CN215989120U

CN215989120U - Square battery monomer, battery and consumer

Info

Publication number: CN215989120U
Application number: CN202121752289.4U
Authority: CN
Inventors: 李星; 徐善敏; 金海族
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2022-03-08
Anticipated expiration: 2031-07-29

Abstract

The application relates to the technical field of batteries, in particular to a square battery monomer, a battery and electric equipment. The square battery cell includes: a housing having an opening; the end cover assembly comprises a cover plate and a first electrode terminal, the cover plate covers the opening, and the first electrode terminal is arranged on the cover plate; the electrode assembly is arranged in the shell and is formed by winding a first pole piece, a second pole piece and a diaphragm, the first pole piece is provided with a plurality of first pole lugs, and the first pole lugs are subjected to rubbing treatment to form a first electric leading-out part; a first adaptor for electrically connecting the first electrical lead-out portion and the first electrode terminal; wherein a plurality of the first tabs are stacked one on another to form a cylinder-like body before being subjected to the flattening treatment. Class cylinder structure can match current equipment of rubbing flatly, consequently can rub flatly through current equipment of rubbing flatly and realize that the free utmost point ear of square battery is rubbed flatly, forms the first electricity extraction portion of compact structure, small, saves the free inner space of square battery, improves energy density.

Description

Square battery monomer, battery and consumer

Technical Field

The application relates to the technical field of batteries, in particular to a square battery monomer, a battery and electric equipment.

Background

Batteries are widely applied in the field of new energy resources, such as electric vehicles, new energy vehicles and the like, and the new energy vehicles and the electric vehicles become new development trends of the automobile industry.

In the development of battery technology, how to improve the energy density of the battery is one of the research and development directions.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a square battery monomer, a battery and electric equipment so as to improve the energy density of the battery.

The embodiment of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a square battery cell, which includes:

a housing having an opening;

an end cap assembly including a cap plate covering the opening and a first electrode terminal disposed at the cap plate;

the electrode assembly is arranged in the shell and is formed by winding a first pole piece, a second pole piece and a diaphragm, the first pole piece is provided with a plurality of first pole lugs, and the plurality of first pole lugs are subjected to rubbing treatment to form a first electricity leading-out part;

a first adaptor for electrically connecting the first electrical lead-out portion and the first electrode terminal;

wherein the plurality of first tabs are stacked on one another to form a cylinder-like body before being subjected to the flattening treatment.

The existing flattening equipment is inconvenient to flatten the single pole lug of the existing square battery, the pole lug is folded generally, and the space occupied by the folded pole lug is large, so that the energy density of the single battery is small. Among this application technical scheme, a plurality of first utmost point ears of electrode subassembly are range upon range of each other and are formed a class cylinder, and this type cylinder can be put into the circular flat chamber of rubbing of current machinery and rub flat device, can also match the circular flat head of rubbing of current supersound flat device, consequently can rub flat equipment through current and realize that utmost point ear is rubbed flatly, forms the first electricity derivation portion that compact structure, small, effectively saves the free inner space of square battery, improves energy density. And the lugs form an integral electric leading-out part with a compact structure after being kneaded flat, so that the situation that individual lugs are redundant and are inserted into the gaps of the electrode assembly to cause short-circuit risks is not easy to occur, and the safety is better. In addition, generally through ultrasonic bonding between current foldable utmost point ear and the adaptor, be not convenient for through other modes welding, ultrasonic bonding can produce the metal dust, and the adaptor is connected to the first utmost point ear accessible laser welding's of kneading the processing in this application, is difficult to produce the metal dust, can reduce the short circuit risk that the metal dust gets into the clearance of electrode subassembly and leads to, and the security is better.

In one embodiment of the present application, the electrode assembly includes a flat region, a first corner region and a second corner region, the flat region being located between the first corner region and the second corner region, and the first tab being located at the first corner region.

In the technical scheme, the first pole lug is arranged in the first corner area, when the first pole piece is wound, the part of the arc surface of the first pole lug is formed by utilizing the wound radian, so that the first pole lug is convenient to mold and produce and process.

In one embodiment of the present application, each of the first tabs is U-shaped before undergoing the flattening process, and the length of each of the first tabs in the winding direction is equal.

The plurality of first tabs are sequentially stacked in the first corner area, that is, the plurality of U-shaped tabs are sequentially stacked. Along inlayer to outer direction, the diameter of the arc portion of U type increases in proper order, because the length of every first utmost point ear equals, then along inlayer to outer direction in two arms of U type shorten in proper order to form similar curved profile, a plurality of first utmost point ears that also stack up each other constitute the class cylinder that makes up by arc and class arc, so that a plurality of first utmost point ears can the current machinery of adaptation rub flat equipment and supersound and rub flat equipment.

In one embodiment of the present application, the first tab has a length L in a winding direction, the electrode assembly has a thickness D, and L and D satisfy the following relationship:

L＝π＊D/2。

in the technical scheme, the first pole lug on the outermost layer is semicircular, the arc-like outline formed by the two arms of the first pole lug on the multilayer layer is closer to the semicircle, so that the cylinder-like body is formed by combining the semicircle and the semicircle-like body, the outline of the cylinder-like body is closer to the cylinder, the ultrasonic flattening device is more suitable for the existing mechanical flattening device and the ultrasonic flattening device, the flattening effect is good, the structure is more compact, the size is smaller, and the battery density is effectively improved.

In one embodiment of the present application, the second pole piece has a plurality of second pole tabs, the plurality of second pole tabs are subjected to a flattening treatment to form a second electric lead-out portion, and before the flattening treatment, the plurality of second pole tabs are laminated with each other to form a cylinder-like body;

the end cover assembly further comprises a second electrode terminal, the second electrode terminal is arranged on the cover plate, the square battery further comprises a second adapter, and the second adapter is used for electrically connecting the second electric leading-out part and the second electrode terminal.

In the technical scheme, the second tabs are also mutually stacked to form a similar cylinder, so that the tabs are flattened through the conventional flattening equipment, a second electric leading-out part with a compact structure and a small size is formed, the internal space of a square battery is further saved, and the energy density of the battery is improved. And the second tab and the first tab are positioned at the same end of the electrode assembly, so that the two tabs can be kneaded flat or connected with an electrode terminal without turning over the electrode assembly, the tabs are conveniently processed, and the production efficiency of the battery monomer is improved.

In one embodiment of the present application, the second pole ear is located at the second corner region.

In the technical scheme, the second pole lug is arranged in the second corner area, when the second pole piece is wound, the part of the cambered surface of the second pole lug is formed by utilizing the winding radian, so that the second pole lug is convenient to mold and produce and process.

In one embodiment of the present application, the cap plate is formed with a first recess corresponding to the first electrical lead-out position and a second recess corresponding to the second electrical lead-out position, the first recess being recessed toward the electrode assembly, the first electrode terminal being disposed in the first recess, the second recess being recessed toward the second electrode terminal, the second electrode terminal being disposed in the second recess.

In the technical scheme, the cover plate is sunken to reduce the height of the protruding cover plate of the electrode terminal, so that the appearance of the battery monomer is more regular, and the battery is convenient to assemble and pack.

In one embodiment of the present application, the first pole piece further has a plurality of third tabs, and the plurality of third tabs are stacked on one another; and/or the second pole piece is also provided with a plurality of fourth pole lugs, and the fourth pole lugs are mutually stacked.

In above-mentioned technical scheme, utilize and set up the remaining space behind first utmost point ear and the second utmost point ear between apron and the electrode subassembly to form third utmost point ear and fourth utmost point ear in this space, third utmost point ear and fourth utmost point ear do not connect the electrode terminal in order to derive the electric energy, but play the effect that increases pole piece heat radiating area, are favorable to deriving the space between electrode subassembly and the casing with the inside heat of electrode subassembly, improve electrode subassembly's radiating effect, improve the free security of battery.

In an embodiment of the present application, the third tab is located in the flat region and close to the first corner region, and the fourth tab is located in the flat region and close to the second corner region.

The heat in the electrode assembly is mainly emitted from the gap, the third lug and the fourth lug are arranged in the straight area, the heat of the electrode assembly can be better guided out to the space between the electrode assembly and the shell, the heat dissipation effect of the electrode assembly is improved, and the safety of a battery monomer is improved.

In a second aspect, an embodiment of the present application provides a battery, which includes the foregoing square battery cell.

The application provides a battery, square battery monomer's among them energy density is great, effectively improves the holistic energy density of battery.

In a third aspect, an embodiment of the present application provides an electric device, which includes the foregoing battery.

The application provides a consumer, the energy density of its battery that adopts is big, and the electric quantity is sufficient, and stability is good.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic illustration of a vehicle provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a battery provided in an embodiment of the present application;

fig. 3 is an exploded view of a battery cell according to an embodiment of the present disclosure;

fig. 4 is a top view of a battery cell provided in an embodiment of the present application;

FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4;

FIG. 6 is a schematic view of an electrode assembly provided in an embodiment of the present application before electrical leads are formed;

fig. 7 is a top view of a plurality of tabs stacked on one another according to an embodiment of the present application;

FIG. 8 is a schematic view of an electrode assembly provided in accordance with an embodiment of the present application after forming an electrical lead;

fig. 9 is a top view of a plurality of tabs stacked on one another according to another embodiment of the present application;

FIG. 10 is a schematic view of an end cap assembly provided by an embodiment of the present application;

FIG. 11 is an enlarged view of portion B of FIG. 4;

FIG. 12 is an enlarged view of portion C of FIG. 4;

FIG. 13 is a schematic view of an electrode assembly provided in accordance with yet another embodiment of the present application;

fig. 14 is a cross-sectional view of a battery cell according to yet another embodiment of the present application;

fig. 15 is a schematic view of an electrode assembly according to yet another embodiment of the present application.

Icon: 100-a battery; 101-a box body; 1011-first part; 1012-second part; 1-square battery monomer; 11-a housing; 111-opening; 12-an electrode assembly; 12 a-a flat zone; 12 b-a first corner region; 12 c-a second corner region; 121-a first tab; 122-a second tab; 123-a third tab; 124-a fourth tab; 131-a first transition piece; 132-a second adaptor; 14-an end cap assembly; 141-a cover plate; 1411-a first recess; 1412-a second recess; 142-a first electrode terminal; 143 — a second electrode terminal; 200-a motor; 300-a controller; 1000-vehicle.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and claims of this application or in the above-described drawings are used for distinguishing between different elements and not for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "attached" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in this application generally indicates that the former and latter related objects are in an "or" relationship.

In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.

The "plurality" in the present application means two or more (including two), and similarly, "plural" means two or more (including two) and "plural" means two or more (including two).

In this application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, and may also be a solid-state battery or a semi-solid-state battery, and the embodiment of the present application is not limited thereto.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The case may prevent liquid or other foreign substances from affecting the charge or discharge of the battery 100 cells.

The battery cell includes an electrode assembly and an electrolyte. When the electrolyte is a solid electrolyte, the electrode assembly consists of a positive electrode plate and a negative electrode plate; when the electrolyte is a liquid electrolyte (i.e., an electrolyte), the electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece includes anodal mass flow body and anodal active substance layer, and anodal active substance layer coats in anodal mass flow body's surface, and the mass flow body protrusion on the anodal active substance layer of uncoated positive active substance layer is in the mass flow body of coating anodal active substance layer, and the mass flow body on the anodal active substance layer of uncoated positive is as anodal utmost point ear. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece includes negative current collector and negative active material layer, and the negative active material layer coats in the surface of negative current collector, and the mass flow body protrusion in the mass flow body of coating the negative active material layer of uncoated negative active material layer, the mass flow body of uncoated negative active material layer is as negative pole utmost point ear. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the diaphragm can be PP or PE, etc. In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The battery cell further includes a case having an opening for receiving the electrode assembly and a cap plate for closing the opening. The cover plate is provided with a positive electrode terminal and a negative electrode terminal, a positive electrode tab of the electrode assembly is connected with the positive electrode terminal, and a negative electrode tab of the electrode assembly is connected with the negative electrode terminal, so that electric energy output is realized through the positive electrode terminal and the negative electrode terminal.

The development of battery technology should take into consideration various design factors, such as safety, energy density, cycle life, discharge capacity, charge and discharge rate, etc. Among them, increasing the energy density of batteries is one of the development directions of battery technology development.

The distance between the electrode assembly and the cap plate of the prismatic battery cell is large due to the height of the tabs of the prismatic battery cell, resulting in a reduction in energy density thereof. In a battery cell, one of the methods for improving energy density is to reduce the volume of a structural member while ensuring the function. The inventor finds that the square battery cell has a rectangular shape formed by stacking a plurality of tabs, or has a U-shaped shape, so that the volume of the tabs can be reduced only by folding, and the space occupied by the folded tabs is still large, resulting in still low energy density of the battery cell. In addition, the pole lugs positioned on the folding surfaces in the folding pole lugs are easy to generate redundancy, so that the end parts of the pole lugs are easy to insert into gaps among pole pieces of the electrode assembly, the short circuit risk is caused, and the safety is low. In addition, the existing foldable tab and the adaptor are generally welded by ultrasonic waves, and other welding modes are inconvenient to adopt, however, metal dust is generated by ultrasonic welding, and the metal dust enters a gap between the pole pieces of the electrode assembly to easily cause short circuit, so that the safety is low.

In the prior art, a scheme of processing the lugs of the square battery monomer in a rubbing square mode is also adopted, so that the structure between the multiple layers of lugs is more compact. The existing flattening equipment comprises two types, namely mechanical flattening equipment and ultrasonic flattening equipment. The mechanical flattening equipment comprises a circular flattening cavity, the circular flattening cavity covers the outside of the lug, and the lug is flattened when the circular flattening cavity moves. The ultrasonic flattening equipment comprises a round flattening head, and the round flattening head is in contact with the lug and is used for ultrasonically flattening. The existing flattening equipment is mainly used for cylindrical electrode assemblies, the lugs of the cylindrical electrode assemblies are mutually laminated to form a cylinder, and the cylinder is matched with a circular flattening cavity and a circular flattening head in shape. The lug of the square battery monomer in the shape of the rectangular body or the U-shaped body is not matched with the shapes of the round flattening cavity and the round flattening head, and if the lug needs to be flattened, the existing flattening equipment needs to be improved, so that the improvement cost is high.

In view of this, the present application provides a technical solution to increase the energy density of the square battery cell, and the improvement cost is low. This technical scheme does, sets up a plurality of utmost point ears of the free electrode subassembly of square battery, makes a plurality of utmost point ears range upon range of each other, makes a plurality of utmost point ears be the class cylinder in the shape before the punishment is rubbed to the process, and this type of cylinder is rubbed flat chamber and circular the flat head of rubbing with the circular of the flat equipment of current and is comparatively adapted, uses current flat equipment of rubbing to rub and to rub the free utmost point ear of square battery to it is flat to realize the free utmost point ear of square battery with less improvement cost, improves the energy density of battery.

The technical scheme described in the embodiment of the application is applicable to various electric equipment using batteries, such as mobile phones, portable equipment, notebook computers, battery cars, electric toys, electric tools, electric vehicles, ships, spacecrafts and the like, and the spacecrafts comprise airplanes, rockets, space shuttles, spacecrafts and the like.

It should be understood that the technical solutions described in the embodiments of the present application are not limited to be applied to the above-described devices, but may also be applied to all devices using batteries, and for brevity of description, the following embodiments are all described by taking an electric vehicle as an example.

For example, as shown in fig. 1, in a vehicle 1000 according to an embodiment of the present disclosure, the vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or an extended range automobile. The vehicle 1000 may be provided with a battery 100, a controller 300, and a motor 200 inside, and the controller 300 is configured to control the battery 100 to supply power to the motor 200. For example, the battery 100 may be provided at the bottom or the head or tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operation power supply of the vehicle 1000 for a circuit system of the vehicle 1000, for example, for power demand for operation in starting, navigation, and running of the vehicle 1000. In another embodiment of the present application, the battery 100 may be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power to the vehicle 1000.

In order to meet different power requirements, the battery 100 may include a plurality of battery cells, wherein the plurality of battery cells may be connected in series or in parallel or in series-parallel, and the series-parallel refers to a mixture of series connection and parallel connection. The battery 100 may also be referred to as a battery pack. Alternatively, as shown in fig. 2 and fig. 3, a plurality of square battery cells 1 may be connected in series or in parallel or in series-parallel to form a battery module 102, and a plurality of battery modules 102 may be connected in series or in parallel or in series-parallel to form a battery 100. That is, the plurality of prismatic battery cells 1 may be directly assembled into the battery 100, or the battery module 102 may be assembled first, and then the battery module 102 is assembled into the battery 100.

The battery 100 may include a plurality of prismatic battery cells 1. The battery 100 may further include a case 101 (or a cover), the inside of the case 101 is a hollow structure, and the plurality of square battery cells 1 are accommodated in the case 101. The housing 101 may include two portions for receiving (see fig. 2), referred to herein as a first portion 1011 and a second portion 1012, respectively, the first portion 1011 and the second portion 1012 snap together. The shape of the first and

second portions

1011 and 1012 may be determined according to the shape of the combination of the plurality of prismatic battery cells 1, and the first and

second portions

1011 and 1012 may each have one opening 111. For example, each of the first portion 1011 and the second portion 1012 may be a hollow rectangular parallelepiped and only one surface of each may be an opening surface, the opening 111 of the first portion 1011 and the opening 111 of the second portion 1012 are disposed to face each other, and the first portion 1011 and the second portion 1012 are engaged with each other to form the box 101 having a closed chamber. One of the first and

second portions

1011 and 1012 may be a rectangular parallelepiped having the opening 111, and the other may be a cover plate structure to close the opening 111 of the rectangular parallelepiped. A plurality of square battery cells 1 are connected in parallel or in series-parallel combination and then placed in a box 101 formed by buckling a first part 1011 and a second part 1012.

Optionally, battery 100 may also include other structures. For example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of prismatic battery cells 1, such as parallel connection or series-parallel connection. Specifically, the bus member may achieve electrical connection between the square battery cells 1 by connecting the electrode terminals of the square battery cells 1. Further, the bus bar member may be fixed to the electrode terminals of the prismatic battery cells 1 by welding. The electric energy of the square battery cells 1 can be further led out through the box 101 by the conductive mechanism. Alternatively, the conductive means may also belong to the bus bar member.

As will be described in detail below with respect to any one of the prismatic battery cells 1, fig. 3 shows a prismatic battery cell 1 according to an embodiment of the present application, where the prismatic battery cell 1 includes a case 11, an electrode assembly 12, and an end cap assembly 14. The housing 11 is a hollow rectangular parallelepiped or a cube, and one of the planes of the housing 11 has an opening 111 configured to have no wall so that the housing 11 communicates inside and outside. The end cap assembly 14 covers the opening 111 and is coupled to the case 11 to form a closed cavity for housing the electrode assembly 12, and the closed cavity is filled with an electrolyte, such as an electrolytic solution.

The electrode assembly 12 has a first pole piece, a second pole piece and a separator wound to form the electrode assembly 12, and the first pole piece, the second pole piece and the separator are not shown in the drawings of the present application, but those skilled in the art will understand how the first pole piece, the second pole piece and the separator are wound to form the electrode assembly 12 and will not be described in detail herein.

As shown in fig. 3, the first pole piece has a plurality of first tabs 121, and the plurality of first tabs 121 are subjected to a flattening treatment to form a first electricity lead-out portion; the second tab has a plurality of second tabs 122, and the plurality of second tabs 122 are subjected to a flattening treatment to form a second electrical lead-out portion. In the present embodiment, the first tab 121 and the second tab 122 are located at the same end of the electrode assembly 12, and the end cap assembly 14 is provided with a first electrode terminal 142 and a second electrode terminal 143, respectively, as shown in fig. 4 and 5, the first electrode terminal 142 is connected to the first tab 121 through the first adaptor 131, and the second electrode terminal 143 is connected to the second tab 122 through the second adaptor 132.

In other embodiments, the first tab 121 and the second tab 122 may be respectively located at two ends of the electrode assembly 12, the housing 11 of the prismatic battery cell 1 may respectively have openings 111 at two ends, each opening 111 is respectively provided with an end cap assembly 14, and the electrode terminal of each end cap assembly 14 is respectively connected with the corresponding tab through an adaptor.

Fig. 6 shows a schematic view of the first tab 121 and the second tab 122 flattened out of the front electrode assembly 12, fig. 7 shows a top view of the first tab 121 before flattening, fig. 7 can also be seen as a top view of the second tab 122 before flattening, a plurality of the first tabs 121 are stacked on each other and form a cylinder-like body, and a plurality of the second tabs 122 are also stacked on each other to form a cylinder-like body. The cylinder-like body can be placed into a round flattening cavity of the mechanical flattening device or completely covered by a round flattening head of the ultrasonic flattening device, so that the pole lugs can be flattened through the existing flattening device, a first electric leading-out part and a second electric leading-out part which are compact in structure and small in occupied space are formed, the distance between the electrode assembly 12 and the end cover assembly 14 is effectively reduced, and the energy density of the square battery monomer 1 is improved.

After the first tab 121 and the second tab 122 are respectively subjected to flattening treatment to form electric leading-out parts, the multilayer first tab 121 forms a compact integral first electric leading-out part, and the multilayer second tab 122 forms two compact integral second electric leading-out parts, so that the situation that an individual first tab 121 or an individual second tab 122 is redundant and inserted into a pole piece gap of the electrode assembly 12 is not easy to occur, the short circuit risk is reduced, and the safety is improved.

First utmost point ear 121 and second utmost point ear 122 are handled formation electricity extraction portion back through rubbing the level respectively, can use laser welding's mode to weld respectively in first adaptor 131 and second adaptor 132 to connect first electrode terminal 142 and second electrode terminal 143, need not like adopting ultrasonic welding's mode among the current square battery monomer, adopt laser welding's mode to be difficult to produce metal dust, effectively reduce the risk that the square battery monomer 1 of this application takes place the short circuit, and the security is better.

As shown in fig. 6, the electrode assembly 12 includes a flat region 12a, a first corner region 12b, and a second corner region 12c, the flat region 12a being located between the first corner region 12b and the second corner region 12 c. The first tab 121 is located in the first corner region 12b, and the second tab 122 is located in the second corner region 12 c.

As shown in fig. 6 and 7, during winding, the first tab 121 follows the first pole piece around the first corner region 12b to form a U-shape, and the second tab 122 follows the second pole piece around the second corner region 12c to form a U-shape. Wherein, the lengths of the first tabs 121 in the winding direction are equal, and the lengths of the second tabs 122 in the winding direction are equal.

In the direction from the inner layer to the outer layer of the electrode assembly 12, since the plurality of first tabs 121 are sequentially stacked in the first corner region 12b, the diameter of the U-shaped arc portion is sequentially increased, and both arms of the U-shape are sequentially shortened, so that both arms of the U-shape of the plurality of first tabs 121 form an arc-like profile, and thus the arc portion of the first tabs 121 and the arc-like portion are combined to form a cylinder-like body.

When the outermost first tab 121 is semicircular, the shape of the planar profile of the cylinder is more approximate to a circle, and the device can be better applied to the existing flattening equipment, and at this time, the length of the two arms of the U-shape of the outermost first tab 121 is 0. The length of the other first tab 121 of the inner layer can be obtained from the length of the outermost first tab 121, that is, as shown in fig. 7, the length of each first tab 121 in the winding direction is L, the thickness of the electrode assembly 12 is D, and L ═ pi × D/2.

Similarly, in the direction from the inner layer to the outer layer of the electrode assembly 12, since the plurality of second tabs 122 are sequentially stacked in the second corner region 12c, the diameter of the U-shaped arc portion is sequentially increased, and the two arms of the U-shape are sequentially shortened, so that the two arms of the U-shape of the plurality of second tabs 122 form an arc-like shape, and thus the arc portion of the second tab 122 and the arc-like portion are combined to form a cylinder-like body.

When the outermost second tab 122 is semicircular, the shape of the planar profile of the cylinder is more approximate to a circle, and the device can be better applied to the existing flattening equipment, and at this time, the two arms of the U-shape of the outermost second tab 122 are 0. The length of the other second tab 122 in the inner layer can be obtained from the length of the outermost second tab 122, that is, as shown in fig. 7, the length of each second tab 122 in the winding direction is L, the thickness of the electrode assembly 12 is D, and L ═ pi ×, D/2.

Fig. 8 shows a structure in which the cylinder-like body formed of the first tab 121 is subjected to a flattening process, and a structure in which the cylinder-like body formed of the second tab 122 is subjected to a flattening process. After the flattening treatment, the entire first tabs 121 serve as first electrical lead-out portions, and the entire second tabs 122 serve as second electrical lead-out portions.

In another embodiment, the first tab 121 and the second tab 122 may also be disposed in the flat region 12a, as shown in fig. 9, a plurality of tabs are sequentially stacked, the axes of symmetry of the plurality of tabs are on the same straight line, the thickness of the electrode assembly is D, and the length of the tabs gradually decreases from the inner layer to the outer layer of the electrode assembly 12 along the thickness direction of the electrode assembly, so that two ends of the plurality of tabs respectively form a shape similar to an arc, and the two shapes similar to an arc are combined to form a cylinder.

In order to make the shape of the prismatic battery cell 1 more regular, as shown in fig. 10, the cap plate 141 is formed with first and second

concave portions

1411 and 1412 that are concave toward the electrode assembly 12. As shown in fig. 11, the first concave portion 1411 corresponds to the first electrical lead portion, and the first electrode terminal 142 is provided in the first concave portion 1411. As shown in fig. 12, the second concave portion 1412 corresponds to the second electrical lead portion, and the second electrode terminal 143 is provided in the second concave portion 1412.

Because the cover plate 141 is sunken, the first electrode terminal 142 and the second electrode terminal 143 are respectively flush with the outer surface of the cover plate 141, and the outer surface of the cover plate 141, namely the surface of the cover plate 141 departing from the electrode assembly 12, so that the square battery cell 1 has a more regular appearance and is convenient to assemble and pack.

In order to better dissipate heat generated inside the electrode assembly 12, which is dissipated from the pole piece gaps into the inner space of the prismatic battery cell 1, as shown in fig. 13, in a further embodiment, the first pole piece of the electrode assembly 12 further has a plurality of third pole tabs 123, the second pole piece of the electrode assembly 12 further has a plurality of fourth pole tabs 124, the plurality of third pole tabs 123 are stacked on one another, the plurality of fourth pole tabs 124 are stacked on one another, and the third pole tabs 123 and the fourth pole tabs 124 are located in the flat region 12 a.

As shown in fig. 13, the third tab 123 is located in the flat region 12a and adjacent to the first corner region 12 b; a fourth tab 124 is located in the flat region 12a and adjacent the second corner region 12 c.

The third tab 123 and the fourth tab 124 do not need to be folded or flattened, and are mainly used to increase the heat dissipation area of the first pole piece and the second pole piece, so as to lead out the heat inside the electrode assembly 12 to the inner space of the single battery 100.

In order to prevent the third tab 123 and the fourth tab 124 from being deformed by pressure and having their ends inserted into the gap of the electrode assembly 12 to cause a short circuit risk, as shown in fig. 14, neither the third tab 123 nor the fourth tab 124 contacts the cap assembly 14.

Further, as shown in fig. 15, the height of the third tab 123 is less than or equal to the flattened height of the first tab 121, and the height of the fourth tab 124 is less than or equal to the flattened height of the second tab 122, so as to ensure that the third tab 123 and the fourth tab 124 do not contact the end cap assembly 14, and avoid the third tab 123 and the fourth tab 124 from being compressed.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A prismatic battery cell, comprising:

a housing having an opening;

2. A square battery cell according to claim 1, wherein the electrode assembly comprises a flat region, a first corner region and a second corner region, the flat region being located between the first corner region and the second corner region, the first tab being located at the first corner region.

3. The prismatic battery cell according to claim 2, wherein each of the first tabs is U-shaped before undergoing the flattening process, and each of the first tabs has an equal length in the winding direction.

4. The prismatic battery cell according to claim 3, wherein the first tab has a length L in the winding direction, the electrode assembly has a thickness D, and L and D satisfy the following relationship:

L＝π＊D/2。

5. the prismatic battery cell according to any one of claims 2 to 4, wherein the second tab has a plurality of second tabs, the plurality of second tabs are subjected to a flattening treatment to form a second power lead-out portion, and the plurality of second tabs are laminated with each other to form a cylinder-like body before being subjected to the flattening treatment;

6. The prismatic cell of claim 5, wherein the second tab is located at the second corner region.

7. The square battery cell according to claim 5, wherein the cap plate is formed with a first recess corresponding to the first electrical lead-out position and a second recess corresponding to the second electrical lead-out position, the first recess being recessed toward the electrode assembly, the first electrode terminal being provided in the first recess, and the second electrode terminal being provided in the second recess.

8. The prismatic battery cell according to claim 1, wherein the second tab has a plurality of second tabs, the plurality of second tabs are subjected to a flattening treatment to form a second electricity lead-out portion, and the plurality of second tabs are stacked on each other to form a cylinder-like body before being subjected to the flattening treatment;

9. The prismatic battery cell according to claim 8, wherein the electrode assembly comprises a flat region, a first corner region and a second corner region, the flat region being located between the first corner region and the second corner region, the second tab being located at the second corner region.

10. The square battery cell according to claim 8, wherein the cap plate is formed with a first recess corresponding to the first electrical lead-out position and a second recess corresponding to the second electrical lead-out position, the first recess being recessed toward the electrode assembly, the first electrode terminal being provided in the first recess, and the second electrode terminal being provided in the second recess.

11. The prismatic cell according to any of claims 2-4, wherein the first pole piece further has a plurality of third tabs, the plurality of third tabs being stacked on top of each other; and/or the presence of a gas in the gas,

the second pole piece also has a plurality of fourth lugs, and the plurality of fourth lugs are stacked on one another.

12. The prismatic battery cell of claim 11, wherein the third tab is located in the flat region and proximate to the first corner region and the fourth tab is located in the flat region and proximate to the second corner region.

13. The prismatic cell according to claim 1, wherein the first pole piece further has a plurality of third tabs, the plurality of third tabs being stacked on one another; and/or the presence of a gas in the gas,

14. The prismatic battery cell of claim 13, wherein the electrode assembly comprises a flat region, a first corner region and a second corner region, the flat region being located between the first corner region and the second corner region, the third tab being located at the flat region and proximate to the first corner region, and the fourth tab being located at the flat region and proximate to the second corner region.

15. A battery comprising a prismatic cell according to any one of claims 1 to 14.

16. An electrical device comprising the battery of claim 15.