CN217933933U

CN217933933U - Non-deformable's positive plate and secondary battery

Info

Publication number: CN217933933U
Application number: CN202222036134.1U
Authority: CN
Inventors: 蒙宏潜; 韦远雄; 陈婕; 万剑锋; 苏鹏鉴; 王仲民; 乔涛; 凌大爱
Original assignee: Guangxi Huaguixing Times New Energy Technology Co ltd
Current assignee: Guangxi Huaguixing Times New Energy Technology Co ltd
Priority date: 2022-08-03
Filing date: 2022-08-03
Publication date: 2022-11-29
Anticipated expiration: 2032-08-03

Abstract

The utility model provides a non-deformable's positive plate and secondary battery belongs to secondary battery's technical field. This non-deformable's positive plate, including anodal substrate and anodal material, anodal material covers anodal substrate forms anodal material district, the positive plate still exposes the district including the substrate that does not cover anodal material, anodal material district with the substrate exposes district interval and sets up, makes behind the battery core of runway type after positive plate process and negative pole piece coiling, the substrate exposes the position in the corner of battery core. The utility model provides a technical scheme has solved the uneven quality problems that distributes of book core stress and the uneven distribution of book core electrolyte, has improved the cycle life of battery core effectively.

Description

Non-deformable's positive plate and secondary battery

Technical Field

The utility model belongs to the technical field of secondary battery technique and specifically relates to a non-deformable's positive plate and secondary battery are related to.

Background

With the continuous breakthrough of the material technology and the manufacturing process of secondary batteries such as lithium ion batteries, sodium ion batteries and the like, the secondary batteries are widely applied to the fields of consumer battery products, electric automobiles, wind and light power generation and energy storage, household energy storage and the like.

With the wide application of secondary batteries, in order to reduce the use cost of the secondary battery, save production resources and improve the environmental protection of the secondary battery, the service life of the battery is more and more emphasized, and particularly in the field of wind, light and electricity energy storage, the service life of the battery in the whole life cycle is required to be up to 20 years. The battery that accounts for on the existing market and surpasss 50% all is the square shell electricity core that uses winding structure, and this structure electricity core uses the later stage can appear because roll up the uneven quality problems such as core stress distribution and roll up core electrolyte and distribute unevenly, leads to the reduction of electric core cycle life.

Based on the above problems, the prior patent "a negative electrode sheet for improving deformation of a lithium battery and a non-deformable lithium battery" (application No. 2019208063897) discloses a non-deformable lithium battery, which improves the problem of expansion of the lithium battery electrode sheet by alternately arranging thick coating regions and thin coating regions on the negative electrode sheet, and the thin coating regions of the negative electrode sheet are positioned at the corners of a roll core during winding. However, in this scheme, since the negative electrode sheet is provided with the thin coating region, which is equivalent to reducing the capacity of the negative electrode sheet, during the cyclic charge and discharge of the battery, the lithium precipitation phenomenon is easily generated on the negative electrode sheet, thereby affecting the cycle life of the lithium battery.

SUMMERY OF THE UTILITY MODEL

To the technical problem, the utility model provides a non-deformable's positive plate and secondary battery can improve the expanded problem of secondary battery effectively, improves secondary battery's life.

In a first aspect, the utility model provides a non-deformable's positive plate, including anodal substrate and anodal material, anodal material covers anodal substrate forms anodal material district, the positive plate still exposes the district including the substrate that does not cover anodal material, anodal material district with the substrate exposes district interval setting, makes behind the battery core of runway type after coiling positive plate process with the negative pole piece, the substrate exposes the position in the corner of battery core.

Further, the positive electrode substrate is aluminum foil or electroplated aluminum.

Further, the positive electrode material is a lithium-based compound or a sodium-based compound.

The utility model provides a non-deformable's positive plate, the turning of the battery core of the runway type of coiling formation by this positive plate and negative pole piece is provided with substrate exposure layer, substrate exposure layer is formed through coiling for the anodal substrate that does not cover positive electrode material. Due to the design, the thickness change of the corner of the battery core caused by the embedding and the separation of metal ions (such as lithium ions and sodium ions) can be avoided in the cyclic operation of charging and discharging of the battery, so that the stress change of the corner can be avoided, the dynamic maintenance of the original state of the battery core at each position can be ensured, and the battery core and even the secondary battery can not be deformed easily; meanwhile, the phenomenon of local precipitation of metal ions can be avoided due to the fact that the phenomenon of metal ion desorption does not occur, and the problems that capacity is rapidly attenuated and service life is rapidly reduced of a battery core can be effectively solved.

In a second aspect, the present invention provides a secondary battery comprising a battery core of a runway type formed by winding the positive electrode sheet and the negative electrode sheet, wherein the corner of the battery core comprises a substrate exposure layer formed by a substrate exposure region of the positive electrode sheet.

Further, at the corners of the battery core, a substrate exposure group consisting of a plurality of substrate exposure layers and a positive electrode material group consisting of a plurality of positive electrode material layers are alternately arranged, and the positive electrode material layers are formed by the positive electrode material areas of the positive electrode plate.

Further, the substrate exposure group comprises a plurality of substrate exposure layers, and the number of the substrate exposure groups is the same; the positive electrode material group comprises 1 positive electrode material layer.

Further, the substrate exposure group comprises 2 to 4 substrate exposure layers, and the number of the layers of each substrate exposure group is the same.

Furthermore, the positive electrode material group comprises a plurality of positive electrode material layers, and the number of layers of each positive electrode material group is the same; the substrate exposure set includes 1 substrate exposure layer.

Furthermore, the corners of the battery core are exposed layers of the base material.

Further, the secondary battery is a lithium battery or a sodium battery.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a positive plate provided by an embodiment of the present invention;

fig. 2 is a schematic structural view of a battery cell of a secondary battery provided in an embodiment of the present invention;

fig. 3 is a first schematic structural view of a corner of a battery cell provided in an embodiment of the present invention;

fig. 4 is a schematic structural diagram ii of a corner of a battery cell provided in an embodiment of the present invention.

The reference numbers in the figures illustrate:

1-an exposed layer of the substrate; 2-a layer of positive electrode material; 3-a substrate exposed area; 4-a positive electrode material region; and 5-negative pole piece.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The terms "comprising" and "having," and any variations thereof, as referred to in the embodiments of the present invention, are intended to cover non-exclusive inclusions.

As shown in fig. 1, the embodiment of the present invention provides a non-deformable secondary battery, which comprises a battery core formed by winding a positive plate and a negative plate 5 in a runway shape, wherein a substrate exposing layer 1 is arranged at the corner of the battery core, and the substrate exposing layer 1 is formed by winding a positive substrate which is not covered with a positive material. Therefore, in order to form the battery cell as described above, as shown in fig. 2, the positive electrode sheet specifically includes a positive electrode material region 4 covered with the positive electrode material and a substrate exposed region 3 not covered with the positive electrode material, and the positive electrode material region 4 and the substrate exposed region 3 are disposed at an interval such that the positive electrode sheet can form the battery cell of the secondary battery as described above after being wound with the negative electrode sheet 5.

In the embodiment of the present invention, since the turn of the racetrack-type battery core of the secondary battery is provided with the substrate exposure layer 1, the substrate exposure layer 1 is formed by winding the positive electrode substrate that is not covered with the positive electrode material. Due to the design, the thickness change of the corner of the battery core caused by the embedding and the separation of metal ions (such as lithium ions and sodium ions) can be avoided in the cyclic operation of charging and discharging of the battery, so that the stress change of the corner can be avoided, the dynamic maintenance of the original state of the battery core at each position can be ensured, and the battery core and even the secondary battery can not be deformed easily; meanwhile, the phenomenon of local precipitation of metal ions can be avoided due to the fact that the phenomenon of metal ion desorption does not occur, and the problems that capacity is rapidly attenuated and service life is rapidly reduced of a battery core can be effectively solved.

Furthermore, the embodiment of the utility model provides a secondary battery's battery core's corner is owing to be provided with the substrate exposure layer 1 that does not cover positive electrode material for the ability that whole corner held electrolyte obtains improving, also contributes to increasing cycle life. Meanwhile, the gaps among the positive plate, the diaphragm and the negative plate at the corner can generate a capillary phenomenon, so that the electrolyte can be favorably infiltrated into other areas of the battery core from two sides of the corner, particularly into the positive material area, the uniform distribution degree of the electrolyte in the graded plate is improved, and the requirement of long cycle life is met.

Specifically, in the technical solution provided by the embodiment of the present invention, as shown in fig. 1, the corners of the battery core may be all set as the substrate exposure layer 1; as shown in fig. 3 or 4, several substrate exposure layers 1 may be formed into a substrate exposure group, while several cathode material layers 2 may be formed into a cathode material group, and the substrate exposure group and the cathode material group may be alternately arranged. Hereinafter, the present invention will be described with reference to various embodiments, in which the lithium battery is used for the battery, in order to improve the service life of the battery.

Comparative example

The conventional lithium battery, in which all the corners of the battery cell are the positive electrode material layers 2, is used as a comparative example. The number of 1C (i.e., the charge of the cell was discharged in one hour) cycles of this cell at room temperature (i.e., 25 ℃) was 4519 weeks.

Example one

The corners of the battery core of the lithium battery provided in this example are all the exposed substrate layer 1, the cycle number under the same conditions as the comparative example is 5316 weeks, the cycle number of the conventional lithium battery exceeding the comparative example is about 800 weeks, and the cycle life of the battery is greatly improved.

Example two

The corners of the lithium battery according to the present embodiment are formed by alternately arranging a substrate exposure group consisting of a plurality of substrate exposure layers 1 and a cathode material group consisting of 1 cathode material layer 2, as shown in fig. 3.

Specifically, assuming that the total number of positive electrodes at the corner of the lithium battery is 100, through experimental simulation, the cycle life cycle is shown in the following table.

TABLE 1

As shown in table 1 above, when the number of layers of the substrate exposed group is 3, the cycle life of the battery is 6123 weeks, which is the optimum solution in this example. However, in other schemes, the cycle number of the battery is also more than 5300 weeks, which is about 800 weeks more than that of the traditional lithium battery, and far exceeds that of the traditional lithium battery. It is obvious that the life of the lithium battery in this embodiment is greatly improved.

In this embodiment, the total number of positive electrodes at the corners of the battery cells of the lithium battery is 100, and in the case where one group is not placed enough in the remaining number of layers after the groups are alternately arranged, the remaining number of layers is filled according to the original rule. For example, if the total number of positive electrodes of 100 layers is 50, one positive electrode material layer 2 is provided after the total number of positive electrode exposed groups is 50, and the remaining total number of positive electrode layers is 49, all of the 49 layers may be provided as the base exposed layer 1.

EXAMPLE III

The corners of the lithium battery according to the present embodiment are formed by alternately arranging a substrate exposure group consisting of 1 substrate exposure layer 1 and a cathode material group consisting of several cathode material layers 2, as shown in fig. 4.

TABLE 2

As shown in table 2 above, in this embodiment, as the number of layers of the set positive electrode material group increases, the life of the battery decreases, that is, the number of layers of the positive electrode material group has a negative correlation with the battery life. Nevertheless, the overall life of the lithium battery in this embodiment is still higher than that of the conventional lithium battery. It is apparent that the life of the lithium battery in this embodiment is improved to some extent.

In this embodiment, the total number of positive electrodes at the corners of the battery cells of the lithium battery is also 100, and in the case where one group is not placed enough after the groups are alternately arranged, the remaining number of layers is filled up according to a rule. This will not be described in detail.

The utility model discloses technical scheme is applicable to the positive pole district and adopts aluminium foil or electro-plated aluminium, anodal material to be the lithium cell of lithium base compound, or anodal material is the sodium battery of sodium base compound, and the metal ion battery of other similar principle, similar technology, similar structure, no longer too much repeated here.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the technical solutions of the present invention, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: those skilled in the art can still modify or easily conceive of changes in the technical solutions described in the foregoing embodiments or make equivalent substitutions for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention. Are all covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a non-deformable's positive plate, includes anodal substrate and anodal material, anodal material covers anodal substrate forms anodal material district, a serial communication port, the positive plate still includes that the substrate that does not cover anodal material exposes the district, anodal material district with the substrate exposes district interval and sets up, makes behind the battery core of runway type after positive plate process and negative pole piece coiling, the substrate exposes the position in the corner of battery core.

2. The positive electrode sheet according to claim 1, wherein the positive electrode base material is aluminum foil or plated aluminum.

3. The positive electrode sheet according to claim 1, wherein the positive electrode material is a lithium-based compound or a sodium-based compound.

4. A secondary battery comprising a racetrack-type battery core formed by winding the positive-electrode sheet and the negative-electrode sheet according to any one of claims 1 to 3, the corners of the battery core comprising exposed layers of the substrate formed by exposed regions of the substrate of the positive-electrode sheet.

5. The secondary battery according to claim 4, wherein a substrate exposure group consisting of several substrate exposure layers and a positive electrode material group consisting of several positive electrode material layers, which are formed of the positive electrode material regions of the positive electrode sheet, are alternately arranged at the corners of the battery core.

6. The secondary battery of claim 5, wherein the substrate exposure group comprises a plurality of substrate exposure layers, and the number of layers in each substrate exposure group is the same; the positive electrode material group comprises 1 positive electrode material layer.

7. The secondary battery of claim 6, wherein the substrate exposure set comprises 2 to 4 substrate exposure layers, and the number of layers in each substrate exposure set is the same.

8. The secondary battery according to claim 5, wherein the positive electrode material group comprises a plurality of positive electrode material layers, and the number of layers of each positive electrode material group is the same; the substrate exposure set includes 1 substrate exposure layer.

9. The secondary battery according to claim 4, wherein at corners of the battery cell, each of the substrate layers is exposed.

10. The secondary battery according to claim 4, wherein the secondary battery is a lithium battery or a sodium battery.