CN114597594A

CN114597594A - Battery, terminal and method for manufacturing battery

Info

Publication number: CN114597594A
Application number: CN202210321888.3A
Authority: CN
Inventors: 周文扬
Original assignee: Xiamen Haichen New Energy Technology Co Ltd
Current assignee: Xiamen Haichen New Energy Technology Co Ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2022-06-07

Abstract

The application discloses a battery, a terminal and a manufacturing method of the battery. The battery comprises a shell, a plurality of pole pieces, a separation film and electrolyte, wherein the pole pieces are arranged at intervals in the shell, the separation film is arranged in the shell and positioned between two adjacent pole pieces, the electrolyte is arranged in the shell and filled in gaps between the pole pieces and the separation film, and the density of the electrolyte is 1.1g/cm3-1.3g/cm 3. In the battery of this application embodiment, the density of electrolyte is 1.1g/cm3-1.3g/cm3, is a low density electrolyte, under the prerequisite that keeps original structure of battery and size unchangeable, when the electrolyte quality is the same, the volume of pouring into the inside electrolyte of shell is bigger, the volume that occupies is more in electric core inside, the space that can be better fills barrier film, pole piece and the clearance between barrier film and the pole piece, it is better to soak the effect.

Description

Battery, terminal and method for manufacturing battery

Technical Field

The present application relates to the field of battery devices, and more particularly, to a battery, a terminal, and a method of manufacturing the battery.

Background

Lithium ion batteries are widely used in the field of energy storage due to their advantages of high energy density, high operating voltage, wide operating temperature, long cycle life, etc. The PP isolating film has the advantages of uniform thickness, strong flexibility, high tensile strength, low possibility of cracking, low cost and the like, and is widely applied to lithium ion batteries. However, in the related art, there is no adhesion between the PP separator and the pole piece, and it is necessary to ensure a sufficient electrolyte injection amount to fill up the gap between the separator and the pole piece, so as to ensure the pole piece interface. However, increasing the amount of injected liquid increases the production cost and lowers the energy density.

Disclosure of Invention

The embodiment of the application provides a battery, a terminal and a manufacturing method of the battery.

The battery of this application embodiment includes shell, a plurality of pole pieces, barrier film and electrolyte, a plurality of pole pieces all set up interval setting in the shell, the barrier film sets up just be located adjacent two in the shell between the pole piece, electrolyte sets up in the shell and fills the pole piece with in the clearance of barrier film, the density of electrolyte is 1.1g/cm3-1.3g/cm 3.

In the battery of this application embodiment, the density of electrolyte is 1.1g/cm3-1.3g/cm3, is a low density electrolyte, under the prerequisite that keeps original structure of battery and size unchangeable, when the electrolyte quality is the same, the volume of pouring into the inside electrolyte of shell is bigger, the volume that occupies is more in electric core inside, the space that can be better fills barrier film, pole piece and the clearance between barrier film and the pole piece, it is better to soak the effect.

In certain embodiments, the electrolyte has a density of 1.1g/cm 3.

In certain embodiments, the concentration of lithium salt in the electrolyte is 1 mol/L.

In certain embodiments, the release film comprises a polypropylene film.

The terminal of the embodiment of the present application includes the battery of any one of the above.

In the terminal and the battery of this application embodiment, the density of electrolyte is 1.1g/cm3-1.3g/cm3, is a low density electrolyte, under the prerequisite that keeps original structure of battery and size unchangeable, when the electrolyte quality is the same, the volume of pouring into the inside electrolyte of shell is bigger, the volume that occupies is more in electric core inside, can be better fill barrier film, the space of pole piece and the clearance between barrier film and the pole piece, the infiltration effect is better.

The method for manufacturing a battery according to the embodiment of the present application includes: providing a battery main body, wherein the battery main body comprises a shell, a plurality of pole pieces and an isolating membrane, the pole pieces are arranged in the shell at intervals, and the isolating membrane is arranged in the shell and positioned between two adjacent pole pieces; and injecting electrolyte into the shell so that the electrolyte is filled in a gap between the pole piece and the isolating membrane, wherein the density of the electrolyte is 1.1g/cm3-1.3g/cm 3.

In the battery and the manufacturing method thereof, the density of the electrolyte is 1.1g/cm3-1.3g/cm3, the electrolyte is low-density electrolyte, the volume of the electrolyte injected into the shell is larger when the quality of the electrolyte is the same under the premise that the original structure and the size of the battery are not changed, the volume occupied inside the battery cell is more, the isolating membrane, the gaps of the pole pieces and the gaps between the isolating membrane and the pole pieces can be better filled, and the infiltration effect is better.

In some embodiments, injecting the electrolyte into the housing comprises: injecting the electrolyte into the shell for the first time; and after a preset time, injecting the electrolyte into the shell for the second time.

In certain embodiments, the method of manufacturing comprises: after the electrolyte is injected into the shell for the first time, standing the pole piece at high temperature for a first preset time; carrying out formation treatment on the pole piece; and after the pole piece is kept stand at the high temperature for a second preset time, injecting the electrolyte into the shell for the second time.

In certain embodiments, the first predetermined length of time ranges from 12 hours to 24 hours; and/or the second predetermined period of time ranges from 5 hours to 12 hours.

In some embodiments, the temperature of high temperature resting on the pole piece is from 40 ℃ to 50 ℃.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a terminal according to an embodiment of the present application;

fig. 2 is a schematic structural view of a battery according to an embodiment of the present application;

fig. 3 is a schematic flow chart of a method of manufacturing a battery according to an embodiment of the present application;

fig. 4 is another schematic flow chart of a method of manufacturing a battery according to an embodiment of the present application;

fig. 5 is another schematic flow chart of the method for manufacturing a battery according to the embodiment of the present application.

Description of the main element symbols:

a battery 100;

shell 10, pole piece 20, barrier film 30, electrolyte 40, terminal 200.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar 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 accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. To simplify the disclosure of the present application, the components and settings of a specific example are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or reference letters in the various examples, which have been repeated for purposes of brevity and clarity and do not in themselves dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Referring to fig. 1, a terminal 200 according to an embodiment of the present application includes a battery 100 according to an embodiment of the present application.

Referring to fig. 2, a battery 100 according to an embodiment of the present disclosure includes a case 10, a plurality of pole pieces 20, a separation film 30, and an electrolyte 40, where the pole pieces 20 are disposed at intervals in the case 10, the separation film 30 is disposed in the case 10 and located between two adjacent pole pieces 20, the electrolyte 40 is disposed in the case 10 and filled in a gap between the pole pieces 20 and the separation film 30, and a density of the electrolyte 40 is 1.1g/cm3-1.3g/cm 3.

In the battery 100 of the embodiment of the application, the density of the electrolyte 40 is 1.1g/cm3-1.3g/cm3, which is a low-density electrolyte 40, on the premise of keeping the original structure and size of the battery 100 unchanged, when the mass of the electrolyte 40 is the same, the volume of the electrolyte 40 injected into the shell 10 is larger, the volume occupied inside the battery cell is more, the isolating membrane 30, the gap of the pole piece 20 and the gap between the isolating membrane 30 and the pole piece 20 can be better filled, and the infiltration effect is better.

Specifically, it is understood that the pole pieces 20 may include both positive and negative pole pieces 20, and the pole pieces 20 are sheet-shaped and are disposed at intervals inside the housing 10. In the process of forming the pole piece 20, a void is formed on the surface of the pole piece 20, and a void is also formed on the surface of the separator 30 itself. In the embodiment of the present application, the electrolyte 40 is filled between the pole piece 20 and the isolation film 30, and simultaneously, the surface gaps of the pole piece 20 and the isolation film 30 can be filled, so that the wetting effect is better, and the stable operation of the battery 100 is ensured.

Illustratively, the density of the electrolyte 40 may be 1.1g/cm3, 1.15g/cm3, 1.2g/cm3, 1.25g/cm3, and 1.3g/cm3, and the smaller the density of the electrolyte 40, the smaller the weight of the electrolyte 40, and thus the weight of the battery 100 may be reduced to reduce the weight of the terminal 200 as a whole. In the embodiment of the present application, the type of the electrolyte 40 is not limited, and the electrolyte 40 may be obtained by dissolving lithium hexafluorophosphate (LiPF6) in a solvent of the electrolyte 40 and uniformly mixing the solution. Meanwhile, in the embodiment of the present application, the solvent of the electrolyte 40 is not limited, and the solvent of the electrolyte 40 may be formed by mixing a plurality of solvents such as Ethylene Carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and Ethyl Methyl Carbonate (EMC), and in one example, the mass ratio of Ethylene Carbonate (EC), Ethyl Methyl Carbonate (EMC), and dimethyl carbonate (DMC) is 1:1:2 to obtain a solvent, and lithium hexafluorophosphate (LiPF6) is added to the solvent and uniformly mixed to obtain the electrolyte 40 having a density of 1.1g/cm3-1.3g/cm 3.

In addition, in the embodiment of the present application, the type of the terminal 200 is not limited, the terminal 200 may be an electric vehicle such as an electric automobile and an electric bicycle, and the terminal 200 may also be a mobile terminal device such as a mobile phone, a tablet, and a watch, so as to meet various requirements.

Referring to FIG. 2, in some embodiments, the electrolyte 40 has a density of 1.1g/cm 3. Thus, the electrolyte 40 has a lower density, and when filled in the battery 100, the weight of the battery 100 can be reduced while the wetting effect is ensured.

Specifically, lithium hexafluorophosphate (LiPF6) was added to the solvent to form the electrolyte 40 of the embodiment of the present application, and the density of the electrolyte 40 was 1.1g/cm3, that is, 1.1g per cubic centimeter of the weight of the electrolyte 40, so that the weight of the battery 100 was lower without substantially changing the shape and size of the battery 100. Or say that, under the prerequisite of pouring into the electrolyte 40 of the same weight into in the shell 10, the volume of the electrolyte 40 of this application embodiment is bigger, can be better fill the inside space of shell 10, avoid having air and other impurity in clearance and the space between pole piece 20 and barrier film 30, and then promoted battery 100's stability.

Referring to FIG. 2, in some embodiments, the concentration of lithium salt in the electrolyte 40 is 1 mol/L. That is, 1mol of the lithium salt is contained per one liter of the electrolytic solution 40. Thus, when the concentration of the lithium salt in the electrolyte 40 is 1mol/L, on one hand, the problem of conductivity reduction caused by too high concentration of lithium ions in the electrolyte 40 is avoided, and on the other hand, the battery 100 can be ensured to have higher energy density.

Referring to fig. 2, in some embodiments, electrolyte 40 fills the voids formed by the pole piece 20 itself. Therefore, the electrolyte 40 can fill the gap on the pole piece 20, so that the soaking effect of the electrolyte 40 is better, and the air in the gap is prevented from influencing the normal use of the battery 100.

It can be understood that, in the process of manufacturing the pole piece 20, the material powders with different densities need to be extruded to form the pole piece 20 with the positive electrode and the negative electrode having the same density, and in this process, voids are formed on the surface of the pole piece 20, and air molecules or other impurities in the voids often affect the normal operation of the battery 100. In the embodiment of the present application, the electrolyte 40 can fill the gap on the pole piece 20 itself, and the electrolyte 40 has a good wetting effect, so as to ensure the normal use of the battery 100.

Referring to fig. 2, in some embodiments, the separator 30 comprises a polypropylene film. Thus, the polypropylene has better toughness, so that the tensile strength of the isolation film 30 is higher, and the isolation film 30 can be isolated by two adjacent pole pieces 20.

Specifically, in the embodiment of the present application, the material and thickness of the isolation film 30 are not limited, for example, the isolation film 30 may be formed by one of polypropylene, polyethylene and polypropylene, or a combination of several of polypropylene, polyethylene and polypropylene to meet different requirements. For example, the separator 30 may be a single-layer separator 30 of polypropylene with a thickness of 12 μm, so that the separator 30 has a good tensile strength without affecting the normal operation of the electrolyte 40 and the pole piece 20.

Referring to fig. 3, a method for manufacturing a battery 100 according to an embodiment of the present disclosure includes:

s10, providing a battery 100 main body, wherein the battery 100 main body comprises a shell 10, a plurality of pole pieces 20 and an isolating film 30, the pole pieces 20 are arranged in the shell 10 at intervals, and the isolating film 30 is arranged in the shell 10 and located between two adjacent pole pieces 20;

s20, injecting the electrolyte 40 into the shell 10 to fill the electrolyte 40 into the gap between the pole piece 20 and the isolating membrane 30, wherein the density of the electrolyte 40 is 1.1g/cm3-1.3g/cm 3.

In the manufacturing method of the battery 100 in the embodiment of the application, the density of the electrolyte 40 is 1.1g/cm3-1.3g/cm3, which is a low-density electrolyte 40, on the premise of keeping the original structure and size of the battery 100 unchanged, when the mass of the electrolyte 40 is the same, the volume of the electrolyte 40 injected into the shell 10 is larger, the volume occupied inside the battery core is more, the gaps of the isolating membrane 30 and the pole piece 20 and the gaps between the isolating membrane 30 and the pole piece 20 can be better filled, and the infiltration effect is better.

Referring to fig. 4, in some embodiments, injecting the electrolyte 40 into the housing 10 (step S20) includes the steps of:

s21, injecting the electrolyte 40 into the case 10 for the first time;

s22, after a predetermined period of time, the electrolyte 40 is injected into the case 10 for a second time.

So, inject into inside shell 10 with electrolyte 40 twice, guarantee that electrolyte 40 can be with the clearance and the space filling between pole piece 20 and the barrier film 30 abundant, avoid once only injecting electrolyte 40 and lead to electrolyte 40 to spill over.

It can be understood that the space inside the case 10 is small, and the plurality of pole pieces 20 and the isolation film 30 arranged inside the case 10 result in a narrow space inside the battery 100, and the electrolyte 40 is put into the case 10 through the liquid injection hole at one time, so that the electrolyte 40 overflows, and the electrolyte 40 is prevented from plugging air and other impurities in the case 10.

Referring to fig. 5, in some embodiments, the manufacturing method includes the steps of:

s30, after the electrolyte 40 is injected into the casing 10 for the first time, the counter electrode plate 20 is left standing at a high temperature for a first predetermined time;

s40, carrying out chemical conversion treatment on the pole piece 20;

s50, after the counter electrode piece 20 is left standing at a high temperature for a second predetermined period of time, the second injection of the electrolyte 40 into the case 10 is performed.

Thus, the first predetermined time period of standing the pole piece 20 at a high temperature can enable the electrolyte 40 to be fully absorbed by the pole piece 20, so that the electrolyte 40 can be sufficiently soaked. The formation treatment of the pole piece 20 can make lithium of the positive pole piece 20 slowly enter the negative pole piece 20, so that the negative pole piece 20 can generate a Solid Electrolyte Interface (SEI) film, the SEI film is a passivation film layer, can stably exist in the electrolyte 40, and simultaneously avoids damage to the pole piece 20 material caused by co-intercalation of solvent molecules in the electrolyte 40, thereby greatly improving the cycle performance and the service life of the pole piece 20. The pole piece 20 is kept standing at a high temperature for a second predetermined time, so that an SEI film generated by the negative pole piece 20 is stable, and continuous capacity attenuation in a circulation process caused by subsequent decomposition is avoided.

It is understood that, in step S40, the formation treatment of the electrode sheet 20 refers to a process of charging the battery 100 for the first time, in which the battery 100 can be activated with a small current, so that the lithium in the positive electrode sheet 20 slowly enters the negative electrode sheet 20 to form a stable SEI film on the surface of the negative electrode sheet 20, and the gas generated by the chemical reaction in the process can be pumped away through the liquid injection hole.

Referring to FIG. 5, in some embodiments, the first predetermined period of time ranges from 12 hours to 24 hours; the second predetermined length of time ranges from 5 hours to 12 hours. In other embodiments, the first predetermined period of time may be limited to a range of 12 hours to 24 hours, and the second predetermined period of time is not limited. In still other embodiments, the second predetermined period of time may be limited to a range of 5 hours to 24 hours, and the first predetermined period of time is not limited.

Therefore, the first preset time is 12-24 hours, which not only can ensure that the pole piece 20 can fully absorb the electrolyte 40, but also avoids the influence on the normal production of the battery 100 caused by too long standing time. The second predetermined time is in the range of 5 hours to 12 hours, which not only can ensure the stability of the SEI film generated by the negative electrode plate 20, but also can avoid the influence of too long standing time on the normal production of the battery 100.

Illustratively, the first predetermined period of time may be any of 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours. The second predetermined period of time may be any of 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours. In one example, the first predetermined length of time may be 16 hours; the second predetermined period of time may be 8 hours.

Referring to fig. 5, in some embodiments, the counter electrode sheet 20 is left to stand at a high temperature of 40 ℃ to 50 ℃. Thus, under such temperature conditions, the electrolyte 40 can be sufficiently absorbed by the pole piece 20, so that the electrolyte 40 can be sufficiently soaked.

Illustratively, the temperature at which the counter electrode sheet 20 is left standing at a high temperature is any of 40 ℃, 41 ℃, 42 ℃, 43 ℃, 44 ℃, 45 ℃, 46 ℃, 47 ℃, 48 ℃, 49 ℃ and 50 ℃. In one example, the counter electrode sheet 20 may be left to stand at a high temperature for 16 hours at 48 ℃.

In the description of the embodiments of the present application, the terms "first", "second" 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" and "second" may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

In the description herein, references to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present application have been shown and described above, it is to be understood that the above embodiments are exemplary and not to be construed as limiting the present application, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. A battery, comprising:

a housing;

the pole pieces are arranged in the shell at intervals;

the isolating film is arranged in the shell and positioned between two adjacent pole pieces;

the electrolyte is arranged in the shell and filled in the gap between the pole piece and the isolating membrane, and the density of the electrolyte is 1.1g/cm3-1.3g/cm 3.

2. The battery of claim 1, wherein the electrolyte has a density of 1.1g/cm 3.

3. The battery of claim 1, wherein the concentration of lithium salt in the electrolyte is 1 mol/L.

4. The battery of claim 1, wherein the separator comprises a polypropylene film.

5. A terminal characterized by comprising a battery according to any one of claims 1 to 4.

6. A method of manufacturing a battery, comprising:

providing a battery main body, wherein the battery main body comprises a shell, a plurality of pole pieces and an isolating membrane, the pole pieces are arranged in the shell at intervals, and the isolating membrane is arranged in the shell and positioned between two adjacent pole pieces;

and injecting electrolyte into the shell so that the electrolyte is filled in a gap between the pole piece and the isolating membrane, wherein the density of the electrolyte is 1.1g/cm3-1.3g/cm 3.

7. The manufacturing method according to claim 6, wherein injecting the electrolyte into the housing includes:

injecting the electrolyte into the shell for the first time;

and after a preset time, injecting the electrolyte into the shell for the second time.

8. The manufacturing method according to claim 7, characterized by comprising:

after the electrolyte is injected into the shell for the first time, standing the pole piece at high temperature for a first preset time;

carrying out formation treatment on the pole piece;

and after the pole piece is kept stand at the high temperature for a second preset time, injecting the electrolyte into the shell for the second time.

9. The method of manufacturing of claim 8, wherein the first predetermined length of time ranges from 12 hours to 24 hours; and/or;

the second predetermined length of time ranges from 5 hours to 12 hours.

10. The manufacturing method according to claim 8, wherein the temperature for standing the pole piece at high temperature is 40-50 ℃.