WO2023133810A1

WO2023133810A1 - End cover assembly, battery cell, battery and device using battery

Info

Publication number: WO2023133810A1
Application number: PCT/CN2022/072061
Authority: WO
Inventors: 苏华圣; 邢承友; 李全坤; 杨道伟; 王鹏; 金海族
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-01-14
Filing date: 2022-01-14
Publication date: 2023-07-20
Also published as: CN117044014A

Abstract

The embodiments of the present application relate to the field of batteries, and provide an end cover assembly, a battery cell, a battery and a device using the battery, which are configured to improve the performance of a battery cell. The end cover assembly is configured to seal a housing of a battery cell and comprises a cover plate, a first insulating member, an electrode terminal and a sealing assembly, wherein the cover plate comprises a first through hole, and the first through hole penetrates the cover plate in a thickness direction of the cover plate; the first insulating member is located on an outer side of the cover plate in the thickness direction, the first insulating member comprises a second through hole, and the second through hole is in communication with the first through hole and penetrates the first insulating member; and the sealing assembly is arranged between the cover plate and the first insulating member, the sealing assembly encloses and forms a closed annular area, and the first through hole is located in the annular area. According to the technical solution, the sealing assembly is provided to achieve the effect of blocking an electrolyte, so that the electrolyte cannot flow into a gap between the cover plate and the electrode terminal, thereby effectively reducing the probability of electronic conduction between the electrode terminal and the cover plate and the housing.

Description

End cap assembly, battery cell, battery, and device using battery

technical field

The present application relates to the field of battery technology, in particular to an end cover assembly, a battery cell, a battery and a device using the battery.

Background technique

Secondary batteries have the advantages of high energy density and environmental friendliness, and are currently widely used in electronic devices such as mobile phones and notebook computers. With the vigorous development of new energy technologies, the application of secondary batteries has rapidly expanded to gasoline-electric hybrid vehicles, electric vehicles and energy storage systems.

During the manufacturing process of the secondary battery, electrolyte needs to be injected into the interior of the secondary battery along the liquid injection hole. During the injection of the electrolyte, the electrolyte may flow into the gap between the electrode terminal and the cover plate, causing a safety problem.

Contents of the invention

The present application provides an end cap assembly, a battery cell, a battery and a device using the battery, which are used to reduce the possibility of electronic conduction between the shell of the battery cell and the electrode terminals, and improve the safety performance of the battery cell.

An embodiment of the present invention provides an end cover assembly for sealing the casing of a battery cell. The end cover assembly includes a cover plate, a first insulating member, an electrode terminal, and a sealing assembly; the cover plate includes a first through hole, and the first through hole A through hole runs through the cover plate along the thickness direction of the cover plate; the first insulating member is located on the outer side of the cover plate along the thickness direction, the first insulating member includes a second through hole, and the second The through hole communicates with the first through hole and passes through the first insulating member; the electrode terminal is installed in the first through hole and the second through hole; the sealing assembly is arranged on the cover plate and the first through hole. Between the insulating members, the sealing assembly encloses a closed annular area, and the first through hole is located in the annular area.

In the end cover assembly provided by the above technical solution, a gap is provided between the cover plate and the first insulating member to prevent the electrolyte from entering the gap between the cover plate and the first insulating member along the gap between the cover plate and the electrode terminal sealing components. After the end cover assembly is installed on the battery cell, the electrolyte can be injected into the battery cell by using an existing electrolyte injection process. Due to the technical solution of the present application, a sealing assembly is provided between the cover plate and the first insulating member, and the sealing assembly plays a role in blocking the electrolyte, so that the electrolyte cannot continue to flow into the gap between the cover plate and the electrode terminal, This effectively reduces the possibility of electronic conduction between the cover plate and the shell of the battery cell and the electrode terminal due to the presence of by-products of the electrolyte, and improves the safety performance of the battery cell.

In some embodiments, the seal assembly includes a raised portion and a recessed portion. One of the cover plate and the first insulating member is provided with a protrusion, and the other is provided with a recess, and at least a part of the protrusion is accommodated in the recess to form the sealing assembly.

In the above technical solution, the convex part is accommodated in the concave part, so that a sealed connection is formed between the cover plate and the first insulating member, thereby preventing the electrolyte from going along the gap between the surfaces where the cover plate and the first insulating member are attached to each other. It enters the first through hole, so that the electrode terminal and the cover plate will not be electrically connected directly due to the presence of the electrolyte, so that the case will not have the migration of metal ions due to the electronic conduction, which improves the safety of the battery cell performance.

In some embodiments, the protrusion height of the protrusion is greater than the indentation depth of the recess.

In the above technical solution, after the protrusion is installed in the recess, the top of the protrusion abuts against the bottom of the recess, so that the two form a sealed area, and when the electrolyte flows to the area between the cover plate and the first insulating member, it will It is blocked by the raised part and cannot continue to flow.

In some embodiments, the protrusion and the recess are an interference fit.

In the above technical solution, after the protruding part is installed in the concave part, the protruding part and the concave part have an interference fit, and there is no gap in the contact surface of the two, so that the two form a seal.

In some embodiments, the cross-sectional shape of the protrusion is configured as a tapered, T-shaped. The cross-sectional shape of the convex part is constructed into a conical, T-shaped and other shapes. The tip of the convex part is small in size and easy to deform and compress, so that the convex part and the inner concave part can easily form an interference fit, thereby ensuring Electrolyte cannot flow from one side of the raised portion to the other.

In some embodiments, the cover plate is provided with the recess, and the recess is configured in an annular shape; the first insulating member is provided with the protrusion, and the protrusion is snapped into the recess.

The thickness of the cover plate is greater than that of the first insulating member, and the recess is provided on the cover plate, which not only facilitates processing, but also hardly affects the strength of the cover plate. The protruding part is arranged on the first insulating member, and the two are fixedly connected or integrated. Disposing the first insulating member on the raised portion is beneficial to increase the strength of the first insulating member, so that the sealing assembly formed by the recessed portion and the raised portion is more stable.

In some embodiments, the cover plate is provided with the protrusion, and the protrusion is configured in a ring shape; the first insulating member is provided with the recess, and the protrusion is snapped into the recessed part.

In the above technical solution, by providing the raised portion on the cover plate and the recessed portion on the first insulating member, a seal is formed between the cover plate and the first insulating member, effectively preventing the electrolyte from flowing along the cover plate and the first insulating member. The gap between the bonded surfaces enters the first through hole, so that the electrode terminal and the cover plate will not be electronically conducted due to the presence of electrolyte, thereby improving the safety performance of the battery cell.

In some embodiments, the seal assembly includes a seal, at least one of the cover plate and the first insulating member is provided with a groove, and the seal is located in the groove.

In the above technical solution, only one of the cover plate and the first insulating member needs to be processed and manufactured to realize the installation of the seal. And electron conduction.

In some embodiments, the groove is disposed on the cover plate, the seal is fixed on the surface of the first insulating member facing the cover plate, and the seal is pressed on the groove middle.

The cover plate is provided with the groove, and the sealing member can be inserted into the groove more conveniently, so as to realize the sealing between the first insulating member and the cover plate. The above technical solution only needs to process and manufacture the cover plate to realize the installation of the seal, the whole manufacturing process is simple, and the sealing effect is good, effectively avoiding the electronic conduction between the electrode terminal and the cover plate due to the presence of electrolyte.

In some embodiments, the number of the electrode terminals is at least one, and all the electrode terminals are located in the same annular area; or, one electrode terminal is arranged in each of the annular areas.

The end cover assembly provided by the above technical solution can protect all poles if only a circle of convex part and concave part is provided on the outer circumference of all poles, the number of parts to be processed is small, the installation is easier, and it also has the advantages of Good protective effect. In the end cap assembly provided by the above technical solution, if a ring of raised parts and inner concave parts are provided on the outer side of each pole, the size of the raised parts and inner concave parts can be set relatively small, which is relatively small for the cover plate and the first insulation. Parameters such as the structural strength of the component have little influence, and when abnormal conditions such as connection failure occur on the convex part and the concave part outside one pole, the sealing effect of the convex part and the concave part outside the other pole will not be affected.

In some embodiments, the cover plate is provided with an explosion-proof hole, and the explosion-proof hole is located outside the annular area. The above-mentioned technical scheme realizes the double effects of explosion-proof and liquid injection through the explosion-proof hole.

An embodiment of the present invention also provides a battery cell, including an electrode assembly, a casing, and an end cap assembly provided by any technical solution of the present application, the casing is used to accommodate the electrode assembly, and the end of the casing is configured as Open, the end cover assembly is arranged at the end of the housing.

The above-mentioned battery cell has the end cover assembly provided by the above-mentioned technical solution, so it can also effectively prevent the casing from being electrified.

In some embodiments, the battery cell further includes a negative end cap assembly and a positive end cap assembly; the negative end cap assembly is located on one side of the electrode assembly, and the positive end cap assembly is located on the other side of the electrode assembly The two ends of the casing are configured to be open, and the negative end cap assembly and the positive end cap assembly are respectively covered on the two ends of the casing; the negative end cap Assemblies employ the end cap assembly.

After the negative electrode terminal is electronically connected to the casing, it is easy to cause corrosion of the casing. In the above technical solution, the negative end cap assembly is used as the end cap assembly, which effectively prevents the casing from being electrified and improves the performance of the battery cell.

In some embodiments, the positive end cap assembly is provided with a liquid injection hole.

The positive end cap assembly of the negative end cap assembly and the positive end cap assembly is provided with a liquid injection hole, and the negative electrode adopts the end cap assembly provided above with a sealing assembly, so that each structure can be effectively arranged, and This makes the structure of the battery cell more reasonable.

An embodiment of the present invention further provides a battery, including the battery cell provided by any technical solution of the present invention. The battery provided by the above technical solution uses the above-mentioned battery cells to provide energy, which effectively prevents the case from being charged and improves the performance of the battery.

An embodiment of the present invention further provides a device using a battery, including the battery provided by any technical solution of the present invention. The electrical equipment provided by the above technical solution uses the above battery to provide energy, which effectively prevents the casing from being charged and improves the performance of the device.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the embodiments of the present application. Obviously, the accompanying drawings described below are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on the accompanying drawings on the premise of not paying creative efforts.

FIG. 1 is a schematic structural diagram of a battery-using device provided by some embodiments of the present application.

FIG. 2 is a schematic diagram of a three-dimensional structure of a battery cell disclosed in some embodiments of the present application.

FIG. 3 is a schematic diagram of an exploded structure of a battery cell disclosed in some embodiments of the present application.

Fig. 4 is a schematic diagram of an exploded structure of an end cap assembly disclosed in some embodiments of the present application.

Fig. 5 is a schematic front view of an end cap assembly disclosed in some embodiments of the present application.

FIG. 6 is a schematic cross-sectional view along line A-A of FIG. 5 .

FIG. 7 is a partially enlarged schematic diagram of B in FIG. 6 .

Fig. 8 is a schematic perspective view of the cover plate of the end cover assembly disclosed in some embodiments of the present application.

Fig. 9 is a schematic perspective view of the first insulating member of the end cap assembly disclosed in some embodiments of the present application.

Fig. 10 is a schematic diagram of the three-dimensional structure of the cover plate of the end cover assembly disclosed in other embodiments of the present application.

Fig. 11 is a schematic diagram of the three-dimensional structure of the first insulating member of the end cover assembly disclosed in other embodiments of the present application.

Fig. 12 is a schematic diagram of an exploded structure of an end cap assembly disclosed in some other embodiments of the present application.

Fig. 13 is a schematic front view of an end cap assembly disclosed in other embodiments of the present application.

FIG. 14 is a schematic cross-sectional view along line C-C of FIG. 13 .

FIG. 15 is a partially enlarged schematic diagram of D in FIG. 14 .

Fig. 16 is a schematic diagram of an exploded structure of an end cap assembly disclosed in other embodiments of the present application.

Fig. 17 is a schematic front view of an end cap assembly disclosed in other embodiments of the present application.

FIG. 18 is a schematic cross-sectional view along line E-E of FIG. 17 .

In the drawings, the drawings are not drawn to scale.

Mark Description:

1. Battery cell;

10. Sealing component; 11. Cover plate; 12. First insulating member; 13. Electrode terminal; 10. Sealing component; 14. Protruding part; 15. Recessed part; Block; 18, the second insulating member; 101, explosion-proof valve; 102, explosion-proof patch; 103, adapter piece; 104, O-ring; 105, liquid injection hole;

110, explosion-proof hole; 111, first through hole; 112, groove; 121, second through hole; 122, installation groove; 171, third through hole; 190, cavity;

100. Electrode assembly; 200. End cap assembly; 300. Housing; 201. Negative end cap assembly; 202. Positive end cap assembly;

1000, battery.

Detailed ways

The implementation manner of the present application will be further described in detail below with reference to the accompanying drawings 1 to 18 and examples. The detailed description and drawings of the following embodiments are used to illustrate the principles of the application, but not to limit the scope of the application, that is, the application is not limited to the described embodiments.

In the description of this application, it should be noted that, unless otherwise specified, the meaning of "plurality" is more than two; the terms "top", "bottom", "upper", "lower", "left", " The orientations or positional relationships indicated by "right", "inner" and "outer" are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation or be constructed in a specific orientation. and operation, and therefore should not be construed as limiting the application. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

In order to describe the technical solutions of the various embodiments of the present disclosure more clearly, a coordinate system is established in FIG. 2 , and subsequent descriptions about various orientations of the battery cells are based on this coordinate system. Referring to FIG. 2 , the X axis is the diameter direction of the cover plate of the battery cell. The Y axis is perpendicular to the X axis in the horizontal plane. The Z axis is perpendicular to the plane formed by the X axis and the Y axis, and the Z axis represents the height direction of the battery cells. In the description of the present disclosure, the terms "up" and "down" are all relative to the Z-axis direction.

In the related art, the inside of the battery cell needs to be injected with electrolyte. The inventors found that after the electrolyte is injected into the battery cell, the electrolyte will flow downward along the shell of the battery cell in the direction of gravity under the action of its own gravity and external liquid injection power. When the amount of electrolyte at the bottom of the battery cell is sufficient, the electrolyte will overflow from the bottom of the battery cell toward the liquid injection hole along the interlayer of the battery cell, that is, flow upward. When the electrolyte overflows to the upper surface of the cover plate, it may flow along the gap between the cover plate and the first insulating member toward the installation hole where the electrode terminal is located. There is a certain gap between the inner wall of the mounting hole of the cover plate and the outer wall of the electrode terminal; if the electrolyte enters the gap, the electrode terminal, the cover plate, and the housing will be ionically conducted due to the presence of the electrolyte; It will lead to the generation of by-products in the battery cell, and the by-products are attached to the insulating member between the electrode terminal and the cover plate and the shell, so that the electrode terminal, the cover plate, and the shell are electrically connected. If the positive pole is electrically connected to the shell, it will cause the shell to be positively charged, that is, the positive pole and the shell are at the same potential; if the negative pole is electrically connected to the shell, it will cause the shell to be negatively charged, that is Positive and negative electrodes are at the same potential. No matter whether the shell is at low potential or high potential, it will bring certain potential safety hazards. Moreover, the low potential of the casing may cause the casing to be corroded and cause liquid leakage. The technical solution provided by the present disclosure can make the electrolyte enter the gap between the electrode terminal and the cover plate as much as possible, thereby reducing or even eliminating the occurrence of electronic conduction between the electrode terminal, the cover plate and the casing, and improving the battery life. safety performance.

The inventor found through further research that the above problems cannot be solved by improving the manufacturing process of the battery cells at present, so the inventor of the present invention proposes the following solutions.

An embodiment of the present invention provides a device using a battery.

The device is, for example, a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, and the like. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles; spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.; electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric boat toys and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and more. The embodiment of the present application does not impose special limitations on the above electric equipment.

In the following embodiments, for convenience of description, a vehicle is used as an example for description.

Referring to FIG. 1 , a battery 1000 is disposed inside the vehicle, and the battery 1000 is disposed at the bottom or head or tail of the vehicle. The battery 1000 supplies power to the vehicle, for example, the battery 1000 serves as an operating power source for the vehicle.

Referring to FIG. 1 , the battery 1000 can be used as a power source for new energy vehicles, ships, smart electrical cabinets and other devices. The battery 1000 is used as a power supply component to provide required electric energy to various electrical components of the device.

In some embodiments, the battery 1000 includes a case and one or more battery cells disposed in the case. Each battery cell is electrically connected, such as in series, in parallel or in parallel, so as to achieve the required electrical performance parameters of the battery 1000 . A plurality of battery cells are arranged in a row, and one or more rows of battery cells can be arranged in the box as required.

The arrangement of each battery cell 1 of the battery 1000 will be described below. In some embodiments, the battery cells 1 of the battery 1000 are arranged along the length direction of the case. Six rows of battery cells are arranged along the width direction of the battery 1000 . In practical applications, other numbers of rows may also be set. According to needs, one or more layers of battery cells 1 can also be arranged in the height direction of the battery 1000 .

In some embodiments, a plurality of battery cells 1 are connected in series, parallel or mixed to form a battery module, and then the battery modules are connected in series, parallel or mixed to form a whole and accommodated in the box. In some other embodiments, all the battery cells 1 are directly connected in series, parallel or mixed, and then all the battery cells 1 are housed in the box as a whole.

Referring to FIG. 1 and FIG. 3 , some implementations of the battery cell 1 are introduced below.

Some embodiments of the present disclosure provide a battery cell 1 , including an electrode assembly 100 , an end cap assembly 200 and a casing 300 . The case 300 is used to house the electrode assembly 100 . The ends of the housing 300 are configured to be open. The end cover assembly 200 is disposed at the end of the casing 300 .

The number of end cap assemblies 200 may be one or two, depending on the number of end openings of the housing 300 . For example, both ends of the casing 300 are open, and there are two end cover assemblies 200, one is located at one end of the battery cell 1 in the height direction, and the other is located at the other end of the battery cell 1 in the height direction, The height direction here is parallel to the thickness direction of the end cap assembly 200 .

The housing 300 has a cavity 301 . The electrode assembly 100 is installed in the cavity 301 of the case 300 .

In some embodiments, the battery cell includes two end cap assemblies 200, namely a negative end cap assembly 201 and a positive end cap assembly 202; the negative end cap assembly 201 is located on one side of the electrode assembly 100, and the positive end cap assembly 202 is located on the electrode The other side of the assembly 100. Both ends of the casing 300 are configured to be open, and the negative end cap assembly 201 and the positive end cap assembly 202 respectively cover the two ends of the casing 300 ; the negative end cap assembly 201 adopts the end cap assembly 200 .

The negative end cap assembly 201 and the positive end cap assembly 202 can mostly adopt the structure with the sealing assembly 10 described above, so as to prevent the case 300 of the battery cell from being charged. Preferably, the negative end cover assembly 201 adopts the above-mentioned end cover assembly 200 with the sealing assembly 10 , which can effectively prevent the casing 300 from being negatively charged.

Since the negative charge of the housing 300 may cause corrosion and leakage of the battery cell 1, the above technical solution makes the housing 300 and the electrode terminal 13 electrically conductive without the by-products generated by the electrolyte, so the housing 300 is not charged. The possibility of corrosion of the casing 300 is effectively reduced.

In other embodiments, the positive end cap assembly 202 is provided with a liquid injection hole 105 . Each end cap assembly of the negative end cap assembly 201 and the positive end cap assembly 202 is arranged at the opening of one end of the casing 300 to close the end opening of the casing 300, and the end cap assembly 200 and the electrode assembly 100 of the electrode assembly 100 are electrically connect. The above arrangement makes the liquid injection hole 105 disposed on the positive end cap assembly 202 , so that the position of the liquid injection hole 105 can be arranged more flexibly, making the structure of the battery cell 1 more reasonable.

As mentioned above, the battery cell 1 includes an electrode assembly 100 and an electrolyte, and the electrode assembly 100 is composed of a positive pole piece, a negative pole piece and a separator. The manufacturing methods of the electrode assembly 100 include lamination and winding. The laminated electrode assembly is to cut the positive pole piece, negative pole piece, and separator into a specified size, and then stack the positive pole piece, separator, and negative pole piece into an electrode assembly. The wound electrode assembly is formed by winding the positive pole piece, the negative pole piece, and the separator. In some of the following embodiments, the battery cell takes a wound-type electrode assembly as an example, and the case 300 is also cylindrical. The end cap assemblies are generally circular to match the shape of the openings at both ends of the housing 300 . The battery cell 1 mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the positive electrode collector without the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. Fluid, the positive electrode current collector not coated with the positive electrode active material layer is used as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode collector without the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. Fluid, the negative electrode current collector not coated with the negative electrode active material layer is used as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current is passed without fusing, the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together. The material of the isolation film may be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene).

Referring to FIG. 2 to FIG. 7 , the top and bottom of FIG. 2 and FIG. 3 are reversed, and the reverse relationship can be seen from the flow path M of the electrolyte marked in FIG. 2 and FIG. 3 . The embodiment of the present invention provides an end cover assembly 200 for closing the casing 300 of the battery cell 1 . The end cap assembly 200 includes a cap plate 11 , a first insulating member 12 , an electrode terminal 13 and a sealing assembly 10 . The cover plate 11 includes a first through hole 111 , and the first through hole 111 penetrates through the cover plate 11 along the thickness direction of the cover plate 11 . The first insulating member 12 is located outside the cover plate 11 along the thickness direction. The first insulating member 12 includes a second through hole 121 , which communicates with the first through hole 111 and passes through the first insulating member 12 . The electrode terminals 13 are attached to the first through hole 111 and the second through hole 121 . The sealing assembly 10 is disposed between the cover plate 11 and the first insulating member 12 . The sealing assembly 10 encloses a closed annular area S, and the first through hole 111 is located in the annular area S.

The side of the cover plate 11 away from the electrode assembly 100 is a first insulating member 12 . The cover plate 11 is roughly a flat plate. The first insulating member 12 adopts a rectangular thin plate-like structure. The material of the first insulating member 12 can be selected: polypropylene (Polypropylene, referred to as PP), polycarbonate (Polycarbonate, referred to as PC), polytetrafluoroethylene (Polyfluoroalkoxy, referred to as PFA), polyvinyl chloride (Polyvinyl chloride, referred to as PVC) ), polyethylene (polyethylene, referred to as PE), polyester resin (polyethylene terephthalate, referred to as PET) and other insulating and electrolyte-resistant materials.

The sealing assembly 10 has many implementations, for example, a deformable component is used to compress between the cover plate 11 and the first insulating member 12; the deformable component is, for example, rubber, a fluid absorption component, and the like. The respective structures of the cover plate 11 and the first insulating member 12 may not be changed, and the deformable part is directly pressed between them. Alternatively, a groove is provided in one of the cover plate 11 and the first insulating member 12 to accommodate a part of the deformable component, and the part of the deformable component not located in the groove is against the other of the cover plate 11 and the first insulating member 12 . Various implementations of the sealing assembly 10 will be introduced later.

In the end cover assembly provided by the above technical solution, a device is provided between the cover plate 11 and the first insulating member 12 to prevent the electrolyte from entering the cover plate 11 and the electrode along the gap between the cover plate 11 and the first insulating member 12. The gap between the terminals 13 seals the assembly 10 . After the end cap assembly 200 is installed on the battery cell 1 , the electrolyte solution can be injected into the battery cell 1 using an existing electrolyte injection process. During this process, the electrolyte may flow to the gap between the cover plate 11 and the first insulating member 12 . Due to the technical solution of the present application, a sealing assembly 10 is provided between the cover plate 11 and the first insulating member 12, and the sealing assembly 10 plays a role in blocking the electrolyte so that the electrolyte cannot continue to flow into the cover plate 11 and the electrode terminals 13 This effectively reduces the occurrence of electronic conduction between the cover plate 11 and the electrode terminal 13 , reduces the probability of charging the casing 300 , and reduces the safety risk of the battery cell 1 .

Referring to FIGS. 6 and 7 , in some embodiments, the seal assembly 10 includes a raised portion 14 and a recessed portion 15 . One of the cover plate 11 and the first insulating member 12 is provided with a protrusion 14 , and the other is provided with a recess 15 , at least a part of the protrusion 14 is accommodated in the recess 15 to form the sealing assembly 10 .

According to the different positions of the protrusions 14 and the recesses 15 , it can be subdivided into the following situations: the protrusions 14 are disposed on the cover plate 11 , and the recesses 15 are disposed on the first insulating member 12 . Alternatively, the protruding portion 14 is disposed on the first insulating member 12 , and the concave portion 15 is disposed on the cover plate 11 . The size and quantity of the raised portion 14 and the recessed portion 15 are matched, and all or a part of the raised portion 14 is snapped into the recessed portion 15, so that the raised portion 14 and the recessed portion 15 abut each other and are in close contact to form a sealing assembly 10 , so that the fluid located on one side of the sealing assembly 10 cannot penetrate the sealing assembly 10 and cannot flow to the other side of the sealing assembly 10 .

In some embodiments, the recessed part 15 and the raised part 14 are all configured as rings, such as circular ring or rectangular ring, and the shapes, sizes and positions of the recessed part 15 and the raised part 14 are corresponding, so that the raised parts The part 14 snaps into the concave part 15 smoothly.

The size and number of the recesses 15 and the protrusions 14 are related to the number of the electrode terminals 13 . Generally speaking, at least one circle of recesses 15 and one circle of protrusions 14 are provided on the outside of the electrode terminal 13 . Certainly, in order to achieve multiple sealing effects, it is also possible to make two or more circles of concave portions 15 and one circle of raised portions 14 correspond to the outside of each electrode terminal 13 . The concave part 15 is set on the cover plate 11, and the raised part 14 is set on the first insulating member 12. On the one hand, the material difference between the cover plate 11 and the first insulating member 12 is taken into consideration. The difference in the relative positions of the insulating members 12. Viewed from the direction shown in FIG. 6 , the cover plate 11 is on the bottom and the first insulating member 12 is on the top. The cover plate 11 is provided with a recess 15 , and the first insulating member 12 is provided with a protrusion 14 , so that the protrusion 14 can be inserted into the recess 15 more conveniently.

In the above technical solution, the sealing assembly 10 adopts a structure in which the protrusion 14 and the recess 15 cooperate, the connection between the protrusion 14 and the recess 15 is more firm and reliable, and the protection effect is better.

Referring to FIG. 6 and FIG. 7 , in some embodiments, the protrusion height of the protrusion 14 is greater than the indentation depth of the recess 15 .

After the raised part 14 is installed in the recessed part 15, the top of the raised part 14 abuts against the bottom of the recessed part 15, so that the two form a sealing area. When the electrolyte flows to the area between the cover plate 11 and the first insulating member 12 along M1 to M2 in FIG. 6 , it will be blocked by the protrusion 14 and cannot continue to flow. Therefore, the electrolyte can be prevented from flowing into the gap between the cover plate 11 and the electrode terminal 13 along the paths M1 and M2, so that the electrode terminal 13 and the cover plate 11 will not be electronically conducted due to the presence of the electrolyte, so that the housing The 300 will not migrate metal ions due to electronic conduction, that is, the housing 300 will not be charged, which improves the performance of the battery cell where the end cover assembly 200 is located.

Referring to FIGS. 6 and 7 , in some embodiments, the protrusion 14 and the recess 15 have an interference fit.

After the protruding part 14 is installed in the concave part 15, the protruding part 14 and the concave part 15 have an interference fit, and there is no gap in the contact surface of the two, so that the two form a sealing surface.

Referring to Figures 6 and 7, when the electrolyte flows along M1 to M2 in Figure 6 to the area between the cover plate 11 and the first insulating member 12, it will be blocked by the raised portion 14 and cannot continue to flow, effectively The electrolyte is prevented from flowing into the gap between the cover plate 11 and the electrode terminal 13 through the sealing surface, thereby preventing the electrolyte from entering the second gap along the gap between the surfaces where the cover plate 11 and the first insulating member 12 are attached to each other. A through hole 111, so that the electrode terminal 13 and the cover plate 11 will not be electronically conducted due to the presence of electrolyte, so that the housing 300 will not migrate metal ions due to electronic conduction, that is, the charging of the housing 300 will be reduced. probability, improving the safety performance of the battery cell 1 to which the end cover assembly 200 belongs.

Referring to FIG. 6 and FIG. 7 , in some embodiments, the cross-sectional shape of the protrusion 14 is configured as a tapered, T-shaped. The cross-sectional shape of the concave portion 15 is substantially rectangular, or other shapes that can accommodate the convex portion 14 . After the protruding part 14 is installed in the concave part 15 , the protruding part 14 is compressed and deformed, and the deformed shape of the protruding part 14 is completely accommodated in the concave part 15 . The volume of the recessed part 15 is larger than the volume of the raised part 14 accommodated, and after the raised part 14 is installed in the recessed part 15, there is still a certain space in the recessed part 15, which can be used to accommodate the blocked electrolyte. The cross-sectional shape of the protruding part 14 is configured as a conical shape, a T-shape, etc. The tip of the protruding part 14 is small in size and easy to be deformed and compressed, so that the protruding part 14 and the concave part 15 form an interference fit very conveniently , thereby ensuring that the electrolyte cannot flow from one side of the raised portion 14 to the other.

The specific setting positions of the protruding portion 14 and the concave portion 15 will be described below.

Referring to FIGS. 6 to 11 , in some embodiments, the cover plate 11 is provided with a recess 15 configured in a ring shape. The first insulating member 12 is provided with a protruding portion 14 , and the protruding portion 14 is snapped into the concave portion 15 .

The cover plate 11 is provided with one or more recesses 15 , and the number of the protrusions 14 is the same as the number of the recesses 15 . The concave portion 15 does not penetrate the cover plate 11 , and is specifically, for example, 1/3˜1/2 of the thickness of the cover plate 11 . The thickness of the protrusion 14 is greater than the depth of the recess 15 to ensure that the protrusion 14 is compressed, which makes the cooperation between the protrusion 14 and the recess 15 tighter.

The thickness of the cover plate 11 is greater than that of the first insulating member 12 , and the recess 15 is provided on the cover plate 11 , which not only facilitates processing, but also hardly affects the strength of the cover plate 11 . The protruding portion 14 is disposed on the first insulating member 12, and the two are fixedly connected or integrated. Disposing the first insulating member 12 on the raised portion 14 is beneficial to increase the strength of the first insulating member 12, so that the sealing assembly 10 formed by the recessed portion 15 and the raised portion 14 is more stable.

12 to 15, in some other embodiments, the cover plate 11 is provided with a raised portion 14, and the raised portion 14 is configured in a ring shape; the first insulating member 12 is provided with a concave portion 15, and the raised portion 14 snaps into Recess 15.

The number of protruding parts 14 is, for example, one or more, and the number may be equal to or less than the number of electrode terminals 13 . For example, the protruding portion 14 surrounds the outer sides of all the electrode terminals 13 ; or, the protruding portion 14 is provided on the outer side of each electrode terminal 13 . The number, size, and location of the recesses 15 correspond to the protrusions 14 , so that the protrusions 14 snap into the recesses 15 . The concave portion 15 does not penetrate through the thickness direction of the first insulating member 12 , and the concave portion 15 is relatively shallow, such as 1/4˜1/3 of the thickness of the first insulating member 12 .

In the above technical solution, by providing the raised portion 14 on the cover plate 11 and the concave portion 15 on the first insulating member 12, a seal is formed between the cover plate 11 and the first insulating member 12, effectively preventing the electrolyte from flowing along the cover plate 11 and the first insulating member 12. The gap between the surfaces of the first insulating member 12 that are attached to each other enters the first through hole 111, so that the electrode terminal 13 and the cover plate 11 will not be electrically connected due to the presence of the electrolyte, so that the housing 300 will not be caused by electrons. Conduction leads to migration of metal ions, which reduces the probability of charging the casing 300 and improves the safety performance of the battery cell 1 .

Referring to FIGS. 16-18 , in other embodiments, the seal assembly 10 includes a seal 16 . At least one of the cover plate 11 and the first insulating member 12 is provided with a groove 112 , and the sealing member 16 is located in the groove 112 .

The sealing element 16 is, for example, a sealing ring. The sealing member 16 is not fixedly connected to the cover plate 11 and the first insulating member 12 , and the sealing member 16 is installed in the groove 112 as an independent component, and is clamped by the cover plate 11 and the first insulating member 12 .

The above technical solution only needs to process and manufacture one of the cover plate 11 and the first insulating member 12 to realize the installation of the sealing member 16. The whole manufacturing process is simple, and the sealing effect is good, effectively avoiding the electrode terminal 13 and the cover plate. 11 Electronic conduction due to the presence of electrolyte.

In some embodiments, the groove 112 is disposed on the cover 11 , the seal 16 is fixed on the surface of the first insulating member 12 facing the cover 11 , and the seal 16 is pressed into the groove 112 .

The thickness of the cover plate 11 is greater than that of the first insulating member 12 , and the groove 112 is provided on the cover plate 11 , which not only facilitates processing, but also hardly affects the strength of the cover plate 11 .

The above technical solution only needs to process and manufacture the cover plate 11 to realize the installation of the sealing member 16, the whole manufacturing process is simple, and the sealing effect is good, effectively avoiding the electron conduction between the electrode terminal 13 and the cover plate 11 due to the presence of electrolyte. Pass.

In some embodiments, at least one electrode terminal 13 is included, and one electrode terminal 13 is arranged in each annular region S; or, all electrode terminals 13 are located in the same annular region S.

In some embodiments, the number of electrode terminals 13 is one or two. Referring to FIGS. As shown in FIG. 14 and FIG. 15 , a circle of protrusions 14 and a circle of recesses 15 are provided on the outside of all electrode terminals 13 .

According to the number of electrode terminals 13, it can be specifically divided into a single-electrode terminal structure and a double-electrode terminal structure. In some embodiments, taking the double-electrode terminal structure as an example, adopting the structure of the double-electrode terminal 13 can prevent phenomena such as rotation of the end cover assembly 200 relative to the housing 300 after installation. Since there may be electrolyte between each electrode terminal 13 and the cover plate 11 , this will lead to electronic conduction between the two, thereby causing the case 300 to be charged. Therefore, the above-described convex portion 14 and concave portion 15 can be provided for each electrode terminal 13 . According to the different positions of the protruding part 14 and the recessed part 15, there are many ways to realize the whole end cover assembly.

A circle of protrusions 14 and a circle of recesses 15 may be provided on the outer side of each electrode terminal 13, and the two cooperate with each other. Specifically, the cover plate 11 has two first through holes 111 , and a circle of recesses 15 is provided on the outer circumference of each first through hole 111 . The first insulating member 12 has two second through holes 121 , each second through hole 121 corresponds to one first through hole 111 , and the axes of the second through holes 121 and the corresponding first through holes 111 coincide. The outer circumference of each second through hole 121 is provided with an end protrusion 14 . The concave portion 15 on the outer side of each first through hole 111 is matched with the corresponding convex portion 14 on the outer ring of the second through hole 121 .

In the end cap assembly 200 provided by the above technical solution, a circle of raised portions 14 and recessed portions 15 are provided on the outside of each electrode terminal 13, and the size of the raised portions 14 and recessed portions 15 can be set relatively small, which is relatively small for the cover plate 11. It has little influence on parameters such as the structural strength of the first insulating member 12, and when abnormal conditions such as connection failure occur on the protrusion 14 and the recess 15 outside one electrode terminal 13, it will not affect the protrusions on the outside of the other electrode terminals 13. 14 and the sealing effect of the recess 15.

Referring to Fig. 10 and Fig. 11, Fig. 10 and Fig. 11 schematically show that a large circle of protrusions 14 and a large circle of recesses 15 are arranged on the outer sides of the two electrode terminals 13, and the two cooperate with each other. In other words, the cover plate 11 has two first through holes 111 , and the outer circumferences of the two first through holes 111 are provided with a circle of recesses 15 , and the circle of recesses 15 surrounds the two first through holes 111 . The first insulating member 12 has two second through holes 121 , each second through hole 121 corresponds to one first through hole 111 , and the axes of the second through holes 121 and the corresponding first through holes 111 coincide. The outer rings of the two second through holes 121 are provided with a protruding portion 14 at one end, and this ring of concave portions 15 surrounds the two second through holes 121 . The raised portion 14 and the recessed portion 15 are mated.

The end cover assembly 200 provided by the above technical solution only needs to set a ring of protrusions 14 and recesses 15 on the outer circumference of all the electrode terminals 13 to realize the protection of all the electrode terminals 13, the number of parts required to be processed is small, and the installation is easier , and also has a good protective effect.

In some embodiments, the cover plate 11 is provided with an explosion-proof hole 110 , and the explosion-proof hole 110 is located outside the annular area S.

Referring back to FIG. 4 , the explosion-proof hole 110 is used to install the explosion-proof valve 101 , and the explosion-proof sticker 102 can be pasted on the outside of the explosion-proof valve 101 . The explosion-proof hole 110 can also be used as liquid injection. During the manufacturing process, the electrolyte is injected into the battery through the explosion-proof hole 110 . After the battery is manufactured, an explosion-proof valve 101 is installed, and an explosion-proof sticker 102 is pasted on the outside of the explosion-proof valve 101 .

Returning to FIG. 4 , in some embodiments, the end cover assembly 200 further includes a fixing block 17, the first insulating member 12 is provided with a mounting groove 122, and the mounting groove 122 communicates with the second through hole 121; the fixing block 17 is installed in the mounting groove 122 in. The fixing block 17 has a third through hole 171 communicating with the third through hole 171 , and the electrode terminal 13 is installed in the first through hole 111 , the second through hole 121 and the third through hole 171 .

The material of the fixing block 17 can be metal conductive material, such as aluminum. Returning to FIG. 4 , in order to prevent the electrolyte from leaking from inside the battery cell along the first through hole 111 and the second through hole 121 , an O-ring 104 is installed between the cover plate 11 and the battery cell. The O-ring 104 is installed in the first through hole 111 of the cover plate 11 , and the O-ring is located between the electrode terminal 13 and the cover plate 11 to prevent the electrolyte inside the battery cell from leaking through the installation through hole. The central portion of the seal 16 is provided with a hole. The electrode terminal 13 passes through the above third through hole 171 and the hole of the O-ring 104 , and then passes through the second through hole 121 of the first insulating member 12 .

Continuing to refer to FIG. 4 , in some embodiments, the end cap assembly 200 further includes a second insulating member 18 , and the second insulating member 18 is located on a side of the cover plate 11 away from the first insulating member 12 . An adapter plate 103 is disposed on a side of the second insulating member 18 away from the cover plate 11 . The second insulating member 18 adopts a rectangular thin plate-like structure. The material of the second insulating member 18 can be selected: polypropylene (Polypropylene, referred to as PP), polycarbonate (Polycarbonate, referred to as PC), polytetrafluoroethylene (Polyfluoroalkoxy, referred to as PFA), polyvinyl chloride (Polyvinyl chloride, referred to as PVC) ), polyethylene (polyethylene, referred to as PE), polyester resin (polyethylene terephthalate, referred to as PET) and other insulating and electrolyte-resistant materials. In the above technical solution, by providing the second insulating member 18, the performance of the end cover assembly is improved.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

An end cap assembly for closing a casing (300) of a battery cell (1), comprising:

The cover plate (11), comprising a first through hole (111), the first through hole (111) passing through the cover plate (11) along the thickness direction of the cover plate (11);

The first insulating member (12) is located on the outer side of the cover plate (11) along the thickness direction, the first insulating member (12) includes a second through hole (121), and the second through hole (121 ) communicating with the first through hole (111) and penetrating through the first insulating member (12);

an electrode terminal (13), installed in the first through hole (111) and the second through hole (121); and

A sealing assembly (10), arranged between the cover plate (11) and the first insulating member (12), the sealing assembly (10) enclosing a closed annular area (S), the first through Holes (111) are located within said annular region (S).
The end cap assembly according to claim 1, wherein the sealing assembly (10) comprises:

raised portion (14); and

Recess (15);

Wherein, one of the cover plate (11) and the first insulating member (12) is provided with a raised portion (14), and the other is provided with a concave portion (15), and the raised portion (14) is at least A part is accommodated in the recess (15) to form the sealing assembly (10).
The end cover assembly according to claim 2, wherein the raised height of the raised portion (14) is greater than the concave depth of the recessed portion (15).
The end cover assembly according to claim 2 or 3, wherein the protrusion (14) and the recess (15) are interference fitted.
The end cover assembly according to any one of claims 2-4, wherein the cross-sectional shape of the protrusion (14) is configured as a conical, T-shaped shape.
The end cap assembly according to any one of claims 2-5, wherein, the cover plate (11) is provided with the recess (15), and the recess (15) is configured in an annular shape; the first insulation The member (12) is provided with said raised portion (14), said raised portion (14) snapping into said recessed portion (15).
The end cover assembly according to any one of claims 2-5, wherein, the cover plate (11) is provided with the raised portion (14), and the raised portion (14) is configured in an annular shape; the The first insulating member (12) is provided with the recess (15), and the protrusion (14) is snapped into the recess (15).
According to the end cap assembly according to any one of claims 1-7, the sealing assembly (10) comprises:

The seal (16), at least one of the cover plate (11) and the first insulating member (12) is provided with a groove (112), and the seal (16) is located in the groove (112) middle.
The end cover assembly according to claim 8, wherein, the groove (112) is provided on the cover plate (11), and the seal (16) is fixed on the first insulating member (12) toward the the surface of the cover plate (11), and the seal (16) is squeezed into the groove (112).
The end cap assembly according to any one of claims 1-9, wherein the number of the electrode terminals (13) is at least one, and all the electrode terminals (13) are located in the same annular region (S); or , one electrode terminal (13) is arranged in each annular region (S).
The end cover assembly according to any one of claims 1-10, wherein: the cover plate (11) is provided with an explosion-proof hole (110), and the explosion-proof hole (110) is located outside the annular area (S).
A battery cell, comprising:

electrode assembly (100);

a case (300) for accommodating the electrode assembly (100); the end of the case (300) is configured to be open; and

The end cover assembly (200) according to any one of claims 1-11, wherein the end cover assembly (200) is arranged at the end of the casing (300).
The battery cell according to claim 12, further comprising a negative end cap assembly (201) and a positive end cap assembly (202); the negative end cap assembly (201) is located on one side of the electrode assembly (100) , the positive end cap assembly (202) is located on the other side of the electrode assembly (100);

Both ends of the casing (300) are configured to be open, and the negative end cap assembly (201) and the positive end cap assembly (202) are respectively covered on the casing (300) the two ends of

The negative end cover assembly (201) adopts the end cover assembly (200).
The battery cell according to claim 13, wherein the positive end cap assembly is provided with a liquid injection hole (105).
A battery, comprising the battery cell (1) according to any one of claims 12-14.
A device using a battery, comprising the battery (1000) according to claim 15.