Battery monomer, battery, power utilization device and energy storage device

Abstract

The utility model discloses a battery monomer, a battery, a power utilization device and an energy storage device. The battery cell includes a case having an opening on one side in a first direction, and an electrode assembly accommodated in the case. The electrode assembly comprises an insulating part and a battery cell, and the insulating part comprises a bag type structure. The end part of the bag type structure on one side in the first direction is opened to form a bag opening, the other end part in the first direction is closed, and at least part of the battery core is embedded into the bag type structure. According to the battery monomer, the battery cell is embedded into the bag type structure, and an active substance falling from the battery cell can fall and be accommodated in the closed end of the bag type structure under the action of gravity, so that the contact probability of the active substance and the shell is reduced, the corrosion of the shell is delayed, and the service life of the battery monomer is prolonged.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells, batteries, electrical devices and energy storage devices. Background Art

[0002] New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in areas such as energy storage.

[0003] During the manufacturing process of the battery, the battery cell needs to be placed in the shell to complete the assembly. In order to prevent the battery cell from directly contacting the shell and causing corrosion to the shell, a polyester film (Mylar film) is usually placed between the shell and the battery cell, but the problem of shell corrosion still exists. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a battery cell, a battery, an electrical device and an energy storage device. The active material dropped from the battery cell in the battery cell can fall under the action of gravity and be contained in the closed end of the bag structure, thereby reducing the probability of the active material contacting the shell, delaying the corrosion of the shell, and extending the service life of the battery cell.

[0005] This application is implemented through the following technical solutions.

[0006] The first aspect of the present application provides a battery cell, which includes: a shell and an electrode assembly, the shell having an opening on one side in a first direction; the electrode assembly is accommodated in the shell; wherein the electrode assembly includes an insulating member and a battery cell, the insulating member includes a bag-type structure, the end of the bag-type structure located on one side of the first direction is open to form a bag opening, and the other end located in the first direction is closed, and at least part of the battery cell is embedded in the bag-type structure.

[0007] The battery cell in the battery cell is embedded in the bag structure, and the active material dropped from the battery cell falls under the action of gravity and is contained in the closed end of the bag structure, thereby reducing the probability of the active material contacting the shell, delaying the corrosion of the shell, and extending the service life of the battery cell.

[0008] In some embodiments, the bag-like structure includes an annular side wall and a bottom surface, the bottom surface is closed at one end of the side wall, and the side wall protrudes from the bottom surface in the first direction.

[0009] With such a design, the side wall protrudes from the bottom surface in the first direction, and the side wall can prevent the active material deposited on the bottom surface from moving toward the shell, thereby delaying the corrosion of the shell and extending the service life of the battery cell.

[0010] In some embodiments, the insulating member further includes: at least one folding structure, the folding structure being connected to one side of the bag opening of the bag-type structure; the folding structure surrounding the battery cell along the circumference of the battery cell, and the circumference of the battery cell is perpendicular to the first direction.

[0011] With such a design, the folding structure can surround the portion of the battery cell that is not covered by the bag structure, reducing the risk of scratching the battery cell during assembly. In addition, the folding structure is folded around the circumference of the battery cell, and the folding method of the folding structure can be adjusted according to the shape of the battery cell, and the insulating member has good universality.

[0012] In some embodiments, the insulating member includes two folded structures, and the two folded structures are arranged opposite to each other along a second direction, and the second direction is perpendicular to the first direction.

[0013] Such a design makes it convenient for the foldable structure to be arranged around the circumference of the battery cell.

[0014] In some embodiments, each of the folding structures includes a first flap and a second flap, and a portion of the first flap is connected to the bag-like structure through the second flap.

[0015] With such a design, at least part of the space between the second folded sheet and the bag-type structure can be hollowed out, and the hollowed-out position can be used as a flow channel for the electrolyte, which is beneficial for the electrolyte to infiltrate the battery cell.

[0016] In some embodiments, the battery cell includes a winding structure, the winding structure includes a straight portion and a bent portion connected to the straight portion, and the winding axis direction of the winding structure is consistent with the first direction; the portion of the first folding piece corresponding to the straight portion is connected to the bag-type structure through the second folding piece, and a hollow portion is provided between the portion of the first folding piece corresponding to the bent portion and the bag-type structure.

[0017] With such a design, the hollow portion is arranged at the portion corresponding to the bent portion, and the hollow portion can be used as a flow guide channel for the electrolyte, which is beneficial for the electrolyte to infiltrate the battery cell.

[0018] In some embodiments, the bag-like structure includes two first sub-side surfaces arranged opposite to each other in a second direction and two second sub-side surfaces arranged opposite to each other in a third direction, the size of the first sub-side surface in the second direction being larger than the size of the second sub-side surface in the third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other; the portion of the first fold piece corresponding to the first sub-side surface is connected to the bag-like structure through the second fold piece, and a hollow portion is provided between the portion of the first fold piece corresponding to the second sub-side surface and the bag-like structure.

[0019] With such a design, the second folded piece as a connecting member has a large size, thereby ensuring the structural stability of the insulating member.

[0020] In some embodiments, at least one through hole penetrating the side wall is provided in the side wall.

[0021] With such a design, the through hole can be used as a flow channel for the electrolyte, which is beneficial for the electrolyte to infiltrate the battery cell.

[0022] In some embodiments, the shortest distance from the outer periphery of the through hole to the bottom surface is greater than or equal to 0.05 mm.

[0023] Such a design is beneficial to the circulation of the electrolyte and prolongs the service life of the battery cell to a certain extent.

[0024] In some embodiments, the maximum distance from the outer periphery of the through hole to the bottom surface is less than or equal to 50 mm; and / or the aperture of the through hole is less than or equal to 10 mm and greater than or equal to 0.1 mm; and / or the total area of ​​the through hole is greater than or equal to 0.1 mm. 2 .

[0025] By controlling the maximum distance from the outer periphery of the through hole to the bottom surface within the above range, the probability of active materials deposited on the bottom surface flowing to the shell can be reduced, the corrosion of the shell can be delayed, and the service life of the battery cell can be extended.

[0026] By setting the aperture of the through hole within the above range, the probability of the active material contacting the shell is reduced, and it is also beneficial for the electrolyte to infiltrate the battery cell.

[0027] By setting the total area of ​​the through holes within the above range, the probability of the active material contacting the shell is reduced, and it is also beneficial for the electrolyte to infiltrate the battery cell.

[0028] In some embodiments, the battery core includes a winding structure, the winding structure includes a straight portion and a bent portion connecting the straight portion, the winding axis direction of the winding structure is consistent with the first direction; the through hole passes through the part of the side wall corresponding to the straight portion.

[0029] With such a design, the through hole passes through the portion of the side wall corresponding to the straight portion, and the through hole avoids the position where the active material is easily deposited, which can reduce the probability of the active material deposited on the bottom surface flowing to the shell, and further extend the service life of the battery cell.

[0030] In some embodiments, when the bottom surface is observed along the first direction, the shape of the bottom surface is a rectangle.

[0031] With such a design, the shapes of the bag-type structure, the shell and the battery cell are highly adaptable, which is conducive to realizing a small-volume battery cell.

[0032] In some embodiments, the size of the bag structure in the second direction is X1, and the size of the bag structure in the third direction is Y1. The third direction is perpendicular to the first direction and the second direction respectively. X1 and Y1 satisfy the following relationship: the size of the battery cell in the second direction < X1 < the size of the housing in the second direction; the size of the battery cell in the third direction < Y1 < the size of the housing in the third direction.

[0033] With such a design, it is ensured that the battery cell can be embedded in the bag structure, and the bag structure can be accommodated in the housing.

[0034] In some embodiments, the bag structure includes a plurality of first sides, and adjacent first sides are connected by a first arc with a radius of R1. The housing includes a plurality of second sides, and adjacent second sides are connected by a second arc with a radius of R2. The radius of the bending portion of the battery cell is R3. Among them, R1, R2, and R3 satisfy the following relationship: R3 ≤ R1 ≤ R2.

[0035] With such a design, it is ensured that the battery cell can be embedded in the bag structure, and the bag structure can be accommodated in the housing.

[0036] In some embodiments, the height of the bag structure is H11, and the height of the housing is H2. H11 and H2 satisfy the following relationship: 0.3H2 ≤ H11 ≤ H2.

[0037] With such a design, it is ensured that the bag structure has a certain size in the first direction, which is beneficial to preventing the active material deposited on the bottom surface of the bag structure from moving towards the housing, thereby delaying the corrosion of the housing and prolonging the service life of the battery cell.

[0038] In some embodiments, the battery cell further includes: an end cap that closes the opening of the housing, and an insulating member is fixed to the end cap.

[0039] Compared with the embodiment in which the insulating member is fixed to the battery cell, in this embodiment, the insulating member is fixed to the end cap, which can reduce the interference of the insulating member on the battery cell to a certain extent.

[0040] In some embodiments, the distance from the end of the insulating member adjacent to the end cap to the end of the end cap adjacent to the insulating member is greater than 0 mm and does not exceed 2 mm.

[0041] With such a design, it is convenient to thermally fuse and fix the insulating member to the end cap, simplifies the manufacturing process of the battery cell, and is beneficial to the mass production of the battery cell.

[0042] A second aspect of the present application provides a battery, comprising: a box body; and at least one of the above-mentioned battery cells, wherein the battery cell is accommodated in the box body.

[0043] A third aspect of the present application provides an electrical device, which includes the above-mentioned battery cell or the above-mentioned battery for providing electrical energy.

[0044] A fourth aspect of the present application provides an energy storage device, which includes the above-mentioned battery cell or the above-mentioned battery for providing electrical energy.

[0045] Utility Model Effect

[0046] The present application provides a battery cell, a battery, an electrical device and an energy storage device comprising the battery cell. The active material dropped from the battery cell in the battery cell can fall under the action of gravity and be contained in the closed end of the bag structure, thereby reducing the probability of the active material contacting the shell, delaying the corrosion of the shell, and extending the service life of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference numerals are used to represent the same components throughout the drawings.

[0048] In the attached picture:

[0049] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application;

[0050] Figure 2 A three-dimensional exploded schematic diagram of a battery provided in some embodiments of the present application;

[0051] Figure 3 A three-dimensional exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0052] Figure 4 A top view of a battery cell provided for some embodiments of the present application;

[0053] Figure 5 for Figure 4 Section view on plane AA;

[0054] Figure 6 A top view of a battery cell with an end cover removed provided for some embodiments of the present application;

[0055] Figure 7 A schematic diagram of an electrode assembly provided for some embodiments of the present application;

[0056] Figure 8 A schematic diagram of an insulating member in a folded state provided for some embodiments of the present application;

[0057] Fig. 9 A schematic diagram of an insulating member in an unfolded state provided for some embodiments of the present application;

[0058] Fig.10 A schematic diagram of an insulating member in a folded state provided for other embodiments of the present application;

[0059] Description of Reference Numerals

[0060] 1000 vehicle; 100 battery; 200 controller; 300 motor; 10 battery box; 20 battery cell; 101 box cover; 102 box body; 1 shell; 2 electrode assembly; 3 positive electrode terminal, 4 negative electrode terminal; 5 pressure relief structure; 11 shell, 12 end cover; 21 battery cell; 22 insulating member; 23 hollow portion; 24 through hole; 221 bag-type structure; 222 folding structure; 2211 first sub-side surface; 2212 second sub-side surface; 2221 first folding piece; 2222 second folding piece. DETAILED DESCRIPTION

[0061] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0063] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0064] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0065] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0066] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0067] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0068] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0069] Below, this application is described in detail.

[0070] At present, new energy batteries are increasingly used in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0071] The battery mentioned in the embodiments of the present application may include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in mixed connection through a busbar. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. The battery generally includes a battery box for encapsulating one or more battery cells. The battery box can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells. The battery can also be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0072] In the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0073] A battery cell may include: a shell and a battery cell and an electrolyte contained inside the shell. Among them, the battery cell may include a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions in the electrolyte between the positive electrode sheet and the negative electrode sheet to achieve charge and discharge cycles. In the present application, both the positive electrode sheet and the negative electrode sheet include a current collector and an active material layer arranged on the surface of the current collector. Among them, the active material layer is a film layer formed by coating the active material on the surface of the current collector. For example, the positive active material is coated on the current collector surface of the positive electrode sheet to form a positive active material layer. The negative active material is coated on the current collector surface of the negative electrode sheet to form a negative active material layer. The separator is an insulator, which is arranged between the positive electrode sheet and the negative electrode sheet to separate the positive active material layer from the negative active material layer.

[0074] In the manufacturing process of battery cells, the battery cells need to be placed in a hard shell (for example, an aluminum shell) to complete the assembly after manufacturing. In the process of placing the battery cells into the shell, the aluminum shell has the risk of scratching the battery cells due to its hard texture; in addition, insulation protection needs to be done between the battery cells and the aluminum shell to prevent short circuits between the shell and the battery cells. Therefore, before placing the battery cells into the shell, the battery cells need to be covered with an insulating, soft and flexible polyester film to prevent the shell from damaging the battery cells and to prevent short circuits between the battery cells and the shell.

[0075] Research has found that after multiple charge and discharge cycles, battery cells will generate gas, which causes the cell to deform and causes the active material (e.g., carbon powder) in the cell to fall off. In addition, the battery cells may be in a vibrating condition, which will aggravate the shedding of active materials.

[0076] Most Mylar films currently have a single-piece structure. The single-piece Mylar film is folded and spliced, wrapped around the surface of the battery cell, and arranged between the battery cell and the shell. There is a certain gap at the splicing of the spliced ​​Mylar film. The active material dropped from the battery cell will pass through the gap and contact the body shell, causing corrosion of the body shell. In severe cases, the battery cell will have problems such as leakage and short circuit, which seriously affects the service life of the battery cell.

[0077] Based on this, the present application provides a battery cell including a shell and an electrode assembly contained in the shell, wherein the shell has an opening on one side in a first direction. The electrode assembly includes an insulating member and a battery cell. The insulating member includes a bag-type structure, wherein the end of the bag-type structure located on one side in the first direction is open to form a bag opening, and the other end located in the first direction is closed. At least part of the battery cell is embedded in the bag-type structure. The battery cell in the battery cell is embedded in the bag-type structure. The active material dropped from the battery cell can fall and be contained in the closed end of the bag-type structure under the action of gravity, thereby reducing the probability of the active material contacting the shell, delaying the corrosion of the shell, and extending the service life of the battery cell.

[0078] The battery cells provided in the embodiments of the present application can be used in, but are not limited to, electrical devices such as vehicles, ships, or aircraft, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships, and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0079] The present application also provides a battery, which may include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid connection through a busbar component.

[0080] In some embodiments of the present application, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0081] In some embodiments of the present application, the battery may be a battery pack, which includes a battery box and battery cells, wherein the battery cells or battery modules are accommodated in the battery box.

[0082] In some embodiments of the present application, the battery box can be used as part of the chassis structure of the vehicle. For example, part of the battery box can become at least a part of the floor of the vehicle, or part of the battery box can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0083] The battery provided in the embodiments of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships or aircraft, such as mobile phones, portable devices, laptop computers, battery cars, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0084] An embodiment of the present application provides an energy storage device, which includes a battery cell or a battery for providing electrical energy.

[0085] The energy storage device provided in the embodiment of the present application may be, but is not limited to, an energy storage container, an energy storage cabinet, etc.

[0086] An embodiment of the present application provides an electrical device, which includes a battery cell or a battery for providing electrical energy.

[0087] The electric device provided in the embodiment of the present application may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0088] In the following embodiments, for the convenience of description, the electric device of one embodiment of the present application is taken as a vehicle 1000 as an example for description. The following is a description with reference to the accompanying drawings.

[0089] Figure 1 A schematic diagram of the structure of a vehicle 1000 is provided for some embodiments of the present application.

[0090] The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. Figure 1As shown, a battery 100 is disposed inside the vehicle 1000, and the battery 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, the battery 100 can be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating, and operating power requirements of the vehicle 1000 during driving.

[0091] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0092] Figure 2 This is a schematic three-dimensional exploded view of a battery 100 provided in an embodiment of the present application.

[0093] like Figure 2 As shown, the battery 100 includes a battery box 10 and at least one battery cell 20. The battery box 10 is provided with a receiving space, and the at least one battery cell 20 is received in the receiving space.

[0094] In some embodiments of the present application, the battery box 10 includes a box body 102 and a box cover 101 , and the box cover 101 covers the box body 102 , thereby forming a receiving space between the box body 102 and the box cover 101 .

[0095] The box body 102 may be a hollow structure with one end open, and the box cover 101 may be a plate-like structure, and the box cover 101 covers the open side of the box body 102, so that the box cover 101 and the box body 102 jointly define a storage space; the box cover 101 and the box body 102 may also be hollow structures with one side open, and the open side of the box cover 101 covers the open side of the box body 102. Of course, the battery box 10 formed by the box cover 101 and the box body 102 may be in various shapes, such as cylindrical, square, etc.

[0096] A battery cell 20 refers to the smallest unit that makes up a battery. In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. Multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is placed in the accommodation space formed by the box body 102 and the box cover 101; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are accommodated in the accommodation space formed by the box body 102 and the box cover 101. The battery 100 may also include other structures. For example, the battery 100 may also include a converging component for realizing electrical connection between multiple battery cells 20.

[0097] In the embodiment of the present application, the battery cell 20 may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0098] The battery cell 20 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0099] Below, refer to Figures 3 to 10 Some embodiments of the present application are described in detail.

[0100] Figure 3 A three-dimensional exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 4 A top view of a battery cell provided for some embodiments of the present application; Figure 5 for Figure 4 Section view on plane AA; Figure 6 A top view of a battery cell with an end cover removed provided for some embodiments of the present application; Figure 7 A schematic diagram of an electrode assembly provided for some embodiments of the present application; Figure 8 A schematic diagram of an insulating member in a folded state provided for some embodiments of the present application; Fig. 9 A schematic diagram of an insulating member in an unfolded state provided for some embodiments of the present application. Fig.10 Schematic diagrams of an insulating member in a folded state provided for other embodiments of the present application.

[0101] like Figure 3 As shown, the battery cell 20 includes a housing 1 and at least one electrode assembly 2. The housing 1 is used to encapsulate the electrode assembly 2 and components such as electrolyte. The housing 1 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film.

[0102] like Figure 3 As shown, in some embodiments, the housing 1 includes a body shell 11. The shell 11 has a receiving cavity and an opening in a first direction A, and the electrode assembly 2 and components such as electrolyte are received in the receiving cavity of the shell.

[0103] like Figure 3 As shown, the housing 1 further includes an end cover 12 which seals the opening of the shell 11 and forms a closed space together with the shell 11 for accommodating components such as the electrode assembly 2 and the electrolyte.

[0104] like Figure 3 As shown, in some embodiments, the battery cell 20 further includes a positive electrode terminal 3, a negative electrode terminal 4 and a pressure relief structure 5. Among them, the positive electrode terminal 3, the negative electrode terminal 4 and the pressure relief structure 5 are all installed on the end cover 12. The positive electrode terminal 3 and the negative electrode terminal 4 are both used to be electrically connected to the electrode assembly 2 to output the electrical energy generated by the electrode assembly 2. The pressure relief structure 5 is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value. The pressure relief structure 5 can be a component such as an explosion-proof valve, an explosion-proof disk, a gas valve, a pressure relief valve or a safety valve, but is not limited thereto.

[0105] The embodiment of the present application does not specifically limit the position between the positive electrode terminal 3, the negative electrode terminal 4 and the pressure relief structure 5. For example, Figure 3 As shown, in some embodiments, the pressure relief structure 5 is located between the positive electrode terminal 3 and the negative electrode terminal 4. Of course, in other embodiments, the positive electrode terminal 3 is located between the pressure relief structure 5 and the negative electrode terminal 4, or the negative electrode terminal 4 is located between the pressure relief structure 5 and the positive electrode terminal 3.

[0106] In other embodiments, the housing 1 may also be other structures, for example, the housing 1 includes a body shell 11 and two end caps 12, the body shell 11 is a hollow structure with two opposite openings, and one end cap 12 is correspondingly covered at one opening of the body shell 11 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 2 and the electrolyte. In this structure, the positive electrode terminal 3 and the negative electrode terminal 4 may be installed on the same end cap 12 or on different end caps 12; the pressure relief structure 5 may be installed on one end cap 12 or on both end caps 12.

[0107] like Figure 4-Figure 6 As shown, the battery cell 20 further includes an electrode assembly 2 and an electrolyte (not shown in the figure). The electrode assembly 2 and the electrolyte are both contained in a closed space formed by the end cap 12 closing the opening of the housing 11 .

[0108] In the present application, the electrolyte plays the role of conducting ions, and the electrolyte may include an electrolyte salt and a solvent, wherein the electrolyte salt is used to provide ions. The embodiment of the present application has no specific restrictions on the type of electrolyte, and a suitable electrolyte salt and solvent can be selected according to the type of battery cell 20. Exemplarily, in an embodiment where the battery cell 20 is a lithium-ion battery cell, the electrolyte salt can be selected from lithium hexafluorophosphate, lithium tetrafluoroborate, etc., and the solvent can be selected from ethylene carbonate, propylene carbonate, etc.

[0109] The electrode assembly 2 is used as a core component of the battery cell 20 to generate electric energy. The electrode assembly 2 includes a battery cell 21, wherein the battery cell 21 includes a positive electrode sheet, a negative electrode sheet and a separator.

[0110] In the present application, the positive electrode sheet includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector. Taking a lithium-ion battery cell as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc.

[0111] In the present application, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material can be carbon or silicon.

[0112] In the present application, any known porous structure isolation membrane with good chemical stability and mechanical stability can be selected. As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0113] The embodiment of the present application does not specifically limit the number of battery cells 21 included in the electrode assembly 2. In some embodiments, the electrode assembly 2 may include one battery cell 21. Of course, in other embodiments, the electrode assembly 2 may also include multiple battery cells 21.

[0114] In the embodiment where the electrode assembly 2 includes a plurality of battery cells 21, the plurality of battery cells 21 may be electrically connected to each other in series, in parallel, or in a mixed manner. The embodiment of the present application does not specifically limit the arrangement of the plurality of battery cells. For example, Figure 3 As shown, a plurality of battery cells 21 may be arranged side by side in the third direction C.

[0115] The embodiment of the present application does not specifically limit the structure of the battery cell 21, and any battery cell with a known structure can be selected. As an example, in some embodiments, the battery cell 21 includes a winding structure. Of course, in other embodiments, the battery cell 21 may also include other structures, such as a stacked structure.

[0116] In the present application, the stacked structure includes a negative electrode sheet, a separator, and a positive electrode sheet stacked in sequence to form a stacked body. The wound structure includes a structure formed by winding the stacked body more than two times.

[0117] In the present application, the winding structure may include a straight portion and a bent portion connecting the straight portion. The bent portion is the bent portion of the battery cell 21, and the straight portion is the straight portion of the battery cell 21. In some embodiments, the battery cell 21 is a prism, and the bent portion is the angular portion of the battery cell. Figure 3 As shown, in some embodiments, the battery cell 21 is flat, and the bent portion is an arc-shaped portion of the battery cell 21 . Figure 3 The left side portion of the left dotted line and the right side portion of the right dotted line of the middle battery cell 21 are bent portions, and the portion between the two dotted lines is a straight portion of the battery cell 21 .

[0118] Generally, compared with the straight part, the bent part is more prone to indentation or cracking and dropping of active material. In some embodiments, a protective layer can be provided on the surface of the bent part, which can reduce the risk of indentation, cracking and dropping of active material on the bent part.

[0119] In the present application, any known protective layer with good toughness and strength can be selected. In some embodiments, the material used for the protective layer may include any one or more combinations of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoropropylene-vinylidene fluoride copolymer, trifluorochloropropylene-vinylidene fluoride copolymer, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polyarylate, fiber, nylon, and non-woven fabric. The protective layer comprising the above materials has good toughness and strength, and can better reduce the risk of indentation, cracking, and falling active substances in the bending portion.

[0120] The embodiment of the present application does not specifically limit the installation direction of the battery cell in the housing 11. For example, in an embodiment where the battery cell 21 includes a winding structure, the winding axis direction of the battery cell 21 is consistent with the first direction A.

[0121] like Figure 7 As shown, the electrode assembly 2 further includes an insulating member 22. The insulating member 22 is disposed between the battery cell 21 and the housing 11 to prevent the battery cell 21 from short-circuiting with the housing 11. In addition, during the manufacturing process of the battery cell 20, the insulating member 22 is preliminarily covered on the surface of the battery cell 21, and the insulating member 22 is assembled with the battery cell 21 to form a Figure 7The electrode assembly 2 shown. After that, the electrode assembly 2 is installed in the shell 11. Since the insulating member 22 covers the surface of the battery cell 21, the insulating member 22 can protect the battery cell 21 during the process of the electrode assembly 2 being installed in the shell 11, reducing the risk of scratching the battery cell 21. Furthermore, the insulating member 22 is arranged between the battery cell 21 and the shell 11, and the insulating member 22 can prevent the active material dropped from the battery cell 21 from contacting the shell 11, delaying the corrosion of the shell 11, and extending the service life of the battery cell 20.

[0122] like Figure 7 As shown, the insulating member 22 includes a bag structure 221. The end of the bag structure 221 located on one side of the first direction A is open to form a bag mouth, and the other end located in the first direction A is closed, and at least part of the battery cell 21 is embedded in the bag structure 221. Since the end of the bag structure 221 in the first direction A is closed, the active material dropped from the battery cell 21 can fall and be accommodated in the closed end of the bag structure 221 under the action of gravity, thereby reducing the contact between the active material and the shell 11, delaying the corrosion of the shell 11, and extending the service life of the battery cell 20.

[0123] In some embodiments, the battery cell 21 is partially embedded in the pouch structure 221 . In this embodiment, the bottom and part of the side wall of the battery cell 21 are covered by the pouch structure 221 , while the top and part of the side wall of the battery cell 21 are not covered by the pouch structure 221 .

[0124] In some embodiments, the battery cell 21 is completely embedded in the bag structure 221. In this embodiment, the bottom and side walls of the battery cell 21 are completely covered by the bag structure 221. The battery cell 21 is completely embedded in the bag structure 221, which can also be understood as the battery cell 21 is contained in the bag structure 221.

[0125] In some embodiments, the projection of the battery cell 21 in the first direction A falls within the projection of the bag opening in the first direction A, ensuring that the battery cell 21 can pass through the bag opening and be embedded in the bag structure 221 .

[0126] Usually, the active material dropped from the battery cell 21 falls on the bottom surface of the bag structure 221 under the action of gravity and gathers on the bottom surface. The electrolyte inside the shell 11 is flowing, and the flow of electrolyte will drive the active material to move toward the shell, corrode the shell 11, and affect the service life of the battery cell 20.

[0127] To prevent the active material accumulated on the bottom surface from moving towards the housing. In some embodiments, the bag - like structure 221 includes an annular side wall and a bottom surface. The bottom surface is closed at one end of the side wall, and the side wall protrudes from the bottom surface in the first direction A. A bag mouth is formed on the side of the side wall away from the bottom surface. In this embodiment, since the side wall protrudes from the bottom surface in the first direction A, the side wall can prevent the active material accumulated on the bottom surface from moving towards the housing 11, delay the corrosion of the housing 11, and extend the service life of the battery cell 20.

[0128] In some embodiments, the bottom surface and the side wall are connected into an integral structure. By designing the bottom surface and the side wall into an integral structure, it is beneficial for the bag - like structure 221 to further exert its own advantages and extend the service life of the battery cell 20. The own advantages of the bag - like structure 22 include but are not limited to reducing the risk of scratching the battery core 21, preventing the active material from contacting the housing 11, and preventing the battery core 21 from being electrically connected to the housing 11 to cause a short - circuit, etc.

[0129] The embodiment of the present application does not specifically limit the shape of the bottom surface of the bag - like structure, and the shape of the bottom surface can be designed according to requirements. Exemplarily, in some embodiments, when observing the bottom surface along the first direction A, the shape of the bottom surface is rectangular. When the shape of the bottom surface is rectangular, the shape of the bag - like structure 221 formed by enclosing the bottom surface and the side wall, the shape of the housing 11, and the shape of the battery core 21 have high adaptability, which is beneficial to realizing a battery cell 20 with a small volume. In the present application, the rectangle includes but is not limited to a right - angled rectangle, a rounded - corner rectangle, etc.

[0130] Of course, in other embodiments, when observing the bottom surface along the first direction A, the shape of the bottom surface can also be other shapes. For example, an ellipse, an N - sided polygon (N>4), etc.

[0131] In the present application, the dimension of the bag - like structure 221 in the second direction B is X1, and the dimension of the bag - like structure 221 in the third direction C is Y1. The dimension of the battery core 21 in the second direction B is X2, and the dimension of the battery core 21 in the third direction C is Y2. Among them, the first direction A is perpendicular to the second direction B and the third direction C respectively.

[0132] In some embodiments, X1, Y1, X2, Y2 satisfy the following relationship: X2 < X1, Y2 < Y1. With such a design, it is ensured that the battery core 21 can be embedded into the bag - like structure 221.

[0133] In the present application, the dimension of the housing 11 in the second direction is X3, and the dimension of the housing 11 in the third direction is Y3.

[0134] In some embodiments, X1, Y1, X3, Y3 satisfy the following relationship: X1 < X3, Y1 < Y3. With such a design, it is ensured that the bag - like structure 221 can be accommodated in the housing 11.

[0135] In some embodiments, X1, Y1, X2, Y2, X3, and Y3 satisfy the following relationships: X2 < X1 < X3, Y2 < Y1 < Y3. With such a design, it is ensured that the battery cell 21 can be embedded in the bag structure 221, and the bag structure 221 can be accommodated in the housing 11.

[0136] In some embodiments, the bag structure 221 includes a plurality of first side surfaces, and the plurality of first side surfaces are sequentially connected to form an annular side wall. Adjacent first side surfaces are connected by a first arc, and the radius of the first arc is R1; the radius of the bent portion of the battery cell is R2. R1 and R2 satisfy the following relationship: R2 ≤ R1. With such a design, it is ensured that the battery cell 21 can be embedded in the bag structure 221.

[0137] In some embodiments, the housing 11 includes a plurality of second side surfaces, and adjacent second side surfaces are connected by a second arc, and the radius of the second arc is R3. R1 and R3 satisfy the following relationship: R1 ≤ R3. With such a design, it is ensured that the bag structure 221 can be accommodated in the housing 11.

[0138] In some embodiments, R1, R2, and R3 satisfy the following relationship: R2 ≤ R1 ≤ R3. With such a design, it is ensured that the battery cell 21 can be embedded in the bag structure 221, and the bag structure 221 can be accommodated in the housing 11.

[0139] In this application, the dimension of the bag structure 221 in the first direction A is H11. There is no specific limitation on H11 in the embodiments of this application, and it only needs to satisfy 0 < H11 ≤ H2, where H2 is the dimension of the housing 11 in the first direction. With such a design, it is ensured that the bag structure 221 can be accommodated in the housing 11.

[0140] In some embodiments, H11 and H2 satisfy the following relationship: 0.3H2 ≤ H11 ≤ H2. With such a design, it is ensured that the bag structure 221 has a certain dimension in the first direction A, which is beneficial for it to block the movement of the active material deposited on the bottom surface towards the housing 11, thereby delaying the corrosion of the housing 11.

[0141] There is no specific limitation on the formation method of the above-mentioned bag structure 221 in the embodiments of this application. Exemplarily, in some embodiments, the above-mentioned bag structure 221 can be formed by blow molding. Of course, in other embodiments, the above-mentioned bag structure 221 can be formed by other methods, such as hot melting.

[0142] In the embodiments of the present application, there is no specific limitation on the material used for the above-mentioned bag structure 221, and any well-known insulating material can be selected. In some embodiments, the material used for the bag structure 221 may include any one or a combination of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoropropylene-vinylidene fluoride copolymer, trifluorochloropropylene-vinylidene fluoride copolymer, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polyarylate, fiber, nylon, non-woven fabric. The bag structure 221 made of the above-mentioned insulating material has good toughness and strength, which is beneficial to the bag structure 221 to exert its own advantages.

[0143] As Figure 7 shown, in the embodiments where H11 < H2, part of the battery cell 21 is embedded in the bag structure 221. In these embodiments, the insulating member 22 may further include: at least one folding structure 222. Among them, the folding structure 222 is connected to the bag mouth of the bag structure 221; the folding structure 222 surrounds the battery cell 21 along the circumferential direction of the battery cell 21, and the circumferential direction of the battery cell 21 is perpendicular to the first direction A.

[0144] Designed in this way, the folding structure 222 can surround the part of the battery cell 21 not covered by the bag structure 221, further reducing the risk of scratching the battery cell 21. In addition, the folding structure 222 surrounds the circumferential direction of the battery cell 21 by folding, and the folding method of the folding structure 222 can be adjusted according to the shape of the battery cell 21, and the insulating member 22 has good universality.

[0145] In the embodiments of the present application, there is no specific limitation on the number of folding structures 222 included in the insulating member 22. In some embodiments, the insulating member 22 may include one folding structure 222. Of course, in other embodiments, the insulating member 22 may also include a plurality of folding structures 222. For example, the number of folding structures 222 included in the insulating member 22 is 2, 3, 4, etc. Exemplarily, as Fig. 9 shown, the insulating member 22 may include two folding structures 222.

[0146] In the embodiments where the insulating member 22 includes one folding structure 222, the folding structure 222 can be connected to any position of the bag mouth.

[0147] In the embodiments where the insulating member 22 includes a plurality of folding structures 222, there is no specific limitation on the positions where the plurality of folding structures 222 are distributed. Exemplarily, refer to Fig. 9In the embodiment where the insulating member 22 includes two folding structures 222, the two folding structures 222 may be arranged relatively to each other along the second direction B. Of course, in other embodiments, the two folding structures may be arranged relatively to each other along the third direction C, or one of the folding structures may be arranged in the second direction B and the other folding structure may be arranged in the third direction C.

[0148] See also Figure 7-10 In some embodiments, each folding structure 222 includes a first folding piece 2221 and a second folding piece 2222. Part of the first folding piece 2221 is connected to the bag structure 221 through the second folding piece 2222. With such a design, at least part of the space between the second folding piece 2222 and the bag structure 221 can be hollowed out, and the hollowed-out position can be used as a flow channel for the electrolyte, which is conducive to the infiltration of the electrolyte into the battery cell.

[0149] The hollowed-out portion between the second folding piece 2222 and the bag-like structure 221 may be referred to as a hollowed-out portion. The embodiment of the present application does not specifically limit the shape of the hollowed-out portion. For example, Figure 7 As shown, when the hollow portion 23 is observed along the second direction B, the shape of the hollow portion 23 may be a trapezoid. Of course, in other embodiments, when the hollow portion 23 is observed along the second direction B, the shape of the hollow portion 23 may be other shapes, such as a rectangle, a circle, etc.

[0150] The embodiment of the present application does not specifically limit the position of the hollow portion 23 , and the hollow portion 23 can be disposed at any position between the second folding piece 2222 and the bag-like structure 221 .

[0151] See also Figure 7 In the embodiment where the battery cell 21 includes a winding structure, the portion of the first folded piece 2221 corresponding to the straight portion is connected to the bag structure 221 through the second folded piece 2222, and a hollow portion 23 is provided between the portion of the first folded piece 2221 corresponding to the bent portion and the bag structure 221. In this embodiment, the hollow portion 23 is provided at the portion corresponding to the bent portion, and the hollow portion 23 can serve as a flow channel for the electrolyte, which is conducive to the electrolyte infiltration into the battery cell 21.

[0152] In some embodiments, a protective layer is disposed on the portion of the bent portion corresponding to the hollow portion. In addition, since the protective layer is disposed on the portion of the bent portion corresponding to the hollow portion, the protective layer can prevent the active material from falling from the bent portion and passing through the hollow portion 23.

[0153] like Figure 8-Figure 10As shown, if the bag-like structure 221 includes two first sub-side surfaces 2211 arranged opposite to each other in the second direction B and two second sub-side surfaces 2212 arranged opposite to each other in the third direction C, wherein the size of the first sub-side surface 2211 in the second direction is greater than the size of the second sub-side surface 2212 in the third direction, wherein the first direction A, the second direction B and the third direction C are perpendicular to each other. In some embodiments, the portion of the first folded piece 2221 corresponding to the first sub-side surface 2211 is connected to the bag-like structure 221 through the second folded piece 2222, and a hollow portion 23 is provided between the portion of the first folded piece 2221 corresponding to the second sub-side surface 2212 and the bag-like structure 221. With such a design, the second folded piece 2222 as a connecting member has a large size to ensure the structural stability of the insulating member 22.

[0154] Of course, in other embodiments, the portion of the first folded sheet corresponding to the second sub-side surface is connected to the bag-type structure through the second folded sheet, and a hollow portion is provided between the portion of the first folded sheet corresponding to the first sub-side surface and the bag-type structure. With such a design, there is a large-sized hollow portion between the first folded sheet and the bag-type structure, which is conducive to the infiltration of the electrolyte into the battery cell.

[0155] The embodiment of the present application does not specifically limit the position of the second folding piece 2222. The second folding piece 2222 can be arranged at any position of the first folding piece 2221 adjacent to one end of the bag-like structure 221. For example, Fig. 9 As shown, in some embodiments, the second folded piece 2222 can be disposed at a position where the first folded piece 2221 is adjacent to the central axis of one end of the bag-like structure 221, that is, the central axis of the first folded piece 2221 in the first direction A coincides with the central axis of the second folded piece 2222 in the first direction A. Of course, in other embodiments, the second folded piece 2222 can also be disposed at other positions where the first folded piece 2221 is adjacent to one end of the bag-like structure 221.

[0156] The present embodiment of the application has no specific limitation on the material used for the folding structure 222, and any known insulating material with good chemical stability and mechanical stability can be selected. In some embodiments, the folding structure 222 can be any one or more combinations of the insulating materials listed above.

[0157] In some embodiments, the folding structure 222 and the bag-type structure 221 may use the same insulating material. In some embodiments, the folding structure 222 and the bag-type structure 221 may use different insulating materials. In the embodiment where the folding structure 222 and the bag-type structure 221 use the same insulating material, the folding structure 222 and the bag-type structure 221 may be an integrated structure to ensure the structural stability of the insulating member 22.

[0158] In the present application, the size of the folding structure 222 in the first direction A is H12. The present application embodiment has no specific limitation on H12, and H11 and H12 can be designed as needed, as long as the sum of H11 and H12 is less than or equal to the size of the shell in the first direction A. For example, in some embodiments, H11 = H12. In some embodiments, H11> H12. In some embodiments, H11 <H12。

[0159] See also Figure 8-Figure 10 In some embodiments, at least one through hole 24 is provided on the side wall. With such a design, the through hole 24 can be used as a flow channel for the electrolyte, which is conducive to the electrolyte infiltration into the battery cell 21.

[0160] The embodiment of the present application has no particular limitation on the location of the through hole, and the through hole 24 can be disposed at any location on the side wall.

[0161] If the battery cell 21 includes a winding structure, as mentioned above, the bent portion of the battery cell 21 is more prone to the problem of active material falling than the straight portion of the battery cell 21. Accordingly, the active material tends to be deposited on the bottom surface corresponding to the bent portion.

[0162] like Figure 7 As shown, in some embodiments, the through hole 24 passes through the portion of the side wall corresponding to the straight portion. In this design, the through hole 24 passes through the portion of the side wall corresponding to the straight portion, and the position of the through hole 24 avoids the position where the active material is easily deposited, which can reduce the probability of the active material deposited on the bottom surface flowing to the housing 11, and further extend the service life of the battery cell 20.

[0163] Of course, in some embodiments, through holes can be provided on the side walls corresponding to the bent portion. In some embodiments, through holes can be provided on both the side walls corresponding to the straight portion and the side walls corresponding to the bent portion to provide more flow channels for the electrolyte, which is beneficial for the electrolyte to infiltrate the battery cell.

[0164] If the side wall of the bag-like structure includes two first sub-side surfaces 2211 arranged opposite to each other in the second direction B and two second sub-side surfaces 2212 arranged opposite to each other in the third direction C, wherein the size of the first sub-side surface 2211 in the second direction is greater than the size of the second sub-side surface 2212 in the third direction. Figure 8 and Fig. 9 As shown, in some embodiments, the through hole 24 may penetrate the second sub-side surface 2212. Fig.10 As shown, in some embodiments, the through hole 24 may penetrate the first sub-side surface 2211. Of course, in other embodiments, through holes may be provided on both the first sub-side surface and the second sub-side surface to provide more flow channels for the electrolyte, which is beneficial for the electrolyte to infiltrate the battery cell.

[0165] In some embodiments, the shortest distance H3 from the outer edge of the through hole 24 to the bottom surface is greater than or equal to 0.05 mm. For example, H3 is 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, or a range between any two values, but is not limited thereto. By controlling H3 within the above range, the probability of the active material deposited on the bottom surface of the bag structure flowing to the housing can be reduced.

[0166] Fig. 9 It is exemplarily shown that any two through holes have the same H3, which is only a schematic representation. In fact, the H3 of the through holes can be set according to requirements. For example, the two through holes can have the same H3 or different H3.

[0167] The charging and discharging process of battery cells mainly relies on the electrolyte to conduct ions to embed and de-embed between the positive electrode and the negative electrode. The circulation of the electrolyte is crucial to the battery cells.

[0168] In order to extend the life of the battery cell, in some embodiments, the maximum distance H4 from the outer edge of the through hole to the bottom surface is less than or equal to 50 mm; illustratively, H4 is 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm or a value between any two values, but not limited thereto. In this embodiment, by controlling H4 within the above range, it is beneficial to the circulation of the electrolyte and to extend the life of the battery cell to a certain extent.

[0169] In some embodiments, the aperture R of the through hole is less than or equal to 10 mm and greater than or equal to 0.1 mm; illustratively, R is 0.1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm or a value between any two values, but not limited thereto. By setting R within the above range, it is helpful to reduce the probability of contact between the active material and the shell, and at the same time, it is beneficial to the infiltration of the electrolyte into the battery cell.

[0170] In the present application, the aperture R of the through hole is the diameter of the through hole in any cross section. If the cross section of the through hole is not a regular circle, the aperture R refers to the length of the longest line segment where the straight line passing through the geometric center point of the cross section intersects the edge of the cross section.

[0171] In some embodiments, the total area S of the through holes is greater than or equal to 0.1 mm 2 ; Exemplarily, S is 0.1 mm 2 , 1mm 2 , 2mm 2 , 3mm 2 , 4mm 2 , 5mm 2, 6mm 2 , 7mm 2 , 8mm 2 , 9mm 2 , 10mm 2 Or a value between any two values, but not limited thereto. By setting S within the above range, it is helpful to reduce the probability of the active material contacting the shell, and it is also beneficial to the electrolyte infiltration into the battery cell.

[0172] Figure 8-Figure 10 The through hole 24 is exemplarily shown as an example of a circular hole. In fact, the shape of the through hole can be set according to requirements. The through hole can include any one of a square hole and an oblong hole.

[0173] Figure 8-Figure 10 An example of the insulating member 22 being provided with through holes 24 of the same shape is exemplarily shown. In fact, the shape of each through hole can be independently set according to the requirements. For example, the insulating member 22 can be provided with round holes, square holes, oblong holes, etc. at the same time.

[0174] Figure 8-Figure 10 An example of equidistant arrangement of the plurality of through holes 24 is shown exemplarily. In fact, the distance between any two through holes can be independently set according to the requirements, and the plurality of through holes 24 can be arranged at equal intervals or at non-equidistant intervals.

[0175] in addition, Figure 8-Figure 10 An example is shown in which the heights of the plurality of through holes 24 from the bottom surface are the same. In fact, the distance between each through hole 24 and the bottom surface can be independently set according to the requirements, and the distances between any two through holes 24 and the bottom surface can be the same or different.

[0176] The embodiment of the present application has no specific limitation on the fixing method of the insulating member 22 , and any known fixing method may be selected. For example, the insulating member 22 may be attached to the surface of the battery cell 21 to achieve the purpose of fixing the insulating member 22 .

[0177] Of course, in other embodiments, the insulating member 22 may be fixed in other ways. For example, in some embodiments, the insulating member 22 is fixed to the end cover 12. Compared with the embodiment in which the insulating member is fixed to the battery cell 21, the insulating member 22 is fixed to the end cover 12, which can reduce the interference of the insulating member 22 on the battery cell 21 to a certain extent.

[0178] The embodiment of the present application does not specifically limit the fixing method of the insulating member 2 and the end cover 12. In some embodiments, the end of the insulating member 22 adjacent to the end cover 12 extends between the end cover 12 and the housing 11, and the fixing of the insulating member 22 and the end cover 12 is achieved by the squeezing force between the end cover 12 and the housing 11. In some embodiments, the insulating member 22 can be fixed to the end cover 12 by hot melt fixing.

[0179] In the embodiment where the insulating member 22 is fixed to the end cap 12 by hot-melt fixing, the distance h from one end of the insulating member 22 adjacent to the end cap 12 to one end of the end cap 12 adjacent to the insulating member is greater than 0 and does not exceed 2 mm. Exemplarily, h is 0, 0.5 mm, 1 mm, 1.5 mm, 2 mm, or a value between any two values, but is not limited thereto. By controlling h within the above range, it is beneficial to hot-melt fixing of the insulating member and the end cap, simplifying the preparation process of the battery cell, and facilitating mass production of the battery cell 20.

[0180] The following is an explanation of the assembly process of the insulating member 22 including the bag structure 221 and the folding structure 222 and the battery cell 21 .

[0181] Before assembly, the structure of the insulating member 22 is as follows Fig. 9 As shown. The bag-type structure 221 is a structure with one end closed and the other end open. The folding structure 222 is a monolithic structure. One end of the battery cell 21 is embedded in the bag-type structure 221. Then, the folding structure 222 is folded so that the folding structure 222 surrounds the battery cell 21 along the circumference of the battery cell to obtain the assembled electrode assembly 2. The structure of the assembled electrode assembly 2 is as shown Figure 7 shown.

[0182] Specific examples of some embodiments of the present application are described below with reference to the accompanying drawings.

[0183] The battery cell 20 includes a shell 11 and an electrode assembly 2. The shell 11 has an opening on one side in the first direction A; the electrode assembly 2 is accommodated in the shell 11; the electrode assembly 2 includes a battery cell 21 and an insulating member 22 including a bag structure 221 and two folding structures 222. Among them, the bag structure 221 includes two first sub-side surfaces 2211 arranged opposite to each other in the second direction B and two second sub-side surfaces 2212 arranged opposite to each other in the third direction C, and the size of the first sub-side surface 2211 in the second direction B is greater than the size of the second sub-side surface 2212 in the third direction C. Each folding structure 222 includes a first folding piece 2221 and a second folding piece 2222, and the portion of the first folding piece 2221 corresponding to the first sub-side surface 2211 is connected to the bag structure 221 through the second folding piece 2222, and a hollow portion 23 is provided between the portion of the first folding piece 2221 corresponding to the second sub-side surface 2212 and the bag structure 221. The battery cell reduces the probability of the active material dropped from the battery core contacting the shell by arranging the insulating member, delays the corrosion of the shell, and prolongs the service life of the battery cell.

[0184] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: A housing, wherein the housing has an opening on one side in a first direction; an electrode assembly, the electrode assembly being accommodated in the housing; Among them, the electrode assembly includes an insulating part and a battery cell, the insulating part includes a bag-type structure, the end of the bag-type structure located on one side of the first direction is open to form a bag opening, and the other end located in the first direction is closed, and at least part of the battery cell is embedded in the bag-type structure.

2. The battery cell according to claim 1, characterized in that: The bag structure comprises: Annular side walls, A bottom surface is closed at one end of the side wall, and the side wall protrudes from the bottom surface in the first direction.

3. The battery cell according to claim 1 or 2, characterized in that: The insulating member further comprises: At least one folding structure is connected to the bag opening of the bag structure; the folding structure surrounds the battery cell along the circumference of the battery cell, and the circumference of the battery cell is perpendicular to the first direction.

4. The battery cell according to claim 3, characterized in that: The insulating member includes two folding structures, and the two folding structures are arranged opposite to each other along a second direction, and the second direction is perpendicular to the first direction.

5. The battery cell according to claim 4, characterized in that: Each of the folding structures includes a first flap and a second flap, and a portion of the first flap is connected to the bag-like structure through the second flap.

6. The battery cell according to claim 5, characterized in that: The battery core comprises a winding structure, the winding structure comprises a straight portion and a bent portion connecting the straight portion, and the winding axis direction of the winding structure is consistent with the first direction; The portion of the first folding piece corresponding to the straight portion is connected to the bag-like structure through the second folding piece, and a hollow portion is provided between the portion of the first folding piece corresponding to the bent portion and the bag-like structure.

7. The battery cell according to claim 5, characterized in that: The bag-like structure comprises two first sub-side surfaces arranged opposite to each other in a second direction and two second sub-side surfaces arranged opposite to each other in a third direction, wherein the size of the first sub-side surface in the second direction is larger than the size of the second sub-side surface in the third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other; The portion of the first folding piece corresponding to the first sub-side surface is connected to the bag-like structure through the second folding piece, and a hollow portion is provided between the portion of the first folding piece corresponding to the second sub-side surface and the bag-like structure.

8. The battery cell according to claim 2, characterized in that: The side wall is provided with at least one through hole penetrating the side wall.

9. The battery cell according to claim 8, characterized in that: The battery core comprises a winding structure, the winding structure comprises a straight portion and a bent portion connecting the straight portion, and the winding axis direction of the winding structure is consistent with the first direction; The through hole passes through a portion of the side wall corresponding to the straight portion.

10. The battery cell according to claim 9, characterized in that: The shortest distance from the outer periphery of the through hole to the bottom surface is greater than or equal to 0.05 mm.

11. The battery cell according to claim 10, characterized in that: The maximum distance from the outer periphery of the through hole to the bottom surface is less than or equal to 50 mm; and / or, The diameter of the through hole is less than or equal to 10 mm and greater than or equal to 0.1 mm; and / or, The total area of ​​the through holes is greater than or equal to 0.1 mm 2 .

12. The battery cell according to claim 11, characterized in that: When the bottom surface is viewed along the first direction, the bottom surface has a rectangular shape.

13. The battery cell according to claim 12, characterized in that: The size of the bag-type structure in the second direction is X1, and the size of the bag-type structure in the third direction is Y1, wherein the first direction, the second direction and the third direction are perpendicular to each other, and X1 and Y1 satisfy the following relationship: The dimension of the battery cell in the second direction < X1 < the dimension of the housing in the second direction; The dimension of the battery cell in the third direction < Y1 < the dimension of the housing in the third direction.

14. The battery cell according to claim 2, characterized in that: The annular side wall includes a plurality of first side surfaces, and adjacent first side surfaces are connected by a first arc with a radius of R1. The housing includes a plurality of second side surfaces, and adjacent second side surfaces are connected by a second arc with a radius of R2. The fillet radius of the bent portion of the battery cell is R3. Among them, R1, R2, and R3 satisfy the following relationship: R3 ≤ R1 ≤ R2.

15. The battery cell according to claim 14, characterized in that: The height of the pouch structure in the first direction is H11, and the height of the housing in the first direction is H2. H11 and H2 satisfy the following relationship: 0.3H2 ≤ H11 ≤ H2.

16. The battery cell according to claim 15, characterized in that: The battery cell further includes: an end cap, the end cap closes the opening of the housing, and the insulating member is fixed to the end cap.

17. The battery cell according to claim 16, characterized in that: The distance from the end of the insulating member adjacent to the end cap to the end of the end cap adjacent to the insulating member is greater than 0 mm and does not exceed 2 mm.

18. A battery, characterized in that: Comprising: A box body; At least one battery cell according to any one of claims 1-17, and the battery cell is accommodated in the box body.

19. An electrical device, characterized in that: The electrical device includes the battery cell according to any one of claims 1-17 for providing electrical energy or the battery according to claim 18.

20. An energy storage device, characterized in that: The energy storage device includes the battery cell according to any one of claims 1-17 for providing electrical energy or the battery according to claim 18.

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