CN213042944U

CN213042944U - Electrode assembly, laminate polymer battery core and power battery

Info

Publication number: CN213042944U
Application number: CN202021865043.3U
Authority: CN
Inventors: 范大兵
Original assignee: Evergrande New Energy Technology Shenzhen Co Ltd
Current assignee: Evergrande New Energy Technology Shenzhen Co Ltd
Priority date: 2020-08-27
Filing date: 2020-08-27
Publication date: 2021-04-23
Anticipated expiration: 2030-08-27

Abstract

The utility model relates to the technical field of batteries, the utility model provides an electrode assembly, soft-packaged electrical core and power battery, above-mentioned electrode assembly includes a plurality of electrode units and at least one adsorption piece that is used for adsorbing electrolyte, each electrode unit is established ties in proper order, each adsorption piece is located respectively between two adjacent electrode units, above-mentioned electrode assembly is through establishing ties a plurality of electrode units in proper order, effectively increase the length size of soft-packaged electrical core, make the capacity of soft-packaged electrical core increase thereupon, can effectively reduce the quantity of the auxiliary connection spare between each soft-packaged electrical core simultaneously, thereby effectively improve power battery's energy density; in addition, above-mentioned each adsorbs the piece and can effectively adsorb and store the electrolyte in the laminate polymer battery core, and the electrolyte in each adsorbs the piece can flow in the electrode unit that corresponds to keep the inside electrolyte of each electrode unit sufficient, thereby effectively improve laminate polymer battery core's charge-discharge cycle life, and then effectively improve power battery's life.

Description

Electrode assembly, laminate polymer battery core and power battery

Technical Field

The utility model relates to the technical field of batteries, especially, provide an electrode subassembly, laminate polymer battery core and power battery.

Background

With the development of new energy industry, electric vehicles are gradually popularized, and the working performance of the power battery, which is used as a core component of the electric vehicle, directly affects the popularization and application of the electric vehicle.

Power battery passes through the series-parallel mode by a plurality of laminate polymer battery cores and constitutes usually, however, because the size of traditional laminate polymer battery core is less, the capacity also reduces thereupon, leads to power battery's energy density to descend, does not accord with electric automobile's continuation of the journey requirement, and traditional laminate polymer battery core's charge-discharge cycle life is shorter moreover, leads the life of power battery to shorten, also does not accord with battery car's durability requirement.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an electrode subassembly, laminate polymer core and power battery aims at solving the technical problem that current laminate polymer core is capacious and charge-discharge cycle life is short.

In order to achieve the above object, the utility model adopts the following technical scheme: an electrode assembly comprises a plurality of electrode units and at least one adsorption piece for adsorbing electrolyte, wherein the electrode units are sequentially connected in series, and each adsorption piece is arranged between every two adjacent electrode units.

The utility model provides an electrode subassembly has following beneficial effect at least: the plurality of electrode units are sequentially connected in series, so that the length size of the soft-package battery cell is effectively increased, the capacity of the soft-package battery cell is increased, the number of auxiliary connecting pieces among the soft-package battery cells can be effectively reduced, and the energy density of the power battery is effectively improved; in addition, above-mentioned each adsorbs the piece and can effectively adsorb and store the electrolyte in the laminate polymer core, at laminate polymer core's charge-discharge cycle in-process, the inside electrolyte of each electrode unit can be consumed by a large amount, lead to the inside electrolyte concentration of each electrode unit to rise fast, at this moment, the electrolyte in each adsorbs the piece can flow in the electrode unit that corresponds, in order to keep the inside electrolyte of each electrode unit sufficient, thereby effectively improve laminate polymer core's charge-discharge cycle life, and then effectively improve power battery's life.

In one embodiment, the electrode assembly further comprises at least one electrical connector, and two adjacent electrode units are connected in series through the electrical connector.

By adopting the technical scheme, the connection stability between the two adjacent electrode units is effectively improved.

In one embodiment, one end of each electrode unit extends outwards to form a positive current collector, the other end of each electrode unit extends outwards to form a negative current collector, each electrical connector comprises a first clamping portion and a second clamping portion which are connected with each other, each first clamping portion is used for clamping the corresponding positive current collector, and each second clamping portion is used for clamping the corresponding negative current collector.

By adopting the technical scheme, the connection stability between the two adjacent electrode units can be further improved.

In one embodiment, the electrode assembly comprises a plurality of adsorption pieces, each electric connection piece is provided with a first surface and a second surface which are arranged oppositely, and each adsorption piece covers the first surface and the second surface of each electric connection piece respectively.

Through adopting above-mentioned technical scheme, when the inside electrolyte concentration of each electrode unit risees, the electrolyte in each absorption piece can be supplemented to corresponding electrode unit in evenly, can further improve the charge-discharge cycle life of laminate polymer core, and then improve power battery's life more effectively.

In one embodiment, the electrode assembly further includes a positive tab, a negative tab, and a first protection member and a second protection member disposed adjacent to each other, the positive tab and the negative tab are disposed at opposite ends of the electrode assembly, the first protection member is electrically connected to the positive tab, and the second protection member is electrically connected to the negative tab.

Through adopting above-mentioned technical scheme, when the laminate polymer core received external force and produced when warping, first protection piece takes place the contact with the second protection piece easily, in case first protection piece contacts with the second protection piece, can be with the laminate polymer core short circuit, reach the purpose to laminate polymer core fast discharge, produced heat also can be fast through first protection piece and second protection piece outside diffusion behind the laminate polymer core short circuit simultaneously, effectively avoid laminate polymer core to cause the condition of thermal runaway because of warping, thereby effectively improve power battery's security performance.

In one embodiment, the electrode assembly has a third surface and a fourth surface which are oppositely arranged, the first protection piece and the second protection piece are both in a plate-shaped structure, the first protection piece covers the third surface of the electrode assembly, and the second protection piece covers the fourth surface of the electrode assembly.

By adopting the technical scheme, on one hand, when the soft package battery core is deformed due to external force, the first protection piece is effectively ensured to be in contact with the second protection piece, so that the purpose of quickly discharging the soft package battery core is achieved, and meanwhile, heat generated after the short circuit of the soft package battery core can be quickly diffused to the outside through the first protection piece and the second protection piece, so that the situation of thermal runaway caused by deformation of the soft package battery core is effectively avoided, and the safety performance of the power battery is effectively improved; on the other hand, be in under normal condition at soft-packaged electrical core, first protection piece and second protection piece are common with each electrode unit centre gripping, effectively promote soft-packaged electrical core's structural strength, and soft-packaged electrical core also can pass through first protection piece and second protection piece external diffusion at the produced heat of during operation simultaneously, effectively promotes soft-packaged electrical core's radiating effect.

In one embodiment, the first protective member has a thickness of 100 μm to 200 μm, and/or the second protective member has a thickness of 100 μm to 200 μm.

Through adopting above-mentioned technical scheme, can effectively guarantee the support intensity of first protection piece and second protection piece, the weight and the occupation space that can effectively control first protection piece simultaneously and the weight and the occupation space of second protection piece to guarantee power battery's energy density.

In one embodiment, each electrode unit comprises a positive plate, a negative plate and a diaphragm, and each diaphragm is arranged between the corresponding positive plate and the corresponding negative plate.

In order to achieve the above object, the utility model also provides a soft-packaged electrical core, including plastic-aluminum membrane and above-mentioned electrode subassembly, the plastic-aluminum membrane is used for wrapping up electrode subassembly.

Since the above-mentioned soft package battery cell adopts all embodiments of the above-mentioned electrode assembly, at least all the beneficial effects of the above-mentioned embodiments are obtained, and are not described in detail herein.

In order to achieve the above object, the utility model also provides a power battery, including above-mentioned laminate polymer core.

Since the power battery adopts all the embodiments of the soft package battery core, at least all the beneficial effects of the embodiments are achieved, and the detailed description is omitted.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a soft-package battery cell provided in an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an electrode assembly according to an embodiment of the present invention;

FIG. 3 is a schematic structural view illustrating a connection portion between two adjacent electrode units in the electrode assembly shown in FIG. 2;

FIG. 4 is a schematic view of the electrode assembly of FIG. 2 with the absorbent member removed;

FIG. 5 is a schematic structural view illustrating a connection portion between two adjacent electrode units in the electrode assembly shown in FIG. 4;

FIG. 6 is a schematic structural view of the electrode assembly shown in FIG. 2 after the first and second protectors are provided;

fig. 7 is a sectional view taken along line a-a of the electrode assembly shown in fig. 6.

Wherein, in the figures, the respective reference numerals:

10. the electrode assembly comprises an electrode assembly body 11, an electrode unit 111, a positive electrode current collector 112, a negative electrode current collector 113, a positive electrode sheet 114, a negative electrode sheet 115, a diaphragm 12, an adsorption piece 13, an electric connection piece 131, a first clamping part 132, a second clamping part 133, a first surface 134, a second surface 14, a positive electrode tab 15, a negative electrode tab 16, a first protection piece 161, a first electric connection part 17, a second protection piece 20 and an aluminum plastic film.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second", "third", "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", "third", "fourth" may explicitly or implicitly include one or more of the features. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 1 and fig. 2, a pouch core includes an aluminum-plastic film 20 and the electrode assembly 10, where the aluminum-plastic film 20 is used to wrap the electrode assembly 10.

The above-described electrode assembly 10 will be described in detail with reference to the accompanying drawings.

Referring to fig. 2, an electrode assembly 10 includes a plurality of electrode units 11 and at least one adsorbing member 12 for adsorbing an electrolyte, the electrode units 11 are connected in series, and each adsorbing member 12 is disposed between two adjacent electrode units 11.

In the electrode assembly 10, the plurality of electrode units 11 are sequentially connected in series, so that the length size of the soft-package battery cell is effectively increased, the capacity of the soft-package battery cell is increased, and meanwhile, the number of auxiliary connecting pieces among the soft-package battery cells can be effectively reduced, so that the energy density of the power battery is effectively improved; in addition, above-mentioned each absorption piece 12 can be effectively adsorb and store the electrolyte in the laminate polymer core, in the charge-discharge cycle in-process of laminate polymer core, the inside electrolyte of each electrode unit 11 can be consumed by a large amount, lead to the inside electrolyte concentration of each electrode unit 11 to rise fast, at this moment, the electrolyte in each absorption piece 12 can flow in corresponding electrode unit 11, in order to keep the inside electrolyte of each electrode unit 11 sufficient, thereby effectively improve the charge-discharge cycle life of laminate polymer core, and then effectively improve power battery's life.

Specifically, the adsorption member 12 is made of a lipid material including, but not limited to, one of vinyl acetate, butyl acrylate and methyl methacrylate copolymer; in addition, in order to ensure that the adsorption member 12 has good adsorption performance, the porosity of the adsorption member 12 may be limited to 50% to 80%.

In the present embodiment, as shown in fig. 3 to fig. 5, the electrode assembly 10 further includes at least one electrical connection member 13, and two adjacent electrode units 11 are connected in series through the electrical connection member 13. By connecting the two adjacent electrode units 11 in series through the electric connecting pieces 13, the connection stability between the two adjacent electrode units 11 is effectively improved.

Specifically, as shown in fig. 3 and fig. 5, one end of each electrode unit 11 extends outward to form a positive current collector 111, and the other end of each electrode unit extends outward to form a negative current collector 112, each electrical connector 13 includes a first clamping portion 131 and a second clamping portion 132 connected to each other, each first clamping portion 131 is used for clamping a corresponding positive current collector 111, and each second clamping portion 132 is used for clamping a corresponding negative current collector 112. Each first clamping portion 131 clamps the corresponding positive electrode current collector 111 and then correspondingly performs ultrasonic welding on each first clamping portion 131 and each positive electrode current collector 111, and each second clamping portion 132 clamps the corresponding negative electrode current collector 112 and then correspondingly performs ultrasonic welding on each second clamping portion 132 and each negative electrode current collector 112, so that the connection stability between two adjacent electrode units 11 can be further improved.

Specifically, as shown in fig. 3, the electrode assembly 10 includes a plurality of absorption members 12, each of the electrical connection members 13 has a first surface 133 and a second surface 134 that are opposite to each other, and each of the absorption members 12 covers the first surface 133 and the second surface 134 of each of the electrical connection members 13, respectively. By adopting the technical scheme, when the concentration of the electrolyte inside each electrode unit 11 is increased, the electrolyte in each adsorption piece 12 can be uniformly supplemented into the corresponding electrode unit 11, so that the charge-discharge cycle life of the soft package battery cell can be further prolonged, and the service life of the power battery can be further effectively prolonged.

Specifically, because the absorption piece 12 can expand gradually after adsorbing electrolyte, can set up the thickness of absorption piece 12 under the initial condition into one-third to one-half of the thickness of electrode unit 11 to the surface that makes the surface of absorption piece 12 after the inflation try hard to flush with electrode unit 11, avoids above-mentioned soft-package battery core to appear the pit in the surface after accomplishing the encapsulation, improves soft-package battery core's outward appearance roughness.

In this embodiment, referring to fig. 6 and 7, the electrode assembly 10 further includes a positive tab 14, a negative tab 15, and a first protection member 16 and a second protection member 17 disposed close to each other, the positive tab 14 and the negative tab 15 are respectively disposed at two opposite ends of the electrode assembly 10, the first protection member 16 is electrically connected to the positive tab 14, and the second protection member 17 is electrically connected to the negative tab 15. Through adopting above-mentioned technical scheme, when soft-packaged electrical core received external force and produced when warping, first protection piece 16 and second protection piece 17 take place the contact easily, in case first protection piece 16 contacts with second protection piece 17, can be with the short circuit of soft-packaged electrical core, reach the purpose to the quick discharge of soft-packaged electrical core, produced heat also can be fast through first protection piece 16 and second protection piece 17 outside diffusion behind the short circuit of soft-packaged electrical core simultaneously, effectively avoid soft-packaged electrical core to cause the condition of thermal runaway because of warping, thereby effectively improve power battery's security performance.

Specifically, as shown in fig. 6 and 7, a first electrical connection portion 161 is disposed at one end of the first protection member 16, the first electrical connection portion 161 is electrically connected to the positive tab 14 for ultrasonic welding, so as to electrically connect the first protection member 16 to the positive tab 14, a second electrical connection portion is disposed at one end of the second protection member 17, and the second electrical connection portion is ultrasonically welded to the negative tab 15, so as to electrically connect the second protection member 17 to the negative tab 15.

Specifically, in order to ensure the electrical conductivity of the first protector 16 and the electrical conductivity of the second protector 17, the first protector 16 and the second protector 17 are made of copper or a copper alloy, but the first protector 16 and the second protector 17 may be made of other conductive metals, such as aluminum, iron, and the like, respectively, and are not particularly limited thereto.

Specifically, as shown in fig. 6 and 7, the electrode assembly 10 has a third surface and a fourth surface which are away from each other, the first protector 16 and the second protector 17 each have a plate-shaped structure, the first protector 16 covers the third surface of the electrode assembly 10, and the second protector 17 covers the fourth surface of the electrode assembly 10. By adopting the technical scheme, on one hand, when the soft package battery core is deformed due to external force, the first protection piece 16 is effectively ensured to be in contact with the second protection piece 17, so that the purpose of quickly discharging the soft package battery core is achieved, and meanwhile, heat generated after the soft package battery core is short-circuited can be quickly diffused to the outside through the first protection piece 16 and the second protection piece 17, so that the situation of thermal runaway caused by deformation of the soft package battery core is effectively avoided, and the safety performance of the power battery is effectively improved; on the other hand, be in under normal condition at soft-packaged electrical core, first protection piece 16 and second protection piece 17 are jointly with the 11 centre grippings of each electrode unit, effectively promote soft-packaged electrical core's structural strength, and soft-packaged electrical core also can pass through first protection piece 16 and second protection piece 17 to outside diffusion at the produced heat of during operation simultaneously, effectively promotes soft-packaged electrical core's radiating effect.

Specifically, when the first protector 16 and the second protector 17 are connected, the first protector 16 may be first placed on the third surface of the electrode assembly 10, then tapes may be adhered to both opposite sides of the first protector 16, then the second protector 17 may be placed on the fourth surface of the electrode assembly 10, then the tapes may be adhered to the second protector 17 to pre-position the first protector 16 and the second protector 17, and finally the first protector 16 may be welded to the positive tab 14 and the second protector 17 may be welded to the negative tab 15.

Specifically, the first protector 16 has a thickness of 100 μm to 200 μm, such as 100 μm, 150 μm, 200 μm, etc., and/or the second protector 17 has a thickness of 100 μm to 200 μm, such as 100 μm, 150 μm, 200 μm, etc. Through adopting above-mentioned technical scheme, can effectively guarantee the support intensity of first protection piece 16 and second protection piece 17, can effectively control the weight and the occupation space of first protection piece 16 and the weight and the occupation space of second protection piece 17 simultaneously to guarantee power battery's energy density.

In this embodiment, please refer to fig. 7, each electrode unit 11 includes a positive electrode plate 113, a negative electrode plate 114, and a separator 115, and each separator 115 is disposed between the corresponding positive electrode plate 113 and the corresponding negative electrode plate 114.

Specifically, one end of each positive electrode tab 113 extends outward to form the positive electrode collector 111, and one end of each negative electrode tab 114 facing away from the corresponding positive electrode collector 111 extends outward to form the negative electrode collector 112.

Specifically, there are a plurality of positive electrode sheets 113, negative electrode sheets 114 and separators 115 in each electrode unit 11, and each electrode unit 11 is sequentially stacked in such a manner that a separator 115 is disposed between one positive electrode sheet 113 and one negative electrode sheet 114, so that the thickness dimension of the electrode assembly 10 is effectively increased, and the capacity of the pouch cell can be further improved.

A power battery comprises the soft package battery core.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. An electrode assembly, characterized by: the electrode assembly comprises a plurality of electrode units and at least one adsorption piece for adsorbing electrolyte, the electrode units are sequentially connected in series, and the adsorption pieces are respectively arranged between every two adjacent electrode units.

2. The electrode assembly of claim 1, wherein: the electrode assembly also comprises at least one electric connecting piece, and two adjacent electrode units are connected in series through one electric connecting piece.

3. The electrode assembly of claim 2, wherein: one end of each electrode unit extends outwards to form a positive current collector, the other end of each electrode unit extends outwards to form a negative current collector, each electric connector comprises a first clamping part and a second clamping part which are connected with each other, each first clamping part is used for clamping the corresponding positive current collector, and each second clamping part is used for clamping the corresponding negative current collector.

4. The electrode assembly of claim 2, wherein: the electrode assembly comprises a plurality of adsorption pieces, each electric connection piece is provided with a first surface and a second surface which are arranged oppositely, and each adsorption piece covers the first surface and the second surface of each electric connection piece respectively.

5. The electrode assembly of claim 1, wherein: the electrode assembly further comprises a positive electrode lug, a negative electrode lug, a first protection piece and a second protection piece, wherein the first protection piece and the second protection piece are close to each other, the positive electrode lug and the negative electrode lug are respectively arranged at two opposite end portions of the electrode assembly, the first protection piece is electrically connected with the positive electrode lug, and the second protection piece is electrically connected with the negative electrode lug.

6. The electrode assembly of claim 5, wherein: the electrode assembly has a third surface and a fourth surface disposed apart from each other, the first protector and the second protector each have a plate-like structure, the first protector covers the third surface of the electrode assembly, and the second protector covers the fourth surface of the electrode assembly.

7. The electrode assembly of claim 6, wherein: the first protector has a thickness of 100 to 200 μm, and/or the second protector has a thickness of 100 to 200 μm.

8. The electrode assembly of any of claims 1-7, wherein: each electrode unit comprises a positive plate, a negative plate and diaphragms, and each diaphragm is arranged between the corresponding positive plate and the corresponding negative plate.

9. The utility model provides a soft packet of electricity core which characterized in that: comprising an aluminium-plastic film and an electrode assembly according to any one of claims 1 to 8, said aluminium-plastic film being intended to envelop said electrode assembly.

10. A power battery, characterized by: comprising the flexible pouch cell of claim 9.