Battery pack, battery pack and electric device

Abstract

The embodiment of the application provides a battery pack, a battery pack and a power utilization device, and relates to the technical field of batteries. The battery pack comprises a plurality of battery monomers arranged in sequence; the battery monomer comprises a shell, the shell has a first wall plate, two pole column assemblies are arranged on the first wall plate at intervals, the pole column assembly has a first end face, and a bus bar is welded on the first end face; an insulating top plate covers the first wall plate; the insulating top plate is provided with an opening; a pressing strip corresponds to the plurality of battery monomers; the pressing strip is connected to the first wall plate through the opening; the pressing strip has a first orthographic projection on the insulating top plate, the opening at least partially overlaps with the first orthographic projection to form an overlapping area, the overlapping area has an overlapping area s1mm 2 ; the overlapping area and the pole column assembly have a first distance d1mm; the ratio of the welding mark area of the bus bar on the first end face to the area of the first end face is a, and 2.3 <= (s1*a) / d1 <= 75. The embodiment of the application can guarantee the stability of the connection between the pressing strip and the first wall plate, and guarantee that the battery pack has high modal and structural stability.

Description

Technical Field

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

[0002] In related technologies, a battery pack has a housing and a battery pack, with the battery pack housed within the housing. The battery pack includes multiple battery cells arranged sequentially, and a pressure strip is provided on the battery pack. The pressure strip connects multiple battery cells within the corresponding battery pack to improve the modal and structural stability of the entire battery pack.

[0003] However, in some cases, the connection stability between the pressure strip and the battery cell is poor, affecting the modal and structural stability of the entire battery pack. Summary of the Invention

[0004] This application provides a battery pack, a battery module, and an electrical device that can ensure the stability of the connection between the pressure strip and the battery cell, and ensure the modal and structural stability of the battery pack.

[0005] In a first aspect, embodiments of this application provide a battery pack, including...

[0006] A battery cell, wherein multiple battery cells are arranged sequentially along a first direction, the first direction being the width direction of the battery cell; the battery cell includes a housing, and one end of the housing has a first wall plate in a second direction, the second direction being the height direction of the battery cell, and two terminal post assemblies are spaced apart on the first wall plate;

[0007] An insulating top plate is provided on the first wall panel; the insulating top plate is provided with an opening; the opening is located between two terminal posts of the same battery cell;

[0008] A pressure strip extends along the first direction and covers a plurality of the battery cells in the second direction; the pressure strip is connected to the first wall panel through the opening in the second direction.

[0009] The pressure strip has a first orthographic projection along the second direction on the insulating top plate, and the opening at least partially coincides with the first orthographic projection, forming an overlapping area with an area of ​​s1mm. 2 The overlapping area has a first distance d1mm between itself and the electrode assembly along a third direction, where the third direction is the length direction of the battery cell; the electrode assembly has a first end face along the second direction, and a busbar is welded on the first end face, where the ratio of the area of ​​the busbar on the first end face to the area of ​​the first end face is a, where 2.3≤(s1*a) / d1≤75.

[0010] Secondly, embodiments of this application provide a battery pack, including the battery pack as described above.

[0011] Thirdly, embodiments of this application provide an electrical device, including a battery pack as described above, or a battery module as described above.

[0012] The battery pack, battery module, and electrical equipment provided in this application embodiment have an opening on the insulating top plate through which the pressure strip is directly connected to the first wall plate, thereby enabling the pressure strip to be stably pressed onto the corresponding battery cell. This allows the pressure strip to stably connect multiple battery cells in the corresponding battery pack, thereby improving the modal and structural stability of the battery pack.

[0013] By limiting 2.3≤(s1*a) / d1≤75, this application embodiment can ensure the stability of the connection between the pressure strip and the first wall panel, ensure that the battery pack has high modal and structural stability, ensure the welding strength between the terminal assembly and the busbar, ensure that the battery pack has high working efficiency and safety, and reduce the probability of short circuit in individual battery cells, ensuring that the battery pack has high safety. Attached Figure Description

[0014] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0015] Figure 1 This is a schematic diagram of the battery pack after the pressure strip has been removed, provided in some embodiments of this application;

[0016] Figure 2 This is a first schematic diagram of a battery pack provided in some embodiments of this application;

[0017] Figure 3 This is a second schematic diagram of a battery pack provided in some embodiments of this application;

[0018] Figure 4 This is a third schematic diagram of a battery pack provided in some embodiments of this application;

[0019] Figure 5 This is a first schematic diagram of a battery cell provided in some embodiments of this application;

[0020] Figure 6 A schematic diagram of an insulating top plate provided in some embodiments of this application;

[0021] Figure 7 A cross-sectional view of a battery cell provided in some embodiments of this application;

[0022] Figure 8This is a second schematic diagram of a battery cell provided in some embodiments of this application;

[0023] Figure 9 This is a partial structural schematic diagram of the battery pack provided in some embodiments of this application;

[0024] Figure 10 This is a schematic diagram of a pressure strip provided in some embodiments of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] 10. Battery pack;

[0027] 100. Battery cell; 110. Housing; 111. First mounting cavity; 112. First wall panel; 112a. First side; 112b. Second side; 120. Battery cell; 121. Tab; 130. Terminal assembly; 130a. First terminal assembly; 130b. Second terminal assembly; 131. First end face; 140. Insulating top plate; 141. Opening; 141a. First inner wall surface; 141b. Second inner wall surface; 141c. Third inner wall surface; 150. Explosion-proof valve;

[0028] 200. Busbar;

[0029] 300, pressure strip; 301, first orthographic projection; 301a, overlapping area; 310, clearance hole; 310a, second orthographic projection; 320, third side; 330, protrusion.

[0030] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0031] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0032] First, let me explain the terms used in this application:

[0033] Battery cell: It can store chemical energy and controllably convert chemical energy into electrical energy. In a recyclable battery cell, the active materials can be activated by charging after discharge and continue to be used. The battery cell includes a casing and a cell disposed inside the casing.

[0034] Housing: A housing is a component used to provide a space to house electrode assemblies and other parts and isolate them from the external environment. A housing generally includes a body with an opening at at least one end and a receiving cavity. The opening of the housing can be closed by a cover plate, sealing and isolating the internal environment of the battery cell from the external environment. Housing materials include, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and aluminum-plastic film.

[0035] First wall panel: The first wall panel, also known as the battery cell cover, is a component that seals the opening of the casing to isolate the internal environment of the battery cell from the external environment. The cover panel can be made of materials including, but not limited to, copper, iron, aluminum, stainless steel, and aluminum alloy.

[0036] A battery cell is the component in a battery where electrochemical reactions occur; it is the smallest unit in a battery capable of performing electrochemical reactions such as charging and discharging. A battery cell is the basic unit of a battery and typically includes a positive electrode, a negative electrode, and a separator. Lithium-ion battery cells primarily function by the movement of lithium ions between the positive and negative electrodes. In cylindrical cells, a three-layer thin-film structure is wound into a cylindrical electrode assembly, while in cuboid cells, the thin-film structure is wound or stacked into an electrode assembly with a roughly cuboid shape.

[0037] Tabs: Tabs are located on one side of the positive / negative current collector and are formed separately from or integrally with the current collector. They are electrically connected to the current collector to conduct current through the corresponding current collector. Tabs are made of a metal material with good conductivity (such as copper, aluminum, or nickel).

[0038] Terminal assembly: The terminal assembly is used to electrically connect the electrode assembly located inside the housing to external devices (adjacent batteries or other electrical equipment) located outside the housing. A single battery cell can discharge to an external device through its cell output terminal (tab) and the external device output terminal (terminal assembly). An external power source can charge the battery cell through the terminal assembly and the tab. The terminal assembly can be directly electrically connected to the cell tab or through a metal adapter. Terminal assemblies are made of metals including, but not limited to, copper, aluminum, aluminum alloy, and copper-aluminum alloy.

[0039] Explosion-proof valve: An explosion-proof valve is a component or part that can be actuated to release internal pressure or temperature when the internal pressure or temperature of a battery cell reaches a predetermined threshold. During battery use, explosion-proof valves are mainly used to prevent excessive pressure buildup that could cause deformation or explosion of the battery in the event of thermal runaway or other situations. They allow gas to escape from the battery, thus reducing internal pressure. The materials used in explosion-proof valves are not limited, including but not limited to aluminum, steel, and alloys. The shape of the explosion-proof valve is also not limited, including square, oblong, elliptical, racetrack-shaped, etc. The type of explosion-proof valve is also not limited, such as a notched explosion-proof valve, which can be formed by stamping or laser etching.

[0040] Busbar: A busbar is used to electrically connect the terminals (current output terminals) of at least two battery cells to enable series or parallel connection of multiple battery cells. Busbars are made of metals such as copper, aluminum, tungsten, and manganese, or alloys such as copper-aluminum composites, which have excellent electrical conductivity.

[0041] Insulating top plate: The insulating top plate is made of insulating material to ensure the external insulation of the cover plate surface and prevent short circuit between the pole and the cover plate. Its material is generally polyphenylene sulfide, polycarbonate, epoxy resin, glass fiber, polypropylene, cast polypropylene, etc.

[0042] Battery Pack: A battery pack consists of multiple battery cells connected in series and / or parallel, a Battery Management System (BMS), a Thermal Management System, an Electrical Connection System (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (casing, brackets, etc.), and protective parts. These components are housed within a casing and sealed with a cover, forming a complete functional unit capable of directly outputting electrical energy. As a rechargeable battery, the battery pack is the power source for new energy vehicles. A battery pack generally includes cell modules, a Battery Management System (BMS) control module, and a casing that houses the cell modules and the BMS control module. The battery pack comprises a casing and multiple individual battery cells housed within it. The casing is divided into upper and lower parts, which are sealed together.

[0043] Pressure strip: Pressure strip is generally a long strip-shaped structural component that is fixed on the battery pack along the direction of the battery cells to improve the structural strength of the battery pack. Reinforcing ribs or hollow thin-walled structures can be set on the pressure strip. The material of the pressure strip can be nylon plastic, polypropylene, resin glass fiber composite material, carbon fiber, aluminum alloy (6063 / 6005 / 6061, etc.), steel, etc.

[0044] Battery Pack: The battery pack includes a frame and a base plate, which together form a housing cavity. The battery pack is bonded to the base plate with an adhesive layer. A pressure strip is located on the side of the battery pack away from the base plate, along the arrangement direction of the batteries in the battery pack. The length of the pressure strip is greater than the length of the battery pack. Both ends of the pressure strip are fixedly connected to the frame with fasteners to improve the fixing strength between the pressure strip and the battery pack housing. Furthermore, the adhesive connection between the pressure strip and the battery pack can fix the battery pack to the housing through the pressure strip, thereby improving the overall strength. A battery pack generally includes a housing, which includes a frame and a base plate. The housing is divided into a battery compartment and an electrical compartment. The battery compartment houses the battery modules, and the electrical compartment houses the Battery Energy Distribution Unit (BDU) and the Battery Management System (BMS). The battery modules, the BDU, and the BMS are electrically connected to realize the corresponding functions of the battery pack.

[0045] Electrical equipment: Battery devices can serve as the operating power source for electrical equipment, or as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power for vehicles. Electrical equipment includes: energy storage devices, electric ships, aircraft, laptops, power tools, electric bicycles, electric motorcycles, electric cars, military equipment, aerospace and many other technological fields.

[0046] In related technologies, a battery pack has a housing and a battery pack, with the battery pack housed within the housing. The battery pack includes multiple battery cells arranged sequentially, and a pressure strip is provided on the battery pack. The pressure strip connects multiple battery cells within the corresponding battery pack to improve the modal and structural stability of the entire battery pack.

[0047] However, in some cases, the battery cell is covered with an insulating top plate, and the pressure strip is bonded to the insulating top plate. This causes the pressure strip to be indirectly connected to the battery cell housing through the insulating top plate, resulting in poor connection stability between the pressure strip and the battery cell, which affects the modal and structural stability of the entire battery pack.

[0048] The battery pack, battery module, and electrical equipment provided in this application, by setting an opening on the insulating top plate, allow the pressure strip to be directly connected to the first wall plate through the opening, thereby enabling the pressure strip to be stably pressed onto the corresponding battery cell, thus enabling the pressure strip to stably connect multiple battery cells in the corresponding battery pack, thereby improving the modal and structural stability of the battery pack.

[0049] Furthermore, by limiting 2.3≤(s1*a) / d1≤75, this embodiment of the application can ensure the stability of the connection between the pressure strip and the first wall panel, ensure that the battery pack has high modal and structural stability, ensure the welding strength between the terminal assembly and the busbar, ensure that the battery pack has high working efficiency and safety in use, and reduce the probability of short circuit in the battery cell, ensuring that the battery pack has high safety in use.

[0050] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0051] Firstly, see [the following] Figure 1 As shown, this application embodiment provides a battery pack 10, which includes battery cells 100. The number of battery cells 100 is set to multiple, and the multiple battery cells 100 are arranged sequentially along a first direction X, where the first direction X is the width direction of the battery cell 100.

[0052] See Figures 5-7 As shown, the battery cell 100 includes a housing 110 and a battery cell 120. A first mounting cavity 111 is provided inside the housing 110, and the battery cell 120 is housed within the first mounting cavity 111. The housing 110 has a first wall plate 112 in a second direction Y, where the second direction Y is perpendicular to the first direction X, and the second direction Y is the height direction of the battery cell 100. Two terminal post assemblies 130 are provided on the first wall plate 112, and the two terminal post assemblies 130 are spaced apart along a third direction Z, where the third direction Z is perpendicular to the first direction X and the second direction Y, and the third direction Z is the length direction of the battery cell 100. The terminal assembly 130 passes through the first wall panel 112. More specifically, part of the terminal assembly 130 extends into the first mounting cavity 111 through the first wall panel 112 and is connected to the tab 121 of the cell 120. Part of the terminal component extends out of the housing 110 through the first wall panel 112 and is connected to the busbar 200. The terminal assembly 130 can guide the current on the cell 120 to the busbar 200. The busbar 200 is also connected to the terminal assemblies 130 of other battery cells 100 in the battery pack 10, so that the busbar 200 can realize the electrical connection between multiple battery cells 100.

[0053] Further, see Figure 1 and Figures 5-7As shown, an insulating top plate 140 is provided on the first wall panel 112 of the housing 110, and two pole post assemblies 130 pass through the insulating top plate 140 and are exposed to the outside, so that the two pole post assemblies 130 can be connected to different busbars 200 respectively.

[0054] Further, see Figures 2-4 As shown, the battery pack 10 also includes a retaining strip 300 extending along a first direction X, such that the extending direction of the retaining strip 300 is consistent with the arrangement direction of the plurality of battery cells 100. The position of the retaining strip 300 in the second direction Y corresponds to the plurality of battery cells 100. For example, see [link to relevant documentation]. Figures 2-4 As shown, the position of the pressure strip 300 in the second direction Y corresponds to all the number of battery cells 100 in the corresponding battery pack 10, that is, the pressure strip 300 covers all the number of battery cells 100 in the corresponding battery pack 10 in the second direction Y.

[0055] In the embodiments of this application, see Figures 1-7 As shown, an opening 141 is provided on the insulating top plate 140, and the pressure strip 300 is directly connected to the first wall plate 112 through the opening 141, so that the pressure strip 300 can be stably pressed on the corresponding battery cell 100, thereby enabling the pressure strip 300 to stably connect multiple battery cells 100 in the corresponding battery pack 10, so as to improve the modal and structural stability of the battery pack 10.

[0056] When the battery pack 10 has a higher modal frequency, the battery pack 10 has a higher overall natural frequency, greater structural rigidity, is less prone to resonance, and has better seismic safety.

[0057] Furthermore, in the embodiments of this application, see... Figure 8 As shown, the pressure strip 300 has a first orthographic projection 301 on the insulating top plate 140 along the second direction Y. At least a portion of the opening 141 forms an overlapping area 301a with the first orthographic projection 301. Within this overlapping area 301a, the pressure strip 300 is bonded and fixed to the first wall panel 112. The overlapping area 301a has an overlapping area s1mm. 2 The overlapping region 301a has a first distance d1mm between it and the pole assembly 130 along the third direction Z. The pole assembly 130 has a first end face 131 along the second direction Y, and the first end face 131 is located on the side of the insulating top plate 140 away from the housing 110, wherein the busbar 200 is welded to the first end face 131 of the pole assembly 130; the ratio of the solder area of ​​the busbar 200 on the first end face 131 to the area of ​​the first end face 131 is a, wherein 2.3≤(s1*a) / d1≤75.

[0058] For example, (s1*a) / d1 can be selected as 2.3, 2.5, 2.7, 2.8, 3, 3.4, 4.7, 5.2, 6.6, 8.3, 9.4, 11, 12.7, 15, 17.6, 18, 19.2, 21.7, 23, 25.5, 26.4, 28, 29.1, 32, 33.3, 34.8, 35.5, 36.1, 38, 41.2, 42.6. The numbers 43.8, 44.7, 46, 47, 49.8, 50.7, 51, 52, 53.4, 54.8, 55.9, 56.1, 57.2, 58, 59.4, 60, 61.7, 62.2, 63.7, 64.5, 65.1, 66, 67.8, 68, 69.2, 70.9, 71.1, 72, 73.4, 74.8, or 75 are not specifically limited to.

[0059] Understandably, when (s1*a) / d1 is less than 2.3, on the one hand, the bonding strength between the pressure strip 300 and the first wall panel 112 is poor, and the pressure strip 300 is easy to detach from the first wall panel 112, resulting in poor modal and structural stability of the battery pack 10; on the other hand, the current-carrying capacity between the terminal assembly 130 and the busbar 200 is poor, as is the welding strength between the terminal assembly 130 and the busbar 200, leading to poor working efficiency and safety of the battery pack 10.

[0060] When (s1*a) / d1 is greater than 75, the battery cell 100 is prone to short circuit, resulting in poor safety of the battery pack 10.

[0061] This application embodiment, by limiting 2.3≤(s1*a) / d1≤75, can ensure the stability of the connection between the pressure strip 300 and the first wall panel 112, ensure that the battery pack 10 has high modal and structural stability, and ensure the welding strength between the terminal assembly 130 and the busbar 200, ensuring that the battery pack 10 has high working efficiency and safety in use. It can also reduce the probability of short circuit in the battery cell 100, ensuring that the battery pack 10 has high safety in use.

[0062] In some embodiments of this application, 200mm 2 ≤s1mm 2 ≤600mm 2 The overlapping region 301a is the area where a single battery cell 100 overlaps with the pressure strip 300, and the overlapping region 301a has an overlapping area of ​​s1mm. 2 .

[0063] For example, s1mm 2 200mm can be selected 2 204mm 2 219mm2 226mm 2 237mm 2 243mm 2 251mm 2 268mm 2 275mm 2 284mm 2 293mm 2 300mm 2 305mm 2 311mm 2 327mm 2 339mm 2 342mm 2 357mm 2 368mm 2 372mm 2 384mm 2 399mm 2 400mm 2 407mm 2 419mm 2 427mm 2 433mm 2 441mm 2 458mm 2 462mm 2 479mm 2 482mm 2 491mm 2 500mm 2 507mm 2 512mm 2 527mm 2 538mm 2 544mm 2 553mm 2 561mm 2 579mm 2 584mm 2 599mm 2 Or 600mm 2 No special restrictions are imposed on this.

[0064] It is understandable that when s1mm 2 Less than 200mm 2 At that time, the bonding between the pressure strip 300 and the first wall panel 112 through the opening 141 is unstable, and the pressure strip 300 is easy to separate from the corresponding battery cell 100, affecting the modal and structural stability of the battery pack 10.

[0065] When s1mm 2Greater than 600mm 2 If the opening 141 is too large, electrical conduction may easily occur in the terminal assembly 130, busbar 200 and first wall panel 112, and the risk of short circuit in the battery cell 100 is relatively high, resulting in poor safety of the battery pack 10.

[0066] This application embodiment limits the size to 200mm. 2 ≤s1mm 2 ≤600mm 2 On the one hand, it can ensure the stability of the pressure strip 300 bonding to the first wall panel 112 through the opening 141, and ensure the modal and structural stability of the battery pack 10; on the other hand, it can reduce the risk of short circuit of the battery cell 100 and ensure the safety of the battery pack 10 in use.

[0067] Preferably, 300mm 2 ≤s1mm 2 ≤450mm 2 This can further ensure the stability of the pressure strip 300 bonding to the first wall panel 112 through the opening 141, ensure the modal and structural stability of the battery pack 10, further reduce the risk of short circuit of the battery cell 100, and ensure the safety of the battery pack 10 in use.

[0068] In some embodiments of this application, see Figure 8 As shown, 3mm≤d1mm≤14mm.

[0069] For example, d1mm can be selected as 3mm, 3.7mm, 4mm, 4.2mm, 5mm, 5.3mm, 6mm, 6.1mm, 7mm, 7.9mm, 8mm, 8.3mm, 9mm, 9.1mm, 10mm, 10.2mm, 11mm, 11.5mm, 12mm, 12.6mm, 13mm, 13.8mm or 14mm, without any particular limitation.

[0070] It is understandable that when d1mm is less than 3mm, the distance between the terminal assembly 130 and the opening 141 is relatively short, and the terminal assembly 130, the busbar 200 and the first wall panel 112 are prone to electrical conduction, which increases the risk of short circuit in the battery cell 100 and results in poor safety of the battery pack 10.

[0071] When d1mm is greater than 14mm, the pressure strip 300 is close to or located in the middle region of the first wall plate 112 along the third direction Z. Since the battery cell 100 generates gas during the charge and discharge cycle, the casing 110 will expand. In other words, the first wall plate 112 will bend outward. During this process, the bending deformation of the first wall plate 112 in the middle region along the third direction Z is the most obvious, which can easily lead to the separation of the pressure strip 300 and the first wall plate 112. The bonding stability between the pressure strip 300 and the first wall plate 112 is poor, which affects the modal and structural stability of the battery pack 10.

[0072] By limiting the diameter of the battery cell 100 to 3mm≤d1mm≤14mm, this embodiment of the application can reduce the risk of short circuit in the battery cell 100 and ensure the safety of the battery pack 10. On the other hand, it can ensure the bonding stability between the pressure strip 300 and the first wall panel 112, thereby ensuring the modal and structural stability of the battery pack 10.

[0073] Preferably, 4mm≤d1mm≤12mm can further reduce the risk of short circuit in the battery cell 100, ensure the safety of the battery pack 10, and further ensure the bonding stability between the pressure strip 300 and the first wall panel 112, thereby ensuring the modal and structural stability of the battery pack 10.

[0074] In some embodiments of this application, 0.15 ≤ a ≤ 0.4.

[0075] For example, 'a' can be selected as 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, or 0.4, without any particular limitation.

[0076] Understandably, when a is less than 0.15, the solder area of ​​busbar 200 on the first end face 131 of terminal assembly 130 is relatively small, resulting in poor current flow capacity between terminal assembly 130 and busbar 200, affecting the working efficiency of battery pack 10. Furthermore, the heat generation at the welding point of terminal assembly 130 and busbar 200 is relatively concentrated, and the welding strength of terminal assembly 130 and busbar 200 is poor, leading to poor safety of battery pack 10. In addition, terminal assembly 130 occupies the space of first wall panel 112, limiting the size of opening 141, resulting in poor stability of pressure strip 300 bonding to first wall panel 112 through opening 141, thus causing poor modal and structural stability of battery pack 10.

[0077] When a is greater than 0.4, the distance between the busbar 200 and the first wall panel 112 is too close, and electrical conduction is easily achieved between the terminal assembly 130, the busbar 200 and the first wall panel 112. This increases the risk of short circuit in the battery cell 100, resulting in poor safety of the battery pack 10.

[0078] This embodiment of the application, by limiting 0.15≤a≤0.4, can, on the one hand, ensure the current-carrying capacity between the terminal assembly 130 and the busbar 200, ensuring the working efficiency of the battery pack 10, and can also disperse the heat at the welding point of the terminal assembly 130 and the busbar 200, ensuring the welding strength of the terminal assembly 130 and the busbar 200, ensuring the safety of the battery pack 10 in use, and can also ensure the stability of the pressure strip 300 bonding to the first wall panel 112 through the opening 141, ensuring the modal and structural stability of the battery pack 10; on the other hand, it can reduce the risk of short circuit of the battery cell 100, ensuring the safety of the battery pack 10 in use.

[0079] Preferably, 0.18≤a≤0.35 can further ensure the current flow capacity between the terminal assembly 130 and the busbar 200, ensure the working efficiency of the battery pack 10, further disperse the heat at the welding point of the terminal assembly 130 and the busbar 200, ensure the welding strength of the terminal assembly 130 and the busbar 200, ensure the safety of the battery pack 10, further ensure the stability of the pressure strip 300 bonding to the first wall panel 112 through the opening 141, ensure the modal and structural stability of the battery pack 10, further reduce the risk of short circuit of the battery cell 100, and ensure the safety of the battery pack 10.

[0080] In some embodiments of this application, see Figures 1-8 As shown, the opening 141 provided on the insulating top plate 140 is located between the two pole post assemblies 130.

[0081] For example, in a conventional battery cell 100, two terminal post assemblies 130 are spaced apart along a third direction Z on a first wall panel 112, and the distance between the two terminal post assemblies 130 is relatively large. For example, see [link to relevant documentation]. Figure 5 and Figure 7 As shown, the first wall panel 112 has a first side 112a and a second side 112b that are positioned opposite each other along the third direction Z. The two pole post assemblies 130 include a first pole post assembly 130a and a second pole post assembly 130b. The first pole post assembly 130a is disposed near the first side 112a, and the second pole post assembly 130b is disposed near the second side 112b, thereby making the distance between the first pole post assembly 130a and the second pole post assembly 130b in the third direction Z larger.

[0082] In related technologies, the pressure strip 300 is disposed between the first side 112a and the first terminal assembly 130a, or the pressure strip 300 is disposed between the second side 112b and the second terminal assembly 130b. Because the distance between the first terminal assembly 130a and the second terminal assembly 130b is relatively large, with the first terminal assembly 130a closer to the first side 112a and the second terminal assembly 130b closer to the second side 112b, the space between the first side 112a and the first terminal assembly 130a, as well as the space between the second side 112b and the second terminal assembly 130b, is limited. This restricts the bonding area between the pressure strip 300 and the battery cell 100, resulting in poor modal and structural stability of the battery pack 10.

[0083] See Figures 1-8 As shown, in this embodiment of the application, by providing an opening 141 on the insulating top plate 140 and placing the opening 141 between the two pole post assemblies 130, the opening 141 can be further extended in the third direction Z due to the large distance between the two pole post assemblies 130 in the third direction Z, resulting in a larger area of ​​the opening 141 in the second direction Y. This allows the pressure strip 300 to be directly bonded to the first wall panel 112 through the opening 141, thereby improving the modal and structural stability of the battery pack 10.

[0084] In some embodiments of this application, see Figures 1-8 As shown, the battery cell 100 includes an explosion-proof valve 150, which is disposed on the housing 110. When the battery cell 100 experiences thermal runaway, the internal pressure of the first mounting cavity 111 of the housing 110 increases and damages the structure of the explosion-proof valve 150, allowing the explosion-proof valve 150 to connect the first mounting cavity 111 with the external environment of the battery cell 100. This allows the high-temperature gas in the first mounting cavity 111 to be ejected into the external environment through the explosion-proof valve 150, thereby achieving the effect of depressurizing the battery cell 100.

[0085] Further, see Figures 1-8 As shown, in this embodiment of the application, the explosion-proof valve 150 is disposed on the first wall plate 112 of the housing 110, and the position of the opening 141 on the insulating top plate 140 corresponds to the position of the explosion-proof valve 150 in the second direction Y, so that the opening 141 can completely expose the explosion-proof valve 150.

[0086] Since the opening 141 fully exposes the explosion-proof valve 150, the insulating top plate 140 will not obstruct the explosion-proof valve 150 in the second direction Y, thereby ensuring the pressure relief efficiency of the explosion-proof valve 150 under thermal runaway of the battery cell 100 and ensuring the safety of the battery pack 10.

[0087] In some embodiments of this application, see Figure 2 and Figure 3 As shown, the position of the explosion-proof valve 150 corresponds to the position of the pressure bar 300 in the second direction Y.

[0088] For example, see Figure 3 As shown, the position of a portion of the explosion-proof valve 150 in the second direction Y corresponds to the position of the pressure bar 300, such that the pressure bar 300 blocks a portion of the explosion-proof valve 150 in the second direction Y.

[0089] Another example is seen in [reference 1]. Figure 2 As shown, the position of the explosion-proof valve 150 in the second direction Y corresponds to the position of the pressure bar 300, so that the pressure bar 300 completely covers the entire explosion-proof valve 150 in the second direction Y.

[0090] Furthermore, in the embodiments of this application, see... Figure 2 and Figure 3 As shown, a clearance hole 310 is provided on the pressure strip 300. The clearance hole 310 can expose the explosion-proof valve 150 in the second direction Y, thereby preventing the pressure strip 300 from excessively obstructing the explosion-proof valve 150 in the second direction Y, and avoiding affecting the pressure relief efficiency of the explosion-proof valve 150.

[0091] For example, see Figure 2 As shown, when the pressure bar 300 covers the entire explosion-proof valve 150 in the second direction Y, by opening a clearance hole 310 on the pressure bar 300, a portion of the explosion-proof valve 150 can be exposed, or the entire explosion-proof valve 150 can be exposed, thereby ensuring the pressure relief efficiency of the explosion-proof valve 150.

[0092] Another example is seen in [reference 1]. Figure 3 As shown, when the pressure strip 300 partially obstructs the explosion-proof valve 150 in the second direction Y, by opening a clearance hole 310 on the pressure strip 300, the clearance hole 310 can expose part of the explosion-proof valve 150. More specifically, the clearance hole 310 exposes part of the explosion-proof valve 150, but a portion of the explosion-proof valve 150 is still obstructed by the pressure strip 300. Alternatively, the clearance hole 310 exposes the entire portion of the explosion-proof valve 150 obstructed by the pressure strip 300. In other words, the opening 141 and the clearance hole 310 can expose part of the explosion-proof valve 150, or the opening 141 and the clearance hole 310 can expose the entire explosion-proof valve 150.

[0093] In some embodiments of this application, see Figure 3 As shown, part of the explosion-proof valve 150 corresponds to the position of the pressure bar 300 in the second direction Y. That is, the pressure bar 300 blocks part of the explosion-proof valve 150 in the second direction Y, but part of the explosion-proof valve 150 is still exposed through the opening 141.

[0094] Furthermore, in this embodiment of the application, by opening a clearance hole 310 on the pressure strip 300, the clearance hole 310 can expose part of the explosion-proof valve 150 in the second direction Y, thereby avoiding the pressure strip 300 from excessively obstructing the explosion-proof valve 150 in the second direction Y, and avoiding affecting the pressure relief efficiency of the explosion-proof valve 150.

[0095] For example, the clearance hole 310 exposes a portion of the explosion-proof valve 150 in the second direction Y, but a portion of the explosion-proof valve 150 is still blocked by the pressure strip 300. That is, with the cooperation of the opening 141 and the clearance hole 310, a portion of the explosion-proof valve 150 can be exposed in the second direction Y.

[0096] As another example, the clearance hole 310 exposes the entire portion of the explosion-proof valve 150 that is covered by the pressure strip 300 in the second direction Y. That is, with the cooperation of the opening 141 and the clearance hole 310, the entire explosion-proof valve 150 can be exposed in the second direction Y.

[0097] In some embodiments of this application, see Figure 3 As shown, when the pressure strip 300 partially obstructs the explosion-proof valve 150 in the second direction Y, but a portion of the explosion-proof valve 150 is still exposed through the opening 141, when at least a portion of the explosion-proof valve 150 is exposed in the second direction Y under the cooperation of the opening 141 and the clearance hole 310, the portion of the explosion-proof valve 150 exposed through the opening 141 and the clearance hole 310 has a second area s2mm in the second direction Y. 2 Furthermore, the explosion-proof valve 150 has a third area s3mm in the second direction Y. 2 Where 0.15≤s2mm 2 / s3mm 2 ≤0.42.

[0098] For example, s2mm 2 / s3mm 2 The values ​​can be 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, or 0.42, and there are no special restrictions on these values.

[0099] It is understandable that when s2mm 2 / s3mm 2 When the value is less than 0.15, the pressure bar 300 excessively blocks the explosion-proof valve 150 in the second direction Y, causing the explosion-proof valve 150 to be unable to effectively meet the pressure relief requirements of the battery cell 100 when the battery cell 100 experiences thermal runaway.

[0100] When s2mm 2 / s3mm 2 If the value is greater than 0.42, the explosion-proof valve 150 will not be able to effectively meet the pressure relief requirements of the battery cell 100 when the battery cell 100 experiences thermal runaway.

[0101] This application embodiment limits 0.15 ≤ s2mm 2 / s3mm 2 With a value of ≤0.42, the pressure bar 300 can avoid excessive obstruction of the explosion-proof valve 150 in the second direction Y, and enable the explosion-proof valve 150 to meet the pressure relief requirements of the battery cell 100 under thermal runaway conditions, thereby improving the safety of the battery pack 10.

[0102] For example, 40mm 2 ≤s2mm 2 ≤200mm 2 For example, s2mm 2 40mm can be selected 2 43mm 2 50mm 2 58mm 2 60mm 2 61mm 2 70mm 2 78mm 2 80mm 2 85mm 2 90mm 2 94mm 2 100mm 2 107mm 2 116mm 2 127mm 2 139mm 2 140mm 2 152mm 2 163mm 2 174mm 2 188mm 2 197mm 2 Or 200mm 2 No special restrictions are imposed on this.

[0103] Another example is 200mm 2 ≤s3mm 2 ≤600mm 2 For example, s3mm 2 200mm can be selected 2 215mm 2 226mm 2 248mm2 259mm 2 273mm 2 284mm 2 300mm 2 311mm 2 326mm 2 337mm 2 349mm 2 352mm 2 371mm 2 395mm 2 400mm 2 402mm 2 419mm 2 428mm 2 433mm 2 445mm 2 462mm 2 477mm 2 481mm 2 492mm 2 500mm 2 514mm 2 526mm 2 538mm 2 544mm 2 551mm 2 562mm 2 572mm 2 588mm 2 593mm 2 Or 600mm 2 No special restrictions are imposed on this.

[0104] In some embodiments of this application, see Figure 2 As shown, the position of the explosion-proof valve 150 in the second direction Y corresponds to the position of the pressure bar 300. In other words, the pressure bar 300 covers the entire explosion-proof valve 150 in the second direction Y.

[0105] Furthermore, in this embodiment of the application, by opening a clearance hole 310 on the pressure strip 300, at least a portion of the explosion-proof valve 150 is exposed in the second direction Y, thereby preventing the pressure strip 300 from excessively obstructing the explosion-proof valve 150 in the second direction Y and avoiding affecting the pressure relief efficiency of the explosion-proof valve 150.

[0106] For example, the clearance hole 310 exposes a portion of the explosion-proof valve 150 in the second direction Y, but a portion of the explosion-proof valve 150 is still obscured by the pressure strip 300.

[0107] As another example, the clearance hole 310 exposes the entire explosion-proof valve 150 in the second direction Y.

[0108] In some embodiments of this application, see Figure 2 and Figure 8 As shown, the clearance hole 310 has a second orthographic projection 310a on the first wall panel 112 along the second direction Y, and at least a portion of the explosion-proof valve 150 coincides with the second orthographic projection 310a.

[0109] For example, a portion of the explosion-proof valve 150 coincides with the second orthographic projection 310a, so that the clearance hole 310 can expose a portion of the explosion-proof valve 150 in the second direction Y, thereby preventing the pressure bar 300 from excessively obstructing the explosion-proof valve 150 in the second direction Y and avoiding affecting the pressure relief efficiency of the explosion-proof valve 150.

[0110] Another example is seen in [reference 1]. Figure 2 and Figure 8 As shown, the entire explosion-proof valve 150 coincides with the second orthographic projection 310a. That is, the entire explosion-proof valve 150 coincides with the second orthographic projection 310a, so that the clearance hole 310 can expose the entire explosion-proof valve 150 in the second direction Y, thereby preventing the pressure bar 300 from excessively obstructing the explosion-proof valve 150 in the second direction Y, and avoiding affecting the pressure relief efficiency of the explosion-proof valve 150.

[0111] In some embodiments of this application, see Figure 2 As shown, when the pressure strip 300 covers the entire explosion-proof valve 150 in the second direction Y, and when the clearance hole 310 exposes the entire explosion-proof valve 150 in the second direction Y, the explosion-proof valve 150 has a third area s3mm in the second direction Y. 2 The clearance hole 310 has a fourth area s4mm in the second direction Y. 2 Where 1.05≤s4mm 2 / s3mm 2 ≤1.35.

[0112] For example, s4mm 2 / s3mm 2 You can choose 1.05, 1.06, 1.07, 1.08, 1.09, 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.3, 1.31, 1.32, 1.33, 1.34, or 1.35; there are no special restrictions on this.

[0113] Understandably, when s4mm 2 / s3mm2 When the value is less than 1.05, the alignment accuracy requirement between the clearance hole 310 and the explosion-proof valve 150 in the second direction Y is too high when the pressure strip 300 is set on the insulating top plate 140, which makes the process difficult.

[0114] When s4mm 2 / s3mm 2 If the value is greater than 1.35, the bonding area between the pressure strip 300 and the first wall panel 112 is too small, and the connection between the pressure strip 300 and the battery cell 100 is unstable.

[0115] This application embodiment limits 1.05 ≤ s4mm 2 / s3mm 2 ≤1.35 can reduce the assembly precision of the pressure strip 300 onto the battery pack 10, reduce the assembly process difficulty, and increase the bonding area between the pressure strip 300 and the first wall panel 112, thereby improving the connection stability between the pressure strip 300 and the battery cell 100.

[0116] For example, 240mm 2 ≤s4mm 2 ≤730mm 2 For example, s4mm 2 240mm can be selected 2 252mm 2 267mm 2 271mm 2 283mm 2 294mm 2 308mm 2 315mm 2 327mm 2 334mm 2 342mm 2 351mm 2 369mm 2 373mm 2 384mm 2 391mm 2 408mm 2 415mm 2 423mm 2 439mm 2 446mm 2 452mm 2 461mm 2 477mm 2 481mm 2 495mm 2 500mm 2 508mm 2 516mm2 524mm 2 536mm 2 548mm 2 559mm 2 564mm 2 573mm 2 581mm 2 592mm 2 600mm 2 613mm 2 627mm 2 639mm 2 641mm 2 658mm 2 667mm 2 671mm 2 683mm 2 694mm 2 700mm 2 711mm 2 724mm 2 Or 730mm 2 No special restrictions are imposed on this.

[0117] In some embodiments of this application, see Figures 1-8 As shown, the area of ​​the opening 141 on the insulating top plate 140 in the second direction Y is larger than the area of ​​the explosion-proof valve 150 in the second direction Y, and the opening 141 exposes the entire explosion-proof valve 150 in the second direction Y.

[0118] Further, see Figure 9 As shown, the pressure strip 300 is adjacent to the explosion-proof valve 150 in the direction perpendicular to the second direction Y. That is, in the direction perpendicular to the second direction Y, the edge of the pressure strip 300 contacts the edge of the explosion-proof valve 150. However, the pressure strip 300 does not block the explosion-proof valve 150 in the second direction Y. The entire explosion-proof valve 150 is exposed through the opening 141, thereby enabling the explosion-proof valve 150 to meet the pressure relief requirements of the battery cell 100 in the event of thermal runaway.

[0119] In some embodiments of this application, see Figures 1-8 As shown, the area of ​​the opening 141 on the insulating top plate 140 in the second direction Y is larger than the area of ​​the explosion-proof valve 150 in the second direction Y, and the opening 141 exposes the entire explosion-proof valve 150 in the second direction Y.

[0120] Further, see Figure 4As shown, the pressure strip 300 is spaced apart from the explosion-proof valve 150 in a direction perpendicular to the second direction Y, so that the pressure strip 300 does not obstruct the explosion-proof valve 150 in the second direction Y. The entire explosion-proof valve 150 is exposed through the opening 141, thereby enabling the explosion-proof valve 150 to meet the pressure relief requirements of the battery cell 100 in the event of thermal runaway.

[0121] It is worth mentioning that when the battery cell 100 is in thermal runaway, the high-temperature gas in the first mounting cavity 111 is ejected through the explosion-proof valve 150. Because the pressure strip 300 is spaced apart from the explosion-proof valve 150 in the direction perpendicular to the second direction Y, the high-temperature gas can diffuse rapidly in the direction perpendicular to the second direction Y. This can alleviate the impact force after the high-temperature gas is ejected from the explosion-proof valve 150 and improve the safety of the battery pack 10.

[0122] In some embodiments of this application, see Figure 5 and Figure 6 As shown, the opening 141 has a first inner wall surface 141a close to the pole post assembly 130, that is, the distance between the first inner wall surface 141a and the pole post assembly 130 is minimal, wherein, see Figures 2-4 , Figure 6 and Figures 8-9 As shown, the pressure strip 300 covers the first inner wall surface 141a in the second direction Y, that is, the first orthographic projection 301 covers the first inner wall surface 141a.

[0123] It is understandable that, since the terminal assembly 130 and the bus 200 are welded together for transmitting current, and the housing 110 of the battery cell 100 is normally made of metal, and since the first inner wall surface 141a is close to the terminal assembly 130, in some cases, for example, when the bus 200 contacts the first wall plate 112 of the housing 110 through the opening 141, it can cause the battery cell 100 to short-circuit, affecting the safety of the battery pack 10.

[0124] In this embodiment of the application, a pressure strip 300 is provided to cover the first inner wall surface 141a in the second direction Y, so that the pressure strip 300 can protect the first wall panel 112 inside the opening 141, preventing the terminal assembly 130, busbar 200 and other components from being electrically connected to the first wall panel 112 through the opening 141, thereby reducing the risk of short circuit of the battery cell 100 and improving the safety of the battery pack 10.

[0125] In some embodiments of this application, see Figures 2-4 and Figures 8-9As shown, the pressure strip 300 has a third side 320 in a direction perpendicular to the second direction Y. When the pressure strip 300 is bonded to the first wall panel 112 through the opening 141, the pressure strip 300 covers the first inner wall surface 141a in the second direction Y, such that the third side 320 is located between the pole post assembly 130 and the opening 141.

[0126] Furthermore, in the embodiments of this application, see... Figure 8 As shown, there is a second distance d2mm between the third side 320 and the first inner wall surface 141a, wherein 3mm≤d2mm≤7mm.

[0127] For example, d2mm can be selected as 3mm, 3.1mm, 3.7mm, 4mm, 4.2mm, 4.5mm, 5mm, 5.6mm, 5.9mm, 6mm, 6.1mm, 6.7mm or 7mm, without any particular limitation.

[0128] It is understandable that when d2mm is less than 3mm, the pressure strip 300 does not effectively cover the first inner wall surface 141a in the second direction Y. The pole assembly 130, busbar 200 and first wall panel 112 are prone to electrical conduction, the battery cell 100 is prone to short circuit, and the safety of the battery pack 10 is not good.

[0129] When d2mm is greater than 7mm, the opening 141 on the insulating top plate 140 is small, which results in poor stability of the pressure strip 300 bonding to the first wall plate 112 through the opening 141, leading to poor modal and structural stability of the battery pack 10.

[0130] By limiting the diameter of the battery cell 100 to 3mm≤d2mm≤7mm, this embodiment can reduce the risk of short circuit in the battery cell 100 and improve the safety of the battery pack 10. On the other hand, it can improve the stability of the pressure strip 300 bonded to the first wall panel 112 through the opening 141, thereby improving the modal and structural stability of the battery pack 10.

[0131] In some embodiments of this application, see Figure 5 and Figure 6 As shown, the opening 141 has a second inner wall surface 141b and a third inner wall surface 141c, and the second inner wall surface 141b and the third inner wall surface 141c are positioned opposite each other in the first direction X.

[0132] Further, see Figures 2-4 and Figures 8-9As shown, the pressure strip 300 covers at least a portion of the second inner wall surface 141b and at least a portion of the third inner wall surface 141c in the second direction Y. That is, the first orthographic projection 301 covers at least a portion of the second inner wall surface 141b and at least a portion of the third inner wall surface 141c, thereby improving the protective effect of the pressure strip 300 on the first wall panel 112 inside the opening 141, reducing the risk of short circuit of the battery cell 100, and improving the safety of the battery pack 10.

[0133] In some embodiments of this application, see Figure 5 , Figure 6 and Figure 10 As shown, a protrusion 330 is provided on the side of the pressure strip 300 facing the first wall panel 112. When the pressure strip 300 is pressed onto the battery cell 100, the protrusion 330 on the pressure strip 300 extends into the opening 141, and the pressure strip 300 is bonded to the first wall panel 112 through the protrusion 330, thereby achieving a stable connection between the pressure strip 300 and the battery cell 100.

[0134] It is understandable that, since the protrusion 330 protrudes from the surface of the pressure strip 300 and extends into the opening 141, when the adhesion between the protrusion 330 and the first wall panel 112 is unstable, or when the adhesion between the protrusion 330 and the first wall panel 112 fails, the inner sidewall of the opening 141 can block and limit the protrusion 330, thereby preventing the pressure strip 300 and the corresponding battery cell 100 from moving too far relative to each other, and thus maintaining the modal and structural stability of the corresponding battery pack 10 to a certain extent.

[0135] In some embodiments of this application, see Figure 5 , Figure 6 and Figure 10 As shown, the outer wall of the protrusion 330 abuts against at least a portion of the inner peripheral wall of the opening 141.

[0136] For example, during the process of pressing the strip 300 onto the battery cell 100, adhesive is first applied to the protrusion 330, and then the protrusion 330 is inserted into the opening 141. During this process, at least a portion of the inner peripheral wall of the opening 141 abuts against the protrusion 330, so that the protrusion 330 does not wobble in the opening 141, and the protrusion 330 can be pre-positioned in the opening 141. Then, the protrusion 330 is further inserted into the opening 141, thereby achieving precise adhesion of the protrusion 330 to the first wall panel 112.

[0137] In another example, when the adhesion between the protrusion 330 and the first wall panel 112 is unstable, or when the adhesion between the protrusion 330 and the first wall panel 112 fails, since at least a portion of the inner peripheral wall of the opening 141 abuts against the protrusion 330, the positional stability of the protrusion 330 within the opening 141 can be maintained, thereby maintaining the positional stability between the pressure strip 300 and the corresponding battery cell 100, and thus maintaining the modal and structural stability of the battery pack 10 to a certain extent.

[0138] In some embodiments of this application, see Figure 5 , Figure 6 and Figure 10 As shown, the opening 141 has a first inner wall surface 141a near the pole post assembly 130, wherein a protrusion 330 extending into the opening 141 abuts against the first inner wall surface 141a.

[0139] For example, during the process of pressing the strip 300 onto the battery cell 100, adhesive is first applied to the protrusion 330, and then the protrusion 330 is inserted into the opening 141. During this process, the first inner wall surface 141a of the opening 141 abuts against the protrusion 330, so that the protrusion 330 will not wobble in the opening 141, and the protrusion 330 can be pre-positioned in the opening 141. Then, the protrusion 330 is pushed deeper into the opening 141, thereby achieving precise bonding of the protrusion 330 to the first wall panel 112.

[0140] As another example, when the adhesion between the protrusion 330 and the first wall panel 112 is unstable, or when the adhesion between the protrusion 330 and the first wall panel 112 fails, since the first inner wall surface 141a of the opening 141 abuts against the protrusion 330, the positional stability of the protrusion 330 within the opening 141 can be maintained, thereby maintaining the positional stability between the pressure strip 300 and the corresponding battery cell 100, and thus maintaining the modal and structural stability of the battery pack 10 to a certain extent.

[0141] It is worth mentioning that, since the distance between the first inner wall surface 141a of the opening 141 and the terminal assembly 130 is minimal, the protrusion 330 extends into the opening 141 and abuts against the first inner wall surface 141a, which can further improve the protection effect of the first wall plate 112 inside the opening 141, prevent the terminal assembly 130, busbar 200 and the first wall plate 112 from being electrically connected, reduce the risk of short circuit of the battery cell 100, and thus improve the safety of the battery pack 10.

[0142] In some embodiments of this application, see Figure 5 , Figure 6 and Figure 10As shown, the opening 141 has a second inner wall surface 141b and a third inner wall surface 141c, and the second inner wall surface 141b and the third inner wall surface 141c are positioned opposite each other in the first direction X. The protrusion 330 extending into the opening 141 abuts against the second inner wall surface 141b and the third inner wall surface 141c respectively.

[0143] For example, during the process of pressing the strip 300 onto the battery cell 100, adhesive is first applied to the protrusion 330, and then the protrusion 330 is inserted into the opening 141. During this process, the second inner wall surface 141b and the third inner wall surface 141c of the opening 141 abut against the protrusion 330, so that the protrusion 330 will not wobble in the opening 141, and the protrusion 330 can be pre-positioned in the opening 141. Then, the protrusion 330 is pushed deeper into the opening 141, thereby achieving precise bonding of the protrusion 330 to the first wall panel 112.

[0144] In another example, when the adhesion between the protrusion 330 and the first wall panel 112 is unstable, or when the adhesion between the protrusion 330 and the first wall panel 112 fails, the second inner wall surface 141b and the third inner wall surface 141c of the opening 141 abut against the protrusion 330, which can maintain the positional stability of the protrusion 330 within the opening 141, thereby maintaining the positional stability between the pressure strip 300 and the corresponding battery cell 100, and thus maintaining the modal and structural stability of the battery pack 10 to a certain extent.

[0145] In some embodiments of this application, see Figure 3 , Figure 4 and Figure 9 As shown, the number of pressure strips 300 provided in the battery pack 10 is multiple. Multiple pressure strips 300 are simultaneously pressed on multiple battery cells 100 in the same battery pack 10, which can improve the modal and structural stability of the corresponding battery pack 10.

[0146] Furthermore, in this embodiment of the application, multiple pressure strips 300 are respectively disposed on both sides of the explosion-proof valve 150 along the third direction Z, thereby preventing the explosion-proof valve 150 from being blocked by the pressure strips 300 in the second direction Y, and avoiding affecting the pressure relief efficiency of the explosion-proof valve 150.

[0147] It is understandable that multiple pressure bars 300 can also be set on the same side of the explosion-proof valve 150 along the third direction Z, without any special limitation.

[0148] In some embodiments of this application, see Figure 7As shown, the battery cell 100 has a third spacing d3mm between the two terminal components 130, wherein d3mm ≥ 80mm, and d3mm can be selected from 80mm, 81mm, 82mm, 83mm, 84mm, 85mm, 86mm, 87mm, 88mm, 89mm, 90mm, 91mm, 92mm, 93mm, 94mm, 95mm, 96mm, 97mm, 98mm, 99mm, 100mm, 101mm or 102mm, without any particular limitation.

[0149] For example, two pole post assemblies 130 are arranged at a third distance along the third direction Z, and the two pole post assemblies 130 have a third distance d3mm along the third direction Z.

[0150] It is understandable that when d3mm is less than 80mm, the two terminal post assemblies 130 are easily electrically connected, and the risk of short circuit in the battery cell 100 is relatively high. When the opening 141 is set between the two terminal post assemblies 130, the size of the opening 141 will be restricted, resulting in poor stability of the pressure strip 300 bonding to the first wall panel 112 through the opening 141, which in turn leads to poor modal and structural stability of the battery pack 10.

[0151] By limiting d3mm to ≥ 80mm, this application embodiment can reduce the risk of short circuit in the battery cell 100 and improve the safety of the battery pack 10. On the other hand, it allows the opening 141 to be set larger, which improves the stability of the pressure strip 300 bonding to the first wall panel 112 through the opening 141, thereby improving the modal and structural stability of the battery pack 10.

[0152] In some embodiments of this application, two pole post assemblies 130 have a first end face 131 along the second direction Y, and the first end face 131 is located on the side of the insulating top plate 140 away from the housing 110, wherein the busbar 200 is welded to the first end face 131 of the pole post assembly 130.

[0153] Furthermore, in this embodiment, the two first end faces 131 have a fifth area s5mm in the second direction Y. 2 More specifically, the fifth area is s5mm 2 The sum of the areas of the two first end faces 131. The first wall panel 112 has a sixth area s6mm in the second direction Y. 2 Where 0.04≤s5mm 2 / s6mm 2 ≤0.2.

[0154] For example, s5mm 2 / s6mm 2You can choose 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.2, and there are no special restrictions on this.

[0155] Understandably, when the S5mm... 2 / s6mm 2 When the current is less than 0.04, the overcurrent capacity of the terminal assembly 130 is poor, and the efficiency of the terminal assembly 130 in guiding the current to the busbar 200 is low, resulting in poor working efficiency of the battery pack 10.

[0156] When s5mm 2 / s6mm 2 When the value is greater than 0.2, the pole post assembly 130 restricts the size of the opening 141 on the insulating top plate 140, resulting in poor stability of the pressure strip 300 bonding to the first wall plate 112 through the opening 141, which in turn leads to poor modal and structural stability of the battery pack 10.

[0157] This application embodiment limits 0.04 ≤ s5mm 2 / s6mm 2 ≤0.2, on the one hand, can ensure that the terminal assembly 130 has good current carrying capacity and ensure the working efficiency of the battery pack 10; on the other hand, it can make the opening 141 larger, improve the stability of the pressure strip 300 bonding to the first wall plate 112 through the opening 141, and thus improve the modal and structural stability of the battery pack 10.

[0158] For example, 400mm 2 ≤s5mm 2 ≤1500mm 2 For example, s5mm 2 400mm can be selected 2 415mm 2 429mm 2 435mm 2 447mm 2 456mm 2 461mm 2 473mm 2 481mm 2 495mm 2 500mm 2 517mm 2 529mm 2 534mm 2 547mm 2 552mm 2 561mm 2 573mm2 584mm 2 599mm 2 600mm 2 617mm 2 623mm 2 634mm 2 648mm 2 652mm 2 667mm 2 671mm 2 682mm 2 694mm 2 700mm 2 711mm 2 728mm 2 734mm 2 749mm 2 751mm 2 762mm 2 777mm 2 784mm 2 793mm 2 800mm 2 813mm 2 827mm 2 839mm 2 841mm 2 856mm 2 861mm 2 872mm 2 884mm 2 897mm 2 900mm 2 911mm 2 927mm 2 935mm 2 947mm 2 953mm 2 961mm 2 977mm 2 982mm 2 995mm 2 1000mm 2 1135mm 2 1247mm 2 1364mm 2 1492mm 2 Or 1500mm 2 No special restrictions are imposed on this.

[0159] Another example is 4000mm 2 ≤s6mm2 ≤18000mm 2 For example, s6mm 2 4000mm can be selected 2 4167mm 2 4294mm 2 4364mm 2 4486mm 2 4521mm 2 4638mm 2 4729mm 2 4814mm 2 4937mm 2 5168mm 2 5367mm 2 5428mm 2 5972mm 2 6172mm 2 6274mm 2 6391mm 2 6428mm 2 6617mm 2 6728mm 2 6816mm 2 6972mm 2 7284mm 2 7364mm 2 7428mm 2 7562mm 2 7619mm 2 7728mm 2 7819mm 2 7934mm 2 8000mm 2 8412mm 2 8517mm 2 8627mm 2 8816mm 2 8927mm 2 9107mm 2 9276mm 2 9371mm 2 9468mm 2 9537mm 2 9627mm 2 9726mm 2 9824mm 2 9943mm 2 10000mm 2 11235mm 212846mm 2 13841mm 2 14087mm 2 15716mm 2 16842mm 2 17249mm 2 Or 18000mm 2 No special restrictions are imposed on this.

[0160] In some embodiments of this application, the insulating top plate 140 is made of plastic, and the casing 110 of the battery cell 100 is made of metal.

[0161] It is understandable that, compared to the pressure strip 300 being bonded to the plastic insulating top plate 140, this embodiment of the application provides an opening 141 on the insulating top plate 140, allowing the pressure strip 300 to be bonded to the metal first wall plate 112 through the opening 141. This makes the bond between the pressure strip 300 and the battery cell 100 more secure, thereby improving the modal and structural stability of the battery pack 10.

[0162] In some embodiments of this application, the thickness of the pressure strip 300 in the second direction Y is 3mm-12mm. For example, the thickness of the pressure strip 300 in the second direction Y can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm or 12mm, and there is no particular limitation thereto.

[0163] Furthermore, the width of the pressure strip 300 in the third direction Z is 10mm-30mm. For example, the width of the pressure strip 300 in the third direction Z can be 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm or 30mm, without any particular limitation.

[0164] Secondly, this application provides a battery pack, which specifically includes the battery group 10 as described above, and thus possesses the corresponding technical effects and advantages.

[0165] The battery pack also includes a housing, the interior of which has a second mounting cavity, in which the battery pack 10 is housed.

[0166] The following test examples and comparative examples are used to verify the connection strength between the pressure strip 300 and the battery cell 100 in the battery pack of the present application embodiment, as well as the short circuit of the battery cell 100.

[0167] The testing method for s1:

[0168] The area of ​​the opening in the insulating cover plate was measured using a microscope image measuring instrument along the orthographic projection of the first wall panel. The measurement was performed three times, and the average value was recorded as s1 mm. 2 .

[0169] Test method for a:

[0170] Along the orthographic projection of the first wall panel, the solder area of ​​the busbar and individual pole assembly on the first end face is measured using a microscope image measuring instrument. The measurement is performed three times, and the average value is recorded as a1 mm. 2 Then, the area of ​​the first end face of a single pole assembly is measured three times, and the average value is recorded as a2mm. 2 , a = a1 / a2.

[0171] Test method for d1:

[0172] Along the orthographic projection of the first wall panel, use a micrometer (accuracy 0.1 mm) to measure the shortest distance between the overlapping area of ​​the pressure strip and the opening and the pole post assembly. Measure 3 times and take the average value, which is recorded as d1 mm.

[0173] Preparation method of battery cell

[0174] (1) Preparation of the positive electrode:

[0175] The prepared positive electrode active material, conductive agent (e.g., acetylene black), and binder (e.g., 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 foil, dried at room temperature, and then transferred to an oven for further drying. The positive electrode sheet is then obtained by rolling and slitting.

[0176] Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98): (4~1): (4~1).

[0177] (2) Preparation of negative electrode:

[0178] The negative electrode active material, conductive agent (e.g., acetylene black), thickener (e.g., carboxymethyl cellulose (CMC)), and binder (e.g., styrene-butadiene rubber (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 foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, the negative electrode sheet is obtained by rolling and slitting.

[0179] Specifically, the ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96): (4~2): (2~1): (4~1).

[0180] (3) Preparation of electrolyte:

[0181] 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.

[0182] (4) Preparation of the diaphragm:

[0183] Polyethylene film is selected as the diaphragm.

[0184] (5) Preparation of lithium-ion battery cells:

[0185] The positive electrode, separator, and negative electrode are stacked in sequence and wound to form a battery cell. The tabs of the battery cell are welded to the terminal assembly, placed inside the battery cell housing, and a cover plate is welded to the housing. An insulating top plate with an opening is placed on the surface of the cover plate. The battery cell is dried, injected with electrolyte, and then encapsulated, allowed to stand, formed, and volume-adjusted to obtain a lithium-ion battery cell.

[0186] In this application, other materials may be selected for the battery cell material selection, and the materials are not limited to those specified in the above preparation method. The positive electrode active material may 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 conductive agent in the positive electrode sheet may also be selected from one or more of graphite, superconducting carbon, Ketjen black, Super P, carbon nanotubes, graphene, and carbon nanofibers. The binder in the positive electrode sheet may also be selected from one or more of polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene ternary copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene ternary copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan. The positive electrode current collector may also be selected from one or more of stainless steel with surface silver plating, stainless steel, aluminum, nickel, carbon electrode, carbon, nickel, and titanium. The positive electrode current collector may also include a composite current collector, which may include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming metallic materials (aluminum, aluminum alloys, copper, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer substrate (such as a substrate of polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene, etc.).

[0187] The negative electrode active material can be selected from one or more of the following negative electrode active main materials: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.; the conductive agent in the negative electrode sheet can be selected from one or more of the following: conductive carbon black, conductive graphite, carbon nanotubes, graphene, carbon fiber, etc.; the binder in the negative electrode sheet can be selected from one or more of the following: styrene-butadiene rubber, polyacrylic acid and its salts, sodium alginate, etc.; the thickener in the negative electrode sheet can be selected from one or more of the following: sodium carboxymethyl cellulose, polyacrylonitrile multi-component copolymer, etc.; the negative electrode current collector can also be selected from one or more of the following: stainless steel with silver plating, stainless steel, copper, nickel, carbon electrode, carbon, nickel, titanium, etc.; the negative electrode current collector can also include composite current collectors, which can 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, copper, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene, etc.). The negative electrode active layer includes the negative electrode active material, conductive components, adhesives, etc.

[0188] The connection strength between the pressure strip 300 and the battery cell 100 in the battery pack was tested as follows:

[0189] For both the experimental and comparative examples, 200 battery cells were prepared. The battery cells were stacked with their larger side surfaces arranged in an array. The terminals of the 200 battery cells were welded together using a busbar. Pressure strips were placed on the upper surface of each battery cell and bonded to the opening of the insulating top plate with adhesive. The bottom surfaces of the battery cells were then bonded to the bottom plate of the housing. After completing these steps, the battery pack was sealed with a cover. The s1, a, and d1 values ​​of the battery cells in each experimental and comparative example are shown in Table 2 below. Apart from this, the remaining structures and test conditions were identical.

[0190] According to GB / T2423.43, the battery pack of the test object was mounted on a vibration table. The test 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 pack 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.

[0191] Table 1

[0192]

[0193] After the vibration is completed, observe whether the adhesion between each battery cell and the pressure strip is detached. Record the number of battery cells that are detached from the pressure strip, denoted as N. Calculate (N / 200)×100%. If (N / 200)×100% is less than or equal to 2%, it is qualified. If (N / 200)×100% is greater than 2%, it is unqualified.

[0194] The short-circuit test of individual battery cells 100 in the battery pack is as follows:

[0195] For both the experimental and comparative examples, 200 battery cells were prepared. The battery cells were stacked with their larger side surfaces arranged, and the terminals of the 200 battery cells were welded together via a busbar to form a battery pack. Pressure strips were placed on the upper surface of each battery cell and bonded to the opening of the insulating top plate with adhesive. The bottom surfaces of the battery cells were then bonded to the bottom plate of the housing. The s1, a, and d1 values ​​of the battery cells in each experimental and comparative example are shown in Table 2 below. Apart from this, the remaining structures and test conditions were identical.

[0196] At 25°C, the battery packs prepared in the experimental and comparative examples were subjected to cyclic testing according to the following procedure.

[0197] 1) Charge at a constant current rate of 1C to the upper limit voltage, and then charge at a constant voltage until the current drops to 0.05C;

[0198] 2) Let it stand for 10 minutes;

[0199] 3) Discharge the individual battery cells at a 1C rate to the lower limit voltage;

[0200] 4) Let it stand for 10 minutes;

[0201] Perform 400 charge-discharge cycles following steps 1)-4).

[0202] Set the alarm current value of the withstand voltage tester to 0.1mA and the voltage value between the two output terminals to 1kV. Connect the two output terminals of the withstand voltage tester to the casing and terminal assembly of the battery cell respectively, and apply the set voltage value. If the withstand voltage tester issues an alarm, it is determined that a short circuit has occurred between the terminal assembly and the casing. Record the number of batteries that have short-circuited, denoted as N. The battery cell short circuit rate = (N / 200) × 100%. If the battery cell short circuit rate is less than or equal to 2%, it is qualified; if the battery cell short circuit rate is greater than 2%, it is unqualified.

[0203] For different battery cell systems, the upper and lower voltage limits need to be adjusted accordingly: For positive electrode active materials including LFP (LiFePO4, lithium iron phosphate) - upper voltage limit 3.65V, lower voltage limit 2.5V; For positive electrode active materials including NCM (lithium nickel cobalt manganese oxide) - upper voltage limit 4.25V, lower voltage limit 2.5V; For positive electrode active materials including LFMP (lithium manganese iron phosphate) - upper voltage limit 4.25V, lower voltage limit 2.5V; For positive electrode active materials including lithium nickel manganese oxide - upper voltage limit 4.8V, lower voltage limit 3.5V.

[0204] In this test, the positive electrode active material of the battery cell was selected from LiNi. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, other positive electrode active materials all meet the above test requirements, and the mass ratio of positive electrode active material: conductive agent: binder meets 96:2:2; the negative electrode active material is selected from artificial graphite, and other negative electrode active materials all meet the above test requirements, and the mass ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2.

[0205] The test results of multiple experimental cases and comparative examples are shown in Table 2 below.

[0206] Table 2

[0207]

[0208] Thirdly, this application provides an electrical device that includes the battery pack 10 as described above, or the electrical device includes the battery module as described above, thus possessing the corresponding technical effects and advantages.

[0209] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A battery pack, characterized in that: include, A battery cell (100) is provided, and multiple battery cells (100) are arranged sequentially along a first direction, the first direction being the width direction of the battery cell (100); the battery cell (100) includes a housing (110), and the housing (110) has a first wall plate (112) at one end in a second direction, the second direction being the height direction of the battery cell (100), and two terminal post assemblies (130) are spaced apart on the first wall plate (112). An insulating top plate (140) is provided on the first wall panel (112); the insulating top plate (140) is provided with an opening (141); the opening (141) is located between two terminal post assemblies (130) of the same battery cell (100); A pressure strip (300) extends along the first direction and covers a plurality of the battery cells (100) in the second direction; the pressure strip (300) is connected to the first wall panel (112) through the opening (141) in the second direction. The pressure strip (300) has a first orthographic projection (301) on the insulating top plate (140) along the second direction. The opening (141) at least partially coincides with the first orthographic projection (301) and forms an overlapping region (301a). The area of ​​the overlapping region (301a) is s1mm. 2 The overlapping area (301a) has a first distance d1mm between itself and the terminal assembly (130) along a third direction, where the third direction is the length direction of the battery cell (100); the terminal assembly (130) has a first end face (131) along the second direction, and a busbar (200) is welded on the first end face (131). The ratio of the area of ​​the solder mark of the busbar (200) on the first end face (131) to the area of ​​the first end face (131) is a, where 2.3≤(s1*a) / d1≤75.

2. The battery pack according to claim 1, characterized in that: An explosion-proof valve (150) is provided on the first wall panel (112), and the opening (141) exposes the explosion-proof valve (150) in the second direction.

3. The battery pack according to claim 2, characterized in that: The position of the explosion-proof valve (150) corresponds to the position of the pressure bar (300) in the second direction. The pressure bar (300) is provided with a clearance hole (310), which exposes the explosion-proof valve (150) in the second direction.

4. The battery pack according to claim 3, characterized in that: The pressure strip (300) partially obscures the explosion-proof valve (150) in the second direction.

5. The battery pack according to claim 4, characterized in that: The opening (141) and the clearance hole (310) work together to expose the entire explosion-proof valve (150).

6. The battery pack according to claim 4, characterized in that: The opening (141) and the clearance hole (310) cooperate to expose a portion of the explosion-proof valve (150).

7. The battery pack according to claim 6, characterized in that: The portion of the explosion-proof valve (150) exposed via the opening (141) and the clearance hole (310) has a second area s2mm in the second direction. 2 The explosion-proof valve (150) has a third area s3mm in the second direction. 2 Where 0.15≤s2mm 2 / s3mm 2 ≤0.

42.

8. The battery pack according to claim 3, characterized in that: The pressure strip (300) completely blocks the explosion-proof valve (150) in the second direction.

9. The battery pack according to claim 8, characterized in that: The clearance hole (310) has a second orthographic projection (310a) on the first wall panel (112) along the second direction, and the explosion-proof valve (150) at least partially coincides with the second orthographic projection (310a).

10. The battery pack according to claim 9, characterized in that: The entire explosion-proof valve (150) coincides with the second orthographic projection (310a).

11. The battery pack according to claim 9, characterized in that: A portion of the explosion-proof valve (150) coincides with the second orthographic projection (310a).

12. The battery pack according to claim 10, characterized in that: The explosion-proof valve (150) has a third area s3mm in the second direction. 2 The clearance hole (310) has a fourth area s4mm in the second direction. 2 Where 1.05≤s4mm 2 / s3mm 2 ≤1.

35.

13. The battery pack according to claim 2, characterized in that: The pressure strip (300) is adjacent to the explosion-proof valve (150) in a direction perpendicular to the second direction.

14. The battery pack according to claim 2, characterized in that: The pressure strip (300) is spaced apart from the position of the explosion-proof valve (150) in a direction perpendicular to the second direction.

15. The battery pack according to claim 1, characterized in that: The opening (141) has a first inner wall surface (141a) near the pole assembly (130); the pressure strip (300) covers the first inner wall surface (141a) in the second direction.

16. The battery pack according to claim 15, characterized in that: The pressure strip (300) has a first side (112a) in a direction perpendicular to the second direction. The first side (112a) is located between the pole post assembly (130) and the opening (141). The first side (112a) has a second distance d2mm between itself and the first inner wall surface (141a) in the third direction, wherein 3mm≤d2mm≤7mm.

17. The battery pack according to claim 1, characterized in that: The opening (141) has a second inner wall surface (141b) and a third inner wall surface (141c) positioned opposite each other along the first direction; the pressure strip (300) covers at least a portion of the second inner wall surface (141b) and at least a portion of the third inner wall surface (141c) in the second direction.

18. The battery pack according to claim 1, characterized in that: The pressure strip (300) has a protrusion (330) on the side facing the first wall panel (112), the protrusion (330) extends into the opening (141) and is connected to the first wall panel (112).

19. The battery pack according to claim 18, characterized in that: The outer wall of the protrusion (330) abuts against at least a portion of the inner peripheral wall of the opening (141).

20. The battery pack according to claim 19, characterized in that: The opening (141) has a first inner wall surface (141a) near the pole assembly (130), and the protrusion (330) abuts against the first inner wall surface (141a).

21. The battery pack according to claim 19, characterized in that: The opening (141) has a second inner wall surface (141b) and a third inner wall surface (141c) that are opposite to each other along the first direction, and the protrusion (330) abuts against the second inner wall surface (141b) and the third inner wall surface (141c) respectively.

22. The battery pack according to claim 2, characterized in that: The number of pressure strips (300) is provided in multiples, and the multiple pressure strips (300) are respectively provided on both sides of the explosion-proof valve (150) along the third direction.

23. The battery pack according to claim 1, characterized in that: The two pole assembly (130) have a third spacing d3mm along the third direction, wherein d3mm ≥ 80mm.

24. The battery pack according to claim 1, characterized in that: The sum of the areas of the two first end faces (131) in the second direction is the fifth area s5mm. 2 The first wall panel (112) has a sixth area s6mm in the second direction. 2 Where 0.04≤s5mm 2 / s6mm 2 ≤0.

2.

25. The battery pack according to any one of claims 1-24, characterized in that: 200mm 2 ≤s1mm 2 ≤600mm 2 。 26. The battery pack according to claim 25, characterized in that: 3mm≤d1mm≤14mm.

27. The battery pack according to claim 26, characterized in that: 0.15≤a≤0.4。 28. The battery pack according to any one of claims 1-24, characterized in that: The insulating top plate (140) is made of plastic, and the housing (110) is made of metal.

29. A battery pack, characterized in that: Includes the battery pack as described in any one of claims 1-28.

30. An electrical appliance, characterized in that: It includes the battery pack as described in any one of claims 1-28, or the battery pack as described in claim 29.

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