CN219937107U

CN219937107U - Battery core

Info

Publication number: CN219937107U
Application number: CN202320967925.8U
Authority: CN
Inventors: 车佩佩; 翟玮
Original assignee: Vision Power Technology Hubei Co ltd
Current assignee: Vision Power Technology Hubei Co ltd
Priority date: 2023-04-25
Filing date: 2023-04-25
Publication date: 2023-10-31
Anticipated expiration: 2033-04-25

Abstract

The utility model provides a battery cell, and relates to the technical field of battery cells. The battery cell comprises a shell, and a containing cavity is arranged in the shell; the electrode assembly comprises a plurality of pole pieces, a diaphragm is arranged between the pole pieces, and the electrode assembly is arranged in the accommodating cavity; and the extrusion part is arranged outside the electrode assemblies and extrudes the pole piece so that the pole piece is attached to the adjacent diaphragm. According to the utility model, the extrusion part is arranged outside the electrode assembly, and the extrusion part extrudes the electrode plate, so that the electrode plate is attached to the adjacent diaphragm, the electrode plate in the electrode assembly is in an extruded state, the electrode plate has larger initial pressure, the electrode plate is attached tightly to the electrode plate, the expansion and contraction of the electrode plate during charging and discharging are reduced, and the occurrence of wrinkling is reduced.

Description

Battery core

Technical Field

The utility model relates to the field of electric cores, in particular to an electric core.

Background

The lithium ion power battery is currently generally used as a main power source of a new energy automobile, various technologies of the lithium ion power battery are rapidly developed in recent years, and the square lithium ion power battery is a very common battery structure of the lithium ion power battery for the automobile.

In order to reduce wrinkling of the pole piece, the existing method is to increase a pattern making gap on the pole piece, reserve a space for charge-discharge expansion and contraction, adjust winding tension and the like, but the wrinkling caused by the contraction and expansion of the pole piece cannot be greatly improved.

Disclosure of Invention

In view of the above drawbacks of the prior art, the present utility model provides a battery cell to improve the technical problem that the existing pole piece is easy to wrinkle.

To achieve the above and other related objects, the present utility model provides a battery cell comprising: a housing provided with a receiving chamber; the electrode assembly comprises a plurality of pole pieces, a diaphragm is arranged between the pole pieces, and the electrode assembly is arranged in the accommodating cavity; and the extrusion part is arranged outside the electrode assemblies and extrudes the pole piece so that the pole piece is attached to the adjacent diaphragm. In an embodiment of the utility model, the extruding part comprises a plate-shaped extruding part arranged parallel to the pole piece, a plurality of electrode assemblies are arranged in the accommodating cavity, and the plate-shaped extruding part is arranged between at least two adjacent electrode assemblies.

In one embodiment of the present utility model, the projection of the plate-shaped pressing portion in the direction perpendicular to the large surface of the electrode assembly covers the projection of the electrode assembly in the direction of the large surface of the electrode assembly.

In an embodiment of the utility model, the plate-shaped pressing portion is an elastic member.

In one embodiment of the present utility model, the ratio of the sum of the thickness of the electrode assembly and the thickness of the plate-shaped pressing portion to the thickness of the receiving chamber is 87% to 94%.

In an embodiment of the utility model, the extruding part includes a heat shrinkage film, and the heat shrinkage film is sleeved outside the electrode assembly.

In an embodiment of the utility model, the heat-shrinkable film is a bag-shaped structure with an opening at one end, and the direction of the opening of the heat-shrinkable film is the same as the direction of the opening of the shell.

In an embodiment of the present utility model, a plurality of through holes are disposed on the heat shrinkable film.

In one embodiment of the present utility model, the heat shrink film covers the through holes in the large area of the electrode assembly at a greater arrangement density than the through holes in other areas of the heat shrink film.

In an embodiment of the utility model, the plurality of electrode assemblies form a combined core body, and the heat shrinkage film is sleeved outside the combined core body.

The utility model has the beneficial effects that in combination with the prior art:

the existing pole piece has the phenomenon of wrinkling, and the wrinkling of the pole piece cannot be well improved by reserving a charge-discharge expansion space, adjusting winding tension and the like. According to the utility model, the extrusion part is arranged outside the electrode assembly, and the extrusion part extrudes the electrode plate, so that the electrode plate is attached to the adjacent diaphragm, the electrode plate in the electrode assembly is in an extruded state, the electrode plate has larger initial pressure, the electrode plate is attached tightly to the electrode plate, the expansion and contraction of the electrode plate during charging and discharging are reduced, and the occurrence of wrinkling is reduced.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a front view of an exemplary cell of the present utility model;

FIG. 2 is a left side view of an exemplary cell portion structure of the present utility model;

FIG. 3 is a schematic view of another exemplary cell segment structure according to the present utility model;

fig. 4 is a left side view of another exemplary cell segment structure of the present utility model.

Description of element reference numerals

100. A housing; 110. a receiving chamber; 200. an electrode assembly; 210. a pole; 310. a plate-like pressing portion; 320. a heat shrinkage film; 321. a through hole; 400. an insulating film; 500. and a top cover.

Detailed Description

Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. It is also to be understood that the terminology used in the examples of the utility model is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the utility model. The test methods in the following examples, in which specific conditions are not noted, are generally conducted under conventional conditions or under conditions recommended by the respective manufacturers.

Where numerical ranges are provided in the examples, it is understood that unless otherwise stated herein, both endpoints of each numerical range and any number between the two endpoints are significant both in the numerical range. 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 utility model belongs and to which this utility model belongs, and any method, apparatus, or material of the prior art similar or equivalent to the methods, apparatus, or materials described in the examples of this utility model may be used to practice the utility model.

It should be understood that the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like are used in this specification for descriptive purposes only and not for purposes of limitation, and that the utility model may be practiced without materially departing from the novel teachings and without departing from the scope of the utility model.

The term "and/or" in the present utility model is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present utility model, the character "/" generally indicates that the front and rear related objects are an or relationship.

The term "plurality" as used herein refers to two or more (including two).

In the process of charging and discharging the battery cell, the pole piece expands and contracts, so that the pole piece is wrinkled, the existing method is to increase the space reserved for the expansion and contraction of charging and discharging on the pole piece, or to adjust the winding tension, and the like, but the wrinkling caused by the expansion and contraction of the pole piece cannot be improved greatly.

Referring to fig. 1 to 2, the present utility model provides a battery cell, which includes a case 100, an electrode assembly 200, an extrusion part, and a top cap 500.

The case 100 has a hollow structure provided with an opening, and a receiving chamber 110 for receiving the electrode assembly 200 and the electrolyte is formed in the case 100. The housing 100 may be provided with one opening or two openings, and if two openings are provided, the two openings are preferably symmetrically disposed on two sides of the housing. The housing 100 may be of various shapes, such as a cylinder, a prism (e.g., a rectangular parallelepiped), etc. The electrode assembly 200 may be a lamination structure or a winding structure. The top cap 500 closes the opening of the case 100 to seal the receiving chamber 110, facilitating electrolyte infiltration of the electrode assembly 200.

The electrode assembly 200 includes a plurality of electrode sheets with a separator disposed therebetween. The pole pieces comprise a positive pole piece and a negative pole piece, wherein the positive pole piece and the negative pole piece are arranged at intervals, and a diaphragm is arranged between the positive pole piece and the negative pole piece. The battery cell mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector; the positive current collector comprises a positive current collecting part and a positive lug connected to the positive current collecting part, wherein the positive current collecting part is coated with a positive active material layer, and the positive lug is not coated with the positive active material layer. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector comprises a negative electrode current collecting part and a negative electrode tab connected to the negative electrode current collecting part, wherein the negative electrode current collecting part is coated with a negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the anode current collector may be copper, the anode active material layer includes an anode active material, and the anode active material may be carbon or silicon, or the like. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc.

Illustratively, the pressing part is disposed outside the electrode assembly 200, and presses the electrode sheets such that the electrode sheets are attached to adjacent separators, in other words, the electrode sheets are attached to each other. The pole pieces are subjected to larger initial pressure, the pole pieces in the electrode assembly 200 are tightly attached, and in the charging and discharging process, the pole pieces are difficult to expand and contract due to the pressure of the extrusion part, so that pole piece wrinkling caused by expansion and contraction of the pole pieces is reduced. Preferably, the extrusion part extrudes the pole piece along the direction vertical to the pole piece, which is more beneficial to the lamination of the pole piece and the diaphragm, and the pole piece is tightly laminated with the adjacent pole piece.

Referring to fig. 2, the extrusion part includes a plate-shaped extrusion part 310, the plate-shaped extrusion part 310 is disposed parallel to the pole piece, and after the plate-shaped extrusion part 310 and the electrode assembly 200 are coated together, the plate-shaped extrusion part 310 extrudes the pole piece in a direction perpendicular to the pole piece, in other words, the pole piece is subjected to extrusion force perpendicular to the pole piece, so that the mutual lamination between the pole pieces can be better ensured.

Illustratively, the electrode assembly 200 is coated with Mylar (polyester film) and the Mylar is coated with a glue and then wrapped around the electrode assembly 200. The plate-shaped pressing part 310 may be disposed between the electrode assembly 200 and the Mylar film, i.e., the plate-shaped pressing part 310 is uniformly covered with the Mylar film after being stacked with the electrode assembly 200. The plate-shaped pressing part 310 may be disposed outside the Mylar-coated electrode assembly 200. Preferably, after the plate-shaped extrusion part 310 is stacked with the electrode assembly 200, the plate-shaped extrusion part 310 is uniformly coated by a Mylar film, the positions of the plate-shaped extrusion part 310 and the electrode assembly 200 are kept relatively fixed, the stress stability of the pole piece is ensured, and particularly, when the electrode assembly 200 is installed in the accommodating cavity 110, the battery cell is used in a bumpy manner, and the like, the positions between the electrode assembly 200 and the extrusion part 310 are kept relatively unchanged.

Referring to fig. 2, in the development and production of square lithium ion batteries, cost reduction is required, the Mylar film is expensive, and a dedicated rubberizing mechanism is required for rubberizing, which results in high cost when the Mylar film covers the electrode assembly 200, so that other insulating films 400 such as PP film and PET film are considered to replace the Mylar film. However, insulating films such as PP films, which do not have a ceramic coating, do not have a PVDF gel layer, have less binding to the electrode assembly 200 than a rubberized Mylar film, and are more prone to pole piece wrinkling. In one embodiment, a plurality of electrode assemblies 200, such as 2, 3, 4 or more, are disposed in the battery cell, and a plate-shaped pressing portion 310 is disposed between at least two adjacent electrode assemblies 200. By providing the plate-shaped pressing parts 310 between the electrode assemblies 200, the electrode assemblies 200 are effectively pressed, so that the pole pieces in the electrode assemblies 200 are ensured to be mutually stuck when the non-Mylar film is used, and pole piece wrinkling is reduced.

Referring to fig. 2, an exemplary electrode assembly 200 includes a composite core body, an insulating film 400 is coated outside the composite core body, a plate-shaped extrusion part 310 is disposed between the electrode assemblies 200, and the plate-shaped extrusion part 310 and the electrode assembly 200 are jointly coated in the composite core body through the insulating film 400, so that the plate-shaped extrusion part 310 and the electrode assembly 200 can be effectively fixed, the electrode assembly 200 and the plate-shaped extrusion part 310 are ensured to be relatively fixed, and the plate-shaped extrusion part 310 always extrudes a pole piece in the electrode assembly 200. Illustratively, the plate-shaped extrusion part 310 may be further disposed at the outer side of the core assembly, in other words, two large surfaces of the core assembly are abutted against the plate-shaped extrusion part 310, and the plate-shaped extrusion part 310 and the core assembly are coated together by the insulating film 300, so that the pole piece in the electrode assembly 200 can be effectively extruded, and pole piece wrinkling is reduced.

Illustratively, the plate-shaped pressing portion 310 is an elastic member having elastic deformation, and the plate-shaped pressing portion 310 may be PE foam, PP foam, or the like. In one embodiment, the plate-shaped pressing part 310 having elastic deformation is disposed between the electrode assemblies 200, on one hand, a great pressure can be applied to the pole pieces in the initial stage to bind the pole pieces, and the shrinkage and expansion of the pole pieces caused by charge and discharge are reduced, so that the wrinkling of the pole pieces is reduced; on the other hand, the plate-shaped pressing part 310 may increase an initial group margin, i.e., a ratio of the sectional area of the electrode assembly 200 to the sectional area of the receiving chamber 110 is large. When the battery cell is in the later period of life, the expansion force of the electrode assembly 200 can compress the plate-shaped extrusion part 310, so that on one hand, the pole piece can be always kept under larger pressure and is not easy to expand and contract, and on the other hand, the plate-shaped extrusion part 310 is elastically deformed in a certain pressure range, and on the premise of not wasting the internal space of the battery cell, the rigid stress of the shell 100 is relieved, the extrusion of the electrode assembly 200 to the shell 100 is reduced, so that the bulge degree of the shell 100 is reduced, the influence on a module is reduced, the service lives of a battery module and a battery pack are prolonged, and the use safety of the battery pack is ensured. PE foam, PP foam and the like are easy to process, and the battery cell with various sizes is easy to customize foam with proper sizes, so that the adaptation cost and the production cost are low. The PE and PP foam has low price and low material cost; the assembly is convenient, the production process cost is low, and the production cost is effectively reduced. In another embodiment, the plate-shaped pressing part 310 is disposed between the electrode assembly 200 and the case 100.

Referring to fig. 2, the ratio of the sum of the thickness of the electrode assembly 200 and the thickness of the plate-shaped pressing portion 310 to the thickness of the receiving chamber 110 is 87% to 94%, and the thickness direction of the receiving chamber 110 is the X-axis direction in fig. 2, and the ratio may be any value between 87% and 94%, such as 87%, 89%, 90%, 91%, 94%, etc. The sum of the thicknesses of the electrode assembly 200 and the plate-shaped pressing part 310 accounts for 87% -94% of the thickness of the receiving chamber 110, thereby ensuring a group margin and facilitating the placement into the case 100 after the insulating film 400 is wrapped.

Referring to fig. 2, exemplary projections of the plate-shaped pressing part 310 in a direction perpendicular to the large-surface direction of the electrode assembly 200 cover projections of the electrode assembly 200 in the large-surface direction of the electrode assembly 200, in other words, the outer circumference of the electrode assembly 200 does not exceed the outer circumference of the plate-shaped pressing part 310. Illustratively, the cross section of the plate-shaped extrusion part 310 may be rectangular, circular, diamond-shaped or any other shape, preferably, the cross section of the plate-shaped extrusion part 310 is the same as the large surface of the electrode assembly 200, the large surface of the electrode assembly 200 refers to the largest surface of the outer surface of the electrode assembly 200, when the electrode assembly 200 and the plate-shaped extrusion part 310 are jointly wrapped by the insulating film 400, the periphery of the pole piece does not exceed the plate-shaped extrusion part 310, and when the insulating film 400 is tightened, the plate-shaped extrusion part 310 reduces the stress of the pole piece parallel to the pole piece direction, ensures the extrusion force perpendicular to the pole piece direction, avoids the problem of wrinkling of the pole piece when the insulating film 400 is wrapped, improves the product quality, and reduces pole piece wrinkling. For example, when a composite core composed of a plurality of electrode assemblies 200 is disposed in one receiving chamber 100, the plate-shaped pressing parts 310 may be disposed between the electrode assemblies 200 or may be disposed at both sides of the composite core. When the plate-shaped pressing parts 310 are disposed between the electrode assemblies 200, the number of the plate-shaped pressing parts 310 can be reduced while the amount of pressing deformation of the plate-shaped pressing parts 310 in the Y-axis direction is reduced, the space inside the accommodating chamber 100 can be saved, and the electrode assemblies 200 having a larger thickness can be accommodated in the accommodating chamber 110. The plate-shaped pressing parts 310 are disposed at both sides of the lamination body, that is, when the plate-shaped pressing parts 310 are in contact with the large surface of the lamination body, the plate-shaped pressing parts 310 provide support, effectively preventing the electrode assembly 200 from being deformed by pressing in the Y-axis direction. Preferably, plate-shaped pressing parts 310 are disposed between the electrode assemblies 200 to increase the cell energy density while reducing pole piece wrinkling. Referring to fig. 3 to 4, in an embodiment, the extruding portion includes a heat-shrinkable film 320, the heat-shrinkable film 320 is sleeved outside the electrode assembly 200, the heat-shrinkable film 320 can bind the electrode assembly 200 after heat shrinkage, so as to improve the extrusion force applied to the electrode sheet, and to bind the electrode sheet, thereby reducing wrinkling of the electrode sheet. The electrode assembly 200 is placed in the receiving cavity of the heat shrinkage film 320, and then the heat shrinkage film 320 is heated to 95-110 ℃ so that the heat shrinkage film 320 tightly binds the electrode assembly 200, thereby binding the expansion and contraction of the electrode sheet. The heat shrinkage film 320 can be a heat shrinkage film 320 such as PVC, PET, PP, PE, preferably a PP heat shrinkage film 320 or a PET heat shrinkage film 320, the existing diaphragm is more in PP film selection, and the PP heat shrinkage film 320 and the diaphragm are the same in material, so that the cost can be reduced. The extrusion part selects the heat-shrinkable film 320 to replace the original Mylar film, a rubberizing mechanism is needed for rubberizing during the production of the existing Mylar, the production process is complicated, the cost is high, the heat-shrinkable film 320 is used for replacing the Mylar, on one hand, the raw material cost can be reduced, and the purchase cost of the heat-shrinkable film 320 is far lower than that of Myalr; on the other hand, the heat-shrinkable film 320 does not need a special rubberizing mechanism for rubberizing, and the existing electric core baking device can be utilized for baking and heating the heat-shrinkable film 320, so that the production procedures are reduced, and the production cost is reduced; the process change difficulty is small, the change of the original cell production and manufacturing process is small, and the change cost is low. In the existing production process of the battery cell, the battery cell needs to be baked before the electrolyte is injected to ensure the drying of the electrode assembly 200, and the baking of the heat shrinkage film 320 can be performed by using the existing baking process without additionally adding the baking process.

Illustratively, the heat shrinkage film 320 is a pouch-shaped structure provided with an opening, the opening of the heat shrinkage film 320 faces the opening of the receiving cavity 110, the opening of the heat shrinkage film 320 is consistent with the opening of the case 100, and the electrode tab of the electrode assembly 200 is electrically connected with the electrode post provided on the case 100, thereby facilitating the assembly of the top cap 500.

For example, one or more electrode assemblies 200 may be included in the battery cell, and when only one electrode assembly 200 is included, a heat shrink film 320 is wrapped around the electrode assembly 200 to insulate the electrode assembly 200 from the case 100. Referring to fig. 4, in an embodiment, the accommodating cavity 110 includes a plurality of electrode assemblies 200, and each electrode assembly 200 uses a heat-shrinkable film 320, that is, only one electrode assembly 200 is in the accommodating cavity of one heat-shrinkable film 320, so that each electrode assembly 200 can be bound to ensure that the pole piece is subjected to an initial extrusion force. In another embodiment, the battery core includes a plurality of electrode assemblies 200, the plurality of electrode assemblies 200 form a combined core body, each combined core body uses a heat shrinkage film 320, in other words, a containing cavity of the heat shrinkage film 320 contains the plurality of electrode assemblies 200, preferably, a containing cavity 110 contains the plurality of motor assemblies 200 using a heat shrinkage film 320, which can effectively reduce the wrapping and heat shrinkage processes and reduce the production cost.

Referring to fig. 3, the heat-shrinkable film 320 is provided with a plurality of through holes 321, so that the electrolyte can infiltrate the electrode assembly 200 conveniently by providing the through holes 321, thereby improving the infiltration efficiency. In an embodiment, the plurality of through holes 321 are arranged in a linear array, the through holes 321 are uniformly arranged, and the electrolyte can uniformly infiltrate the electrode assembly 200, so that the infiltration efficiency is improved, and the infiltration effect is ensured. Illustratively, the diameter of the through hole 321 is 4-12 mm, and any value of 4-12 mm, such as 4mm, 5mm, 7mm, 9mm, 10mm, 12mm, etc., can be selected for the diameter, so that the impregnation efficiency of the electrolyte to the electrode assembly 200 is improved under the premise of ensuring the strength of the heat shrinkage film 320.

In an embodiment, two electrode assemblies 200 form a combined core, the two electrode assemblies 200 are bound and fixed through a binding tape, a heat shrinkage film 320 is wrapped outside the combined core, a plate-shaped extrusion part 310 is arranged between the two electrode assemblies 200 and parallel to the pole piece, the plate-shaped extrusion part 310 is preferably foam, the periphery of the foam is flush with or exceeds the periphery of the electrode assemblies 200, the heat shrinkage film 320 is baked to tighten the heat shrinkage film 320, the electrode assemblies 200 are bound, the pole piece is extruded, and expansion and shrinkage of the pole piece in the charge and discharge process are reduced. The periphery of the foam is flush with or exceeds the periphery of the electrode assembly 200, so that the force applied to the pole pieces in parallel is reduced, the pole pieces are ensured to be subjected to extrusion force perpendicular to the direction of the pole pieces, the pole pieces are mutually close to each other, and wrinkling caused by expansion and contraction of the pole pieces is avoided.

The heat-shrinkable film 320 is wrapped outside the electrode assembly 200, and the side surface of the heat-shrinkable film 320 is baked and heated first, in other words, the side surface of the heat-shrinkable film 320 is baked and heated first, and the side surface of the heat-shrinkable film 320 is pre-shrunk, so that the shrinkage of the heat-shrinkable film 320 parallel to the surface of the electrode plate can be reduced, when the heat-shrinkable film 320 binds the electrode assembly 200, the binding force of the extrusion part acts more in the direction perpendicular to the electrode plate, thereby preventing the electrode plate from wrinkling when the heat-shrinkable film 320 is heat-shrunk, and improving the product quality. Illustratively, the heat shrinkage film 320 heat-shrinks and binds the electrode assembly 200, and after being installed into the casing 100, the battery cell is baked, and the baking temperature is consistent with the shrinkage temperature of the heat shrinkage film 320, so that the production process can be saved, the battery cell can be kept dry before liquid injection, the electrolyte infiltration effect is ensured, and the quality of the battery cell is improved. In one embodiment, the density of the through holes 321 in the large area of the electrode assembly 200 covered by the heat-shrinkable film 320 is greater than the density of the through holes in other areas of the heat-shrinkable film 320, when heat shrinkage is performed, the side surface of the heat-shrinkable film 320 can be pre-shrunk first, and then the whole heat-shrinkable film 320 is heat-shrunk, the pre-shrinking area of the heat-shrinkable film 320 needs to be heat-shrunk twice, the density of the through holes in the pre-shrinking area of the heat-shrinkable film 320 is smaller than the density of the through holes 321 in the large area of the heat-shrinkable film 320, so that the through holes 321 are communicated when the side surface area of the heat-shrinkable film 320 is heat-shrunk, the heat-shrinkable film 320 is prevented from being damaged, and the binding strength of the heat-shrinkable film 320 to the electrode assembly is ensured.

The battery core of the utility model can be used for an electric device, and the electric device can be a vehicle, a mobile phone, portable equipment, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool and the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the utility model does not limit the electric device in particular.

According to the battery cell, the electrode plates are extruded by the extrusion part, so that the electrode plates are attached to adjacent diaphragms, namely, the electrode plates are tightly attached to each other, expansion and shrinkage of the electrode plates in the charge and discharge process are prevented, and the wrinkling problem of the electrode plates is greatly improved; the battery cell can also cancel the use of Mylar film, save working procedures and reduce production and material cost. Therefore, the utility model effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance. The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. A cell, comprising:

a housing provided with a receiving chamber;

the electrode assembly comprises a plurality of pole pieces, a diaphragm is arranged between the pole pieces, and the electrode assembly is arranged in the accommodating cavity;

and the extrusion part is arranged outside the electrode assemblies and extrudes the pole piece so that the pole piece is attached to the adjacent diaphragm.

2. The cell of claim 1, wherein the pressing portion comprises a plate-shaped pressing portion disposed parallel to the pole piece, a plurality of the electrode assemblies are disposed in the receiving chamber, and the plate-shaped pressing portion is disposed between at least two adjacent electrode assemblies.

3. The cell of claim 2, wherein a projection of the plate-like pressing portion in a direction perpendicular to the large-surface direction of the electrode assembly covers a projection of the electrode assembly in a direction perpendicular to the large-surface direction of the electrode assembly.

4. The cell of claim 2, wherein the plate-like compression is an elastic member.

5. The cell of claim 2, wherein the ratio of the sum of the electrode assembly thickness and the plate-like press portion thickness to the receiving cavity thickness is 87% to 94%.

6. The cell of any one of claims 1-5, wherein the extruded portion comprises a heat shrink film that is sleeved outside the electrode assembly.

7. The battery cell according to claim 6, wherein the heat shrinkage film is a bag-shaped structure with an opening at one end, and the direction of the opening of the heat shrinkage film is the same as the direction of the opening of the housing.

8. The cell of claim 6, wherein the heat shrink film is provided with a plurality of through holes.

9. The cell of claim 8, wherein the density of the arrangement of through holes in the area of the large face of the electrode assembly covered by the heat shrink film is greater than the density of the arrangement of through holes in other areas of the heat shrink film.

10. The cell of claim 6, wherein a plurality of the electrode assemblies comprise a composite core body, and the heat shrink film is sleeved outside the composite core body.