Battery module, battery device, and electric device

Abstract

The application relates to the technical field of batteries, and provides a battery module, a battery device and a power utilization device. The battery module comprises a plurality of soft package batteries, a first current output end and a support. The soft package battery comprises an electrode assembly and a shell, the electrode assembly is arranged at least partially in the shell, the battery module comprises a conversion sheet electrically connected to the electrode assembly, and a part of the conversion sheet extends from the shell. The first current output end comprises a first connecting part and a second connecting part, the first connecting part is used for electrically connecting another battery module and is provided with a first connecting hole, and the second connecting part is electrically connected to the conversion sheet. The support is provided with a second recess portion in which a embedding nut is arranged, and a connecting piece is at least partially arranged in the interior of the first connecting hole and the second recess portion to be connected to the output end and the support. The first connecting part comprises copper, the size of the conversion sheet in a third direction is d, the size of the shell in the third direction is D, the ratio of the area of the first connecting hole to the area of the first connecting part is K, and 0.075 <= DK / d <= 0.935.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery module, a battery device, and an electrical device. Background Technology

[0002] With the increasing demand for high energy density and fast charging and discharging in new energy vehicles and energy storage devices, pouch batteries are being widely used. However, the structural characteristics of pouch batteries also bring a series of technical challenges.

[0003] Currently, it is difficult to set a large area of ​​current output terminals on the surface of the pouch battery casing, which limits the overcurrent cross-sectional area of ​​the electrode plates, becoming one of the bottlenecks in current transmission. In addition, the busbars between battery modules are mostly made of aluminum alloy, which has relatively low conductivity, further limiting the current transmission efficiency between battery modules. Summary of the Invention

[0004] In view of this, the present invention provides a battery module, a battery device, and an electrical device, which aims to balance the conductivity and structural reliability of the output terminal of the battery module.

[0005] In a first aspect, the battery module provided in the embodiments of the present invention includes a plurality of pouch cells, a first current output terminal, and a support. The plurality of pouch cells are stacked along a first direction, with the length direction of the pouch cells being a second direction. Each pouch cell includes an electrode assembly and a housing. The electrode assembly is at least partially disposed within the housing. The battery module also includes an adapter plate electrically connecting the electrode assembly. The housing includes a first housing and a second housing disposed opposite to each other. A portion of the adapter plate is located between the first housing and the second housing and is sealed by the first housing and the second housing. The first current output terminal is located on one side of the plurality of pouch cells in the second direction and includes a first connecting portion and a second connecting portion. The first connecting portion is used for electrically connecting to another battery module and has a first connecting hole penetrating through the first connecting portion. The second connecting portion is electrically connected to the adapter plate. The support and output terminal are located on the same side of the multiple pouch batteries in the second direction. The support includes an insulating shell with a second recess for inserting a nut. A connector extends at least partially into the first connecting hole and the second recess to connect with the support and the first current output terminal. The first connecting portion includes copper. The adapter plate has a dimension d (in mm) in the third direction, and the first, second, and third directions are mutually perpendicular. The housing has a dimension D (in mm) in the third direction. The ratio of the area of ​​the first connecting hole to the area of ​​the first connecting portion is K, where 0.075 ≤ D. K / d≤0.935.

[0006] Secondly, embodiments of the present invention provide a battery device, which includes a battery module as described in the first aspect.

[0007] Thirdly, embodiments of the present invention provide an electrical device, which includes the battery device of the second aspect.

[0008] The beneficial effects of the battery module provided in this embodiment of the invention are as follows:

[0009] According to the battery module provided in the embodiment of the present invention, D The K / d ratio is limited to the above-mentioned range, which can avoid excessive contact resistance at the connection between the output terminal and adjacent modules, thereby reducing the risk of local overheating of the battery module and the risk of casing seal failure, and can also ensure the current transmission efficiency between battery modules. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below.

[0011] It should be understood that the following figures only illustrate certain embodiments of the invention and should not be construed as limiting the scope.

[0012] It should also be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0013] It should also be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0014] Figure 1 This is a schematic diagram of the structure of a battery module according to an embodiment of the present invention.

[0015] Figure 2 yes Figure 1 An exploded view of the battery module.

[0016] Figure 3 yes Figure 2 An exploded view of a portion of the battery module.

[0017] Figure 4 yes Figure 2 A schematic diagram of the structure of the first connecting part.

[0018] Figure 5 yes Figure 2 A schematic diagram of the structure of a pouch cell.

[0019] Figure 6 yes Figure 2 An exploded view of the pouch cell in the diagram.

[0020] Figure 7 yes Figure 2 A schematic diagram of a portion of the pouch cell.

[0021] Figure 8 yes Figure 2 A schematic diagram of a portion of the pouch cell.

[0022] Figure 9 This is a schematic diagram of a battery device according to an embodiment of the present invention.

[0023] Figure 10 It is along Figure 9 A portion of the cross-sectional view of the battery device, taken by line AA.

[0024] Figure 11 This is a schematic diagram of the structure of an electrical device according to an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached drawings: Battery module-100; Soft-pack battery-10; Electrode assembly-11; Electrode sheet-111; Adapter piece-112; Housing-12; First housing-121; Second housing-122; Output terminal-20; First current output terminal-201; Second current output terminal-202; First connecting part-21; First connecting hole-211; Second connecting part-22; Support-30; Second recess-31; Nut-32; Connector-40; First sealing layer-50; End plate-60; Battery device-200; Busbar-210; Power-consuming device-300. Detailed Implementation

[0026] The embodiments of the present invention will now be described by way of example with reference to the accompanying drawings. It should be understood that there are many ways to implement the present invention, and it should not be construed as being limited to the embodiments described herein. The embodiments described herein are only for a more thorough and clear understanding of the present invention.

[0027] refer to Figure 5 and Figure 6 The pouch battery 10 provided in this embodiment of the invention includes an electrode assembly 11 and a casing 12. The electrode assembly 11 is the component in the battery where electrochemical reactions occur, and it is also the smallest unit in the pouch battery 10 capable of electrochemical reactions such as charging or discharging. The electrode assembly 11 typically includes a positive electrode, a negative electrode, and a separator. As an example, the electrode assembly 11 can be a lithium-ion electrode assembly, which operates by the intercalation and deintercalation of lithium ions between the positive and negative electrode. Specifically, during the charging and discharging process of the pouch battery 10, positive active ions, such as lithium ions, migrate in tandem with electrons to achieve energy storage and release. During charging, lithium ions are deintercalated from the positive electrode and intercalated into the negative electrode, while electrons are transferred from the positive electrode to the negative electrode via an external circuit to maintain charge balance; during discharging, lithium ions are deintercalated from the negative electrode and reintercalated into the positive electrode, while electrons are transferred from the negative electrode to the positive electrode via an external circuit to complete energy output.

[0028] It is understood that the electrode assembly 11 can be implemented in various ways. For example, the electrode assembly can be a wound electrode assembly or a stacked electrode assembly. A wound electrode assembly is generally a cell made by winding continuous positive electrode sheets, negative electrode sheets, and a separator, with the separator located between adjacent positive and negative electrode sheets. A stacked electrode assembly is made by stacking positive electrode sheets, negative electrode sheets, and a separator, where the positive and negative electrode sheets are separated by a separator. Adjacent layers of positive and / or negative electrode sheets within the electrode assembly are discontinuous. The stacking process includes methods such as layering or Z-shaped folding.

[0029] A positive electrode generally includes a positive current collector and a positive active material layer coated on at least one of its surfaces. The positive active material layer includes a positive active material, a positive conductive agent, and a positive binder.

[0030] The positive electrode active material can be selected from at least one of lithium phosphates, lithium transition metal oxides, and their modified compounds, or other traditional active materials suitable for battery positive electrodes can be used. Lithium phosphates include, but are not limited to, lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Lithium transition metal oxides include, but are not limited to, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified compounds.

[0031] Positive conductive agents include, but are not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, Super P), carbon nanotubes, graphene, and carbon nanofibers.

[0032] The positive electrode binder includes, but is not limited to, one or more combinations of polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan.

[0033] The negative electrode includes a negative current collector and a negative active layer disposed on at least one surface thereon. The negative current collector is a conductive metal foil, the material of which can be selected from stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc., with surface silver plating; a composite current collector can also be used, which includes a polymer material base layer and a metal layer formed thereon, wherein the metal layer material is selected from at least one of aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, and the polymer material base layer can be selected from polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.

[0034] The negative electrode active layer includes negative electrode active material, negative electrode conductive agent and negative electrode binder.

[0035] The negative electrode active material can be carbon-based materials such as graphite, porous carbon, hard carbon, soft carbon, and mesophase carbon microspheres, or silicon-based materials such as elemental silicon, silicon oxides, silicon-carbon composites, and silicon-nitrogen composites.

[0036] The negative electrode conductive agent can be selected from one or more combinations of conductive carbon black and carbon nanotubes.

[0037] The negative electrode binder can be selected from one or more combinations of styrene-butadiene rubber and polyacrylic acid.

[0038] A diaphragm is placed between the positive and negative electrode plates to physically separate them and prevent them from coming into contact and causing a short circuit.

[0039] The diaphragm can be at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. A coating can also be applied to the diaphragm surface; the coating can be an inorganic coating and / or an organic coating. The inorganic coating material includes at least one of alumina, silicon oxide, titanium oxide, magnesium oxide, zirconium oxide, and boehmite, while the organic coating includes at least one of aramid coating and polyvinylidene fluoride coating.

[0040] In the current embodiment, the electrode assembly 11 includes a plurality of electrode sheets 111 stacked along a first direction, and the battery module 100 further includes an adapter piece 112, which is electrically connected to the electrode assembly 11. The adapter piece 112 may be a pole of the electrode sheet 111 extending along a second direction and directly electrically connected to the electrode sheet 111; or it may be a conductive element independent of the electrode sheet 111 and electrically connected to a tab of the electrode sheet 111 extending along the second direction.

[0041] The adapter plate 112 and the electrode assembly 11 can be electrically connected by welding or other connection methods.

[0042] The adapter plate 112 needs to have good conductivity and can be made of one or more of copper, aluminum, nickel, or alloys, and usually adopts a thin metal sheet structure.

[0043] The housing 12 provides a receiving space to house the electrode assembly 11 and other components and isolate them from the outside environment. This receiving space can be obtained by stamping. Figure 6In the current embodiment, the housing 12 includes a first housing 121 and a second housing 122. The first housing 121 has a receiving space to receive the electrode assembly 11. A portion of the adapter piece 112 is located between the first housing 121 and the second housing 122 and is sealed by both. Another portion is exposed outside the housing 12 to conduct current from the electrode assembly 11, thereby enabling battery charging and discharging.

[0044] As one possible implementation, the housing 12 is an aluminum-plastic film, which includes, from the outside to the inside, an insulating layer, a metal layer, and a second sealing layer (distinct from the first sealing layer mentioned below).

[0045] It is understood that the present invention does not impose any particular limitation on the material of the insulating layer. For example, the material of the insulating layer may be one or more of polycaprolactam, polyethylene terephthalate, and polybutylene succinate.

[0046] It is understood that the present invention does not impose any particular restrictions on the material of the metal layer. For example, the metal layer can be one or more of metals such as aluminum, aluminum alloy, copper, and nickel. Of course, the metal layer can also be an alloy material.

[0047] It is understood that the present invention does not impose any particular limitation on the material of the second sealing layer. For example, the material of the second sealing layer can be polypropylene or cast polypropylene. The second sealing layer can be heated and melted under a set temperature condition, and its own adhesiveness allows the second sealing layer of the first housing 121 and the second sealing layer of the second housing 122 to be tightly bonded together, ultimately forming a strong and insulating sealing edge. Of course, the first housing 121 and the second housing 122 can also achieve sealing by adding an insulating adhesive layer.

[0048] It should be noted that the inner side of the housing 12 refers to the side of the housing 12 that is close to the electrode plate 111, and the outer side of the housing 12 refers to the side of the housing 12 that is away from the electrode plate 111.

[0049] refer to Figures 1 to 3 The battery module 100 includes multiple pouch cells 10, an output terminal 20, and a support 30. The multiple pouch cells 10 are arranged along a first direction and extend along a second direction. The output terminal 20 serves as the current output terminal of the battery module 100 and is connected in series or parallel with adjacent battery modules 100. The multiple pouch cells 10 inside the battery module 100, after being connected in series and / or parallel, form a positive current output terminal and a negative current output terminal.

[0050] refer to Figure 2 and Figure 3The output terminal 20 is located on one side of the plurality of pouch batteries 10 in the second direction, and includes a first current output terminal 201 and a second current output terminal 202 with opposite polarities. Either the first current output terminal 201 and the second current output terminal 202 includes a first connection portion 21 and a second connection portion 22. The first connection portion 21 is used to electrically connect to another battery module 100. The first connection portion 21 is provided with a first connection hole 211 that penetrates the first connection portion 21. The second connection portion 22 is electrically connected to the adapter piece 112.

[0051] It is understood that the embodiments of the present invention do not limit the polarity of the first current output terminal 201 and the second current output terminal 202. As long as one of the first current output terminal 201 and the second current output terminal 202 is a positive output terminal, the other is a negative output terminal.

[0052] It is understood that the first current output terminal 201 and the second current output terminal 202 can be located on the same side of the multiple pouch batteries 10 in the second direction, or they can be located on opposite sides of the multiple pouch batteries 10 in the second direction.

[0053] The support 30 and the output terminal 20 are located on the same side of the plurality of pouch batteries 10 in the second direction. The support 30 includes an insulating shell 301, which has a second recess 31 for inserting a nut 32. The connector 40 extends at least partially into the interior of the first connection hole 211 and the second recess 31 to connect to the support 30 and the first current output terminal 201 or the second current output terminal 202.

[0054] It is understood that the embodiments of the present invention do not impose any particular limitation on the implementation of the second recess 31. For example, the second recess 31 can be a through hole penetrating the insulating shell 301, or it can be a recess on the insulating shell 301.

[0055] To improve the external current output rate of the battery module, copper, a material with higher conductivity, was chosen for the busbar to compensate for the overcurrent bottleneck caused by the inability of the soft-pack battery casing to allow for excessive thickness of the adapter plate. However, in actual use, it was found that the copper output end is relatively soft. When the output end of the battery module is fixed to adjacent battery modules, the end face of the output end is prone to deformation when tightened with bolts and metal nuts. This leads to poor contact and increased contact resistance with the external busbar, which not only affects the stability of current transmission but also poses a safety hazard of local overheating leading to fire and explosion.

[0056] In view of this, by adjusting the width ratio of the adapter piece 112 and the ratio of the area of ​​the first connecting hole 211 to the area of ​​the first connecting part 21, the present invention can improve the external current output rate of the battery module 100 while ensuring the structural strength of the output terminal 20 of the soft-pack battery 10, thereby enhancing the safety of use and the reliability of connection of the battery module 100.

[0057] Combination Figure 5 The first connecting part 21 includes copper. The dimension of the adapter piece 112 in the third direction is d (in mm). The dimension of the housing 12 in the third direction is D (in mm). The ratio of the area of ​​the first connecting hole 211 to the area of ​​the first connecting part 21 is K, where 0.075 ≤ D. K / d ≤ 0.935. For example, D K / d can be 0.075, 0.135, 0.195, 0.255, 0.315, 0.375, 0.435, 0.495, 0.555, 0.615, 0.675, 0.735, 0.795, 0.855, or 0.935.

[0058] When D When K / d is too low, the contact resistance at the connection between the output terminal 20 and the adjacent module increases significantly. During high-current charging and discharging, a local heat source will be formed at this connection. This will cause the second housing 122 to undergo material fatigue deterioration under long-term thermal stress cycling, thereby increasing the risk of thermal cracking failure of the housing 12 and threatening the long-term safe operation of the battery module 100.

[0059] When D When K / d is too large, the current transmission efficiency between battery modules 100 is low, which will prolong the charging time of battery modules 100 and make it difficult to meet the charging efficiency requirements.

[0060] According to the battery module 100 provided in the embodiment of the present invention, D The K / d ratio is limited to the above-mentioned range, which can avoid excessive contact resistance at the connection between the output terminal 20 and the adjacent module, thereby reducing the risk of local overheating of the battery module 100 and the risk of sealing failure of the housing 12, and can also ensure the current transmission efficiency between the battery modules 100.

[0061] It should be noted that in the accompanying drawings of this invention, arrows Z+ and Z- are used to indicate opposite sides in the height direction; arrows X+ and X- are used to indicate opposite sides in the first direction; and arrows Y+ and Y- are used to indicate opposite sides in the second direction. The height direction, the first direction, and the second direction are perpendicular to each other.

[0062] refer to Figure 2The battery module 100 also includes an end plate 60, which is disposed on one side of the plurality of pouch cells 10 in a second direction and perpendicular to the second direction. The end plate 60 includes a plate body and a plurality of mounting portions. The large surface of the plate body is perpendicular to the second direction, and the plurality of mounting portions extend from the plate body toward the plurality of pouch cells 10. The end plate 60 can be fixedly mounted by welding the mounting portions to other components. The plate body can form reliable structural protection for the components located inside the battery module 100 and achieve effective environmental isolation. Furthermore, the support 30 is fixed to the end plate 60. Fixing the support 30 through the end plate 60 can effectively reduce the number of components in the battery module 100 and simplify the structure.

[0063] It is understood that the material of the end plate 60 is not particularly limited in the embodiments of the present invention. For example, the end plate 60 can be a metal material such as aluminum or steel, or a non-metallic composite material such as engineering plastics, fiberglass, or carbon fiber.

[0064] It is understood that the embodiments of the present invention do not impose any particular restrictions on the structure of the end plate 60. For example, the end plate 60 can be a flat plate structure with a thickness of 1-25mm. This range of values ​​can balance structural strength and energy density. Specifically, it can ensure that the end plate 60 has sufficient structural strength while avoiding excessive thickness of the end plate 60, which would reduce the energy density of the battery module 100.

[0065] It is understood that the embodiments of the present invention do not impose any particular restrictions on the processing method of the end plate 60. For example, the end plate 60 can be made of aluminum alloy sheet by extrusion and / or machine tool processing.

[0066] refer to Figure 3 The nut 32 has threads formed on its inner wall and includes a second metal with a hardness greater than that of copper. This ensures that when the connector 40 is at least partially inserted into the first connecting hole 211 and the second recess 31 and connected to the support 30, the deformation of the nut 32 is minimal, thereby ensuring the connection strength between the first connecting portion 21 and the support 30.

[0067] As an example, the material of the second metal may be selected from any combination of one or more of the following materials: carbon steel, including medium carbon steel and high carbon steel; stainless steel, including but not limited to grades 304, 316, 2205, 904L, F53, etc.; copper alloys, including brass and copper-nickel alloys; titanium and titanium alloys.

[0068] refer to Figure 4The distances from the first connecting hole 211 to the two edges of the first connecting portion 21 in the first direction are not equal. Since the first connecting portion 21 includes copper, it is prone to deformation after being connected to an adjacent module, with the portion near the centroid of the first connecting portion 21 exhibiting greater deformation. According to the battery module 100 provided by the present invention, by offsetting the first connecting hole 211 from the centroid of the first connecting portion 21 in the first direction, significant warping of the first connecting portion 21 can be avoided, thus preventing risks such as insufficient contact area and poor contact at the connection between the output terminal 20 and the adjacent module.

[0069] Continue to refer to Figure 4 The minimum distance between the two edges of the first connecting hole 211 and the first connecting part 21 in the first direction is D1, in mm, where 3 ≤ D1 ≤ 15. For example, D1 can be 3, 3.2, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10.5, 12, 13.5 or 15.

[0070] When the minimum distance between the first connecting hole 211 and the two edges of the first connecting part 21 in the first direction is too small, it will weaken the structural strength of the first connecting part 21. During the installation of the connector 40 or under conditions such as vibration and impact, the first connecting part 21 is prone to deformation or even breakage, which will lead to the failure of the electrical connection between two adjacent battery modules 100.

[0071] When the minimum distance between the first connecting hole 211 and the two edges of the first connecting part 21 in the first direction is too large, it will limit the size of the first connecting hole 211 in the first direction, which is not conducive to the connection strength of the two adjacent battery modules 100. When the battery module 100 faces vibration and impact conditions, it is easy to cause the connection between the first connecting part 21 and the other battery module 100 to fail.

[0072] According to the battery module 100 provided in the embodiment of the present invention, the minimum distance between the first connecting hole 211 and the two edges of the first connecting portion 21 in the first direction is limited to the above-mentioned numerical range. This can ensure the structural strength of the first connecting portion 21 and prevent the first connecting portion 21 from deforming or even breaking. It can also control the size of the first connecting hole 211 in the first direction, thereby ensuring the connection strength between two adjacent battery modules 100.

[0073] As one possible implementation, the connector 40 includes a third metal with a hardness greater than that of copper. This way, when the connector 40 is at least partially inserted into the first connecting hole 211 and the second recess 31 and connected to the support 30, the deformation of the connector 40 is minimal, thereby ensuring the connection strength between the first connecting portion 21 and the support 30.

[0074] As an example, the third metal can be made of materials such as iron, steel, aluminum, or aluminum alloy, and this embodiment of the invention does not impose any particular limitation on it. It should be noted that the material of the third metal can be the same as that of the second metal, thereby providing better protection for the copper current output terminal 20.

[0075] refer to Figure 3 The thickness of the first connecting part 21 is T1, in mm, and 0.5 ≤ T1 ≤ 2.5. For example, T1 can be 0.5, 0.55, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.25, 1.4, 1.6, 1.8, 2.0, 2.2 or 2.5.

[0076] When the thickness of the first connecting portion 21 is too small, the contact resistance at the connection between the first connecting portion 21 and the adjacent module will increase. During high-current charging and discharging, this connection will form a local heat source, which is detrimental to the safety of the battery module 100. When the thickness of the first connecting portion 21 is too large, it will cause material redundancy, thereby increasing the manufacturing cost and overall weight of the battery module 100.

[0077] According to the battery module 100 provided in the embodiment of the present invention, the thickness of the first connecting portion 21 is limited to the above-mentioned numerical range, which can avoid excessive contact resistance at the connection between the first connecting portion 21 and the adjacent module, thereby reducing the risk of local overheating of the battery module 100, and also avoid material redundancy.

[0078] refer to Figure 3 The thickness of the first connecting portion 21 is greater than or equal to the thickness of the second connecting portion 22. This improves the structural rigidity and mechanical stability of the first connecting portion 21, thereby effectively suppressing the tendency of the first connecting portion 21 to warp due to stress concentration after being connected to an adjacent module. By ensuring that the output terminal 20 has a sufficient and stable contact area with the adjacent module, the risk of poor contact and electrical connection failure can be reduced, and the connection reliability of the battery module 100 can be improved.

[0079] It should be noted that the thickness of the first connecting part 21 refers to the dimension of the first connecting part 21 in the third direction, and the thickness of the second connecting part 22 refers to the dimension of the second connecting part 22 in the second direction.

[0080] As one possible implementation, the adapter piece 112 includes a fourth metal and a fifth metal. Along the thickness direction of the adapter piece 112, the fifth metal is located on the outer layer of the fourth metal. The conductivity of the fourth metal is greater than that of the fifth metal, and the hardness of the fifth metal is greater than that of the fourth metal. This implementation can ensure both the current transmission efficiency of the adapter piece 112 and the welding quality between the adapter piece 112 and the second connection portion 22, thereby reducing contact resistance, reducing the heat generated by the electrode piece 111 and the output terminal 20 during high-current charging and discharging, and reducing the risk of local overheating in the battery module 100.

[0081] As an example, the fourth metal can be copper and the fifth metal can be nickel. Of course, in other embodiments, the fourth and fifth metals can also be other materials, such as aluminum, silver, titanium, etc.

[0082] refer to Figure 7 and Figure 8 The battery module 100 includes a first sealing layer 50, which is located between the housing 12 and the adapter piece 112. The dimension of the first sealing layer 50 in a third direction is larger than that of the adapter piece 112 in a third direction, and the first sealing layer 50 extends beyond the end of the housing 12 in a second direction. In this way, the first sealing layer 50 can protect the adapter piece 112 at the end of the housing 12, preventing the adapter piece 112 from contacting the metal layer of the housing 12 and causing a short circuit.

[0083] Continue to refer to Figure 7 and Figure 8 The thickness of the first sealing layer 50 is T2, in mm, and 0.03 ≤ T2 ≤ 0.2. For example, T2 can be 0.03, 0.035, 0.04, 0.045, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.14, 0.16, 0.18 or 0.2.

[0084] When the thickness of the first sealing layer 50 is too small, the distance between the metal layer of the housing 12 and the adapter piece 112 in the first direction is short. When the second sealing layer and the first sealing layer 50 of the housing 12 are worn and damaged, the metal layer of the housing 12 and the adapter piece 112 will come into direct contact, thereby causing a short circuit.

[0085] When the thickness of the first sealing layer 50 is too large, it will increase the area of ​​the housing 12 that seals the first sealing layer 50, thereby increasing the risk of the second housing 122 failing to seal.

[0086] According to the battery module 100 provided in the embodiments of the present invention, the thickness of the first sealing layer 50 is limited to the above-mentioned numerical range, which can reduce the risk of direct contact between the metal layer of the housing 12 and the electrode sheet 111, and also reduce the risk of sealing failure of the second housing 122.

[0087] It should be noted that the first sealing layer 50 can be the part formed by the thermal fusion connection between the housing 12 and the adapter piece 112, or it can be a separately set sealing layer.

[0088] It should also be noted that the upper and lower surfaces of the adapter piece 112 are both bonded with a first sealing layer 50. The thickness of the first sealing layer 50 refers to the thickness of the first sealing layer 50 bonded to the upper or lower surface of the adapter piece 112.

[0089] As one possible implementation, the dimension of the adapter piece 112 in the third direction is d (in mm), and the dimension of the housing 12 in the third direction is D (in mm), where 0.3 ≤ d / D ≤ 0.7. For example, d / D can be 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.55, 0.58, 0.6, 0.63, 0.68, or 0.7.

[0090] When the ratio of the size of the adapter piece 112 in the third direction to the size of the housing 12 in the first direction is too small, the contact resistance between the adapter piece 112 and the second connection part 22 is large. During high-current charging and discharging, a local heat source will be formed at the connection between the electrode piece 111 and the output terminal 20, which is not conducive to the safety of the battery module 100.

[0091] When the ratio of the size of the adapter piece 112 in the third direction to the size of the housing 12 in the first direction is too large, the risk of sealing failure of the second housing 122 will increase.

[0092] According to the battery module 100 provided in the embodiment of the present invention, the ratio is limited to the above-mentioned numerical range, which can avoid excessive contact resistance at the connection between the electrode sheet 111 and the output terminal 20, thereby reducing the risk of local overheating of the battery module 100, and also avoids excessively increasing the risk of sealing failure of the second housing 122.

[0093] As one possible implementation, the adapter piece 112 has a dimension d in the third direction, in mm, where 3 ≤ d ≤ 35. For example, d can be 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, or 35.

[0094] When the size of the adapter piece 112 in the third direction is too small, the contact resistance between the adapter piece 112 and the second connection part 22 is large. During the high current charging and discharging process, a local heat source will be formed at the connection between the electrode piece 111 and the output terminal 20, which is not conducive to the safety of the battery module 100.

[0095] When the size of the adapter piece 112 in the third direction is too large, it will increase the risk of seal failure of the second housing 122.

[0096] According to the battery module 100 provided in the embodiment of the present invention, the size of the adapter piece 112 in the third direction is limited to the above-mentioned numerical range. This can avoid excessive contact resistance at the connection between the electrode piece 111 and the output terminal 20, thereby reducing the risk of local overheating of the battery module 100, and also avoids excessively increasing the risk of sealing failure of the second housing 122.

[0097] As one possible implementation, the housing 12 has a dimension D in the third direction, in mm, where 10 ≤ D ≤ 50. For example, D can be 10, 13, 16, 19, 22, 25, 28, 30, 34, 37, 40, 43, 46, 48, or 50.

[0098] When the size of the housing 12 in the third direction is too small, it will reduce the capacity of the pouch battery 10, affecting its battery life or discharge time, and will not meet the energy storage requirements of the design.

[0099] When the dimensions of the casing 12 in the third direction are too large, the path for heat generated inside to be transferred to the surface becomes longer. During charging and discharging, heat is prone to accumulate inside the pouch battery 10, forming localized hot spots, which significantly increases the thermal load on the battery and thus triggers the risk of thermal runaway.

[0100] According to the battery module 100 provided in the embodiments of the present invention, the dimensions of the housing 12 in the third direction are limited to the above-mentioned numerical range, which can both ensure the capacity of the pouch battery 10 and reduce the risk of thermal runaway caused by heat accumulation inside the pouch battery 10.

[0101] Preferably, 0.117 ≤ D K / d ≤ 0.75. For example, D K / d can be 0.117, 0.15, 0.19, 0.24, 0.28, 0.32, 0.37, 0.42, 0.47, 0.52, 0.58, 0.63, 0.68, 0.72 or 0.75.

[0102] D The K / d ratio is further limited to the above-mentioned range, which can effectively reduce the contact resistance at the connection between the output terminal 20 and the adjacent module, thereby significantly reducing the risk of local overheating of the battery module 100 and the risk of sealing failure of the housing 12. At the same time, it can further improve the current transmission efficiency between the battery modules 100.

[0103] refer to Figure 2 There are two output terminals 20, and the two output terminals 20 are located on the same side of the multiple pouch cells 10 in the second direction, 0.1≤D K / d ≤ 0.935. For example, D K / d can be 0.1, 0.16, 0.22, 0.28, 0.34, 0.4, 0.46, 0.52, 0.58, 0.64, 0.7, 0.76, 0.82, 0.88 or 0.935.

[0104] Compared to the implementation where the output terminals 20 of the battery module 100 are located on opposite sides, the embodiment of the present invention places both output terminals 20 of the battery module 100 on the same side of the battery module. The closer relative distance between them makes heat concentration more likely at the end of the battery module 100, leading to a higher temperature at that output terminal 20. Increased temperature increases the resistance of the output terminal 20, affecting current transmission efficiency. Therefore, it is necessary to control D... The K / d range is 0.1-0.935 to alleviate the problem of current transmission obstruction caused by heat accumulation.

[0105] refer to Figure 5 and Figure 6 Each pouch cell 10 has two adapter pieces 112, with the two adapter pieces 112 located at opposite ends of the electrode assembly 11 in the second direction. This ensures that the area of ​​the second housing 122 sealing adapter piece 112 at each end of the pouch cell 10 in the second direction is not excessively large, thereby reducing the risk of seal failure of the second housing 122.

[0106] As one possible implementation, the ratio of the area of ​​the first connecting hole 211 to the area of ​​the first connecting portion 21 is K, where 0.05 ≤ K ≤ 0.3. For example, K can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26, or 0.3.

[0107] When the ratio of the area of ​​the first connecting hole 211 to the area of ​​the first connecting part 21 is too small, the battery module 100 is prone to failure in connection with the first connecting part 21 and the other battery module 100 when facing vibration and impact conditions.

[0108] When the ratio of the area of ​​the first connecting hole 211 to the area of ​​the first connecting part 21 is too large, the contact resistance at the connection between the first connecting part 21 and the adjacent module is large. During the high current charging and discharging process, a local heat source will be formed at this connection, which is not conducive to the safety of the battery module 100.

[0109] According to the battery module 100 provided in the embodiment of the present invention, the ratio of the area of ​​the first connection hole 211 to the area of ​​the first connection portion 21 is limited to the above-mentioned numerical range. This can ensure the connection stability between the first connection portion 21 and another battery module 100, and also avoid excessive contact resistance at the connection between the first connection portion 21 and the adjacent module, thereby reducing the risk of local overheating of the battery module 100.

[0110] refer to Figure 2 and Figure 3 The large surface of the second connecting portion 22 is perpendicular to the second direction, and the large surface of the first connecting portion 21 is perpendicular to the second connecting portion 22 and located on the side of the second connecting portion 22 away from the multiple pouch batteries 10. In this way, interference from the multiple pouch batteries 10 on the electrical connection operation between the first connecting portion 21 and another battery module 100 can be avoided, thereby reducing the difficulty of operation and improving the efficiency of operation.

[0111] refer to Figure 2 and Figure 3 The first connecting part 21 is perpendicular to the third direction, and 0.06≤K≤0.3. For example, K can be 0.06, 0.07, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26 or 0.3.

[0112] When battery module 100 is subjected to vibration and impact conditions, especially when the vibration and impact forces act on the first connection portion 21 along a third direction, the risk of connection failure between the first connection portion 21 and another battery module 100 is relatively high. Therefore, when the first connection portion 21 is perpendicular to the third direction, by limiting K to 0.06-0.3, the ratio of the area of ​​the first connection hole 211 to the area of ​​the first connection portion 21 can be increased to ensure the connection stability between the first connection portion 21 and the other battery module 100.

[0113] refer to Figure 5 The dimension of the housing 12 in the second direction is L, in mm, where L ≥ 500, and 0.05 ≤ K ≤ 0.25. For example, K can be 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.09, 0.1, 0.12, 0.14, 0.16, 0.18, 0.22, or 0.25. When the dimension of the housing 12 in the second direction is greater than 500 mm, by limiting K to 0.05-0.25, the ratio of the area of ​​the first connecting hole 211 to the area of ​​the first connecting portion 21 can be reduced, thereby reducing the contact resistance at the connection between the first connecting portion 21 and the adjacent module.

[0114] refer to Figure 9 and Figure 10The battery device 200 includes at least two battery modules 100 and a busbar 210. The busbar 210 connects two adjacent battery modules 100. The busbar 210 is provided with a third connection hole 220. The connector 40 extends at least partially into the interior of the third connection hole 220, the first connection hole 211, and the second recess 31.

[0115] As one possible implementation, the busbar 210 includes copper, which can further improve the conductivity of adjacent battery modules 100. The diameter of the third connection hole 220 is larger than the diameter of the first connection hole 211. The difference between the diameter of the third connection hole 220 and the diameter of the first connection hole 211 is D2, in mm, and D2 ≤ 3. For example, D2 can be 0.03, 0.05, 0.07, 0.1, 0.15, 0.2, 0.3, 0.5, 0.7, 1.0, 1.3, 1.8, 2.4, 2.6, or 3.

[0116] When the difference between the diameter of the third connecting hole 220 and the diameter of the first connecting hole 211 is too large, the contact area between the busbar 210 and the first connecting part 21 will be reduced, thereby increasing the contact resistance at the connection between the first connecting part 21 and the adjacent module. During high current charging and discharging, this connection will form a local heat source, which is not conducive to the safety of the battery module 100.

[0117] According to the battery module 100 provided in the embodiment of the present invention, by limiting the difference between the diameter of the third connection hole 220 and the diameter of the first connection hole 211 to the above-mentioned numerical range, it is possible to avoid excessive contact resistance at the connection between the first connection part 21 and the adjacent module, thereby reducing the risk of local overheating of the battery module 100.

[0118] refer to Figure 11 This invention provides an electrical device 300, which includes a battery device 200.

[0119] By way of example only, electrical appliance 300 can be, but is not limited to, vehicles, ships, aircraft, household appliances, and industrial equipment. For example, a vehicle can be a passenger car, a truck, or a construction vehicle.

[0120] In addition, the electrical device 300 can also be used for the storage, conversion and release of recyclable electrical energy.

[0121] In a non-restrictive example, refer to Figure 11 The electrical device 300 can be an electric vehicle, and the battery device 200 can be used as a power source to provide power to the electric vehicle.

[0122] The following specific embodiments and comparative examples are provided to illustrate how the battery provided by the present invention helps reduce the risk of deformation of the fixed end plate and the risk of thermal runaway of adjacent batteries.

[0123] I. The batteries in the following examples and comparative examples can be prepared using the following methods.

[0124] 1. The prepared 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. After cold pressing and slitting, the positive electrode sheet is obtained. Specifically, the mass ratio of positive electrode material: conductive agent: binder satisfies (92~98): (4~1): (4~1).

[0125] 2. Preparation of the negative electrode:

[0126] The negative electrode active material graphite, 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 graphite: conductive agent: thickener: binder is (90~96): (4~2): (2~1): (4~1).

[0127] 3. Preparation of electrolyte:

[0128] 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.

[0129] 4. Preparation of the diaphragm:

[0130] Polyethylene film is selected as the diaphragm.

[0131] 5. Preparation of lithium-ion batteries:

[0132] The aforementioned positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and then wound or stacked to obtain a bare battery cell. The bare battery cell is placed in an outer packaging shell, dried, injected with electrolyte, and then packaged, allowed to stand, formed, and capacitively adjusted to obtain a lithium-ion battery. 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 materials, including artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0133] In this test, the active material for the positive electrode of the battery was selected from a nickel-cobalt-manganese ternary LiNi alloy. 0.6 Co 0.2 Mn0.2 Taking O2 as an example, 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 the ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2.

[0134] 6. Fabrication of Soft-Pack Battery Modules

[0135] Multiple pouch batteries are connected in series or parallel and then installed into a fixed end plate to form a battery module.

[0136] In this test, the active material for the positive electrode of the battery was selected from a nickel-cobalt-manganese ternary LiNi alloy. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, 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 the ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2.

[0137] II. The performance involved in the following embodiments and comparative examples can be tested using the following methods.

[0138] 1. Test Method 1: Charging DCR of Soft-Pack Battery Module

[0139] 1) Connect the 12 prepared lithium-ion pouch batteries in series to form a pouch battery module, and place the pouch battery module at room temperature (20°C) until thermal equilibrium is reached.

[0140] 2) Perform 3 standard cycles with a 1 / 3C current; record the standard capacity C of the soft-pack battery module. The standard cycle steps are: charge the soft-pack battery module with a constant current of 0.33C to the upper limit voltage, charge it with a constant voltage to 0.05C, and then discharge it with a constant current of 0.33C to the lower limit voltage to obtain the standard capacity C.

[0141] 3) Let the soft-pack battery module stand for 15 minutes;

[0142] 4) Discharge the soft-pack battery module to 50% SOC at a 1 / 3C discharge rate;

[0143] 5) Charge the soft-pack battery module with a 1C current for 10 seconds, record the soft-pack battery module voltage U4, current I before charging stops, and battery voltage U3 after the soft-pack battery module voltage stabilizes. Calculate R2, which represents the charging DCR of the soft-pack battery module, according to the formula R2=(U4-U3) / I.

[0144] R2 greater than 7mΩ is unqualified, R2 less than or equal to 7mΩ and greater than 6.5mΩ is qualified, and R2 less than or equal to 6mΩ is good.

[0145] For different batteries, the upper and lower voltage limits need to be adjusted accordingly during testing: Lithium iron phosphate (LFP) - upper limit 3.65V, lower limit 2.5V; Nickel-cobalt-manganese ternary (NCM) - upper limit 4.25V, lower limit 2.5V; Lithium manganese iron phosphate (LFMP) - upper limit 4.25V, lower limit 2.5V; Lithium nickel manganese oxide (LiMC) - upper limit 4.8V, lower limit 3.5V. The battery used in this test is a nickel-cobalt-manganese ternary battery, with an upper limit voltage of 4.25V during charging.

[0146] 2. Test Method 2: Flatness error of the busbar end after vibration

[0147] Following the battery fabrication method described above, for each embodiment and comparative example, corresponding pouch cells were prepared. The prepared pouch cells were then fabricated into two identical pouch cell modules, each module comprising 20 pouch cells connected in series. The two pouch cell modules were connected using a busbar, with all other test conditions remaining consistent. The flatness of the end face at the connection point between the busbar and the first current output terminal was measured. This involved placing the component on a high-precision standard plate, using the plate as a reference surface, and measuring point by point or along a straight line using a dial indicator or micrometer. The difference between the maximum and minimum values ​​was recorded as the flatness error, ensuring that the flatness error was less than or equal to 0.1 mm.

[0148] According to GB / T2423.43, the pouch battery module 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 connecting the front and rear of the pouch battery module 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. Table 1 Vibration frequency, power spectral density (PSD), and vibration time parameters under random and fixed-frequency vibration tests.

[0149]

[0150] After the vibration is complete, the busbar between the pouch battery modules is removed, and the flatness error of the end face at the connection between the busbar and the first current output terminal is measured again. If the flatness error is less than or equal to 0.5 mm, it is considered good; if the flatness error is greater than 0.5 mm but less than or equal to 1 mm, it is considered qualified; if the flatness error is greater than 1 mm, it is considered unqualified.

[0151] Table 2 lists the test data for several examples and comparative examples.

[0152] Table 2 Test data and test results for multiple embodiments and comparative examples

[0153]

[0154] Referring to Table 2, in any one of Examples 1 to 11, formula D The value of K / d falls within the range of 0.075 to 0.935. Analysis of Table 2 shows that in any of Examples 1 to 11, the battery demonstrated satisfactory or good performance in both Test 1 and Test 2. This verifies the validity of formula d1. When the value of L1 / L falls within the range of 0.075 to 0.935, it not only has a smaller battery module charging DCR, but also a smaller flatness error after the busbar end vibration.

[0155] In contrast, in Comparative Example 1, formula D The value of K / d is less than 0.075. Analysis of Table 2 shows that the battery provided in Example 1 passed test 1, but failed test 2. This verifies the validity of formula d1. When the value of L1 / L is less than 0.075, the charging DCR between battery modules is large and the current transmission efficiency is low.

[0156] Meanwhile, in Comparative Example 2, formula D The value of K / d is greater than 0.935. Analysis of Table 2 shows that the battery provided in Comparative Example 2 passed Test 2, but failed Test 1. This verifies the validity of formula D. When the value of K / d is greater than 0.935, the flatness error of the busbar end after vibration is large, and the interface resistance is large.

[0157] It should be understood that the term "comprising" and its variations as used in this invention are open-ended, meaning "including but not limited to". The term "according to" means "at least in part according to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least another embodiment".

[0158] It should be understood that although terms such as "first" or "second" may be used in this invention to describe various elements (such as the first connecting part and the second connecting part), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0159] The scope of protection of this invention is not limited to the above embodiments. Any variations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in this invention should be included within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A battery module (100), characterized in that, include: Multiple pouch batteries (10) stacked along a first direction, the length direction of the pouch battery (10) being a second direction, the pouch battery (10) including an electrode assembly (11) and a housing (12), the electrode assembly (11) being at least partially disposed within the housing (12), and also including an adapter piece (112) electrically connected to the electrode assembly (11), the housing (12) including a first housing (121) and a second housing (122) disposed opposite to each other, a portion of the adapter piece (112) being located between the first housing (121) and the second housing (122) and sealed by both; The first current output terminal (201) is located on one side of the plurality of soft-pack batteries (10) in the second direction, and includes a first connecting part (21) and a second connecting part (22). The first connecting part (21) is used to electrically connect to another battery module (100). The first connecting part (21) is provided with a first connecting hole (211) penetrating the first connecting part (21). The distances from the first connecting hole (211) to the two edges of the first connecting part (21) in the first direction are not equal. The second connecting part (22) is electrically connected to the adapter piece (112). as well as A support (30) is located on the same side of the plurality of pouch batteries (10) in the second direction as the first current output terminal (201). The support (30) includes an insulating shell (301) with a second recess (31) for inserting a nut (32). A connector (40) extends at least partially into the first connecting hole (211) and the second recess (31) to connect with the support (30) and the first current output terminal (201). The battery module (100) also includes an end plate (60) disposed on one side of the plurality of pouch batteries (10) in the second direction and perpendicular to the second direction. The support (30) is fixed to the end plate (60). The first connecting part (21) is made of copper. The dimension of the adapter piece (112) in the third direction is d (in mm). The first direction, the second direction, and the third direction are perpendicular to each other. The dimension of the housing (12) in the third direction is D (in mm), where 0.3 ≤ d / D ≤ 0.

7. The ratio of the area of ​​the first connecting hole (211) to the area of ​​the first connecting part (21) is K, where 0.075 ≤ D. K / d≤0.935; the large surface of the first connecting part (21) is perpendicular to the third direction, 0.06≤K≤0.3; the inner wall of the nut (32) is threaded, the nut (32) includes a second metal, the hardness of the second metal is greater than the hardness of copper; the connector (40) includes a third metal, the hardness of the third metal is greater than the hardness of copper; the adapter piece (112) includes a fourth metal and a fifth metal, along the thickness direction of the adapter piece (112), the fifth metal is located on the outer layer of the fourth metal, the conductivity rate of the fourth metal is greater than the conductivity rate of the fifth metal, the hardness of the fifth metal is greater than the hardness of the fourth metal; the thickness of the first connecting part (21) is T1, in mm, 0.5≤T1≤2.

5.

2. The battery module (100) according to claim 1, characterized in that, The large surface of the second connecting portion (22) is perpendicular to the second direction, and the large surface of the first connecting portion (21) is perpendicular to the large surface of the second connecting portion (22) and is located on the side of the second connecting portion (22) away from the plurality of soft-pack batteries (10).

3. The battery module (100) according to claim 1, characterized in that, The minimum distance between the first connecting hole (211) and the two edges of the first connecting part (21) in the first direction is D1, in mm, where 3≤D1≤15.

4. The battery module (100) according to claim 1, characterized in that, 0.05≤K≤0.3。 5. The battery module (100) according to any one of claims 1 to 4, characterized in that, The thickness of the first connecting part (21) is greater than or equal to the thickness of the second connecting part (22).

6. The battery module (100) according to any one of claims 1 to 4, characterized in that, It also includes a first sealing layer (50), which is located between the housing (12) and the adapter piece (112). The thickness of the first sealing layer (50) is T2 in mm, and 0.03≤T2≤0.

2.

7. The battery module (100) according to any one of claims 1 to 4, characterized in that, 3≤d≤35。 8. The battery module (100) according to any one of claims 1 to 4, characterized in that, It also includes a second current output terminal (202) with the opposite polarity to the first current output terminal (201), the second current output terminal (202) and the first current output terminal (201) being located on the same side of the plurality of pouch cells (10) in the second direction, 0.1≤D K / d≤0.

935.

9. The battery module (100) according to any one of claims 1 to 4, characterized in that, The battery module (100) includes two adapter pieces (112), which are located at both ends of the electrode assembly (11) in the second direction.

10. The battery module (100) according to claim 9, characterized in that, The dimension of the shell (12) in the second direction is L, in mm, L≥500, 0.05≤K≤0.

25.

11. The battery module (100) according to any one of claims 1 to 4, characterized in that, The housing (12) includes an insulating layer, a metal layer and a second sealing layer from the outside to the inside. The second sealing layer of the second housing (122) is bonded to the second sealing layer of the first housing (121).

12. The battery module (100) according to any one of claims 1 to 4, characterized in that, 0.117≤D K / d≤0.75。 13. A battery device (200), characterized in that, include: At least two battery modules (100) according to any one of claims 1 to 12; as well as A busbar (210) connects two adjacent battery modules (100). The busbar (210) is provided with a third connection hole (220). The connector (40) extends at least partially into the third connection hole (220), the first connection hole (211), and the second recess (31) to fix the support (30), the busbar (210), and the first current output terminal (201).

14. The battery device (200) according to claim 13, characterized in that, The manifold (210) comprises copper, and the diameter of the third connecting hole (220) is greater than the diameter of the first connecting hole (211). The difference between the diameter of the third connecting hole (220) and the diameter of the first connecting hole (211) is D2, in mm, and D2≤6.

15. An electrical appliance (300), characterized in that, Includes the battery device (200) as described in claim 13 or 14.

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