is the height of the second structural adhesive layer in the Z direction of the housing, and the value of H is in the range of 2.5mm ≤ H ≤ 6mm; L is the length of the bonding part between the second structural adhesive layer and the battery cell in the Y direction of the housing, and the value of L is in the range of 110mm ≤ L ≤ 250mm; H0 is the height of the battery cell in the Z direction of the housing, and the value of H0 is in the range of 90mm ≤ H0 ≤ 125mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is in the range of 150mm ≤ L0 ≤ 300mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.6.

[0022] Beneficial effects: This invention quantifies the bonding surface area between the second structural adhesive layer and the battery cell, as well as the corresponding area on the side of the battery cell, by clearly defining the calculation methods for Sb and S2 and limiting the value ranges of H, L, H0, and L0. This ensures that the second structural adhesive layer has appropriate height and length in the Z and Y directions, providing sufficient bonding surface area to enhance the stability of the battery cell, while also avoiding increased cost and weight due to excessive use of structural adhesive or excessively large area by standardizing dimensional parameters.

[0023] In one optional embodiment, the bonding strength β between the insulating film and the structural adhesive is 3 MPa ≤ β ≤ 4.5 MPa.

[0024] Beneficial effects: This utility model controls the bonding strength β between the insulating film and the structural adhesive between 3 MPa and 4.5 MPa, which can ensure that the two have sufficient connection strength to effectively resist the external forces generated by the battery pack under dynamic working conditions (such as vibration and impact), avoid peeling or falling off, and ensure stable fixing and reliable insulation of the battery cell; at the same time, it can avoid excessive adhesive force that makes it difficult to separate during subsequent maintenance or disassembly, thus taking into account both structural safety during use and convenience of later operation.

[0025] In one alternative embodiment, the battery pack further has one or more of the following features:

[0026] The thickness of the insulating film is T1, and the value of T1 is 0.1mm ≤ T1 ≤ 0.15mm;

[0027] The thickness of the first structural adhesive layer is T3, and the value of T3 is 0.5mm≤T3≤3mm;

[0028] The thickness of the second structural adhesive layer is T2, and the value of T2 is 0.5mm≤T2≤2mm.

[0029] Beneficial effects: This invention controls the insulation film thickness to 0.1mm≤T1≤0.15mm, ensuring good insulation performance without excessively increasing the overall thickness of the battery cell, thus contributing to a thinner and lighter battery pack design. Furthermore, by limiting the thickness T3 of the first structural adhesive layer and the thickness T2 of the second structural adhesive layer within the aforementioned range, sufficient bonding strength of the structural adhesive is ensured while avoiding material waste or impeded heat dissipation due to excessive thickness.

[0030] In one optional embodiment, the surface roughness Ra of the insulating film is 1.0 μm < Ra < 1.5 μm.

[0031] Beneficial effects: This invention controls the surface roughness Ra of the insulating film to between 1.0μm and 1.5μm, which can increase the contact area between the insulating film and the structural adhesive, improve the bonding strength between the insulating film and the structural adhesive, and reduce the possibility of separation or detachment of the insulating film and the structural adhesive.

[0032] Secondly, an electrical device includes: a battery pack as described above.

[0033] Beneficial effects: The electrical device of this utility model includes the battery pack as described above, and has all the beneficial technical effects of the battery pack, which will not be repeated here. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present utility model;

[0036] Figure 2 for Figure 1 The diagram shows the structure of the insulating film.

[0037] Figure 3 This is a schematic diagram of the structure of a battery pack according to an embodiment of the present utility model;

[0038] Figure 4 for Figure 3 The diagram shows the structure of the battery pack after one side wall has been removed.

[0039] Figure 5 for Figure 3 Side view of the battery pack shown;

[0040] Figure 6 This is a schematic diagram of the structure of another battery cell according to an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of another battery pack according to an embodiment of the present invention;

[0042] Figure 8 for Figure 7 The diagram shows the structure of the battery pack after one side wall has been removed.

[0043] Figure 9 for Figure 7 The battery pack shown is a side view.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Housing; 2. Structural adhesive; 201. First structural adhesive layer; 202. Second structural adhesive layer; 3. Battery cell; 301. Insulating film. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0047] To address the problem of bonding failure between the insulating film and structural adhesive on the outside of conventional battery cells due to insufficient adhesion, this utility model provides a battery pack and an electrical device.

[0048] The following is combined Figures 1 to 9 The following describes embodiments of the present invention.

[0049] According to embodiments of the present invention, on the one hand, such as Figures 2 to 5 , Figures 7 to 9 As shown, a battery pack is provided, including: a housing 1 and multiple battery cells 3.

[0050] Specifically, multiple battery cells 3 are bonded side-by-side inside the housing 1 along the X direction of the housing 1 using structural adhesive 2; each battery cell 3 includes a battery cell shell and an insulating film 301 wrapped around the outer surface of the battery cell shell; the surface of the insulating film 301 facing the structural adhesive 2 is wavy; the structural adhesive 2 includes a first structural adhesive layer 201 and a second structural adhesive layer 202, the first structural adhesive layer 201 being located between the bottom surfaces of the multiple battery cells 3 and the bottom surface of the housing 1, and the second structural adhesive layer 202 being located between two adjacent battery cells 3 and also between two adjacent battery cells 3. Between the battery cell 3 at one end and the corresponding inner wall of the housing 1; the bottom surface area of ​​the battery cell 3 is S1, and the bonding surface area between the first structural adhesive layer 201 and the bottom surface of any battery cell 3 is Sa. The relationship between Sa and S1 is: 50% ≤ Sa / S1 ≤ 85%; along the X direction of the housing 1, the sum of the surface areas of the opposite sides of the battery cell 3 is S2, and the bonding surface area between the second structural adhesive layer 202 and the opposite sides of the battery cell 3 is Sb. The relationship between Sb and S2 is: 1.5% ≤ Sb / S2 ≤ 4%.

[0051] In this embodiment of the invention, the surface of the insulating film 301 facing the structural adhesive 2 is wavy, which increases the contact area between the insulating film 301 and the structural adhesive 2, thereby improving the adhesion between them. This embodiment of the invention limits the ratio of S1 to Sa to between 50% and 85%, ensuring a stable bond between the battery cell 3 and the bottom of the housing 1, effectively preventing the battery cell 3 from shaking or shifting inside the housing 1, ensuring the stability and safety of the battery cell 3 during operation, and avoiding material waste and disassembly difficulties during subsequent maintenance due to excessive bonding surface area. This embodiment of the invention limits the ratio of S2 to Sb to between 1.5% and 4%, ensuring a reliable connection between the battery cell 3 and the housing 1 with a reasonable bonding surface area, effectively limiting the shaking of the battery cell 3 in the arrangement direction, enhancing the stability of the battery cell 3 within the housing 1, and avoiding increased material costs and disassembly difficulty due to excessive bonding surface area, while also not excessively occupying the side space of the battery cell 3, ensuring that the heat dissipation and other performance characteristics of the battery cell 3 are not affected.

[0052] It is understood that in this embodiment, the ratio of Sa / S1 can be, but is not limited to, 50%, 55%, 60%, 60.7%, 60.8%, 61.3%, 62.8%, 63.2%, 63.3%, 64%, 64.7%, 66.7%, 68%, 70%, 73.3%, 74.3%, 74.8%, 80%, 81.1%, 82.4%, 83.5%, and 85%. The ratio of Sb / S2 can be, but is not limited to, 1.5%, 1.7%, 1.8%, 2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.6%, 3.8%, and 4%.

[0053] Furthermore, in this embodiment of the invention, multiple battery cells 3 are arranged side by side in the cavity. On the one hand, this can make reasonable use of the internal space of the housing 1 and improve the overall energy density of the battery pack. On the other hand, through the synergistic effect of the first structural adhesive layer 201 and the second structural adhesive layer 202, the battery cells 3 can be fixed and constrained in multiple dimensions, so that the bottom surface of the battery cell 3 is tightly bonded to the bottom surface of the housing 1, between adjacent battery cells 3, and between the battery cell 3 and the inner sidewall of the housing 1. This improves the overall structural strength and impact and vibration resistance of the battery pack, and effectively reduces the possibility of relative displacement and collision of the battery cells 3 inside the battery pack under dynamic working conditions.

[0054] It should be noted that the dynamic operating conditions mentioned above refer to the non-static states experienced by the battery pack during use, transportation, or testing. Specifically, these include scenarios where the battery pack is subjected to mechanical vibration (such as the bumps when the vehicle is driving or the vibration when the equipment is running), mechanical impact (such as collisions during handling or accidental drops), and dynamic stress generated by expansion and contraction during the charging and discharging of the battery cell 3. These states will subject the battery cell 3 to continuous or instantaneous forces, which may cause changes in its position or stress state.

[0055] It should be noted that the bottom surface area of ​​the battery cell 3 in this embodiment refers to the surface area of ​​the insulating film 301 located on the bottom surface of the battery cell 3 facing the bottom surface of the housing 1. The sum of the surface areas of the battery cell 3 on both sides is the sum of the surface areas of the insulating film 301 located on both sides of the battery cell.

[0056] Furthermore, since the surface shape of the insulating film 301 facing the structural adhesive 2 is wavy, the surface area of ​​the insulating film 301 is larger than its outline area. Specifically, surface area = K * outline area, where the outline area is equal to the length L0 of the insulating film 301 multiplied by the width W0 of the insulating film 301. After the insulating film 301 wraps around the battery cell 3, the length and width of the insulating film 301 located on a certain side of the battery cell 3 are equal to the length and width of that side of the battery cell 3. In other words, the length and width of the insulating film 301 can be directly measured. K is a coefficient, which is obtained by constructing the shape of the insulating film using a three-dimensional simulation model, calculating its outline area and adhesive surface area, and then dividing the adhesive surface area by the outline area.

[0057] It should be noted that the value of K is also affected by the wave amplitude on the surface of the insulating film and the distance between two adjacent wave peaks. In this invention, the wave amplitude on the surface of the insulating film is 15μm to 40μm, and the distance between two adjacent wave peaks is 120μm to 200μm.

[0058] According to one embodiment of the present invention, such as Figure 1 , Figures 3 to 5As shown, cell 3 is a blade cell. The relationship between Sa and S1 satisfies: 50% ≤ Sa / S1 ≤ 75%; the relationship between Sb and S2 satisfies: 1.5% ≤ Sb / S2 ≤ 3%. This embodiment of the invention, by limiting the ratio of Sa to S1 to 50% ≤ Sa / S1 ≤ 75% and the ratio of Sb to S2 to 1.5% ≤ Sb / S2 ≤ 3%, not only adapts to the structural characteristics of the blade cell and ensures a stable bond between cell 3 and the bottom and inner wall of the housing 1, effectively preventing shaking or displacement during use or movement, but also avoids material waste and inconvenience of disassembly caused by excessive bonding. At the same time, the reasonable bonding surface area does not affect the heat dissipation performance of the blade cell.

[0059] According to one embodiment of the present invention, such as Figure 1 , Figure 4 as well as Figure 5 As shown, S1 = W0 * L0 * K, Sa = W0 * L * K, where W0 is the width of the bottom surface of the battery cell 3 in the X direction of the housing, and the value range of W0 is: 14mm ≤ W0 ≤ 25mm; L0 is the length of the bottom surface of the battery cell 3 in the Y direction of the housing, and the value range of L0 is: 380mm ≤ L0 ≤ 600mm; L is the length of the bonding part between the first structural adhesive layer 201 and the battery cell 3 in the Y direction of the housing, and the value range of L is: 220mm ≤ L ≤ 400mm; K is the ratio of the surface area of ​​the insulating film 301 facing the structural adhesive 2 to the contour area corresponding to the surface area, and the value range of K is: 1.3 ≤ K ≤ 1.6. For blade-shaped battery cells, this embodiment of the invention quantifies the bonding surface area between the structural adhesive 2 and the battery cell 3 by specifying the exact calculation methods for S1 and Sa. This provides a basis for the reasonable layout and dosage control of the structural adhesive 2, ensuring that the bonding of the structural adhesive 2 at different parts of the battery cell 3 better conforms to the shape characteristics of the battery cell 3. Furthermore, by limiting the specific value ranges of W0, L0, and L, the calculation of the bonding surface area can be made more consistent with the actual size characteristics of the blade-shaped battery cell. In this way, it can ensure that there is sufficient bonding surface area between the structural adhesive 2 layer and the battery cell 3 to provide stable adhesion, avoiding the battery cell 3 being not firmly fixed due to insufficient area. It can also prevent excessive use of structural adhesive 2 due to excessive bonding surface area, which would increase the weight and cost of the battery pack. At the same time, standardized dimensional parameters help improve the consistency of battery pack assembly and production efficiency, further optimizing the overall performance of the battery pack.

[0060] It is understood that in this embodiment, the value of L0 can be, but is not limited to, 380mm, 400mm, 420mm, 430mm, 450mm, 500mm, 510mm, 520mm, 530mm, 535mm, 538mm, 580mm, and 600mm; and the value of W0 can be, but is not limited to, 14mm, 14.5mm, 15mm, 16mm, 16.2mm, 17mm, 18mm, 19mm, 20mm, 21mm, and 21.8mm. mm, 22mm, 23mm, 24mm, 25mm; the value of L can be, but is not limited to, 220mm, 230mm, 240mm, 245mm, 250mm, 255mm, 260mm, 270mm, 280mm, 295mm, 300mm, 310mm, 320mm, 330mm, 335mm, 340mm, 350mm, 360mm, 370mm, 375mm, 380mm, 390mm, 400mm.

[0061] According to one embodiment of the present invention, such as Figure 1 , Figure 4 as well as Figure 5 As shown, Sb = 2 * H * L * K, S2 = 2 * H0 * L0 * K, where H is the height of the second structural adhesive layer 202 in the Z direction of the housing, and the value of H is: 2mm ≤ H ≤ 5mm; L is the length of the bonding part between the second structural adhesive layer 202 and the battery cell 3 in the Y direction of the housing, and the value of L is: 220mm ≤ L ≤ 400mm; H0 is the height of the battery cell 3 in the Z direction of the housing, and the value of H0 is: 85mm ≤ H0 ≤ 135mm; L0 is the length of the bottom surface of the battery cell 3 in the Y direction of the housing, and the value of L0 is: 380mm ≤ L0 ≤ 600mm; K is the ratio of the surface area of ​​the insulating film 301 facing the structural adhesive 2 to the contour area corresponding to the surface area, and the value of K is: 1.3 ≤ K ≤ 1.6. This embodiment of the invention quantifies the bonding surface area between the second structural adhesive layer 202 and the battery cell 3, as well as the corresponding surface area of ​​the battery cell 3, by clearly defining the calculation methods for Sb and S2 and limiting the value ranges of H, L, H0, and L0. This ensures that the second structural adhesive layer 202 has appropriate height and length in the Z and Y directions, providing sufficient bonding surface area to enhance the fixing stability of the battery cell 3, while also avoiding increased cost and weight due to excessive use or excessive area of ​​the structural adhesive layer 2 by standardizing dimensional parameters.

[0062] It is understood that in this embodiment, the value of H can be, but is not limited to, 2.5mm, 3mm, 3.2mm, 3.3mm, 3.5mm, 3.7mm, 4mm, 4.1mm, 4.2mm, 4.6mm, and 5mm; the value of H0 can be, but is not limited to, 85mm, 88mm, 90mm, 92mm, 95mm, 100mm, 107mm, 110mm, 115mm, 120mm, 121mm, 125mm, 130mm, and 135mm; and the value of L0 can be, but is not limited to, 380mm, 400mm, 420mm, and 43mm. 0mm, 450mm, 500mm, 510mm, 520mm, 530mm, 535mm, 538mm, 580mm, 600mm; the value of L can be, but is not limited to, 220mm, 230mm, 240mm, 245mm, 250mm, 255mm, 260mm, 270mm, 280mm, 295mm, 300mm, 310mm, 320mm, 330mm, 335mm, 340mm, 350mm, 360mm, 370mm, 375mm, 380mm, 390mm, 400mm.

[0063] According to one embodiment of the present invention, such as Figure 6 , Figure 8 as well as Figure 9As shown, the battery cell 3 is a square battery cell, S1 = W0 * L0 * K, Sa = W0 * L * K, where W0 is the width of the bottom surface of the battery cell 3 in the X direction of the housing, and the value range of W0 is: 25mm ≤ W0 ≤ 55mm; L0 is the length of the bottom surface of the battery cell 3 in the Y direction of the housing, and the value range of L0 is: 150mm ≤ L0 ≤ 300mm; L is the length of the bonding part between the first structural adhesive layer 201 and the battery cell 3 in the Y direction of the housing, and the value range of L is: 110mm ≤ L ≤ 250mm; K is the ratio of the surface area of ​​the insulating film 301 facing the structural adhesive 2 to the contour area corresponding to the surface area, and the value range of K is: 1.3 ≤ K ≤ 1.6. For prismatic battery cells, this embodiment of the invention quantifies the bonding surface area between the structural adhesive 2 and the battery cell 3 by specifying the exact calculation methods for S1 and Sa. This provides a basis for the rational layout and dosage control of the structural adhesive 2, ensuring that the bonding of the structural adhesive 2 at different parts of the battery cell 3 better conforms to the shape characteristics of the battery cell 3. Furthermore, by limiting the specific value ranges of W0, L0, and L, the calculation of the bonding surface area can be made more consistent with the actual size characteristics of the prismatic battery cell. In this way, it can ensure that there is sufficient bonding surface area between the structural adhesive 2 layer and the battery cell 3 to provide stable adhesion, avoiding the battery cell 3 being not firmly fixed due to insufficient area. It can also prevent excessive use of structural adhesive 2 due to excessive bonding surface area, which would increase the weight and cost of the battery pack. At the same time, standardized dimensional parameters help improve the consistency of battery pack assembly and production efficiency, further optimizing the overall performance of the battery pack.

[0064] It is understood that, in this embodiment, the value of L0 can be, but is not limited to, 150mm, 158mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 294mm, or 300mm; and the value of W0 can be, but is not limited to, 25mm, 28mm, or 30mm. 33mm, 35mm, 40mm, 45mm, 50mm, 52mm, 55mm, 50mm, 52mm, 55mm; the value of L can be, but is not limited to, 110mm, 120mm, 130mm, 132mm, 140mm, 145mm, 150mm, 152mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm.

[0065] According to one embodiment of the present invention, such as Figure 6 , Figure 8 as well as Figure 9As shown, Sb = 2 * H * L * K, S2 = 2 * H0 * L0 * K, where H is the height of the second structural adhesive layer 202 in the Z direction of the housing, and the value of H is in the range of 2.5mm ≤ H ≤ 6mm; L is the length of the bonding part between the second structural adhesive layer 202 and the battery cell 3 in the Y direction of the housing, and the value of L is in the range of 110mm ≤ L ≤ 250mm; H0 is the height of the battery cell 3 in the Z direction of the housing, and the value of H0 is in the range of 90mm ≤ H0 ≤ 125mm; L0 is the length of the bottom surface of the battery cell 3 in the Y direction of the housing, and the value of L0 is in the range of 150mm ≤ L0 ≤ 300mm; K is the ratio of the surface area of ​​the insulating film 301 facing the structural adhesive 2 to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.6. This embodiment of the invention quantifies the bonding surface area between the second structural adhesive layer 202 and the battery cell 3, as well as the corresponding surface area of ​​the battery cell 3, by clearly defining the calculation methods for Sb and S2 and limiting the value ranges of H, L, H0, and L0. This ensures that the second structural adhesive layer 202 has appropriate height and length in the Z and Y directions, providing sufficient bonding surface area to enhance the fixing stability of the battery cell 3, while also avoiding increased cost and weight due to excessive use or excessive area of ​​the structural adhesive layer 2 by standardizing dimensional parameters.

[0066] It is understood that in this embodiment, the value of H0 can be, but is not limited to, 90mm, 92mm, 95mm, 100mm, 107mm, 110mm, 120mm, 121mm, and 125mm; the value of H can be, but is not limited to, 2.5mm, 3mm, 3.3mm, 3.5mm, 3.7mm, 4mm, 4.1mm, 4.2mm, 4.6mm, 5mm, 5.3mm, 5.5mm, and 6mm; and the value of L0 can be, but is not limited to, 150mm, 158mm, 165mm, 170mm, 175mm, and 180mm. The values ​​of L are 185mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 294mm, and 300mm; L can be, but is not limited to, 110mm, 120mm, 130mm, 132mm, 140mm, 145mm, 150mm, 152mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, and 250mm.

[0067] It should be noted that, in addition, during the battery pack assembly process, after the structural adhesive 2 comes into contact with the battery cell 3, the structural adhesive 2 will deform under the pressure of the battery cell 3. Since the shape of the structural adhesive 2 after deformation is irregular, in order to reduce calculation errors, H and L in this embodiment are average values. Furthermore, W0 is the distance between two opposite faces of the battery cell 3 in the X direction of the housing, and W0 is the width of the insulating film 301 located on the bottom surface of the battery cell in the X direction of the housing; L0 is the distance between two opposite faces of the battery cell 3 in the Y direction of the housing, and L0 is the length of the insulating film 301 located on the bottom surface of the battery cell in the Y direction of the housing; H0 is the distance between two opposite faces of the battery cell 3 in the Z direction of the housing, and H0 is the height of the insulating film 301 located on the side surface of the battery cell in the Z direction of the housing.

[0068] According to one embodiment of this utility model, the bonding strength β between the insulating film 301 and the structural adhesive 2 is 3 MPa ≤ β ≤ 4.5 MPa. This embodiment of the utility model controls the bonding strength β between the insulating film 301 and the structural adhesive 2 to be between 3 MPa and 4.5 MPa. This ensures sufficient connection strength between the two, effectively resisting external forces generated by the battery pack under dynamic operating conditions (such as vibration and impact), preventing peeling or detachment, and ensuring stable fixation and reliable insulation of the battery cell 3. It also avoids excessive adhesive force that would make separation difficult during subsequent maintenance or disassembly, thus balancing structural safety during use with ease of later operation.

[0069] It is understandable that the adhesive strength β can be, but is not limited to, 3 MPa, 3.5 MPa, 4 MPa, and 4.5 MPa.

[0070] According to one embodiment of the present invention, the battery pack further has one or more of the following features: the thickness of the insulating film 301 is T1, where T1 is 0.1mm ≤ T1 ≤ 0.15mm; the thickness of the first structural adhesive layer 201 is T3, where T3 is 0.5mm ≤ T3 ≤ 3mm; and the thickness of the second structural adhesive layer 202 is T2, where T2 is 0.5mm ≤ T2 ≤ 2mm. This embodiment of the present invention controls the thickness of the insulating film 301 to 0.1mm ≤ T1 ≤ 0.15mm, which ensures good insulation performance of the insulating film 301 without excessively increasing the overall thickness of the battery cell 3, thus contributing to the lightweight design of the battery pack. Furthermore, by limiting the thickness T3 of the first structural adhesive layer 201 and the thickness T2 of the second structural adhesive layer 202 according to the above ranges, it ensures that the structural adhesive 2 maintains sufficient bonding strength while avoiding material waste or heat dissipation obstruction due to excessive thickness.

[0071] It should be noted that during the battery pack assembly process, after the structural adhesive 2 comes into contact with the battery cell 3, the structural adhesive 2 will deform under the pressure of the battery cell 3. Since the thickness of the structural adhesive 2 after deformation is irregular, in order to reduce errors, T2 and T3 in this embodiment are both average values.

[0072] According to one embodiment of the present invention, such as Figures 1 to 4 , Figures 6 to 9 As shown, the surface roughness Ra of the insulating film 301 is 1.0 μm < Ra < 1.5 μm. This embodiment of the invention controls the surface roughness Ra of the insulating film 301 to be between 1.0 μm and 1.5 μm, which increases the contact area between the insulating film 301 and the structural adhesive 2, improves the bonding strength between the insulating film 301 and the structural adhesive 2, and reduces the possibility of separation or detachment between the insulating film 301 and the structural adhesive 2.

[0073] It is understood that in this embodiment, the surface roughness Ra of the substrate layer can be, but is not limited to, 1.05μm, 1.1μm, 1.15μm, 1.2μm, 1.25μm, 1.3μm, 1.35μm, 1.4μm, 1.45μm, and 1.5μm.

[0074] It should be noted that the roughness Ra is measured using the Tokyo Seimitsu roughness tester via a stylus method. Specifically, during measurement, the diamond stylus on the sensor maintains perpendicular contact with the surface being measured (the outer surface of the insulating film 301), and the sensor is dragged at a constant speed by a driver. The contour peaks and valleys of the surface being measured cause the stylus to move up and down. This displacement is synchronized with the magnetic core of the fulcrum, thereby changing the inductance of the differential inductor coil, and thus the roughness Ra is measured.

[0075] According to an embodiment of the present invention, in another aspect, an electrical device is also provided, comprising: a battery pack as described above. The electrical device of this embodiment includes the battery pack as described above, and possesses all the beneficial technical effects of the battery pack, which will not be repeated here.

[0076] It should be noted that electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0077] Taking a vehicle as an example, the battery pack inside the vehicle can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle, for example, as its operating power source. The vehicle may also include a controller and a motor. The controller controls the battery pack to supply power to the motor, for example, to meet the vehicle's power needs during starting, navigation, and driving. In some embodiments of this application, the battery pack can not only serve as the vehicle's operating power source but also as its driving power source, replacing or partially replacing fuel or natural gas to provide propulsion for the vehicle.

[0078] The technical effects of this utility model will be illustrated below with reference to specific embodiments and comparative examples.

[0079] Table 1: Cell 3 in both the example battery pack and the comparative battery pack are square cells, and the test standard is: "Safety Requirements for Power Batteries for Electric Vehicles" (GB 38031-2020).

[0080] Table 1

[0081]

[0082] After simulation analysis and vibration testing, no tearing issues were observed at the insulating film 301 in the battery packs of Examples 1 to 10, and the insulating film 301 and structural adhesive 2 did not easily separate. However, after simulation analysis and vibration testing, tearing issues occurred at the insulating film 301 in the battery packs of Comparative Examples 1 and 2, and the insulating film 301 and structural adhesive 2 easily separated. The reason for this problem in the battery pack of Comparative Example 1 was that the Sa / S1 ratio and the Sb / S2 ratio were too small, resulting in insufficient bonding strength; the reason for this problem in the battery pack of Comparative Example 2 was that the Sa / S1 ratio was too small, resulting in insufficient bonding strength. After simulation analysis and vibration testing, no tearing issues were observed at the insulating film 301 in the battery packs of Comparative Examples 3 and 4, and the insulating film 301 and structural adhesive 2 did not easily separate. However, the battery packs of Comparative Examples 3 and 4 showed excessive adhesive application, increasing costs. It should be noted that the insulating film 301 wrapped by the battery cell 3 in the battery packs corresponding to the embodiments and comparative examples in the table above is the same, that is, the wave amplitude on the surface of the insulating film 301 facing the structural adhesive 2 and the spacing between two adjacent wave peaks are the same. Therefore, the value of K is the same in all embodiments and comparative examples. Specifically, the value of K in the table above is 1.3.

[0083] Table 2: Cell 3 in both the example battery pack and the comparative battery pack are blade cells, and the test standard is: "Safety Requirements for Power Batteries for Electric Vehicles" (GB 38031-2020).

[0084] Table 2

[0085]

[0086]

[0087] In Examples 11 to 20, after simulation analysis and vibration testing, no tearing occurred at the insulating film 301, and the insulating film 301 and structural adhesive 2 did not easily separate. In Comparative Examples 5 and 6, after simulation analysis and vibration testing, tearing occurred at the insulating film 301, and the insulating film 301 easily separated from the structural adhesive 2. The reason for this problem in Comparative Example 5 was that the Sa / S1 ratio and Sb / S2 ratio were too small, resulting in insufficient bonding strength; the reason for this problem in Comparative Example 6 was that the Sb / S2 ratio was too small, resulting in insufficient bonding strength. In Comparative Examples 7 and 8, after simulation analysis and vibration testing, no tearing occurred at the insulating film 301, and the insulating film 301 and structural adhesive 2 did not easily separate. However, Comparative Examples 7 and 8 showed excessive adhesive application, increasing costs. It should be noted that the insulating film 301 wrapped by the battery cell 3 in the battery packs corresponding to the embodiments and comparative examples in the table above is the same, that is, the wave amplitude on the surface of the insulating film 301 facing the structural adhesive 2 and the spacing between two adjacent wave peaks are the same. Therefore, the value of K is the same in all embodiments and comparative examples. Specifically, the value of K in the table above is 1.3.

[0088] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery pack, characterized by, include: Box; Multiple battery cells are bonded side-by-side inside the housing along the X direction of the housing using structural adhesive; each battery cell includes a battery cell housing and an insulating film wrapped around the outer surface of the battery cell housing; the surface of the insulating film facing the structural adhesive is wavy. The structural adhesive includes a first structural adhesive layer and a second structural adhesive layer. The first structural adhesive layer is located between the bottom surface of the plurality of battery cells and the bottom surface of the housing. The second structural adhesive layer is located between two adjacent battery cells and between the battery cells at both ends and the corresponding inner sidewalls of the housing. The bottom surface area of ​​the battery cell is S1, and the bonding surface area between the first structural adhesive layer and any of the bottom surfaces of the battery cell is Sa. The relationship between Sa and S1 is: 50% ≤ Sa / S1 ≤ 85%. Along the X direction of the housing, the sum of the surface areas of the opposite sides of the battery cell is S2, and the sum of the bonding surface areas between the second structural adhesive layer and the opposite sides of the battery cell is Sb. The relationship between Sb and S2 is: 1.5% ≤ Sb / S2 ≤ 4%.

2. The battery pack of claim 1, wherein, The battery cell is a blade battery cell, and the relationship between Sa and S1 satisfies: 50% ≤ Sa / S1 ≤ 75%; the relationship between Sb and S2 satisfies: 1.5% ≤ Sb / S2 ≤ 3%.

3. The battery pack of claim 2, wherein, S1 = W0 * L0 * K, Sa = W0 * L * K, where W0 is the width of the bottom surface of the battery cell in the X direction of the housing, and the value of W0 is: 14mm ≤ W0 ≤ 25mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is: 380mm ≤ L0 ≤ 600mm; L is the length of the bonding part between the first structural adhesive layer and the battery cell in the Y direction of the housing, and the value of L is: 220mm ≤ L ≤ 400mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive side to the contour area corresponding to the surface area, and the value of K is: 1.3 ≤ K ≤ 1.

6.

4. The battery pack of claim 2, wherein, Sb = 2 * H * L * K, S2 = 2 * H0 * L0 * K, where H is the height of the second structural adhesive layer in the Z direction of the housing, and the value of H is in the range of 2mm ≤ H ≤ 5mm; L is the length of the part of the second structural adhesive layer that is attached to the battery cell in the Y direction of the housing, and the value of L is in the range of 220mm ≤ L ≤ 400mm; H0 is the height of the battery cell in the Z direction of the housing, and the value of H0 is in the range of 85mm ≤ H0 ≤ 135mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is in the range of 380mm ≤ L0 ≤ 600mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.

6.

5. The battery pack of claim 1, wherein, The battery cell is a square battery cell, S1 = W0 * L0 * K, Sa = W0 * L * K, where W0 is the width of the bottom surface of the battery cell in the X direction of the housing, and the value of W0 is: 25mm ≤ W0 ≤ 55mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is: 150mm ≤ L0 ≤ 300mm; L is the length of the bonding part between the first structural adhesive layer and the battery cell in the Y direction of the housing, and the value of L is: 110mm ≤ L ≤ 250mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive side to the contour area corresponding to the surface area, and the value of K is: 1.3 ≤ K ≤ 1.

6.

6. The battery pack of claim 1, wherein, Sb = 2 * H * L * K, S2 = 2 * H0 * L0 * K, where H is the height of the second structural adhesive layer in the Z direction of the housing, and the value of H is in the range of 2.5mm ≤ H ≤ 6mm; L is the length of the part of the second structural adhesive layer that is attached to the battery cell in the Y direction of the housing, and the value of L is in the range of 110mm ≤ L ≤ 250mm; H0 is the height of the battery cell in the Z direction of the housing, and the value of H0 is in the range of 90mm ≤ H0 ≤ 125mm; L0 is the length of the bottom surface of the battery cell in the Y direction of the housing, and the value of L0 is in the range of 150mm ≤ L0 ≤ 300mm; K is the ratio of the surface area of ​​the insulating film facing the structural adhesive to the contour area corresponding to the surface area, and the value of K is in the range of 1.3 ≤ K ≤ 1.

6.

7. The battery pack according to any one of claims 1 to 6, characterized in that, The bonding strength β between the insulating film and the structural adhesive is 3 MPa ≤ β ≤ 4.5 MPa.

8. The battery pack of any one of claims 1-6, wherein, The battery pack also has one or more of the following features: The thickness of the insulating film is T1, and the value of T1 is 0.1mm ≤ T1 ≤ 0.15mm; The thickness of the first structural adhesive layer is T3, and the value of T3 is 0.5mm≤T3≤3mm; The thickness of the second structural adhesive layer is T2, and the value of T2 is 0.5mm≤T2≤2mm.

9. The battery pack of any one of claims 1-6, wherein, The surface roughness Ra of the insulating film is 1.0 μm < Ra < 1.5 μm.

10. An electrical device, characterized by include: The battery pack as described in any one of claims 1 to 9.

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