CN219144304U

CN219144304U - Soft packet of battery casing, soft packet of battery and large capacity battery

Info

Publication number: CN219144304U
Application number: CN202222417523.9U
Authority: CN
Inventors: 李超; 雷政军; 郑高锋
Original assignee: Shaanxi Olympus Power Energy Co Ltd
Current assignee: Shaanxi Olympus Power Energy Co Ltd
Priority date: 2022-09-13
Filing date: 2022-09-13
Publication date: 2023-06-06
Anticipated expiration: 2032-09-13

Abstract

The utility model discloses a soft package battery shell, a soft package battery and a large-capacity battery, which are used for accommodating an electrode assembly and electrolyte, wherein the soft package battery shell comprises a main body layer, the main body layer comprises an outer surface and an inner surface, an adhesive layer and a heat sealing layer are sequentially arranged on the inner surface along the direction far away from the main body layer, the outer surface is a surface opposite to the inner cavity of the battery shell, the outer surface is a surface far away from the inner cavity of the battery shell, the main body layer is a porous metal foil layer and is used for communicating the electrolyte inside and outside the battery, the adhesive layer and the protective layer can be dissolved in the electrolyte, the battery shell can be automatically dissolved by the electrolyte, and a plurality of single batteries with the battery shell are arranged in the electrolyte cavity of the large-capacity battery, so that electrolyte sharing of the single batteries can be realized, and the consistency of the battery is improved.

Description

Soft packet of battery casing, soft packet of battery and large capacity battery

Technical Field

The utility model belongs to the field of lithium batteries, and particularly relates to a soft package battery shell, a soft package battery and a high-capacity battery with a multilayer structure.

Background

At present, the lithium battery pack on the market has various advantages and is widely applied to various fields, in the existing lithium battery application, the use of ultra-large capacity batteries is often involved, and in the aspect of the application of large capacity lithium batteries, a plurality of small batteries are mostly connected in parallel, however, in the battery operation process, the gradual consumption of electrolyte can cause capacity attenuation along with the cyclic use of the lithium batteries, the capacity attenuation of each single battery is different, the problem of poor consistency of each single battery can be caused, and if the electrolyte is supplemented to the single battery, and the problem of consistency is solved, the cycle life of the lithium battery can be obviously improved.

The electrolyte cavities of the plurality of single batteries are communicated with the electrolyte cavities of the large-capacity battery, so that all the single batteries are in a unified electrolyte system, the problem of poor consistency caused by different consumption of single electrolyte in the operation process of the large-capacity battery can be solved, but how to communicate the electrolyte cavities of the single batteries is a problem to be solved.

In the prior art, a liquid injection hole is formed in a battery top cover for mechanical liquid injection, but the mode is troublesome to operate, and an electrolyte cavity of a single battery cannot be automatically communicated with an electrolyte cavity of a large-capacity battery.

Patent CN1124905443a discloses a battery top cover, which is provided with a liquid injection hole on a battery manuscript to perform liquid injection of a battery, and still liquid injection is performed mechanically, and electrolyte sharing of a large-capacity battery cannot be formed.

Patent CN1120432058A discloses a battery cell and a battery, which also has a liquid injection hole on the cell for mechanical liquid injection.

Disclosure of Invention

In view of the above, it is necessary to provide a structure that is simple and allows a single battery to communicate with an electrolyte chamber of a large-capacity battery without mechanical operation.

The utility model provides a soft packet of battery casing for hold electrode assembly and electrolyte, a serial communication port, soft packet of battery casing includes the main part layer, the main part layer includes surface and internal surface, follow on the internal surface keep away from main part layer direction is equipped with adhesive linkage and heat-seal layer in proper order, the surface is followed keep away from main part layer direction has set gradually adhesive linkage and protective layer, the internal surface is for the one side of battery casing inner chamber, the surface is for keeping away from the one side of casing inner chamber, the main part layer is porous metal foil layer for make the inside electrolyte intercommunication with outside of battery, the adhesive linkage with the protective layer can dissolve in the electrolyte.

Furthermore, a protective layer is arranged between the bonding layer and the heat sealing layer, and the protective layer is dissolved in electrolyte.

Further, the main body layer is single-layer or multi-layer porous metal, the holes are round, and the hole diameter is 0.5mm-1mm.

Further, the thickness of the main body layer is 40-100 μm.

Further, the protective layer is a nylon protective layer, and the thickness of the protective layer is 10-50 mu m.

Further, the bonding layer is a waterproof bonding layer, the bonding layer is a polyurethane layer or a thermoplastic polyurethane elastomer (TPU) layer, and the bonding layer is used for bonding the main body layer and the protective layer/heat sealing layer.

Further, the heat sealing layer is a composite layer, and the composite layer is prepared by mixing polypropylene (CPP) and nylon in a hot melting way.

Further, the thickness of the heat sealing layer is 10-30 mu m.

In another aspect of the present patent, there is provided a pouch battery case, the foregoing pouch battery case, an electrolyte, and an electrode assembly housed together with the electrolyte in the battery case.

In another aspect of the present patent, a high-capacity battery is provided, including a high-capacity battery housing and the aforementioned soft pack battery, an electrolyte cavity is provided in the high-capacity battery housing, and an electrolyte is filled in the electrolyte cavity, and the battery is accommodated in the electrolyte cavity.

The beneficial effect of this patent:

the utility model provides a soft packet of battery casing is formed by main part layer and its inside and outside surface soluble electrolyte's that have porous metal foil protective layer and heat seal layer bonding, because the material on protective layer and heat seal layer can be dissolved by the electrolyte, place the battery cell that has this soft packet of battery casing in the electrolyte chamber of large capacity battery when a plurality of, protective layer and heat seal layer are dissolved by the electrolyte by oneself, the electrolyte passes the main part layer that has porous metal foil and makes electrode assembly part or whole infiltration in the electrolyte, a plurality of battery cells are in common electrolyte environment, the difference that single battery brought because the electrolyte consumes the difference has been eliminated, consistency and the life-span of group battery have been improved.

The utility model provides a soft packet of battery casing need not through mechanical operation, can realize the electrolyte sharing of a plurality of battery cells, and this battery casing is made by the material of multiple soluble electrolyte, and each material dissolves in the time difference of electrolyte, and the dissolution time of battery casing is adjusted to the material of accessible adjustment each layer, and this casing preparation is convenient, uses reliably.

Additional advantages, objects, and features of the utility model will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the utility model.

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 schematic cross-sectional view of a pouch cell housing according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a pouch cell housing according to an embodiment of the present application;

FIG. 3 is a schematic cross-sectional view of a soft pack battery according to an embodiment of the present disclosure;

fig. 4 is a schematic structural view of a flexible battery according to an embodiment of the present application disposed in a high-capacity battery case.

The reference numerals are as follows:

1-a soft package battery case; 11-a body layer; 110-an inner surface; 111-outer surface; 12-an adhesive layer; 13-a protective layer; 14-a heat seal layer; 2-a battery positive electrode lug; 3-a battery negative electrode tab; 4-single battery; 5-a high-capacity battery case; 6-a high-capacity battery electrolyte cavity; 7-electrode assembly.

Detailed Description

The present utility model is described in further detail below with reference to the drawings to enable those skilled in the art to practice the utility model by referring to the description.

Example 1

The embodiment provides a soft package battery shell, as shown in fig. 1, including a main body layer 11, the main body layer 11 has an inner surface 110 and an outer surface 111, the inner surface 110 is one surface for the shell inner cavity, the outer surface 111 is one surface far away from the shell inner cavity, namely one surface towards the shell outside, the inner surface 110 of the main body layer 11 is provided with an adhesive layer 12 and a heat seal layer 14 in sequence, the adhesive layer is a waterproof adhesive layer, an adhesive used for the adhesive layer is polyurethane or thermoplastic polyurethane elastomer (TPU), the adhesive can bond the heat seal layer 13 on the inner surface of the main body layer 11, the heat seal layer 13 is a composite material layer, the material is polypropylene (CPP) and nylon PA6 which are hot melted, and the thickness of the heat seal layer is 10-50 μm. The outer surface 111 of the main body layer 11 is sequentially provided with an adhesive layer 12 and a protective layer 13, the adhesive layer 12 adheres the protective layer 13 to the main body layer 11, the adhesive layer 12 adopts an adhesive such as polyurethane or thermoplastic polyurethane elastomer (TPU), the protective layer 13 is nylon PA6, and the thickness of the protective layer is preferably 10-50 mu m.

The body layer 11 is a porous aluminum foil, the pores of which may be circular or rectangular, preferably circular, the circular pore diameter is preferably 0.5mm to 1mm, and the thickness is preferably 40 to 100 μm, so that the electrolyte can smoothly pass through the porous aluminum foil,

experiments prove that the materials of polyurethane, thermoplastic polyurethane elastomer, polypropylene and nylon PA6 are all soluble in conventional electrolyte, the dissolution time of each material is different, and the polypropylene (CPP) is an electrolyte-insoluble material.

The components and the preparation method of the adhesive are as follows:

the adhesive comprises at least the following substances (calculated by mass percent):

10% of polyurethane or TPU,1.5% of curing agent, 0.5% of tackifying resin, 0.2% of hydrolysis inhibitor, 58.8% of cyclohexane and 29% of butanone, wherein cyclohexane and butanone are used as solvents.

Wherein the curing agent is tert-butyl peroxy hexane or imidazole compound, the tackifying resin is phenolic resin or modified rosin resin, and the hydrolysis resisting agent is carbodiimide, oxazoline and epoxy compound.

The preparation method of the adhesive comprises the following steps:

heating polyurethane or TPU at 40 ℃ for 24 hours, sequentially adding tackifying resin, an anti-hydrolysis agent, a mixed solvent (cyclohexane and/or butanone) and a curing agent while stirring, filtering by using a polypropylene (PP) filter element, and removing insoluble matters for later use, wherein the total solid content of the adhesive is 10%.

The preparation method of the heat seal layer comprises the following steps:

CPP and PA6 were mixed in a mass ratio of 2:1, heating to 250 ℃, stirring while heating, clamping melted plastic between two rollers after stirring uniformly, rolling to form a film, stretching to ensure that the film is firm, and cooling at room temperature, wherein the thickness of the film is 10-30 mu m.

Because CPP is insoluble in electrolyte, PA6 is easily soluble in electrolyte, and the heat sealing layer formed by hot melting is slower in dissolving speed than PA6 in electrolyte, and the dissolving time of the dissolving layer can be adjusted by adjusting the proportion of CPP and PA 6.

The preparation method of the battery shell comprises the following steps:

1. drying the adhesive: and (3) drying the prepared adhesive in a vacuum drying oven at 60-80 ℃ for 24 hours under the condition of nitrogen.

2. Degreasing the porous aluminum foil: and (3) soaking the porous aluminum foil in a degreasing solvent for 2h at room temperature to degrease. The degreasing solvent is one of acetone, butanone and trichloroethylene.

3. Bonding of the porous aluminum foil layer and the protective layer: and compounding the degreased aluminum foil layer with the dried adhesive, adhering the adhesive layer to the outer surface of the porous aluminum foil layer, curing after compounding, and adhering the protective layer to the outer surface of the porous aluminum foil layer by a roll coating method.

4. Bonding of the porous aluminum foil layer and the heat seal layer: coating adhesive on the inner surface of the heat sealing layer, controlling the thickness of the coated adhesive to be 3 mu m, after the heat sealing layer is dried by a baking oven, compounding the surface coated with the adhesive with aluminum foil in a hot pressing way, bonding the heat sealing layer on the inner surface of the porous aluminum foil, wherein the temperature of the baking oven is 85 ℃, and the coating amount of the dry adhesive is 2.4g/m ² 。

5. And (3) forming a battery shell: the composite battery shell is put into a curing chamber for curing for 5 days, and the curing temperature is 40 ℃.

The materials of the heat-seal layer 14 and the protective layer 13 are soluble in a conventional electrolyte, so that when the soft pack battery case is placed in the electrolyte for a certain period of time, only the main body layer is left to encapsulate the electrode assembly after the heat-seal layer 14 and the protective layer 13 are dissolved by the electrolyte.

Because the thickness of the protective layer 13 and the heat sealing layer 14 is smaller, the hardness of the material is not high, and the main body layer can play a supporting role, so that the protective layer 13 and the heat sealing layer 14 can completely wrap the electrode assembly.

As shown in fig. 4, a plurality of single batteries 4 with the battery housing of this embodiment are placed in a large-capacity battery housing 5, an electrolyte is filled in a large-capacity battery electrolyte cavity 6, a housing protection layer and a heat seal layer of the single batteries 4 are gradually dissolved in the large-capacity battery electrolyte, after the protection layer and the heat seal layer are dissolved and disappear, only a main body layer remains in the housing of the single batteries, and the electrolyte can penetrate through the porous aluminum foil because the main body layer is porous aluminum foil, so that electrode assemblies of all the single batteries are immersed in the electrolyte cavity of the large-capacity battery and are in the same electrolyte system, and therefore, the electrolyte of the single batteries cannot generate consistency difference, and the performance of the large-capacity battery is improved.

When the single battery with the battery shell of the embodiment is placed in the electrolyte cavity of the high-capacity battery, the protective layer and the heat sealing layer can be automatically dissolved in the electrolyte, mechanical operation is not needed, and the shell is simple in structure and high in universality.

The mass ratio of CPP of the heat sealing layer to nylon PA6 is not the only one, because CPP is insoluble in electrolyte, nylon PA5 is soluble in electrolyte, and the CPP is added for adjusting the dissolution time of nylon PA6 in the electrolyte, so the ratio of CPP to nylon PA6 can be adjusted according to the time of dissolving the electrolyte.

Example 2

As shown in fig. 2, this embodiment is different from embodiment 1 in that an adhesive layer 12, a protective layer 13 and a heat seal layer 14 are sequentially provided on an inner surface 110 of a body layer 11 of this embodiment, that is, the protective layer 13 is added between the adhesive layer 12 and the heat seal layer 14 of embodiment 1.

The main body layer 11 is porous aluminum foil, the porous aluminum foil hole can be round or rectangular, the preferred round shape is, the round aperture is 0.5mm, the preferred 40 mu m of thickness, make electrolyte can pass through this porous aluminum foil, the main body layer 11 is internal surface 110 for the one side of casing inner chamber, the one side of keeping away from the casing inner chamber is surface 111, the bonding layer 12 has been set gradually on main body layer 11 internal surface 110, protective layer 13 and heat seal layer 14, bonding layer 12 is waterproof bonding layer, its material is adhesive such as polyurethane or thermoplastic polyurethane elastomer (TPU), can bond heat seal layer 13 in the internal surface of main body layer 11, heat seal layer 13 material is the composite material layer, its material is polypropylene (CPP) and nylon PA6 hot melt to form, heat seal layer 14 thickness is 10 mu m. The adhesive layer 12 and the protective layer 13 are sequentially arranged on the outer surface 111 of the main body layer 11, the adhesive layer 12 adheres the protective layer 13 to the main body layer 11, the adhesive layer 12 is made of polyurethane or thermoplastic polyurethane elastomer (TPU), the protective layer 13 is nylon PA6, and the thickness of the protective layer is preferably 10-50 mu m.

In this example, the composition and the preparation method of the adhesive were the same as those of the adhesive in example 1.

The preparation method of the battery shell comprises the following steps:

2. Degreasing the porous aluminum foil: at room temperature, the aluminum foil is soaked in degreasing solvent for 2 hours to degrease. The degreasing solvent is one of acetone, butanone and trichloroethylene.

3. Bonding of the porous aluminum foil layer and the protective layer: and compounding the dried adhesive on the outer surface of the aluminum foil layer after degreasing treatment, curing after compounding, and adhering the protective layer on the outer surface of the aluminum foil layer by a roller coating method.

4. Coating a heat seal layer on the protective layer: mixing CPP and PA6 particles at a mass ratio of 2:1, heating to 250deg.C, stirring, coating on the protective layer with a thickness of 10-30 μm, and cooling at room temperature.

5. Bonding the porous aluminum foil layer with the protective layer coated with the heat sealing layer: and (3) compositing the dried adhesive on the inner surface of the aluminum foil layer after degreasing treatment, curing after compositing, and bonding the surface of the protective layer, which is not coated with the heat seal layer, in the step (4) on the inner surface of the aluminum foil layer by a roller coating method.

6. And (3) forming a battery shell: and (5) putting the compounded battery shell into a curing chamber for curing for 5 days, wherein the curing temperature is 40 ℃.

Both the heat-seal layer and the protective layer are soluble in conventional electrolytes, and therefore, when the soft pack battery case is placed in the electrolyte for a period of time, the case can be slowly dissolved by the electrolyte.

The purpose of adding the protection layer in this embodiment is to strengthen the protection of the battery case, because the heat seal layer is thinner, to prevent the battery case from being damaged under the action of external force, to support the main body layer, and to increase the dissolution time of the battery case in the electrolyte.

As shown in fig. 4, a plurality of single batteries 4 with the battery housing of this embodiment are placed in a large-capacity battery housing 5, the electrolyte is filled in a large-capacity battery electrolyte cavity 6, the protective layer and the heat seal layer of the housing of the single battery 4 are gradually dissolved in the large-capacity battery electrolyte, and after the protective layer and the heat seal layer are dissolved and disappeared, the housing of the single battery 4 only remains the main body layer, and the electrolyte in the electrolyte cavity can pass through the porous aluminum foil, so that the electrode assemblies of all the single batteries are immersed in the electrolyte cavity of the large-capacity battery and are in the same electrolyte system, therefore, the electrolyte of the single batteries does not generate consistency difference, and the performance of the large-capacity battery is improved.

The single battery with the battery shell of the embodiment can be automatically dissolved in electrolyte when placed in the electrolyte cavity of the high-capacity battery, mechanical operation is not needed, and the shell is simple in structure and high in universality.

Example 3

As shown in fig. 3, this embodiment is a pouch battery including an electrode assembly 7, a battery positive electrode 2 and a battery negative electrode 3, and a pouch battery case 1 as described in

embodiment

1 or 2, in which an electrolyte is contained.

The plurality of soft package batteries 4 with the embodiment are arranged in the large-capacity battery shell, electrolyte is filled in the large-capacity battery electrolyte cavity 6, the protective layer and the heat sealing layer of the shell of the single battery 4 are gradually dissolved in the large-capacity battery electrolyte, after the protective layer and the heat sealing layer are dissolved and disappear, the shell of the single battery only remains the main body layer, and as the main body layer is porous aluminum foil, electrode assemblies of all the single batteries are soaked in the electrolyte cavity of the large-capacity battery and are in the same electrolyte system, and therefore, the electrolyte of the single battery cannot generate consistency difference, and the performance of the large-capacity battery is improved.

It will be understood that terms, such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

In embodiments of the utility model, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

Although embodiments of the utility model have been disclosed above, they are not limited to the use listed in the specification and embodiments. It can be applied to various fields suitable for the present utility model. Additional modifications will readily occur to those skilled in the art. Therefore, the utility model is not to be limited to the specific details and illustrations shown and described herein, without departing from the general concepts defined in the claims and their equivalents.

Claims

1. The utility model provides a soft packet of battery casing for hold electrode assembly and electrolyte, its characterized in that, soft packet of battery casing includes the main part layer, the main part layer includes surface and internal surface, follow on the internal surface keep away from main part layer direction is equipped with adhesive linkage and heat-seal layer in proper order, the surface is followed keep away from main part layer direction has set gradually adhesive linkage and protective layer, the internal surface is for the one side of battery casing inner chamber, the surface is the one side of keeping away from the casing inner chamber, the main part layer is porous metal foil layer for make battery inside and outside electrolyte intercommunication, the adhesive linkage with the protective layer can dissolve in the electrolyte.

2. The flexible battery case according to claim 1, wherein a protective layer is further provided between the adhesive layer and the heat seal layer, the protective layer being soluble in an electrolyte.

3. The flexible battery case according to claim 1 or 2, wherein the main body layer is a single layer or a plurality of layers of porous metal foil, the porous metal foil pores are circular, and the pore diameter is 0.5mm-1mm.

4. The pouch cell case of claim 1, wherein the bulk layer has a thickness of 40-100 μm.

5. The flexible battery housing of claim 1, wherein the protective layer is a nylon PA6 protective layer having a thickness of 10-50 μm.

6. The flexible battery housing of claim 1, wherein the adhesive layer is a waterproof adhesive layer, the adhesive layer is a polyurethane layer, and the adhesive layer is used to bond the body layer to the protective layer/heat seal layer.

7. The flexible package battery housing of claim 1, wherein the heat seal layer has a thickness of 10-30 μιη.

8. A pouch battery comprising the pouch battery case of any one of claims 1 to 7, an electrolyte, and an electrode assembly, the electrode assembly and the electrolyte being contained in the battery case.

9. A high capacity battery comprising a high capacity battery housing having an electrolyte chamber filled with electrolyte and a plurality of the pouch cells of claim 8, the battery being contained in the electrolyte chamber.