Battery pack and electric device

Abstract

The application relates to the field of batteries, and provides a battery pack and an electric equipment, the battery pack comprising a battery pack, the battery pack comprising a first battery column and a second battery column arranged along a second direction, the first battery column and the second battery column respectively comprising at least two battery monomers, the opposite surface of the first battery column and the second battery column being a first side surface, and the first side surfaces of two battery monomers of adjacent battery columns being fixedly connected through an adhesive layer; the battery monomer comprising a shell and a cover plate fixedly connected with each other, the first side surface being arranged on the shell, and at least one end of the shell comprising an opening, the cover plate sealing the opening and being welded with the shell to form a first welding area; wherein, in the height direction, the spacing between the adhesive layer and the first welding area is H(1) mm, the extension thickness of the adhesive layer in the second direction is L(1) mm, and H(1) / L(1) satisfies 1<=H(1) / L(1) <=40.

Description

Technical Field

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

[0002] Large electric commercial vehicles, due to their large total mass, high rated load, long operating mileage, and high continuous output power requirements, have high requirements for the energy storage and integration efficiency of the power battery pack, requiring a large number of battery cells and a large overall size of the battery pack.

[0003] In actual use, commercial vehicles experience severe vibrations. During vibration, the internal seals of individual battery cells may fail, the weld lines may crack, and there is even a safety risk of individual battery cells coming off, affecting the safety of the battery pack. Summary of the Invention

[0004] In view of this, the present application aims to provide a battery pack and electrical equipment to solve the existing technical problems that the internal sealing of battery cells is prone to failure, the welding wire cracks, and even the safety risk of battery cells falling out during vibration, which affects the safety of battery pack use.

[0005] A first aspect of this application provides a battery pack, including a battery assembly; The battery pack includes a first battery column and a second battery column arranged along a second direction. The first battery column and the second battery column each include at least two battery cells. The second direction is the length direction of the battery cell. The at least two battery cells in the first battery column are arranged along a first direction. The first direction, the second direction, and the height direction of the battery cell are perpendicular to each other. The surface of the first battery column opposite to the second battery column is the first side surface, and the first side surface of two battery cells in adjacent battery columns is fixedly connected by an adhesive layer. The battery cell includes a housing and a cover plate fixedly connected to each other. The first side is disposed on the housing, and the housing has an opening at at least one end. The cover plate seals the opening and is welded to the housing to form the first welding area, and the cover plate is perpendicular to the height direction. In the height direction, the distance between the adhesive layer and the first welding area is H(1) mm, the extension thickness of the adhesive layer in the second direction is L(1) mm, and H(1) / L(1) satisfies 1≤H(1) / L(1)≤40.

[0006] A second aspect of this application provides an electrical device including the battery pack.

[0007] In the battery pack of this application embodiment, at least two battery columns are arranged along the second direction, and battery cells in each battery column are arranged along the first direction. An adhesive layer is provided between the first side of the battery cells of two adjacent battery columns. When the ratio H(1) mm between the adhesive layer and the first welding area and the extension thickness L(1) mm of the adhesive layer in the second direction is satisfied that 1≤H(1) / L(1)≤40, the spacing between the adhesive layer and the first welding area of ​​the cover plate and the shell and the thickness of the adhesive layer can be effectively controlled, reducing the tearing of the adhesive layer on the first welding area. By controlling the spacing between the adhesive layer and the first welding area in the height direction, the structural strength of the first welding area is guaranteed, effectively reducing the probability of dangerous situations such as leakage of battery cells, providing a certain space for the normal thermal expansion of battery cells, effectively improving the long-term structural reliability and stability of the battery cells in this application embodiment under long-term vibration conditions, and preventing the first and second battery columns from detaching from each other and preventing the individual battery columns from detaching from each other, the structural stability of the battery pack in this application embodiment is effectively improved. Attached Figure Description

[0008] It should be understood that the following figures only illustrate certain embodiments of this application and should not be construed as limiting the scope.

[0009] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0010] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0011] Figure 1 This is a three-dimensional schematic diagram of the battery pack according to an embodiment of this application.

[0012] Figure 2 This is a side view of the battery pack according to an embodiment of this application.

[0013] Figure 3 This is a side view of the battery cell and adhesive layer in an embodiment of this application.

[0014] Figure 4 This is a side view of the battery cell and adhesive layer in an embodiment of this application.

[0015] Figure 5 This is a side view of the battery cell and adhesive layer in an embodiment of this application.

[0016] Figure 6 This is a cross-sectional schematic diagram of the area where the first welding zone of the battery cell is located, according to an embodiment of this application.

[0017] Attached image labels: 100. Battery pack; 10. Battery cell; 11. Housing; 12. Cover plate; 13. First side; 131. First edge; 132. Second edge; 14. Insulator; 15. Window area; 151. Sub-window; 16. First welding area; 17. First end face; 20. Adhesive layer; 30. Heat insulation pad.

[0018] X - First direction; Y - Second direction; Z - Height direction. Detailed Implementation

[0019] Numerous specific details are set forth below to provide an understanding of the structure, function, and use of the embodiments described and illustrated in the specification and figures. It is to be understood that the embodiments described and illustrated herein are non-limiting examples, and thus it will be appreciated that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes may be made to these embodiments without departing from the scope of the claims.

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Research has found that existing battery packs often employ stacking along the large surface of the battery to suppress deformation of the long side of the cover plate and expansion of the large surface of the battery under vibration conditions, thereby improving the constraint stiffness of the large surface of the battery and the long side of the cover plate. However, this setup leaves the short side of the cover plate unconstrained, causing adjacent battery rows arranged along the long side to separate under vibration conditions. Therefore, by placing an adhesive layer between adjacent battery rows, it is possible to prevent the two battery rows from moving in opposite directions, which could lead to the separation of the battery and the battery pack. This could pose a safety hazard to the internal electrical connections of the battery pack, and the battery casing is more susceptible to internal thermal runaway safety risks when impacted. However, the adhesive layer also subjectes the short side of the cover plate to a certain tearing force, which, combined with the significant vibration tearing force at the short side, increases the risk of the weld lines tearing. Under vehicle vibration conditions, the short side of the cover plate is prone to concentrated alternating vibration loads, and during long-term service, the weld joints are prone to fracture failure, leading to electrolyte leakage from the cells, interconnection between the inside and outside of the battery, and safety hazards such as thermal runaway of the battery pack.

[0022] In the battery pack of this application embodiment, at least two battery columns are arranged along the second direction, and battery cells in each battery column are arranged along the first direction. An adhesive layer is provided between the first side of the battery cells of two adjacent battery columns. When the ratio H(1) mm between the adhesive layer and the first welding area and the extension thickness L(1) mm of the adhesive layer in the second direction is satisfied that 1≤H(1) / L(1)≤40, the spacing between the adhesive layer and the first welding area of ​​the cover plate and the shell and the thickness of the adhesive layer can be effectively controlled, reducing the tearing of the adhesive layer on the first welding area. By controlling the spacing between the adhesive layer and the first welding area in the height direction, the structural strength of the first welding area is guaranteed, effectively reducing the probability of dangerous situations such as leakage of battery cells, providing a certain space for the normal thermal expansion of battery cells, effectively improving the long-term structural reliability and stability of the battery cells in this application embodiment under long-term vibration conditions, and preventing the first and second battery columns from detaching from each other and preventing the individual battery columns from detaching from each other, the structural stability of the battery pack in this application embodiment is effectively improved.

[0023] Specifically, such as Figures 1 to 5 As shown, this application embodiment provides a battery pack. The battery pack of this application embodiment can be a complete functional unit that can directly output electrical energy, which is formed by combining multiple battery cells 10 in series and / or parallel to form a battery pack 100, a battery management system (BMS), a thermal management system, an electrical connection system (high voltage / low voltage connectors, wiring harnesses, etc.), structural components (shell, brackets, etc.), and protective components, and placing the above components into a box and sealing it with a cover plate 12.

[0024] Specifically, the battery pack in this embodiment includes at least a battery pack 100, which includes at least two battery cells 10. The battery pack 100 includes a first battery column and a second battery column arranged along a second direction. Each of the first and second battery columns includes at least two battery cells 10. The surfaces of the first and second battery columns facing each other are first side surfaces 13. The first side surfaces 13 of two battery cells 10 in adjacent battery columns are fixedly connected by an adhesive layer 20. The second direction is the length direction of the battery cells 10 in this embodiment. The at least two battery cells 10 in the first battery column are arranged along the first direction, wherein the first direction, the second direction, and the height direction of the battery cells 10 are perpendicular to each other.

[0025] Specifically, multiple battery cells 10 with similar capacity and internal resistance can be connected in series or parallel to form a battery pack 100. Each battery cell 10 can store chemical energy and controllably convert it into electrical energy. In recyclable batteries, the active materials can be reactivated by charging after discharge for continued use. The battery cells 10 can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and this embodiment is not limited to these types. Heat insulation pads 30 can be provided between the battery cells to effectively block heat transfer.

[0026] A battery cell 10 typically includes a casing, a battery cell, an adapter plate, and an electrolyte. The casing houses the battery cell and the electrolyte. Specifically, in this embodiment, the battery cell 10 includes a housing 11 and a cover plate 12 fixedly connected to each other. A first side 13 is disposed on the housing 11, and at least one end of the housing 11 includes an opening. The cover plate 12 seals the opening and is welded to the housing 11 to form a first welding area 16, and the cover plate 12 is perpendicular to the height direction. Figure 6 As shown, the first welding area 16 is formed between the housing 11 and the cover plate 12.

[0027] The housing 11 of the battery cell 10 is a component that provides a receiving space to house the electrode assembly and other components and isolate them from the outside environment. The housing 11 generally includes a body with an opening at at least one end and a receiving cavity. The opening of the housing 11 can be closed by a cover plate 12 to seal and isolate the internal environment of the battery cell 10 from the external environment. The materials of the housing 11 include, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0028] The cover plate 12 of the battery cell 10 is a component used to close the opening of the housing 11 to isolate the internal environment of the battery cell 10 from the external environment. The material of the cover plate 12 includes, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic. It is understood that at least one positive electrode post and at least one negative electrode post of the battery cell are disposed on the housing 11 and / or the cover plate 12. The battery cell includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and a separator. The separator is located between adjacent positive and negative electrode plates to insulate them. At least one end of the electrode assembly has a tab, one end of which is electrically connected to the tab, and the other end is electrically connected to the electrode post. Adjacent battery cells 10 are connected in series or parallel via conductive busbars. The bottom surface of the battery cell 10 is bonded to the bottom plate of the housing via an adhesive layer 20, or fixed to the bottom plate of the housing via other structural components such as riveting or welding. Figure 2 and Figure 3As shown, the first direction is the extension direction of the short side of the cover plate 12 of the battery cell 10 in this embodiment, the second direction is the extension direction of the long side of the cover plate 12 of the battery cell 10 in this embodiment, and the first side 13 is the smaller side of the battery cell 10. The adhesive layer 20 is used to bond and fix the structural components inside the battery pack. It has the characteristics of high strength, ability to withstand large loads, aging resistance, fatigue resistance, corrosion resistance, and stable performance within the expected lifespan, thereby improving the connection strength.

[0029] like Figure 2 As shown, the first side 13 of two battery cells 10 in adjacent battery rows are fixedly connected by an adhesive layer 20. The adhesive layer 20 can be set separately between the first side 13 of two battery cells 10 in adjacent battery rows, or it can overflow upward through the adhesive layer between the bottom surface of the battery and the bottom plate of the box, and then extend to the first side 13 of the two adjacent battery rows, that is, extend upward from the bottom surface of the battery cell 10, and fix the adjacent battery cells 10. Thus, the adhesive layer 20 is used to fix the battery cells 10 to each other and fix the battery cells 10 to the bottom plate of the box.

[0030] like Figure 2 As shown, in the battery pack of this application embodiment, the distance between the adhesive layer and the first welding area in the height direction is H(1) mm, the extension thickness of the adhesive layer in the second direction is L(1) mm, and H(1) / L(1) satisfies 1≤H(1) / L(1)≤40.

[0031] Specifically, in the embodiments of this application, measuring instruments such as micrometers or calipers can be used to measure parameters such as length, width, depth, diameter, radius, distance, and thickness, and relevant area parameters can be obtained by calculation.

[0032] In this embodiment, the preparation process of the battery cell is as follows: (1) Preparation of the positive electrode: The positive electrode active material, conductive agent acetylene black, and binder PVDF are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, it is cold-pressed and slit to obtain the positive electrode sheet. Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98):(4~1):(4~1).

[0033] (2) Preparation of negative electrode: The negative electrode active material, conductive agent acetylene black, thickener CMC, and binder SBR are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, air-dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained. The ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96):(4~2):(2~1):(4~1).

[0034] (3) Preparation of electrolyte: Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0035] (4) Preparation of the diaphragm: Polyethylene film is selected as the diaphragm.

[0036] (5) Battery fabrication: The positive electrode, separator, and negative electrode are stacked in sequence and wound to form a bare battery cell, which is then placed in a prismatic battery casing. The battery is dried, injected with electrolyte, sealed with a sealing device, and then subjected to settling, formation, and volume adjustment to obtain the battery.

[0037] The positive electrode active material can be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate; the negative electrode active material can be selected from one or more negative electrode active main materials, such as artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0038] The adhesive includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0039] The solvent can be deionized water, NMP (N-methylpyrrolidone), alcohol, ether, ketone or other types of pyrrolidone, etc.

[0040] The positive electrode current collector foil can be a metal foil or a composite current collector. For example, as a metal foil, it can be made of stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0041] The negative electrode current collector foil can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium, and can be surface-plated with silver. Composite current collectors may include a polymer base layer and a metal layer. Composite current collectors can be formed by forming metal materials (aluminum, aluminum alloys, copper, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0042] In this embodiment of the application, Test 1 and Test 2 were performed. Test 1 was used to test the battery leakage rate under vibration conditions, and Test 2 was used to test whether the adhesive layer was peeled off from the battery cell under vibration conditions.

[0043] Test 1: The specific steps for determining the battery leakage rate under vibration conditions are as follows: According to the above-mentioned method for preparing individual battery cells, for each embodiment and comparative example, corresponding batteries are prepared. 500 batteries are prepared, and 4 batteries are grouped together. Two of the batteries are arranged along the width direction of the battery to form a battery column. The two battery columns are arranged along the length direction of the battery. Adjacent battery columns are bonded together with adhesive layer to form a battery pack. A total of 125 battery packs are formed. The values ​​of H(1) and L(1) of each embodiment and comparative example are shown in Table 3 below. Other test conditions are kept consistent.

[0044] The battery was mounted on a vibration table according to GB / T2423.43. The testing procedure was carried out according to GB / T2423.56. Random and fixed-frequency vibration loads were applied in each direction, and the loading sequence should preferably be random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the direction of the line connecting the front and rear of the battery is the x-axis direction, and the other horizontal direction perpendicular to the x-axis direction is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc., are shown in Table 1 below.

[0045] Table 1 After the vibration is complete, observe the junction between the short side of the battery cover and the battery casing to check for leakage. The leakage rate is calculated as (number of leaking batteries / 500). 100%.

[0046] If the battery leakage rate is less than or equal to 1%, the test result is considered good; if the battery leakage rate is less than or equal to 3% but greater than 1%, the test result is considered qualified; if the battery leakage rate is greater than 3%, it is considered unqualified.

[0047] Test Method 2: Under vibration conditions, whether the adhesive layer peels off from the battery. The specific steps are as follows: According to the above battery preparation method, for each embodiment and comparative example, corresponding batteries were prepared. 400 batteries were prepared, and 4 batteries were grouped together. Two batteries were arranged along the width direction of the battery to form a battery column. The two battery columns were arranged along the length direction of the battery. Adjacent battery columns were bonded together with an adhesive layer to form a battery pack. A total of 100 battery packs were formed. The battery packs were tested. The values ​​of H(1) and L(1) of each embodiment and comparative example are shown in Table 3 below. Other test conditions were kept consistent.

[0048] The battery was mounted on a vibration table according to GB / T2423.43. The testing procedure was carried out according to GB / T2423.56. Random and fixed-frequency vibration loads were applied in each direction, and the loading sequence should preferably be random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the direction of the line connecting the front and rear of the battery is the x-axis direction, and the other horizontal direction perpendicular to the x-axis direction is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc., are shown in Table 2 below.

[0049] Table 2 After vibration, observe whether the adhesive layer and the battery are peeled off, and count the number of battery packs that peeled off. The pass rate is calculated as follows: [(Total number of battery packs - Number of battery packs that peeled off) / 100] 100%.

[0050] If the pass rate is greater than or equal to 99%, the test result is considered good; if the pass rate is less than 97% but greater than or equal to 99%, the test result is considered qualified; if the pass rate is less than 97%, it is considered unqualified.

[0051] Table 3 In Table 3 above, H(1) / L(1) of each embodiment satisfies 1≤H(1) / L(1)≤40, and the test results for performance 1: battery leakage ratio and performance 2: peeling of battery cell from adhesive layer are both qualified or good. For Comparative Example 1, H(1) / L(1)<1, and the test result for performance 1: battery leakage ratio is unqualified. For Comparative Example 2, H(1) / L(1)>40, and the test result for performance 2: peeling of battery cell from adhesive layer is unqualified.

[0052] According to the analysis, when H (1) / L (1) is less than 1, the stability of each battery cell 10 in the battery pack is insufficient, and it is easy to detach from the adjacent battery cells 10, thereby reducing the structural stability of the battery cells 10 in the battery pack of this application embodiment; when H (1) / L (1) is greater than 40, the adhesive layer 20 exerts a large pulling force on the first welding area on the short side of the cover plate 12 of the battery cell 10, and the probability of tearing of the first welding area on the short side is large, which can easily lead to dangerous situations such as leakage of the battery cells 10 in this application embodiment. In addition, the thermal expansion space of the battery cell 10 is relatively small, which can easily lead to the risk of the casing 11 bulging or the explosion-proof valve being opened by mistake, thereby reducing the working safety of the battery cells 10 in this application embodiment.

[0053] Therefore, in the battery pack of this application embodiment, at least two battery rows are arranged along the second direction, and the battery cells 10 in each battery row are arranged along the first direction. An adhesive layer 20 is provided between the first side surface 13 of the battery cells 10 of two adjacent battery rows, and the distance H(1) mm between the adhesive layer 20 and the first welding area 16 is equal to the extension thickness L(1) of the adhesive layer 20 in the second direction. When the ratio H(1) / L(1) satisfies 1≤H(1) / L(1)≤40, the spacing between the adhesive layer 20 and the first welding area 16 of the cover plate 12 and the shell 11 and the thickness of the adhesive layer 20 can be effectively controlled, reducing the tearing of the adhesive layer 20 on the first welding area 16. By controlling the spacing between the adhesive layer 20 and the first welding area 16 in the height direction, the structural strength of the first welding area 16 can be guaranteed, effectively reducing the probability of dangerous situations such as leakage of the battery cell 10, providing a certain space for the normal thermal expansion of the battery cell 10, effectively improving the long-term structural reliability and stability of the battery cell 10 under long-term vibration conditions in this embodiment, and at the same time preventing the first battery column and the second battery column from detaching from each other and preventing the individual battery columns from detaching from each other, effectively improving the structural stability of the battery pack in this embodiment.

[0054] In a specific embodiment, H (1) / L (1) can be selected from specific values ​​such as 1, 5, 9, 14, 19, 24, 29, 33, 37, 40, or other reasonable specific values ​​can be selected within the range of 1 to 40, without any restrictions.

[0055] Specifically, in one embodiment of this application, the extension thickness L(1) mm of the adhesive layer 20 in the second direction satisfies 0.05 mm ≤ L(1) mm ≤ 3 mm. It is understood that the extension thickness L(1) mm of the adhesive layer 20 in the second direction can be controlled by controlling the amount of adhesive required for the adhesive layer 20 in the adhesive application process.

[0056] When the extension thickness L (1) mm of the adhesive layer 20 in the second direction is less than 0.05 mm, the adhesive layer 20 is too thin, resulting in insufficient fixing strength between adjacent battery cells 10, and it is also difficult to use the adhesive layer 20 to buffer vibration and impact; when L (1) mm is greater than 3 mm, the adhesive layer 20 is too thick, which will significantly increase the overall size of the battery pack, reduce the energy density of the battery pack, and cause the adhesive layer 20 to exert too much pulling force on the short side welding wire of the cover plate 12 of the battery cell 10, increasing the probability of tearing of the short side welding wire.

[0057] Therefore, when the extension thickness L(1) mm of the adhesive layer 20 in the second direction satisfies 0.05 mm ≤ L(1) mm ≤ 3 mm, the pulling force of the adhesive layer 20 on the short side weld wire of the cover plate 12 of the battery cell 10 can be appropriately reduced while ensuring that the adhesive layer 20 provides reliable connection strength and effective buffering performance. This reduces the tearing probability of the short side weld wire of the battery cell 10 under long-term vibration conditions, improves the practical safety of the battery cell 10 in this embodiment, and controls the thickness dimension of the battery cell 10 in this embodiment, thereby increasing the energy density of the battery pack. In specific embodiments, L(1) mm can be selected from specific values ​​such as 0.05 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1.2 mm, 1.6 mm, 2.0 mm, 2.3 mm, 2.7 mm, and 3 mm, or other reasonable specific values ​​can be selected within the range of 0.05 mm to 3 mm, which are not limited here.

[0058] like Figure 2As shown, in one embodiment of this application, the distance H(1) mm between the adhesive layer 20 and the cover plate 12 satisfies 3 mm ≤ H(1) mm ≤ 100 mm. It can be understood that the distance H(1) mm between the adhesive layer 20 and the cover plate 12 is the vertical distance between the upper edge of the adhesive layer 20 and the lower surface of the cover plate 12 of the battery cell 10 in the height direction; the distance H(1) mm between the adhesive layer 20 and the cover plate 12 can be controlled by controlling the application position of the adhesive.

[0059] When the distance H (1) mm between the adhesive layer 20 and the cover plate 12 is less than 3 mm, the adhesive layer 20 will extend excessively to the area close to the cover plate 12, encroaching on the expansion space above the battery cell 10 and increasing the risk of abnormal increase in internal pressure of the battery cell 10; when H (1) mm is greater than 100 mm, the vertical coverage height of the adhesive layer 20 is insufficient, resulting in a reduction in the effective bonding area between the adhesive layer 20 and the side of the battery cell 10, thereby affecting the structural stability of the battery cell 10.

[0060] Therefore, when the distance H(1) mm between the adhesive layer 20 and the cover plate 12 satisfies 3 mm ≤ H(1) mm ≤ 100 mm, a necessary and sufficient safety space can be reserved on the top of the battery cell 10 to facilitate the normal expansion of the battery cell 10, while ensuring that the adhesive layer 20 can provide a stable connection, thereby improving the working safety of the battery pack under long-term vibration conditions. In a specific embodiment, H(1) mm can be selected from specific values ​​such as 3 mm, 10 mm, 17 mm, 24 mm, 30 mm, 36 mm, 42 mm, 48 mm, 55 mm, 62 mm, 69 mm, 75 mm, 81 mm, 88 mm, 100 mm, etc., or other reasonable specific values ​​can be selected within the range of 3 mm to 100 mm, which are not limited here.

[0061] like Figure 3 As shown, in one embodiment of this application, the adhesive layer 20 extends in the first direction with a width of D(1) mm; the battery cell 10 extends in the first direction with a width of D(2) mm, and D(1) / D(2) satisfies 0.1≤D(1) / D(2)≤0.8.

[0062] When the ratio of the extension width D(1) mm of the adhesive layer 20 in the first direction to the extension width D(2) mm of the battery cell 10 in the first direction, D(1) / D(2) is less than 0.1, the effective bonding area between the adhesive layer 20 and the side of the battery cell 10 is insufficient, and it cannot provide sufficient bonding force. When D(1) / D(2) is greater than 0.8, the width of the adhesive layer 20 is too wide, which will not only increase unnecessary material costs, but also increase the risk of adhesive overflow of the adhesive layer 20 due to the edge of the adhesive layer 20 being too close to the edge of the battery cell 10, causing the adhesive layer 20 to overflow into unnecessary areas.

[0063] Therefore, in the battery pack of this application embodiment, when the ratio D(1) / D(2) of the extension width D(1) mm of the adhesive layer 20 in the first direction to the extension width D(2) mm of the battery cell 10 in the first direction satisfies 0.1≤D(1) / D(2)≤0.8, it can be ensured that the adhesive layer 20 has sufficient width to provide reliable connection strength, while avoiding material waste and avoiding adhesive overflow in the adhesive layer 20. In a specific embodiment, D(1) / D(2) can be selected from specific values ​​such as 0.1, 0.18, 0.26, 0.34, 0.42, 0.5, 0.58, 0.66, 0.74, 0.8, etc., or other reasonable specific values ​​can be selected within the range of 0.1 to 0.8. The range of D(1) mm is 8mm to 78mm, and specific values ​​such as 8mm, 15mm, 23mm, 31mm, 40mm, 48mm, 56mm, 64mm, 71mm, 78mm, etc., or other reasonable values ​​can be selected within the above range. The range of D(2) mm is 10mm to 80mm, and specific values ​​such as 10mm, 18mm, 26mm, 34mm, 42mm, 50mm, 58mm, 66mm, 73mm, 80mm, etc., or other reasonable values ​​can be selected within the above range. No restrictions are imposed here.

[0064] Furthermore, such as Figure 3 As shown, in one embodiment of this application, the adhesive layer 20 is spaced apart from at least one end of the first side in the first direction, and the extension width D(1) mm of the adhesive layer 20 in the first direction is smaller than the extension width D(2) mm of the battery cell 10 in the first direction. This structure can prevent the first welding area from being affected by the adhesive layer 20, ensuring the structural strength of the first welding area, preventing tearing of the first welding area, and effectively reducing the probability of dangerous situations such as leakage from the battery cell 10. Figure 3As shown, in one embodiment of this application, in the first direction, the distance between the two sides of the adhesive layer 20 and the edge of the corresponding battery cell 10 is D(3) mm, where D(3) mm satisfies 1 mm ≤ D(3) mm ≤ 10 mm.

[0065] Specifically, by controlling the coating area of ​​the adhesive layer 20, a specific distance D(3) mm can be maintained between the two edges of the adhesive layer 20 and the two end edges of the first side surface 13 of the battery cell 10 in the first direction.

[0066] In the first direction, when the distance D(3) between the two sides of the adhesive layer 20 and the edge of the corresponding battery cell 10 is less than 1 mm, the adhesive layer 20 is too close to the edge of the casing 11 of the battery cell 10, which easily causes adhesive overflow, resulting in the adhesive layer 20 overflowing into unnecessary areas and interfering with other structures; when D(3) is greater than 10 mm, the effective bonding width of the adhesive layer 20 is greatly reduced, and it cannot provide sufficient bonding force.

[0067] Therefore, in the battery pack of this application embodiment, when the distance D(3) mm between the two sides of the adhesive layer 20 and the edge of the corresponding battery cell 10 in the first direction satisfies 1 mm ≤ D(3) mm ≤ 10 mm, the generation of adhesive overflow can be effectively prevented, the assembly quality of the battery pack of this application embodiment can be improved, and the necessary adhesive width can be maintained, thereby reliably maintaining the positional stability of the battery cell 10 in the battery pack of this application embodiment.

[0068] In a specific embodiment, D(3) mm can be selected from specific values ​​such as 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or other reasonable specific values ​​can be selected within the range of 1mm to 10mm, without limitation. Figure 3 As shown, in one embodiment of this application, in a first direction, the first side surface 13 includes a first edge 131 and a second edge 132. The thickness of the adhesive layer 20 at the center between the first edge 131 and the second edge 132 is greater than the thickness of the adhesive layer 20 at the first edge 131 and / or the second edge 132. That is, compared to the center between the first edge 131 and the second edge 132, the thickness of the adhesive layer 20 at the first edge 131 and / or the second edge 132 is thinner, which can effectively avoid stress concentration at the first edge 131 and / or the second edge 132, prevent tearing at the first edge 131 and / or the second edge 132, and thus avoid leakage of the battery cell 10.

[0069] like Figure 1As shown, in one embodiment of this application, an insulating element 14 is provided on the first side 13 of the battery cell 10. The insulating element 14 includes at least one of an insulating film, an insulating coating, and an insulating sheet. The insulating element 14 can be at least one of an insulating sheet, an insulating film, or an insulating coating. The insulating film can be made of polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), polyethylene (PE), etc. The insulating coating can be made of modified epoxy resin, insulating polyacrylate, polyethylene terephthalate, oil-based insulating resin, water-based insulating resin, or styrene-butadiene rubber emulsion, etc. The main material of the insulating resin includes epoxy resin, acrylic resin, polyurethane resin, hydroxyl acrylic resin, and other multifunctional resins. It may also include various additives, such as photoinitiators, reactive diluents, flame retardants, wetting agents, leveling agents, defoamers, etc. The insulating sheet is a pre-formed sheet-like insulating material, such as an epoxy resin board or mica sheet, which is attached to the surface of the battery cell 10 by an adhesive.

[0070] like Figure 4 As shown, in one embodiment of this application, the area where the first side 13 of the battery cell 10 is bonded and fixed to the adhesive layer 20 is called the bonding area; an opening area 15 is provided on the insulating member 14 of the first side 13 of the battery cell 10, the shell 11 of the battery cell 10 is exposed at the opening area 15, at least a part of the shell 11 exposed in the opening area 15 is directly bonded and fixed to the adhesive layer 20, and the opening area 15 is located inside the bonding area.

[0071] Because a window area 15 is provided on the insulating member 14 of the first side 13 of the battery cell 10, the shell 11 of the battery cell 10 is exposed at the location of the window area 15. At least a portion of the shell 11 exposed in the window area 15 is directly bonded and fixed to the adhesive layer 20, and the window area 15 is located inside the bonding area. That is, the area of ​​the shell 11 exposed in the window area 15 is directly bonded and fixed to a portion of the adhesive layer 20, and the remaining area of ​​the adhesive layer 20 can be bonded and fixed to the insulating member 14 of the battery cell 10. The above structure can ensure that the shell 11 of the battery cell 10 is not exposed, thereby maintaining insulation from other structures and avoiding risks such as short circuits. It also ensures a stable connection between the adhesive layer 20 and the battery cell 10, and prevents the adhesive layer 20 from detaching from the battery cell 10 during long-term vibration, thereby improving the positional stability of the battery cell 10.

[0072] Furthermore, in one embodiment of this application, the distance H(1) mm between the adhesive layer 20 and the first welding area 16 satisfies 10 mm ≤ H(1) mm ≤ 100 mm. It can be understood that when the insulating member 14 is provided with a window area 15, since the area of ​​the shell 11 exposed by the window area 15 is directly bonded and fixed to a part of the adhesive layer 20, the bonding strength of the first side surface 13 of the two battery cells 10 of the adjacent battery row is greater. Therefore, by making the distance H(1) mm between the adhesive layer 20 and the first welding area 16 satisfy 10 mm ≤ H(1) mm ≤ 100 mm, the distance between the adhesive layer 20 and the first welding area 16 can be further increased, thereby effectively improving the structural strength of the first welding area 16. In a specific embodiment, H(1) mm in the above structure can be selected as a specific value such as 10mm, 18mm, 27mm, 35mm, 45mm, 55mm, 65mm, 75mm, 85mm, 100mm, or other reasonable values ​​within the range of 10mm to 100mm, without any restrictions.

[0073] like Figure 4 As shown, in one embodiment of this application, the area of ​​the bonding region within the first side 13 of the battery cell 10 is S(1) mm. 2 The area of ​​the window area 15 is S(2) mm. 2 S(1) / S(2) satisfies 20 ≤ S(1) / S(2) ≤ 120.

[0074] When the area of ​​the bonding area is S(1) mm² and the area of ​​the window area 15 is S(2) mm², and S(1) / S(2) is greater than 120, the area ratio of the window area 15 is too small, resulting in a small increase in the overall connection strength, and the overall bonding strength between the adhesive layer 20 and the battery cell 10 remains low. When S(1) / S(2) is less than 20, the exposed metal area on the surface of the casing 11 of the battery cell 10 is too large, thereby weakening the reliability of electrical insulation and increasing the short-circuit risk of the battery cell 10. Therefore, when the area of ​​the bonding area is S(1) mm², the area of ​​the window area 15 is S(2) mm², and S(1) / S(2) satisfies 20 ≤ S(1) / S(2) ≤ 120, the insulation performance of the battery cell 10 and the fixed connection strength between the casing 11 and the adhesive layer 20 in this embodiment can be effectively balanced, effectively ensuring the fixed connection strength between the adhesive layer 20 and the battery cell 10. In a specific embodiment, S(1) / S(2) can be selected from specific values ​​such as 20, 30, 42, 55, 68, 80, 92, 100, 110, 120, etc., or other reasonable specific values ​​can be selected within the range of 20 to 120. The range of S(1) mm² is 100 mm. 2 Up to 7000mm 2 Specific values ​​such as 100mm², 800mm², 1500mm², 2200mm², 3000mm², 3800mm², 4500mm², 5200mm², 6100mm², and 7000mm² can be selected, or other reasonable specific values ​​can be selected within the above range; the range of S(2) mm² is 50 mm. 2 Up to 6000mm 2 Specific values ​​such as 50mm², 500mm², 1200mm², 2000mm², 2800mm², 3500mm², 4200mm², 4900mm², 5500mm², and 6000mm² can be selected, or other reasonable specific values ​​can be selected within the above range. No restrictions are imposed here.

[0075] like Figure 4 As shown, in one embodiment of this application, the distance between the edge of the window area 15 and the edge of the adhesive area is B mm, where B mm satisfies 2 mm ≤ B mm ≤ 30 mm. The distance B between the edge of the window area 15 and the edge of the adhesive area refers to the shortest straight-line distance between the outer periphery of the window area 15 and the outer periphery of the adhesive area in which it is located. This distance ensures that the window area 15 is completely surrounded within the adhesive area.

[0076] When the distance B mm between the edge of the window area 15 and the edge of the bonding area is less than 2 mm, the window area 15 is too close to the boundary of the bonding area. When there is a slight deviation in the glue application or assembly alignment, the edge of the window area 15 may not be fully covered by the glue, thus forming an exposed area of ​​the casing 11, which can easily cause a short circuit in the battery cell 10. When B mm is greater than 30 mm, the window area 15 can only be concentrated in the center of the bonding area, which not only affects the uniform distribution of the adhesive force, but also affects the arable area of ​​the window area 15.

[0077] Therefore, in the battery pack of this application embodiment, when the distance B mm between the edge of the window area 15 and the edge of the adhesive area satisfies 2 mm ≤ B mm ≤ 30 mm, it can be ensured that the window area 15 is completely covered by the adhesive, avoiding the direct exposure of the battery cell 10 casing 11, ensuring the uniform distribution of the adhesive force of the adhesive layer 20, and ensuring the available area of ​​the window area 15. In specific embodiments, B mm can be selected from specific values ​​such as 2 mm, 5 mm, 8 mm, 11 mm, 14 mm, 17 mm, 20 mm, 23 mm, 26 mm, 30 mm, etc., or other reasonable specific values ​​can be selected within the range of 2 mm to 30 mm, without limitation.

[0078] like Figure 5 As shown, in one embodiment of this application, the window area 15 in the first side 13 of the battery cell 10 includes at least two sub-window portions 151; the sub-window portions 151 are distributed at intervals on the first side 13.

[0079] In one embodiment of this application, the window area 15 is not a single opening, but is composed of multiple spaced-apart sub-windows 151. Specifically, multiple circular, square or elliptical sub-windows 151 can be regularly arrayed in the bonding area, with an insulating member 14 forming a gap between each sub-window 151. After the adhesive layer 20 is applied, it will cover the sub-windows 151 and the gap between them.

[0080] In the battery cell 10 of this application embodiment, when the window area 15 includes at least two sub-window portions 151 that are spaced apart on the first side 13, the adhesive force between the adhesive layer 20 and the shell 11 of the battery cell 10 can be more evenly balanced, reducing stress concentration; and since the sub-window portions 151 are spaced apart, the insulating member 14 area spaced apart in the middle can effectively play an insulating role, further ensuring the shell insulation of the battery cell 10 of this application embodiment.

[0081] Furthermore, in one embodiment of this application, a window area 15 is provided between the first side surfaces 13 of two battery cells 10 in adjacent battery rows, and the orthographic projections of the first side surfaces 13 of the two battery cells 10 along the second direction at least partially overlap. By providing a window area 15 between the first side surfaces 13 of two battery cells 10 in adjacent battery rows, and ensuring that the orthographic projections of the first side surfaces 13 of the two battery cells 10 along the second direction at least partially overlap, the bonding strength of the adhesive layer 20 to the first side surfaces 13 of the two battery cells 10 can be further improved.

[0082] It is understood that in another embodiment of this application, a window area 15 may be provided only on the first side 13 of one of the two battery cells 10 in an adjacent battery row, while no window area 15 may be provided on the first side 13 of the other battery cell 10.

[0083] In one embodiment of this application, the adhesive strength of the adhesive layer 20 is G MPa, which satisfies 3MPa ≤ GMPa ≤ 20 MPa. The adhesive strength G MPa of the adhesive layer 20 is the maximum tensile or shear force per unit area that the adhesive layer 20 can withstand between the battery cell 10 casing 11 or the insulating component 14, and can be measured through standard mechanical tests such as tensile shear tests. It is understood that the adhesive strength of the adhesive layer 20 can be adjusted by selecting the material and adjusting the formulation of the adhesive layer 20.

[0084] When the bonding strength G MPa of the adhesive layer 20 is less than 3 MPa, the bonding strength of the adhesive layer 20 is insufficient, making it difficult to effectively resist the vibration and impact of the battery pack under complex working conditions, which can easily lead to relative displacement or delamination between battery cells 10. When G MPa is greater than 20 MPa, the adhesive layer 20 exerts a large pulling force on the short side weld wire of the cover plate 12 of the battery cell 10, and the probability of tearing the short side weld wire is high, which can easily lead to dangerous situations such as leakage of the battery cell 10 in this embodiment of the application.

[0085] Therefore, in the battery pack of this application embodiment, when the adhesive strength G MPa of the adhesive layer 20 satisfies 3MPa ≤ GMPa ≤ 20 MPa, relative displacement or delamination between battery cells 10 can be effectively avoided. It can also effectively reduce the probability of short-side tearing of the cover plate 12 of the battery cell 10 in this application embodiment, effectively reduce the probability of leakage and other dangerous situations in the battery cell 10, and effectively improve the long-term structural reliability and stability of the battery cell 10 under long-term vibration conditions. In specific embodiments, G MPa can be selected from specific values ​​such as 3MPa, 5MPa, 7MPa, 9MPa, 11MPa, 13MPa, 15MPa, 17MPa, 18MPa, 20MPa, etc., or other reasonable specific values ​​can be selected within the range of 3 MPa to 20 MPa, without limitation.

[0086] In one embodiment of this application, the thermal conductivity of the adhesive layer 20 is KW / (m·K), and KW / (m·K) satisfies 0.5 W / (m·K)≤KW / (m·K)≤15 W / (m·K).

[0087] The thermal conductivity of adhesive layer 20, measured in KW / (m·K), measures the thermal conductivity of the adhesive layer 20 material. It represents the heat flow rate transferred per unit area through a unit thickness of material under a unit temperature gradient, expressed in watts per meter per Kelvin (W / (m·K)). It is understood that the thermal conductivity of adhesive layer 20 can be adjusted by selecting the appropriate material and modifying its formulation.

[0088] When the thermal conductivity KW / (m·K) of the adhesive layer 20 is less than 0.5 W / (m·K), the thermal conductivity of the adhesive layer 20 is poor, which is not conducive to the conduction and equalization of heat generated during the operation or fast charging of the battery cell 10 in this embodiment, and may lead to an excessive increase in the temperature difference within the battery pack 100. When K is greater than 15 W / (m·K), after a single battery cell 10 experiences thermal runaway, it is easy to cause a chain reaction of thermal runaway and heat propagation in the battery pack of this embodiment, resulting in a reduction in the operational safety of the battery pack. Therefore, in the battery pack of this embodiment, when the thermal conductivity KW / (m·K) of the adhesive layer 20 satisfies 0.5 W / (m·K) ≤ KW / (m·K) ≤ 15 W / (m·K), it can be ensured that the temperature difference within the battery pack 100 of this embodiment will not be too large, and it can also effectively avoid the chain reaction of thermal runaway and heat propagation in the battery pack, improve the operational safety of the battery pack of this embodiment, and enhance the overall performance and lifespan of the battery pack of this embodiment.

[0089] In specific embodiments, KW / (m·K) can be selected from specific values ​​such as 0.5W / (m·K), 1.5W / (m·K), 3W / (m·K), 5W / (m·K), 7W / (m·K), 9W / (m·K), 11W / (m·K), 12.5W / (m·K), 14W / (m·K), 15W / (m·K), etc., or other reasonable specific values ​​can be selected within the range of 0.5W / (m·K) to 15W / (m·K), and no restrictions are imposed here.

[0090] Specifically, in one embodiment of this application, the adhesive layer 20 includes at least one of epoxy resin structural adhesive, polyurethane structural adhesive, acrylic structural adhesive, and silane structural adhesive. Including at least one of epoxy resin structural adhesive, polyurethane structural adhesive, acrylic structural adhesive, and silane structural adhesive in the adhesive layer 20 effectively ensures the bonding strength of the adhesive layer 20.

[0091] In one embodiment of this application, the center of the adhesive layer coincides with the center of the first side of the battery cell in the height direction. Since the center of the adhesive layer coincides with the center of the first side of the battery cell in the height direction, the adhesive layer and the first side of the battery cell are substantially aligned, which can effectively improve the bonding strength of the adhesive layer to the first side of the battery cell.

[0092] like Figure 3 As shown, in one embodiment of this application, the housing includes a first end face, the first end face of the housing and the cover plate are disposed opposite each other in the height direction, and the adhesive layer is spaced apart from the first end face in the height direction.

[0093] Specifically, in one embodiment of this application, the first end face of the housing can be the bottom end face, that is, the first end face of the housing is located on the lower side in the height direction, and correspondingly, the cover plate is located on the upper side in the height direction. Therefore, it can effectively prevent the first welding area from being located at the bottom of the battery cell. Even if the bottom of the battery pack in this embodiment of the application is impacted, it can prevent the first welding area from cracking and leaking after being impacted, thus effectively improving the working safety of the battery pack in this embodiment of the application. Since the adhesive layer and the first end face are spaced apart in the height direction, the bonding area of ​​the adhesive layer can be effectively reduced, thereby effectively reducing the impact of the adhesive layer on the first welding area and effectively reducing the probability of leakage of the battery cell.

[0094] In another embodiment of this application, the first end face of the housing can be the top end face, that is, the first end face of the housing is located on the upper side in the height direction, and the cover plate is located on the lower side in the height direction. Therefore, it can effectively prevent the first welding area from being located on the top of the battery cell and leaking after being impacted from above, and can also effectively improve the working safety of the battery pack in this embodiment of the application.

[0095] like Figure 3 As shown, in one embodiment of this application, the distance between the adhesive layer 20 and the first end face 17 in the height direction is N mm, where N mm satisfies 3 mm ≤ N mm ≤ 60 mm. When the distance N mm between the adhesive layer 20 and the first end face 17 in the height direction is less than 3 mm, the adhesive layer 20 exerts a greater pulling force on the first welding area 16 on the short side of the cover plate 12 of the battery cell 10, increasing the probability of tearing of the first welding area 16 on the short side, which can easily lead to dangerous situations such as leakage in the battery cell 10 of this embodiment. When N mm is greater than 60 mm, the coverage area of ​​the adhesive layer 20 is relatively small, making it easy for it to detach from adjacent battery cells 10, thereby reducing the structural stability of the battery cells 10 within the battery pack of this embodiment.

[0096] Therefore, by ensuring that N mm satisfies 3 mm ≤ N mm ≤ 60 mm, the spacing between the adhesive layer 20 and the first welding area 16 of the cover plate 12 and the shell 11, as well as the thickness of the adhesive layer 20, can be effectively controlled. This reduces the tearing of the adhesive layer 20 on the first welding area 16. By controlling the spacing between the adhesive layer 20 and the first welding area 16 in the height direction, the structural strength of the first welding area 16 can be guaranteed. This effectively reduces the probability of dangerous situations such as leakage in the battery cell 10, provides a certain space for the normal thermal expansion of the battery cell 10, and effectively improves the long-term structural reliability and stability of the battery cell 10 under long-term vibration conditions in this embodiment. At the same time, it prevents the first and second battery columns from detaching from the adhesive layer 20, and prevents the individual battery columns from detaching from each other, thus effectively improving the structural stability of the battery pack in this embodiment.

[0097] In specific embodiments, N mm can be selected from specific values ​​such as 3mm, 9mm, 15mm, 22mm, 28mm, 35mm, 42mm, 48mm, 54mm, 60mm, etc., or other reasonable specific values ​​can be selected within the above range, without limitation.

[0098] like Figure 3 As shown, in one embodiment of this application, the housing 11 includes a first end face 17 in the height direction. The first end face 17 of the housing 11 and the cover plate 12 are disposed opposite each other in the height direction, and the adhesive layer 20 extends beyond the side where the first end face 17 is located or is flush with the first end face 17 in the height direction. When the adhesive layer 20 extends beyond the side where the first end face 17 is located or is flush with the first end face 17 in the height direction, the bonding strength of the adhesive layer 20 to the first side surface 13 of the adjacent battery cell 10 can be further improved.

[0099] In one embodiment of this application, the housing 11 includes a first end face 17, and the first end face 17 of the housing 11 is disposed opposite to the cover plate 12 in the height direction; the battery pack also includes a bottom plate, and the battery pack 100 is fixedly disposed on the bottom plate by a bottom adhesive layer, and the bottom adhesive layer is fixedly connected to the adhesive layer 20.

[0100] It is understandable that the battery pack 100 is fixed to the base plate by the bottom adhesive layer, which can further improve the structural stability of the battery pack 100. The bottom adhesive layer and the adhesive layer 20 can be made of the same material or different materials. When the bottom adhesive layer and the adhesive layer 20 are made of the same material, they can be integrally connected, which can further improve the connection strength between the bottom and sides of the battery pack 100.

[0101] In one embodiment of this application, the battery pack 100 extends for a length of E mm along a first direction and extends for a length of F mm along a second direction, E / F ≥ 1.2, and H(1) / L(1) satisfies 1 ≤ H(1) / L(1) ≤ 35.

[0102] When the ratio of the extension length E mm of the battery pack 100 along the first direction to the extension length F mm of the battery pack 100 along the second direction is E / F ≥ 1.2, the length-to-width ratio of the battery cell 10 is large. When H(1) / L(1) satisfies 1 ≤ H(1) / L(1) ≤ 35, the tearing of the adhesive layer 20 on the first welding area 16 can be further reduced, ensuring the structural strength of the first welding area 16, effectively reducing the probability of dangerous situations such as leakage of the battery cell 10, providing a certain space for the normal thermal expansion of the battery cell 10, and effectively improving the long-term structural reliability and stability of the battery cell 10 under long-term vibration conditions in this application embodiment. This application embodiment also provides an electrical device, which includes the aforementioned battery pack. It is understood that the electrical equipment can be various electrical devices such as energy storage devices, electric ships, aircraft, laptops, power tools, electric bicycles, electric motorcycles, and electric vehicles. The aforementioned battery pack can be used as the operating power source for the electrical equipment or as the driving power source for the electrical equipment, replacing or partially replacing fuel or natural gas to provide driving power for vehicles. It can be applied in many fields such as civilian, military equipment, and aerospace, without any restrictions.

[0103] It should be noted that the elements described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0104] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into multiple separate components and / or parts. The use of the public designation "a" or "an" to describe a component or part does not exclude other components or parts.

[0105] It should be understood that while terms such as "first" or "second" may be used in this application to describe various elements, these elements are not limited by these terms; these terms are merely used to distinguish one element from another. The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms "a," "the," and "the" as used in one or more embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0106] In this document, terms such as "upper," "lower," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, and not to limit the absolute position of these related parts. In this document, terms such as "equal" and "same" are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use. Unless otherwise stated, the numerical ranges in this document include not only the entire range within its two endpoints, but also several sub-ranges contained therein. The basic principles of this application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of the various embodiments of this application. Furthermore, the specific details disclosed above are only for illustrative and facilitative purposes, and are not limitations. The above details do not limit the application to the necessity of adopting the above specific details for implementation.

[0107] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery pack, characterized in that, Includes battery pack (100); The battery pack (100) includes a first battery column and a second battery column arranged along a second direction. The first battery column and the second battery column each include at least two battery cells (10). The second direction is the length direction of the battery cell (10). The at least two battery cells (10) in the first battery column are arranged along a first direction. The first direction, the second direction, and the height direction of the battery cell (10) are perpendicular to each other. The surface of the first battery column opposite to the second battery column is the first side surface (13), and the first side surface (13) of two battery cells (10) in adjacent battery columns are fixedly connected by an adhesive layer (20); The battery cell (10) includes a housing (11) and a cover plate (12) fixedly connected to each other. The first side (13) is disposed on the housing (11), and the housing (11) includes an opening at at least one end. The cover plate (12) seals the opening and is welded to the housing (11) to form a first welding area (16). The cover plate (12) is perpendicular to the height direction. In the height direction, the distance between the adhesive layer (20) and the first welding area (16) is H(1) mm, the extension thickness of the adhesive layer (20) in the second direction is L(1) mm, and H(1) / L(1) satisfies 1≤H(1) / L(1)≤40.

2. The battery pack according to claim 1, characterized in that, The adhesive layer (20) has an extension width of D(1) mm in the first direction; the battery cell (10) has an extension width of D(2) mm in the first direction, and D(1) / D(2) satisfies 0.1≤D(1) / D(2)≤0.

8.

3. The battery pack according to claim 1, characterized in that, The adhesive layer (20) is spaced apart from at least one end of the first side in the first direction, and the extension width D(1) mm of the adhesive layer (20) in the first direction is smaller than the extension width D(2) mm of the battery cell (10) in the first direction.

4. The battery pack according to claim 1, characterized in that, In the first direction, the distance between the two sides of the adhesive layer (20) and the corresponding edge of the battery cell (10) is D(3) mm, where D(3) mm satisfies 1 mm ≤ D(3) mm ≤ 10 mm.

5. The battery pack according to claim 1, characterized in that, In the first direction, the first side surface (13) includes a first edge (131) and a second edge (132) in the first direction, and the thickness of the adhesive layer (20) at the center between the first edge (131) and the second edge (132) is greater than the thickness of the adhesive layer (20) at the first edge (131) and / or the second edge (132).

6. The battery pack according to claim 1, characterized in that, The first side (13) of the battery cell (10) is covered with an insulating element (14), which includes at least one of an insulating film, an insulating coating, and an insulating sheet.

7. The battery pack according to any one of claims 1 to 6, characterized in that, The adhesive layer (20) has an extension thickness L(1) mm in the second direction that satisfies 0.05 mm ≤ L(1) mm ≤ 3 mm.

8. The battery pack according to any one of claims 1 to 6, characterized in that, The distance H(1) mm between the adhesive layer (20) and the first welding area satisfies 3 mm ≤ H(1) mm ≤ 100 mm.

9. The battery pack according to claim 6, characterized in that, The area where the first side (13) of the battery cell (10) is bonded and fixed to the adhesive layer (20) is the bonding area; A window area (15) is provided on the insulating part (14) of the first side (13) of the battery cell (10). The housing (11) of the battery cell (10) is exposed at the location of the window area (15). At least a part of the housing (11) exposed by the window area (15) is directly bonded and fixed to the adhesive layer (20), and the window area (15) is located inside the adhesive area.

10. The battery pack according to claim 9, characterized in that, The distance H(1) mm between the adhesive layer (20) and the first welding area satisfies 10 mm ≤ H(1) mm ≤ 100 mm.

11. The battery pack according to claim 9, characterized in that, Within the first side (13) of the battery cell (10), the area of ​​the bonding region is S(1) mm. 2 The area of ​​the window area (15) is S(2) mm. 2 S(1) / S(2) satisfies 20≤ S(1) / S(2) ≤ 120.

12. The battery pack according to claim 9, characterized in that, The distance between the edge of the window area (15) and the edge of the adhesive area is B mm, where B mm satisfies 2 mm ≤ B mm ≤ 30 mm.

13. The battery pack according to claim 9, characterized in that, Within the first side (13) of the battery cell (10), the window area (15) includes at least two sub-window portions (151); the sub-window portions (151) are distributed at intervals on the first side (13).

14. The battery pack according to claim 9, characterized in that, The window area (15) is provided between the first side (13) of two adjacent battery cells (10) in the battery row, and the first side (13) of the two battery cells (10) at least partially overlap in the orthographic projection along the second direction.

15. The battery pack according to any one of claims 1 to 6, characterized in that, The adhesive strength of the adhesive layer (20) is G MPa, which satisfies 3MPa≤ G MPa≤ 20 MPa.

16. The battery pack according to any one of claims 1 to 6, characterized in that, The thermal conductivity of the adhesive layer (20) is KW / (m·K), which satisfies 0.5 W / (m·K)≤KW / (m·K)≤15 W / (m·K).

17. The battery pack according to any one of claims 1 to 6, characterized in that, The adhesive layer (20) includes at least one of epoxy resin structural adhesive, polyurethane structural adhesive, acrylic structural adhesive, and silane structural adhesive.

18. The battery pack according to any one of claims 1 to 6, characterized in that, In the height direction, the center position of the adhesive layer (20) coincides with the center position of the first side (13) of the battery cell (10).

19. The battery pack according to any one of claims 1 to 6, characterized in that, The housing (11) includes a first end face (17), the first end face (17) of the housing (11) and the cover plate (12) are disposed opposite to each other in the height direction, and the adhesive layer (20) and the first end face (17) are spaced apart in the height direction.

20. The battery pack according to claim 19, characterized in that, In the height direction, the distance between the adhesive layer (20) and the first end face (17) is N mm, where N mm satisfies 3 mm ≤ N mm ≤ 60 mm.

21. The battery pack according to any one of claims 1 to 6, characterized in that, In the height direction, the housing (11) includes a first end face (17), the first end face (17) of the housing (11) is disposed opposite to the cover plate (12) in the height direction, and the adhesive layer (20) extends beyond the side where the first end face (17) is located or is flush with the first end face (17) in the height direction.

22. The battery pack according to any one of claims 1 to 6, characterized in that, The housing (11) includes a first end face (17), and the first end face (17) of the housing (11) and the cover plate (12) are disposed opposite to each other along the height direction; The battery pack also includes a base plate, and the battery pack (100) is fixedly disposed on the base plate by a bottom adhesive layer, and the bottom adhesive layer is fixedly connected to the adhesive layer (20).

23. The battery pack according to any one of claims 1 to 6, characterized in that, The battery pack (100) has an extension length of E mm along the first direction and an extension length of F mm along the second direction, E / F ≥ 1.2, and H(1) / L(1) satisfies 1 ≤ H(1) / L(1) ≤ 35.

24. An electrical appliance, characterized in that, Includes the battery pack according to any one of claims 1 to 23.

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