Battery cells, batteries and electrical devices

Abstract

This application provides a battery cell, a battery, and an electrical device. The battery cell includes an electrode assembly, a housing, a cover plate, and a support member. The electrode assembly includes at least one first electrode and at least one second electrode, with at least a portion of the first electrode and the second electrode stacked together. The housing includes two opposing first side plates, two opposing second side plates, and four transition plates. The first side plates are perpendicular to the second side plates, and the transition plates connect the first and second side plates. The first side plates, second side plates, and transition plates define an opening and a receiving cavity, in which the electrode assembly is received. The cover plate is used to close the opening and is perpendicular to the first and second side plates. At least a portion of the support member is disposed between the first side plates and the electrode assembly, and the support member is used to support the electrode assembly.

Description

[0001] This application is a divisional application based on application number 202080102020.3, filed on December 17, 2020, by CATL (Contemporary Amperex Technology Co., Limited), entitled "Battery cell and manufacturing method and system thereof, battery and electrical device". Technical Field

[0002] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0003] Rechargeable batteries, also known as secondary batteries, are batteries that can be recharged after being discharged to reactivate the active materials and continue to be used. Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0004] Rechargeable batteries can include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and secondary alkaline zinc-manganese batteries, etc.

[0005] Currently, the most commonly used batteries in automobiles are lithium-ion batteries. As a rechargeable battery, lithium-ion batteries have advantages such as small size, high energy density, high power density, many cycles, and long storage time.

[0006] A rechargeable battery includes an electrode assembly and an electrolyte solution. The electrode assembly includes a positive electrode, a negative electrode, and a separator between the positive and negative electrodes. The positive electrode, also known as the cathode electrode, has a positive active material layer on both surfaces. For example, the positive active material in the positive active material layer can be lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, or lithium nickel cobalt manganese oxide. The negative electrode, also known as the anode electrode, has a negative active material layer on both surfaces. For example, the negative active material in the negative active material layer can be graphite or silicon.

[0007] Lithium plating is a common abnormal phenomenon in lithium batteries, which can affect the charging efficiency and energy density of lithium ions. In severe cases, lithium plating can also form lithium crystals, which can puncture the separator, leading to internal short circuits and thermal runaway, seriously endangering battery safety.

[0008] Therefore, how to reduce or avoid lithium plating and improve battery safety has become a difficult problem in the industry. Summary of the Invention

[0009] This application provides a battery cell, a battery, and an electrical device that can reduce the risk of lithium plating and enhance battery safety.

[0010] In a first aspect, embodiments of this application provide a battery cell including an electrode assembly, a housing, a cover plate, and a support member. The electrode assembly includes at least one first electrode and at least one second electrode, with at least a portion of the first electrode and the second electrode stacked together. The housing includes two opposing first side plates, two opposing second side plates, and four transition plates. The first side plates are perpendicular to the second side plates, and the transition plates connect the first and second side plates. The first side plates, second side plates, and transition plates define an opening and a receiving cavity, in which the electrode assembly is received. The cover plate is used to close the opening and is perpendicular to the first and second side plates. At least a portion of the support member is disposed between the first side plates and the electrode assembly, and the support member supports the electrode assembly.

[0011] In the battery cell of this application embodiment, the support member can support the electrode assembly, reduce the shaking amplitude of the electrode assembly when the battery cell vibrates, and reduce the force exerted on the electrode assembly by the first side plate. In addition, by providing the support member, the force transmitted to the first electrode is reduced, thereby reducing the risk of active material shedding from the first electrode and reducing lithium plating.

[0012] In some embodiments, the inner surface of the transition plate is an arc surface. The distance between the end of the first electrode facing the first side plate and the first side plate in a first direction is H, the radius of the inner surface of the transition plate is defined as R, and the first direction is a direction perpendicular to the first side plate. H and R satisfy: H ≥ 0.8R. The embodiments of this application can reduce the area of ​​the region where the transition plate may compress the first electrode, reduce the force exerted by the transition plate on the first electrode, and reduce the risk of active material detachment.

[0013] In some embodiments, H and R satisfy: R≤H≤2R.

[0014] In some embodiments, the value of R is 0.5mm-2mm.

[0015] In some embodiments, the area of ​​the second side plate is larger than that of the first side plate. When the electrode assembly presses against the second side plate, the electrode assembly has a larger force-bearing area and receives a more uniform reaction force, thereby reducing the risk of the active material of the electrode falling off when subjected to force from the second side plate.

[0016] In some embodiments, the battery cell further includes a first insulating member disposed on the side of the cover plate facing the electrode assembly, the first insulating member separating the cover plate and the electrode assembly. A support member is spaced apart from the first insulating member along a second direction perpendicular to the cover plate. Embodiments of this application can reduce the risk of interference between the first insulating member and the support member.

[0017] In some embodiments, the housing further includes a bottom plate disposed on the side of the electrode assembly opposite to the cover plate, the bottom plate being perpendicular to the first side plate and the second side plate. Support members are spaced apart from the bottom plate along a second direction, which is perpendicular to the cover plate. Embodiments of this application can reduce the risk of interference between the bottom plate and the support members.

[0018] In some embodiments, the base plate, the first side plate, and the second side plate are integrally formed.

[0019] In some embodiments, the base plate is welded to the first side plate and the second side plate.

[0020] In some embodiments, two first side plates are respectively located on both sides of the electrode assembly along a first direction, which is perpendicular to the first side plates. A support member is provided between the electrode assembly and each of the first side plates. Each support member can reduce the force exerted by the corresponding first side plate on the electrode assembly when the battery cell vibrates, thereby reducing the risk of active material detachment.

[0021] In some embodiments, the electrode assembly includes a first surface facing a first side plate, and a support member is located between the first surface and the first side plate.

[0022] In some embodiments, the two edges of the first surface along the second direction extend beyond the two edges of the support member along the second direction, and the two edges of the first surface along the third direction extend beyond the two edges of the support member along the third direction. The second direction is a direction perpendicular to the cover plate, and the third direction is a direction perpendicular to the second side plate.

[0023] In some embodiments, the battery cell further includes a second insulating member for separating the electrode assembly from the housing. The second insulating member includes a first insulating portion disposed between the first side plate and the first surface. The first insulating portion not only insulatingly separates the first side plate from the electrode assembly but also cooperates with a support member to support the electrode assembly.

[0024] In some embodiments, the second insulating member further includes a second insulating portion and two third insulating portions. The second insulating portion is located on the side of the electrode assembly facing away from the cover plate along the second direction and is connected to the third insulating portion. The two third insulating portions are respectively disposed on both sides of the electrode assembly along a third direction. The second direction is perpendicular to the cover plate, and the third direction is perpendicular to the second side plate. The electrode assembly has first insulating portions connected to the third insulating portions on both sides along the first direction. At least one first insulating portion connects to two third insulating portions. The first direction is perpendicular to the first side plate, and the first direction, the second direction, and the third direction are mutually perpendicular.

[0025] In some embodiments, there are two second insulating portions, each connected to one of two third insulating portions, and the two second insulating portions at least partially overlap in a second direction. The electrode assembly has two first insulating portions on one side along a first direction, each first insulating portion connected to one of two third insulating portions and at least partially overlapping in the first direction.

[0026] In some embodiments, the housing further includes a base plate disposed on the side of the electrode assembly opposite to the cover plate, the base plate being perpendicular to the first and second side plates. The base plate is welded to the first and second side plates to form a solder mark. In a second direction, two second insulating portions separate the solder mark and the electrode assembly.

[0027] In some embodiments, a support member is disposed between a first insulating portion and a first surface. During the process of placing the electrode assembly into the housing, the first insulating portion can protect the support member and guide the support member into the housing, reducing the risk of the support member being scratched by the housing.

[0028] In some embodiments, the battery cell further includes an adhesive member for attaching the support member to the electrode assembly. The adhesive member secures the support member to the electrode assembly, thereby reducing or preventing relative movement between the support member and the electrode assembly when the battery cell vibrates, and lowering the risk of the support member deviating from its intended position within the housing.

[0029] In some embodiments, the electrode assembly includes a first surface facing a first side plate and a second surface connected to the first surface, the second surface being perpendicular to the first side plate and the cover plate. The adhesive member includes a first adhesive portion and a second adhesive portion, the first adhesive portion being bonded to a surface of the support member remote from the first surface, and the second adhesive portion being connected to the first adhesive portion and bonded to the second surface. The adhesive member can cover at least a portion of the connection between the first and second surfaces from the outside and space the connection between the connection and the transition plate, thereby reducing the force on the electrode and lowering the risk of active material detachment.

[0030] In some embodiments, the adhesive member has two second adhesive portions, which are respectively connected to the two ends of the first adhesive portion along a third direction, which is a direction perpendicular to the second side plate.

[0031] In some embodiments, there are multiple adhesive members, which are spaced apart along a second direction perpendicular to the cover plate. Multiple adhesive members can improve the connection strength between the support member and the electrode assembly.

[0032] In some embodiments, the electrode assembly includes a plurality of first electrodes and a plurality of second electrodes, which are stacked alternately, and the stacking direction of the first electrodes and the second electrodes is parallel to the thickness direction of the first electrodes and the thickness direction of the second electrodes.

[0033] In some embodiments, the electrode assembly includes a plurality of second electrodes. Each first electrode includes a plurality of first stacked segments and a plurality of bent segments, the first stacked segments being stacked on top of each other, and each bent segment connecting two adjacent first stacked segments. Each second electrode is disposed between two adjacent first stacked segments.

[0034] In some embodiments, both the first side plate and the second side plate are rectangular flat plates.

[0035] In some embodiments, the support member is flat and parallel to the first side plate.

[0036] Secondly, embodiments of this application provide a battery comprising a plurality of battery cells provided in any of the foregoing embodiments.

[0037] In some embodiments, in a battery cell, a first side plate is located below the electrode assembly in the vertical direction, and at least a portion of a support member is disposed between the electrode assembly and the first side plate located below the electrode assembly.

[0038] Thirdly, embodiments of this application provide an electrical device that includes a battery provided according to any embodiment of the second aspect. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of a vehicle according to one embodiment of this application;

[0041] Figure 2 This is a schematic diagram of the structure of a battery according to one embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the structure of a battery module according to an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0044] Figure 5 for Figure 4 A side view of a single battery cell is shown.

[0045] Figure 6 for Figure 5 The diagram shows a cross-sectional view of a single battery cell along line AA.

[0046] Figure 7 This is a cross-sectional schematic diagram of an electrode assembly according to an embodiment of this application;

[0047] Figure 8 This is a cross-sectional schematic diagram of an electrode assembly according to another embodiment of this application;

[0048] Figure 9 This is a partial structural schematic diagram of an electrode assembly according to an embodiment of this application;

[0049] Figure 10 This is a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0050] Figure 11 for Figure 10 The diagram shows a cross-sectional view of a single battery cell along line BB.

[0051] Figure 12 for Figure 11 The enlarged view of the battery cell shown at point C in the circle;

[0052] Figure 13 for Figure 6 The enlarged schematic diagram of the battery cell shown at point D in the circle;

[0053] Figure 14 for Figure 6 The diagram shows an enlarged view of the battery cell at point E in the circle.

[0054] Figure 15 This is an exploded view of a battery cell according to one embodiment of this application;

[0055] Figure 16 This is a schematic diagram of the structure of the second insulating member of a battery cell according to an embodiment of this application;

[0056] Figure 17 This is a schematic diagram of the second insulating member of a battery cell in an unfolded state according to an embodiment of this application;

[0057] Figure 18 This is a schematic flowchart illustrating a method for manufacturing a single battery cell according to an embodiment of this application;

[0058] Figure 19 This is a schematic block diagram of a battery cell manufacturing system according to one embodiment of this application.

[0059] The accompanying drawings are not drawn to scale. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0061] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0062] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0063] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0064] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0065] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0066] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0067] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0068] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0069] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated current collector protrudes beyond the coated current collector, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated current collector protrudes beyond the coated current collector, serving as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, etc. To ensure that high currents can be carried without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are also stacked together. The separator has numerous interconnected micropores, allowing electrolyte ions to pass freely while maintaining good lithium ion permeability. The separator can be made of PP or PE, etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these. The development of battery technology must consider multiple design factors simultaneously, such as energy density, cycle life, discharge capacity, charge / discharge rate, and other performance parameters. Additionally, battery safety must also be considered.

[0070] During charging, lithium ions are extracted from the positive electrode and inserted into the negative electrode. However, some abnormal situations may occur, such as insufficient space for lithium insertion in the negative electrode, excessive resistance to lithium ion insertion, or lithium ions being extracted from the positive electrode too quickly. The extracted lithium ions cannot be inserted into the negative electrode active material layer in equal quantities. These uninserted lithium ions can only gain electrons on the negative electrode surface, forming silvery-white metallic lithium, a phenomenon known as lithium plating. Lithium plating not only degrades the performance of lithium-ion batteries and significantly shortens their cycle life but also limits their fast-charging capacity. Furthermore, the deposited lithium metal is highly reactive and can react with the electrolyte at relatively low temperatures, causing a decrease in the battery's tonset temperature and an increase in the self-heating rate, seriously jeopardizing battery safety. Moreover, in severe cases of lithium plating, the extracted lithium ions can form lithium crystals on the surface of the negative electrode. These crystals can easily puncture the separator, creating a risk of short circuits between adjacent positive and negative electrodes.

[0071] During the research and development process, the inventors discovered that when electrode components are subjected to vibration or pressure, the active material of either the positive or negative electrode sheet can detach, a phenomenon known as powder shedding. Due to the shedding of active material, especially on the negative electrode sheet, the number of lithium intercalation sites in the negative electrode's active material layer may be less than the number of lithium ions that the adjacent positive electrode's active material layer can provide. Therefore, lithium plating is prone to occur during charging of lithium batteries.

[0072] In view of this, embodiments of this application provide a technical solution by setting support components in a battery cell to reduce the shedding of active materials, reduce the risk of lithium plating, and improve battery safety.

[0073] The technical solutions described in the embodiments of this application are applicable to various battery-powered devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0074] It should be understood that the technical solutions described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0075] For example, such as Figure 1The diagram shown is a structural schematic of a vehicle 1 according to one embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery 10, a controller 20, and a motor 30 can be installed inside vehicle 1. The controller 20 controls the battery 10 to supply power to the motor 30. For example, the battery 10 can be installed at the bottom, front, or rear of vehicle 1. The battery 10 can be used to power vehicle 1. For example, the battery 10 can serve as the operating power source for vehicle 1, for example, to meet the electrical system requirements of vehicle 1, such as for starting, navigation, and operation. In another embodiment of this application, the battery 10 can not only serve as the operating power source for vehicle 1 but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0076] To meet different power demands, battery 10 may include multiple battery cells, which can be connected in series, parallel, or a combination of both. Battery 10 can also be called a battery pack. Optionally, multiple battery cells can first be connected in series, parallel, or a combination of both to form a battery module, and then multiple battery modules can be connected in series, parallel, or a combination of both to form battery 10. That is, multiple battery cells can be directly assembled into battery 10, or they can first be assembled into battery modules, and then the battery modules can be assembled into battery 10.

[0077] For example, such as Figure 2 The diagram shown is a structural schematic of a battery 10 according to an embodiment of this application. The battery 10 may include multiple battery cells 40. The battery 10 may also include a housing (or cover), the interior of which is a hollow structure, and the multiple battery cells 40 are housed within the housing. Figure 2 As shown, the housing may include two parts, referred to here as the first part 111 and the second part 112, which are fastened together. The shapes of the first part 111 and the second part 112 can be determined according to the combined shape of multiple battery cells 40. Both the first part 111 and the second part 112 may have an opening. For example, both the first part 111 and the second part 112 may be hollow cuboids with only one open face. The openings of the first part 111 and the second part 112 are opposite to each other, and the first part 111 and the second part 112 are fastened together to form a housing with a closed cavity. Multiple battery cells 40 are connected in parallel, series, or mixed configurations and placed inside the housing formed by the fastening of the first part 111 and the second part 112.

[0078] Optionally, the battery 10 may also include other structures, which will not be described in detail here. For example, the battery 10 may also include a busbar component for realizing the electrical connection between multiple battery cells 40, such as parallel, series, or mixed connection. Specifically, the busbar component can realize the electrical connection between battery cells 40 by connecting the electrode terminals of the battery cells 40. Further, the busbar component can be fixed to the electrode terminals of the battery cells 40 by welding. The electrical energy of the multiple battery cells 40 can be further led out through the housing by a conductive mechanism. Optionally, the conductive mechanism may also be part of the busbar component.

[0079] The number of battery cells 40 can be set to any value depending on different power demands. Multiple battery cells 40 can be connected in series, parallel, or mixed connections to achieve larger capacity or power. Since each battery 10 may contain a large number of battery cells 40, for ease of installation, the battery cells 40 can be grouped, with each group of battery cells 40 forming a battery module. The number of battery cells 40 included in a battery module is unlimited and can be set according to requirements. For example, Figure 3 This is an example of a battery module. Battery 10 may include multiple battery modules, which may be connected in series, parallel, or a combination thereof.

[0080] Figure 4 This is a schematic diagram of the structure of a battery cell 40 according to an embodiment of this application; Figure 5 for Figure 4 A side view of the battery cell 40 shown; Figure 6 for Figure 5 The diagram shows a cross-sectional view of the battery cell 40 along line AA.

[0081] like Figures 4 to 6 As shown, the battery cell 40 of this embodiment includes an electrode assembly 410, a housing 420, and an end cap assembly 430. The housing 420 has a receiving cavity and an opening, and the electrode assembly 410 is received in the receiving cavity. In some examples, when the housing 420 is a hollow cuboid or cube, one of the planes of the housing 420 is an opening, that is, this plane does not have a wall, allowing communication between the inside and outside of the housing 420. The end cap assembly 430 includes a cover plate 431, which covers the opening and is connected to the housing 420, thereby closing the opening of the housing 420 and placing the electrode assembly 410 in the closed cavity. The housing 420 is filled with an electrolyte, such as an electrolyte solution.

[0082] The end cap assembly 430 may further include two electrode terminals 432, which may be disposed on the cover plate 431. The cover plate 431 is typically flat, and the two electrode terminals 432 are fixed to the flat surface of the cover plate 431, which are respectively a positive electrode terminal and a negative electrode terminal 432. Each electrode terminal 432 is provided with a corresponding connecting member 440, or a current collector, which is located between the cover plate 431 and the electrode assembly 410, for electrically connecting the electrode assembly 410 and the electrode terminal 432.

[0083] Each electrode assembly 410 has a first tab 410a and a second tab 410b. The first tab 410a and the second tab 410b have opposite polarities. For example, when the first tab 410a is a positive tab, the second tab 410b is a negative tab. The first tab 410a of one or more electrode assemblies 410 is connected to an electrode terminal 432 via a connecting member 440, and the second tab 410b of one or more electrode assemblies 410 is connected to another electrode terminal 432 via another connecting member 440. For example, the positive electrode terminal is connected to the positive tab via a connecting member 440, and the negative electrode terminal is connected to the negative tab via another connecting member 440.

[0084] In this battery cell 40, the electrode assembly 410 can be configured as a single unit or multiple units, depending on actual usage requirements. For example, in the illustrated embodiment, the battery cell 40 contains one electrode assembly 410.

[0085] In some embodiments, the end cap assembly 430 may further include a first insulating member 433 disposed on the side of the cover plate 431 facing the electrode assembly 410. The first insulating member 433 can separate the cover plate 431 from the connecting member 440 and from the electrode assembly 410 to reduce the risk of short circuit. The first insulating member 433 may be made of plastic, for example, polypropylene.

[0086] In some embodiments, the housing 420 is generally a hollow cuboid. Specifically, the housing 420 includes two first side plates 421 facing each other and two second side plates 422 facing each other. The first side plates 421 are connected to the second side plates 422 and define receiving cavities and openings. The first side plates 421 and the second side plates 422 are flat and perpendicular to each other. The two first side plates 421 are arranged parallel to each other, and the two second side plates 422 are arranged parallel to each other.

[0087] Cover plate 431 is connected to the first side plate 421 and the second side plate 422 to close the opening of housing 420. For example, cover plate 431 may be welded to the first side plate 421 and the second side plate 422. In battery cell 40, cover plate 431 is perpendicular to the first side plate 421 and the second side plate 422.

[0088] Two first side plates 421 are respectively located on both sides of the electrode assembly 410 along a first direction X, wherein the first direction X is perpendicular to the first side plate 421. The first direction X is parallel to the thickness direction of the first side plate 421. Optionally, the first side plate 421 is generally a rectangular plate. A cover plate 431 is located on one side of the electrode assembly 410 along a second direction Y, wherein the second direction Y is perpendicular to the cover plate 431. The second direction Y is parallel to the thickness direction of the cover plate 431. Optionally, the cover plate 431 is generally a rectangular plate. Two second side plates 422 are respectively located on both sides of the electrode assembly 410 along a third direction Z, wherein the third direction Z is perpendicular to the second side plate 422. The third direction Z is parallel to the thickness direction of the second side plate 422. Optionally, the second side plate 422 is generally a rectangular plate. In some examples, the thickness of the first side plate 421 is equal to the thickness of the second side plate 422.

[0089] In some embodiments, the housing 420 further includes a bottom plate 423 disposed on the side of the electrode assembly 410 opposite to the cover plate 431, i.e., the bottom plate 423 and the cover plate 431 are respectively located on both sides of the electrode assembly 410 along the second direction Y. The bottom plate 423 is perpendicular to the first side plate 421 and the second side plate 422. The bottom plate 423 is generally a rectangular flat plate. In some examples, the bottom plate 423, the first side plate 421, and the second side plate 422 are integrally formed; in other examples, the bottom plate 423 may also be connected to the first side plate 421 and the second side plate 422 by welding or other means.

[0090] In some embodiments, the dimension of the battery cell 40 along the second direction Y is greater than the dimension of the battery cell 40 along the first direction X and the dimension of the battery cell 40 along the third direction Z. Since the vehicle 1 has limited space reserved for the battery 10 in the vertical direction, in order to reduce the height of the battery 10 in the vertical direction, the second direction Y can be made parallel to the horizontal direction, thus reducing the maximum dimension of the battery 10 in the vertical direction.

[0091] In some embodiments, the dimension of the battery cell 40 along the first direction X is larger than the dimension of the battery cell 40 along the third direction Z. Optionally, in the battery 10, the battery cell 40 can be placed sideways. When the battery cell 40 is placed sideways, the first direction X is parallel to the vertical direction.

[0092] Figure 7 This is a cross-sectional schematic diagram of an electrode assembly 410 according to an embodiment of this application; Figure 8This is a cross-sectional schematic diagram of an electrode assembly 410 according to another embodiment of this application; Figure 9 This is a partial structural diagram of an electrode assembly 410 according to an embodiment of this application.

[0093] The electrode assembly 410 of this application embodiment includes at least one first electrode 411 and at least one second electrode 412, wherein the polarity of the first electrode 411 and the polarity of the second electrode 412 are opposite. For example, when the first electrode 411 is a negative electrode, the second electrode 412 is a positive electrode; when the first electrode 411 is a positive electrode, the second electrode 412 is a negative electrode. The electrode assembly 410 also includes a separating membrane 413, which separates the first electrode 411 and the second electrode 412.

[0094] At least a portion of the first electrode 411 is stacked with a second electrode 412, the stacking direction being parallel to the thickness direction of the second electrode 412. The electrode assembly 410 of this embodiment has a stacked structure, comprising a plurality of stacked second electrodes 412. Each second electrode 412 is generally flat and separated from each other. At least a portion of the first electrode 411 is disposed between adjacent second electrodes 412.

[0095] In some embodiments, such as Figure 7 As shown, the electrode assembly 410 includes a plurality of first electrode plates 411 and a plurality of second electrode plates 412, which are alternately stacked. The stacking direction of the first electrode plates 411 and the second electrode plates 412 is parallel to the thickness direction of the first electrode plates 411 and the thickness direction of the second electrode plates 412. In some examples, the first electrode plates 411 and the second electrode plates 412 are both rectangular flat plates and are arranged parallel to each other.

[0096] In the battery cell 40, the first electrode 411 and the second electrode 412 are perpendicular to the cover plate 431. In some examples, the stacking direction of the first electrode 411 and the second electrode 412 is parallel to a third direction Z, that is, the first electrode 411 and the second electrode 412 are parallel to a first direction X and a second direction Y.

[0097] The electrode assembly 410 includes two first surfaces 414 facing each other and two second surfaces 415 facing each other. The first surfaces 414 and the second surfaces 415 are the exposed surfaces of the electrode assembly 410. Each end of the first surface 414 is connected to the two second surfaces 415 along a third direction Z. In some examples, the two first surfaces 414 face each other along a first direction X, and the two second surfaces 415 face each other along a third direction Z.

[0098] In some examples, the outermost part of the electrode assembly 410 is an isolation membrane 413, so the first surface 414 and the second surface 415 are the exposed surfaces of the isolation membrane 413. Specifically, there are two isolation membranes 413, each of which is repeatedly bent into multiple layers and includes multiple isolation layers and multiple bent layers, with each bent layer connecting two adjacent isolation layers. Each isolation layer separates adjacent first electrode 411 and second electrode 412. The two ends of the electrode assembly 410 along the third direction Z are two isolation layers, and the outer surfaces of these two isolation layers are the two second surfaces 415. The first surface 414 includes the exposed surfaces of multiple bent layers. Although the outer surface of the bent layers is an arc surface, the radius of the bent layers is small, and the first surface 414 can be approximated as a plane. That is, the electrode assembly 410 is approximately a cuboid.

[0099] In other examples, the insulating membrane 413 in the electrode assembly 410 may be omitted, and an insulating layer may be formed on the surface of the first electrode 411 or the surface of the second electrode 412 to achieve insulation. Optionally, the two ends of the electrode assembly 410 along the third direction Z are the first electrodes 411, and the exposed surface of the first electrodes 411 is the second surface 415. The ends of the first electrodes 411 along the first direction X extend beyond the second electrodes 412, and the ends of multiple first electrodes 411 are stacked together and approximately form the first surface 414.

[0100] In other embodiments, such as Figure 8 As shown, the electrode assembly 410 includes at least one first electrode 411 and a plurality of second electrodes 412. The first electrode 411 includes a plurality of stacked first stacked segments 411a and a plurality of bent segments 411b, each bent segment 411b connecting two adjacent first stacked segments 411a. Each second electrode 412 is disposed between two adjacent first stacked segments 411a. The first stacked segments 411a are flat and generally parallel to the second electrodes 412, and the bent segments 411b are at least partially bent. In some examples, the first stacked segments 411a and the second electrodes 412 are alternately stacked along a third direction Z, and the bent segments 411b are located on one side of the second electrodes 412 along a first direction X. The electrode assembly 410 is approximately cuboid.

[0101] like Figure 9As shown, the electrode assembly 410 also includes two third surfaces 416, each third surface 416 being connected to the first surface 414 and the second surface 415. In some examples, the two third surfaces 416 face each other along the second direction Y, i.e., in the battery cell 40, one third surface 416 faces the cover plate 431, and the other third surface 416 faces the base plate 423. In the second direction Y, the two ends of the separator 413 extend beyond the first electrode 411 and the second electrode 412, so the two ends of the separator 413 approximately form two surfaces, i.e., two third surfaces 416. Optionally, the first tab 410a and the second tab 410b extend from one third surface 416.

[0102] Figure 10 This is a schematic diagram of the structure of a battery cell 40 according to an embodiment of this application; Figure 11 for Figure 10 A cross-sectional view of the battery cell 40 along line BB; Figure 12 for Figure 11 The enlarged view of the battery cell 40 shown at point C in the circle.

[0103] The inventors further discovered that when the device vibrates during use, the electrode assembly shakes inside the housing, potentially causing it to squeeze against the housing. This squeezing can lead to the shedding of active material from the electrode plates, resulting in lithium plating. Furthermore, the shaking of the electrode assembly can also cause the tabs to tear.

[0104] In view of this, such as Figures 10 to 12 As shown, the battery cell 40 provided in this application also includes a support member 450, which is at least partially disposed between the first side plate 421 and the electrode assembly 410. The support member 450 is used to support the electrode assembly 410 so that the distance between the end of the first electrode 411 facing the first side plate 421 and the first side plate 421 in the first direction X is greater than a predetermined value. The first direction X is a direction perpendicular to the first side plate 421.

[0105] The support member 450 spaces the electrode assembly 410 and the first side plate 421 in the first direction X. In some examples, the support member 450 is entirely located between the electrode assembly 410 and the first side plate 421 in the first direction X. The support member 450 can directly contact and support the electrode assembly 410, or it can indirectly support the electrode assembly 410 through other members. The distance between the end of the first electrode 411 facing the first side plate 421 and the first side plate 421 in the first direction X is the minimum distance between the first electrode 411 and the first side plate 421 in the first direction X. The predetermined value varies depending on the design requirements. This predetermined value may need to take into account the shape and dimensions of the housing 420 and the electrode assembly 410.

[0106] In the battery cell 40 of this application embodiment, the support member 450 can support the electrode assembly 410, reduce the swaying amplitude of the electrode assembly 410 when the battery cell 40 vibrates, reduce the force exerted by the first side plate 421 on the electrode assembly 410, and reduce the risk of electrode tab tearing. In addition, by providing the support member 450, the distance between the end of the first electrode 411 facing the first side plate 421 and the first side plate 421 in the first direction X is greater than a predetermined value, thereby reducing the force transmitted to the end of the first electrode 411, reducing the risk of active material shedding from the first electrode 411, and reducing lithium plating.

[0107] In some embodiments, the support member 450 can also make the distance between the end of the second electrode 412 facing the first side plate 421 and the first side plate 421 in the first direction X greater than a predetermined value, thereby reducing the force transmitted to the end of the second electrode 412 when the battery cell 40 vibrates, reducing the risk of active material shedding from the second electrode 412, and reducing lithium plating.

[0108] In some embodiments, a transition plate 424 is provided between the first side plate 421 and the second side plate 422, and the inner surface of the transition plate 424 is an arc surface. The transition plate 424 is a rounded corner formed during the molding process of the housing 420. By providing the transition plate 424, the sharp corners of the housing 420 can be eliminated, stress concentration can be reduced, and the strength of the housing 420 can be improved. The inner surface of the first side plate 421 facing the electrode assembly 410 is planar and tangent to the inner surface of the transition plate 424, and the inner surface of the second side plate 422 facing the electrode assembly 410 is planar and tangent to the inner surface of the transition plate 424. The transition plate 424 is connected to the end of the first side plate 421 along the third direction Z. There are four transition plates 424, and each transition plate 424 connects one first side plate 421 and one second side plate 422.

[0109] The inventors further discovered that when the battery cell is placed sideways, a first side plate is located on the lower side of the electrode assembly along the vertical direction. Under the influence of gravity, the electrode assembly may compress the inner surface of the transition plate. Since the inner surface of the transition plate is an arc surface, under vibration and impact conditions, the inner surface of the transition plate is prone to compressing the electrode sheet, thereby causing the active material of the electrode sheet to fall off.

[0110] In view of this, in some embodiments, the predetermined value is defined as H, and the radius of the inner surface of the transition plate 424 is defined as R. The predetermined value H and the radius R satisfy: H ≥ 0.8R. In this case, the present application can reduce the area of ​​the region where the transition plate 424 may compress the first electrode 411, reduce the force exerted by the transition plate 424 on the first electrode 411, and reduce the risk of active material detachment.

[0111] The larger the value of H, the less the extrusion pressure exerted by the transition plate 424 on the end of the first electrode 411, and the smaller the size of the electrode assembly 410 will be. Taking into account both the extrusion pressure on the first electrode 411 and the capacity of the battery cell 40, in some embodiments, the predetermined value H and the radius R satisfy: R≤H≤2R.

[0112] The smaller the value of R, the more likely stress concentration will occur in the transition plate 424, and the lower the strength of the casing 420; the larger the value of R, the larger the value of H, the smaller the size of the electrode assembly 410, and the lower the capacity of the battery cell 40. Taking into account both the strength of the casing 420 and the capacity of the battery cell 40, in some embodiments, the value of the radius R is 0.5mm-2mm.

[0113] The area of ​​the second side plate 422 is larger than the area of ​​the first side plate 421. The first side plate 421 and the second side plate 422 are parallel to the second direction Y, and their dimensions in the second direction Y are equal. The dimension of the first side plate 421 along the third direction Z is smaller than the dimension of the second side plate 422 along the first direction X. The second electrode 412 is generally parallel to the second side plate 422, that is, the stacking direction of the plurality of second electrode 412 is perpendicular to the second side plate 422.

[0114] During charging and discharging, the electrode assembly 410 expands. Specifically, the first electrode 411 and the second electrode 412 expand the most in their own thickness direction, resulting in the electrode assembly 410 having the largest expansion in the third direction Z. The expanded electrode assembly 410 presses tightly against the second side plate 422, so the electrode assembly 410 is less prone to shaking in the third direction Z. In addition, the second surface 415 of the electrode assembly 410 is generally planar. When the electrode assembly 410 presses against the second side plate 422, the force-bearing area of ​​the electrode assembly 410 is large, and the reaction force is relatively uniform. Therefore, when subjected to the force from the second side plate 422, the active material of the electrode is less likely to fall off.

[0115] A support member 450 is provided between the electrode assembly 410 and each of the first side plates 421. Specifically, in some examples, there are two support members 450: one support member 450 is located between the electrode assembly 410 and one first side plate 421, and the other support member 450 is located between the electrode assembly 410 and another first side plate 421. Each support member 450 can reduce the force exerted by the corresponding first side plate 421 on the electrode assembly 410 when the battery cell 40 vibrates, thereby reducing the risk of active material shedding.

[0116] In the battery 10 in which the battery cell 40 is placed on its side, both first side plates 421 of the battery cell 40 may be placed downwards, and regardless of which first side plate 421 of the battery cell 40 is placed downwards, the support member 450 can support the electrode assembly 410 from below.

[0117] Figure 13 for Figure 6 The diagram shows an enlarged view of the battery cell 40 at point D within the circular frame. (See diagram below.) Figure 13 As shown, in some embodiments, the surface of the first insulating member 433 facing the electrode assembly 410 is attached to the third surface 416 of the electrode assembly 410 to limit the wobbling of the electrode assembly 410 in the second direction Y.

[0118] In some embodiments, the support member 450 and the first insulating member 433 are spaced apart along a second direction Y. In the second direction Y, the support member 450 and the first insulating member 433 are spaced apart by a certain distance to avoid interference between them. When the battery cell 40 is placed laterally, the support member 450 may move downwards under the action of the electrode assembly 410; during this movement, the first insulating member 433 will not interfere with the support member 450.

[0119] Figure 14 for Figure 6 The diagram shows an enlarged view of the battery cell 40 at point E within the circular frame. (See diagram). Figure 14 As shown, in some embodiments, the support member 450 and the base plate 423 are spaced apart along the second direction Y. In the second direction Y, the support member 450 and the base plate 423 are spaced apart by a certain distance to avoid interference between them.

[0120] Figure 15 This is an exploded view of a battery cell 40 according to one embodiment of this application. Figure 15 As shown, in some embodiments, the support member 450 is located between the first surface 414 and the first side plate 421. Optionally, the support member 450 is flat and parallel to the first side plate 421. The flat support member 450 enables a more uniform force between the electrode assembly 410 and the support member 450.

[0121] In some embodiments, the two edges of the first surface 414 along the second direction Y respectively extend beyond the two edges of the support member 450 along the second direction Y. The dimension of the first surface 414 along the second direction Y is larger than the dimension of the support member 450 along the second direction Y. Thus, in the second direction Y, the edge of the support member 450 near the first insulating member 433 is spaced apart from the first insulating member 433 by a certain distance, and the edge of the support member 450 near the base plate 423 is spaced apart from the base plate 423 by a certain distance.

[0122] To fully utilize the internal space of the housing 420 and ensure the capacity of the electrode assembly 410, the dimension of the first surface 414 along the third direction Z is typically larger than the dimension of the first side plate 421 along the third direction Z. However, to avoid interference between the transition plate 424 and the support member 450, the dimension of the support member 450 along the third direction Z is typically smaller than or equal to the dimension of the first side plate 421 along the third direction Z. That is, the dimension of the first surface 414 along the third direction Z is larger than the dimension of the support member 450 along the third direction Z. In some embodiments, the two edges of the first surface 414 along the third direction Z extend beyond the two edges of the support member 450 along the third direction Z, respectively.

[0123] In some embodiments, the battery cell 40 further includes a second insulating member 460 for separating the electrode assembly 410 and the housing 420. The second insulating member 460 can reduce the risk of electrical continuity between the electrode assembly 410 and the housing 420. The second insulating member 460 may be made of polypropylene.

[0124] Specifically, in some examples, the second insulating member 460 includes a first insulating portion 461 disposed between the first side plate 421 and the first surface 414. The first insulating portion 461 not only insulatingly separates the first side plate 421 from the electrode assembly 410, but also cooperates with the support member 450 to support the electrode assembly 410. The position of the first insulating portion 461 can be set as needed. In some examples, the first insulating portion 461 may be located between the first surface 414 and the support member 450; in other examples, the first insulating portion 461 may also be located between the support member 450 and the first side plate 421. The second insulating member 460 covers the electrode assembly 410 from the outside and may also include other parts. The specific structure of the second insulating member 460 is described in detail later.

[0125] In some embodiments, the battery cell 40 further includes an adhesive member 470 for connecting the support member 450 to the electrode assembly 410. The adhesive member 470 secures the support member 450 to the electrode assembly 410, thereby reducing or preventing relative movement between the support member 450 and the electrode assembly 410 when the battery cell 40 vibrates, and reducing the risk of the support member 450 deviating from its intended position within the housing 420. Furthermore, during the process of placing the electrode assembly 410 into the housing 420, the support member 450 can enter the housing 420 along with the electrode assembly 410, thus simplifying the assembly process of the battery cell 40. In some examples, the adhesive member 470 is an adhesive tape. In other examples, an adhesive may be applied to the surface of the support member 450, and then the support member 450 may be adhered to the first surface 414; the adhesive cures to form the adhesive member 470.

[0126] In some embodiments, the second surface 415 is connected to the first surface 414 and perpendicular to the first side plate 421 and the cover plate 431. The adhesive member 470 includes a first adhesive portion 471 and a second adhesive portion 472. The first adhesive portion 471 is bonded to the surface of the support member 450 remote from the first surface 414, and the second adhesive portion 472 is connected to the first adhesive portion 471 and bonded to the second surface 415. The first adhesive portion 471 also serves to support the electrode assembly 410.

[0127] The junction of the first surface 414 and the second surface 415 is most susceptible to the force exerted by the transition plate 424, making the electrode near this junction more prone to active material detachment. The adhesive member 470 can cover at least a portion of the junction from the outside and space the junction from the transition plate 424, thereby reducing the force exerted on the electrode and lowering the risk of active material detachment.

[0128] In some embodiments, the adhesive member 470 has two second adhesive portions 472, which are respectively connected to the two ends of the first adhesive portion 471 along the third direction Z. The two second adhesive portions 472 are respectively bonded to the two second surfaces 415. The adhesive member 470 is bent into a U-shape.

[0129] In some embodiments, the adhesive members 470 are a plurality of non-continuous members, spaced apart along the second direction Y. The support member 450 has a large dimension in the second direction Y, and the plurality of adhesive members 470 can improve the connection strength between the support member 450 and the electrode assembly 410. The gaps between the adhesive members 470 can be used to accommodate electrolyte.

[0130] In some embodiments, the support member 450 is disposed between the first insulating portion 461 and the first surface 414. During the assembly of the battery cell 40, the support member 450 can first be fixed to the electrode assembly 410 using the adhesive member 470, and then the second insulating member 460 is wrapped around the outside of the electrode assembly 410 and the support member 450. During the process of placing the electrode assembly 410 into the housing 420, the second insulating member 460 can protect the support member 450 and guide it into the housing, preventing the support member 450 from being scratched by the housing 420.

[0131] Figure 16 This is a schematic diagram of the structure of the second insulating member 460 of a battery cell 40 according to an embodiment of this application; Figure 17 This is a schematic diagram of the second insulating member 460 of a battery cell 40 in an unfolded state, according to an embodiment of this application.

[0132] like Figure 16 and Figure 17As shown, in some embodiments, the second insulating member 460 further includes a second insulating portion 462 and two third insulating portions 463. The second insulating portion 462 is located on the side of the electrode assembly 410 facing away from the cover plate 431 along the second direction Y and is connected to the third insulating portion 463. The two third insulating portions 463 are respectively disposed on both sides of the electrode assembly 410 along the third direction Z. The second insulating portion 462 is located between the electrode assembly 410 and the base plate 423 to separate the electrode assembly 410 and the base plate 423. One third insulating portion 463 is located between a second surface 415 and a second side plate 422, and the other third insulating portion 463 is located between another second surface 415 and another second side plate 422; the two third insulating portions 463 separate the two second side plates 422 and the electrode assembly 410. The third insulating portion 463 is flat and parallel to the second side plate 422, and the second insulating portion 462 extends from the end of the third insulating portion 463 along the second direction Y and is bent relative to the third insulating portion 463.

[0133] The electrode assembly 410 has a first insulating portion 461 connected to the third insulating portion 463 on both sides along the first direction X. Specifically, at least one first insulating portion 461 is provided between one first side plate 421 and one first surface 414, and at least one first insulating portion 461 is provided between another first side plate 421 and another first surface 414. In some embodiments, at least one first insulating portion 461 connects two third insulating portions 463.

[0134] In some embodiments, there are two second insulating portions 462, each connected to one of two third insulating portions 463, and the two second insulating portions 462 at least partially overlap in the second direction Y. In some examples, the base plate 423 is welded to the first side plate 421 and the second side plate 422 to form a solder mark. The two stacked second insulating portions 462 can separate the electrode assembly 410 from the solder mark, reducing the risk of the solder mark puncturing the isolation membrane 413. In some examples, the two second insulating portions 462 are fused together.

[0135] In some embodiments, the electrode assembly 410 has two first insulating portions 461 disposed on one side along the first direction X. The two first insulating portions 461 are respectively connected to two third insulating portions 463 and at least partially overlap in the first direction X. These two first insulating portions 461 are located between a first surface 414 and a first side plate 421, and are capable of supporting the electrode assembly 410 in the first direction X. In some examples, the two first insulating portions 461 are fused together.

[0136] The second insulating member 460 can be formed by bending a flat insulating sheet. The insulating sheet has through holes at the junction of the first insulating portion 461 and the third insulating portion 463, and at the junction of the second insulating portion 462 and the third insulating portion 463. The through holes guide the bending of the insulating sheet. Additionally, electrolyte can pass through, improving the wettability of the electrode assembly 410. After bending, the first insulating portion 461 and the third insulating portion 463 surround the outside of the first insulating member 433 and are fixed to the first insulating member 433 by welding.

[0137] Figure 18 This is a schematic flowchart illustrating a method for manufacturing a single battery cell according to one embodiment of this application. Figure 18 As shown, the manufacturing method includes:

[0138] S510, providing an electrode assembly, the electrode assembly including at least one first electrode and at least one second electrode, at least a portion of the first electrode and the second electrode being stacked;

[0139] S520 provides an end cap assembly, the end cap assembly including a cover plate and electrode terminals disposed on the cover plate, connecting the electrode assembly and the electrode terminals;

[0140] S530 provides a support member and connects the support member to the electrode assembly;

[0141] S540, provides a housing having an opening and a receiving cavity for accommodating an electrode assembly, the housing including a first side plate;

[0142] S550, the electrode assembly and the support member connected to the electrode assembly are placed into the receiving cavity, and then the cover plate and the housing are connected so that the cover plate closes the opening and is perpendicular to the first side plate. The support member is at least partially disposed between the first side plate and the electrode assembly. The support member is used to support the electrode assembly so that the distance between the end of the first electrode facing the first side plate and the first side plate in a first direction is greater than a predetermined value. The first direction is the direction perpendicular to the first side plate.

[0143] The relevant structure of the battery cell manufactured by the manufacturing method of this embodiment can be referred to the foregoing. Figure 1-17 The details of the battery cells described in the corresponding embodiments will not be repeated here.

[0144] Figure 19 This is a schematic block diagram of a battery cell manufacturing system according to one embodiment of this application. Figure 19As shown, the manufacturing system 600 includes a first providing device 610, a second providing device 620, a first assembly device 630, a third providing device 640, a second assembly device 650, a fourth providing device 660, and a third assembly device 670. The first providing device 610 provides an electrode assembly, which includes at least one first electrode and at least one second electrode, with at least a portion of the first electrode and the second electrode stacked. The second providing device 620 provides an end cap assembly, which includes a cover plate and electrode terminals disposed on the cover plate. The first assembly device 630 connects the electrode assembly and the electrode terminals. The third providing device 640 provides a support member. The second assembly device 650 connects the support member to the electrode assembly. The fourth providing device 660 provides a housing having an opening and a receiving cavity for accommodating the electrode assembly, and the housing includes a first side plate. The third assembly device 670 is used to place the electrode assembly and the support member connected to the electrode assembly into the receiving cavity, and then connect the cover plate and the housing so that the cover plate closes the opening and is perpendicular to the first side plate. The support member is at least partially disposed between the first side plate and the electrode assembly. The support member is used to support the electrode assembly so that the distance between the end of the first electrode facing the first side plate and the first side plate in a first direction is greater than a predetermined value. The first direction is the direction perpendicular to the first side plate.

[0145] The relevant structure of the battery cell manufactured by the manufacturing system of this embodiment can be referred to the foregoing. Figure 1-17 The details of the battery cells described in the corresponding embodiments will not be repeated here.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized by, The battery monomer comprises: an electrode assembly comprising at least one first pole piece and at least one second pole piece, at least part of the first pole piece and the second pole piece being arranged in a stack; a shell comprising two first side plates arranged oppositely, two second side plates arranged oppositely, and four transition plates, the first side plates being perpendicular to the second side plates, the transition plates connecting the first side plates and the second side plates, the first side plates, the second side plates, and the transition plates defining an opening and a receiving cavity, the electrode assembly being received in the receiving cavity; a cover plate for closing the opening and being perpendicular to the first side plates and the second side plates; a support member for supporting the electrode assembly; the electrode assembly comprises a first surface facing the first side plates, the support member being located between the first surface and the first side plates, two edges of the first surface along a second direction respectively exceeding two edges of the support member along the second direction, two edges of the first surface along a third direction respectively exceeding two edges of the support member along the third direction, the second direction being a direction perpendicular to the cover plate, and the third direction being a direction perpendicular to the second side plates.

2. The battery cell of claim 1, wherein, An inner surface of the transition plate is a circular arc surface. An end of the first pole piece facing the first side plate has a spacing H from the first side plate in a first direction, a radius of the inner surface of the transition plate is defined as R, and the first direction is a direction perpendicular to the first side plate. H and R satisfy: H≥0.8R.

3. The battery cell of claim 2, wherein, H and R satisfy: R≤H≤2R.

4. The battery cell of claim 2, wherein, The value of R is 0.5mm-2mm.

5. The battery cell of claim 1, wherein, An area of the second side plate is greater than an area of the first side plate.

6. The battery cell of claim 1, wherein, The battery monomer further comprises a first insulation member arranged on a side of the cover plate facing the electrode assembly, the first insulation member separating the cover plate and the electrode assembly. The support member and the first insulation member are arranged in a spaced manner along the second direction.

7. The battery cell of claim 1, wherein, The shell further comprises a bottom plate arranged on a side of the electrode assembly away from the cover plate, the bottom plate being perpendicular to the first side plates and the second side plates. The support member and the bottom plate are arranged in a spaced manner along the second direction.

8. The battery cell of claim 7, wherein, The bottom plate, the first side plates, and the second side plates are integrally formed; or The bottom plate is welded to the first side plates and the second side plates.

9. The battery cell of claim 1, wherein, Two of the first side plates are respectively located on two sides of the electrode assembly along a first direction, the first direction being a direction perpendicular to the first side plates. The support member is arranged between the electrode assembly and each of the first side plates.

10. The battery cell of claim 1, wherein, The battery monomer further comprises a second insulation member for separating the electrode assembly and the shell, the second insulation member comprising a first insulation portion arranged between the first side plates and the first surface.

11. The battery cell of claim 10, wherein, The second insulation member further comprises a second insulation portion and two third insulation portions, the second insulation portion being located on a side of the electrode assembly away from the cover plate along the second direction and connected to the third insulation portions, and the two third insulation portions being respectively arranged on two sides of the electrode assembly along the third direction. The electrode assembly is provided with the first insulating part connected to the third insulating part on both sides of the electrode assembly along a first direction, at least one of the first insulating parts connecting two of the third insulating parts, the first direction being perpendicular to the first side plate, the first direction, the second direction and the third direction being perpendicular to each other.

12. The battery cell of claim 11, wherein, The second insulating part is two and is connected to two of the third insulating parts respectively, and the two second insulating parts at least partially overlap in the second direction; The electrode assembly is provided with two first insulating parts on one side of the electrode assembly along the first direction, the two first insulating parts being connected to two third insulating parts respectively and at least partially overlapping in the first direction.

13. The battery cell of claim 12, wherein, The shell further comprises a bottom plate provided on the side of the electrode assembly away from the cover plate, the bottom plate being perpendicular to the first side plate and the second side plate; The bottom plate is welded to the first side plate and the second side plate and forms a welding mark; In the second direction, the two second insulating parts separate the welding mark and the electrode assembly.

14. The battery cell of claim 10, wherein, The support member is provided between the first insulating part and the first surface.

15. The battery cell of claim 1, wherein, The battery monomer further comprises an adhesive member for connecting the support member to the electrode assembly.

16. The battery cell of claim 15, wherein, The electrode assembly comprises a second surface connected to the first surface, the second surface being perpendicular to the first side plate and the cover plate; The adhesive member comprises a first adhesive part and a second adhesive part, the first adhesive part being adhered to the surface of the support member away from the first surface, and the second adhesive part being connected to the first adhesive part and adhered to the second surface.

17. The battery cell of claim 16, wherein, The second adhesive part of the adhesive member is two, and the two second adhesive parts are connected to the two ends of the first adhesive part along the third direction respectively.

18. The battery cell of claim 15, wherein, The adhesive member is multiple, and the multiple adhesive members are arranged at intervals along the second direction.

19. The battery cell of claim 1, wherein, The electrode assembly comprises a plurality of first electrode plates and a plurality of second electrode plates, the plurality of first electrode plates and the plurality of second electrode plates being alternately stacked, the stacking direction of the first electrode plates and the second electrode plates being parallel to the thickness direction of the first electrode plates and the thickness direction of the second electrode plates.

20. The battery cell of claim 1, wherein, The electrode assembly comprises a plurality of second electrode plates; The first electrode plate comprises a plurality of first stacked segments and a plurality of bending segments, the plurality of first stacked segments being arranged in layers, and each of the bending segments connecting two adjacent first stacked segments; Each of the second electrode plates is arranged between two adjacent first stacked segments.

21. The battery cell of claim 1, wherein, The first side plate and the second side plate are both rectangular plates.

22. The battery cell of claim 1, wherein, The support member is a flat plate and is parallel to the first side plate.

23. A battery, characterized by A plurality of battery monomers as claimed in any one of claims 1-22 are included.

24. The battery of claim 23, wherein, In the battery monomer, one of the first side plates is located on the lower side of the electrode assembly in the vertical direction, and at least part of the support member is arranged between the electrode assembly and the first side plate located on the lower side of the electrode assembly.

25. An electrical device, comprising: A battery according to claim 23 or 24 is included.

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