CN221614140U

CN221614140U - Battery cell and battery

Info

Publication number: CN221614140U
Application number: CN202323142726.2U
Authority: CN
Inventors: 盛东辉; 谢继春
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2023-11-21
Filing date: 2023-11-21
Publication date: 2024-08-27
Anticipated expiration: 2033-11-21

Abstract

The application provides a battery cell and a battery, wherein the battery cell comprises a first pole piece, a diaphragm and a second pole piece which are laminated and wound, the polarity of the first pole piece is opposite to that of the second pole piece, the first pole piece comprises a first current collector and a first tab, the second pole piece comprises a second current collector and a second tab, the first current collector is a composite current collector, the second current collector is a metal current collector, the number of the first tabs is n, and the number of the second tabs is m; wherein n and m satisfy: n is more than m; and/or 2*m-1.ltoreq.n.ltoreq.2.m+1. So set up, along the winding direction of electric core, every half circle sets up a first utmost point ear on the first pole piece, and every round sets up a second utmost point ear on the second pole piece, and the first pole piece increases the quantity of first utmost point ear to compensate the charge-discharge performance that first electric current collector is compound electric current collector and lack, solved the electric core that is made by compound electric current collector among the prior art and had the problem that charge-discharge ability is not enough.

Description

Battery cell and battery

Technical Field

The application relates to the technical field of batteries, in particular to a battery cell and a battery.

Background

In order to improve the nailing performance and the shock resistance of the battery core, in the battery industry, a current collector is converted into a composite current collector from a metal foil, and the composite current collector is formed by laminating and compositing a high polymer material layer and a metal layer.

In view of the specificity of the composite current collector structure, the composite current collector has insufficient charging and discharging capability relative to the conventional metal current collector, and is particularly characterized by larger charging and discharging impedance, and the composite current collector has larger heating in the charging and discharging process and cannot be applied to the fast charging technology in a large scale, so that the composite current collector is still one of factors restricting the development of the composite current collector.

Disclosure of utility model

In view of this, the application provides a battery cell and a battery, so as to solve the problem that the battery cell made of the composite current collector in the prior art has insufficient charge and discharge capability.

In order to achieve the above purpose, the present application provides the following technical solutions:

the battery cell comprises a first pole piece, a diaphragm and a second pole piece which are stacked and wound, wherein the polarity of the first pole piece is opposite to that of the second pole piece, the first pole piece comprises a first current collector and a first tab, the second pole piece comprises a second current collector and a second tab, the first current collector is a composite current collector, the second current collector is a metal current collector, the number of the first tabs is n, and the number of the second tabs is m; wherein n and m satisfy:

n＞m；

And/or 2*m-1.ltoreq.n.ltoreq.2.m+1.

Alternatively to this, the method may comprise,

The first current collector comprises a supporting layer and a conductive layer, and the conductive layer is at least positioned on one side surface of the supporting layer;

The first tab comprises a main body part and a connecting part, and the connecting part is connected with the conductive layer;

In the MD direction of the first pole piece, the length of the connection portion of the first pole tab is greater than the length of the main body portion of the first pole tab.

Optionally, the first tab includes a first-type tab and a second-type tab, the first-type tab and the second-type tab are alternately distributed along the MD direction of the first pole piece, and in the MD direction of the first pole piece, the length of the main body portion of the first-type tab is S1, the length of the main body portion of the second-type tab is S2, the length of the connection portion of the first-type tab is S3, and the length of the connection portion of the second-type tab is S4; wherein,

S2＞S1；

Or s2=s1, and S4 > S3.

Optionally, in the MD direction of the first pole piece, the interval distance between the adjacent first-type tab and the second-type tab is L1, and in the MD direction of the second pole piece, the length of the second tab is L2, where L1 and L2 satisfy 1.2xl2 < L1.

Optionally, in the MD direction of the first pole piece, the spacing distance between the first-type tab and the second-type tab is L1, where L1 satisfies 3mm < L1 < 100mm.

Optionally, the first tab is welded with the first current collector, a welding area is formed on the first tab, an edge of the first current collector is located in an edge of the diaphragm, and the diaphragm completely covers the welding area.

A battery comprising a plurality of cells of any of the above, wherein electrical conduction is provided between the first tabs of adjacent cells and between the second tabs of adjacent cells.

Optionally, between two adjacent electric cores, all the first tabs of each electric core are equalized to a first switching piece, and all the second tabs of each electric core are equalized to a second switching piece;

And welding and forming welding marks between the first tab and the first switching piece and between the second tab and the second switching piece.

Optionally, the solder mark is completely located in the edge of the first tab or the second tab, and the distance between the edge of the solder mark and the outer edge of any side of the first tab or the second tab is greater than or equal to 0.5mm and less than or equal to 5mm.

Optionally, adhesive paper is adhered to the first tab and the second tab, and the adhesive paper completely covers all the solder marks.

The battery cell comprises a first pole piece, a diaphragm and a second pole piece which are laminated and wound, wherein the polarity of the first pole piece is opposite to that of the second pole piece, the first pole piece comprises a first current collector and a first tab, the second pole piece comprises a second current collector and a second tab, the first current collector is a composite current collector, the second current collector is a metal current collector, the number of the first tabs is n, and the number of the second tabs is m; wherein n and m satisfy: n is more than m; and/or 2*m-1.ltoreq.n.ltoreq.2.m+1. So set up, along the winding direction of electric core, every half circle sets up a first utmost point ear on the first pole piece, every round sets up a second utmost point ear on the second pole piece, after the coiling finishes, all first utmost point ears are relative, all second utmost point ears are relative, first pole piece increases the quantity of first utmost point ear, thereby make up first electric current collector and the charge-discharge performance that is compound electric current collector and lack, the second electric current collector of second pole piece is the metal electric current collector, the current-carrying capacity of the second utmost point ear that cuts integrated into one piece and obtain is superior to first utmost point ear, do not need too much second utmost point ear and maintain original quantity can, the electric core that is made by compound electric current collector in the prior art has the problem that charge-discharge capacity is not enough. In addition, by arranging the second pole piece formed by the metal current collector and the first pole piece formed by the composite current collector in one cell, the impact resistance of the battery and the quick charge capability of the battery are further balanced.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present application, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present application;

fig. 2 is a schematic diagram of the overall structure of a battery cell according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a first tab according to an embodiment of the present application;

Fig. 4 is a schematic structural diagram of a first pole piece according to an embodiment of the present application;

FIG. 5 is a schematic diagram of parameter indication of a first-type tab and a second-type tab according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a relative position of a first tab and a second tab according to an embodiment of the present application;

fig. 7 is a schematic diagram of electrical connection between two electrical cores according to an embodiment of the present application.

In fig. 1-7:

21. A first type tab; 22. a second type tab;

201. a main body portion; 202. a connection part; 203. a welding area;

1. A first current collector; 2. a first tab; 3. a second current collector; 4. a second lug; 5. a diaphragm; 6. a first tab; 7. a second switching piece; 8. and (5) welding and printing.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

As shown in fig. 1 to 7, the embodiment of the application provides a battery cell, which comprises a first pole piece, a diaphragm 5 and a second pole piece, wherein the first pole piece and the second pole piece are laminated and wound, the polarity of the first pole piece is opposite, the first pole piece comprises a first current collector 1 and a first tab 2, the second pole piece comprises a second current collector 3 and a second tab 4, the first current collector 1 is a composite current collector, the second current collector 3 is a metal current collector, the number of the first tabs 2 is n, and the number of the second tabs 4 is m; wherein n and m satisfy: n is more than m; and/or 2*m-1.ltoreq.n.ltoreq.2.m+1. Illustratively, the first pole piece is a positive pole piece, the second pole piece is a negative pole piece, the second current collector 3 is a metal current collector, and the second lug 4 is integrally formed by cutting the metal current collector. The pole lugs are provided with a plurality of pole pieces along the MD direction of the pole pieces.

So set up, along the winding direction of electric core, every half circle sets up a first utmost point ear on the first pole piece, every round sets up a second utmost point ear on the second pole piece, after the coiling finishes, all first utmost point ears are relative, all second utmost point ears are relative, first pole piece increases the quantity of first utmost point ear, thereby make up first electric current collector and the charge-discharge performance that is compound electric current collector and lack, the second electric current collector of second pole piece is the metal electric current collector, the current-carrying capacity of the second utmost point ear that cuts integrated into one piece and obtain is superior to first utmost point ear, do not need too much second utmost point ear and maintain original quantity can, the electric core that is made by compound electric current collector in the prior art has the problem that charge-discharge capacity is not enough.

In addition, by arranging the second pole piece formed by the metal current collector and the first pole piece formed by the composite current collector in one cell, the impact resistance of the battery and the quick charge capability of the battery are further balanced.

In the application, the MD direction of the pole piece is the direction with larger dimension, namely the length direction of the pole piece in the unfolding state of the pole piece; the TD direction of the pole piece is the direction with smaller dimension, namely the width direction of the pole piece.

In another embodiment, the first current collector 1 is a composite current collector, and includes a supporting layer and a conductive layer, the conductive layer is at least located on one side surface of the supporting layer, the first tab 2 includes a main body portion 201 and a connection portion 202, the main body portion 201 and the connection portion 202 are distributed along the TD direction of the pole piece, and the connection portion 202 and the conductive layer are connected and electrically conducted through welding; in the unfolded state, the length of the connection portion 202 of the first tab 2 is greater than the length of the main body portion 201 of the first tab 2 in the MD direction of the first tab. The first tab 2 is not in a regular rectangular shape, and is often trapezoidal, and the length is the longest length in the MD direction.

So set up, first utmost point ear 2 is special-shaped design, on the basis of conventional utmost point ear, carry out the extension in the part of first utmost point ear 2 and handle, make first utmost point ear 2 wholly divide into main part 201 and connecting portion 202, main part 201 still keeps original specification and dimension, still accord with original design requirement, do not influence the original basic function of first utmost point ear 2, and connecting portion 202 that has relatively great length has the welded relation with the conducting layer of electric current collector, the current-carrying capacity of the welded part that forms is promoted like this, can reduce charge-discharge temperature rise, the utmost point ear welded part current-carrying capacity inadequately of compound electric current collector among the prior art has been solved, easily lead to the problem that this welded part temperature risees.

Illustratively, both sides of the supporting layer are provided with conductive layers, and the conductive layers are metal foils such as copper foils or aluminum foils. Generally, the surface of the conductive layer is coated with an active material layer.

In another embodiment, the first tab 2 is provided with a plurality of first-type tabs 21 and second-type tabs 22, the plurality of first-type tabs 21 and the plurality of second-type tabs 22 are alternately distributed along the MD direction of the first pole piece, and in the MD direction of the first pole piece, the length of the main body portion 201 of the first-type tab 21 is S1, the length of the main body portion 201 of the second-type tab 22 is S2, the length of the connecting portion 202 of the first-type tab 21 is S3, and the length of the connecting portion 202 of the second-type tab 22 is S4; wherein S2 > S1, that is, the length of the main body 201 of the two-type tab 22 is greater than the length of the main body 201 of the one-type tab 21, the length of the connection portion 202 of the two-type tab 22 is necessarily greater than the length of the connection portion 202 of the one-type tab 21; or s2=s1, and S4 > S3, that is, when the length of the second-type tab 22 is identical to the length of the main body portion 201 of the first-type tab 21, the length of the connection portion 202 of the second-type tab 22 is greater than the length of the connection portion 202 of the first-type tab 21.

In this way, since the composite current collector has larger charge-discharge impedance than the conventional metal current collector, the positive electrode is usually a composite current collector, the negative electrode is a metal current collector, or the positive electrode is a metal current collector, the first pole piece is taken as an example, the second current collector 3 of the second pole piece is set as a metal current collector, then the second pole lug 4 is integrally formed by cutting the metal current collector, so the current carrying capacity of the second pole lug 4 is better than that of the first pole lug 2, the number of the second pole lugs 4 is maintained to be the original design, after the positive pole piece and the negative pole piece are wound into the battery core, the first pole lug 2 is divided into two types, the second pole lug 4 and the first pole lug 21 of the first pole lug 2 are positioned on the same side, the first pole lug 21 can avoid the first pole lug 2 of the negative pole piece, and the second pole lug 22 is taken as an additional structure, and is formed on the other side of the second pole lug 4 without considering avoiding factors, so the second pole lug 22 can have a longer design of the connecting part 202, and further increase the area of the connection area of the first pole lug 2 and the first current carrying lug 1 is further improved.

In another embodiment, the following relationship is also provided between the length S1 of the main body 201 of the one-type tab 21 and the length S2 of the main body 201 of the two-type tab 22, S1 satisfies that S1 is 4 mm.ltoreq.S1.ltoreq.50mm; and/or S2 satisfies that S2 is more than or equal to 4mm and less than or equal to 50mm; and/or S1 and S2 satisfy 0.5.ltoreq.S1/S2.ltoreq.1.

So configured, on the one hand, it is verified that the length of the main body portion 201 of the first tab 2 cannot be smaller than 4mm, such first tab 2 is too small and insufficient in overcurrent capability, and the length of the main body portion 201 of the first tab 2 cannot be larger than 50mm, such first tab 2 is too large and is liable to turn over when passing through the overcurrent roller of the cell winding device; on the other hand, in actual production, after the pole piece is wound, the symmetrical central lines of the first pole lugs 2 are inevitably slightly misplaced, and when the ratio of the lengths of the main body parts 201 of the first pole lugs 21 and the second pole lugs 22 meets the above range, even if misplaced, the overlapping area of the first pole lugs 2 in the projection direction can be ensured to meet the design requirement.

In another embodiment, regarding the length S3 of the connection portion 202 of the one-type tab 21, the length S4 of the connection portion 202 of the two-type tab 22, on the premise that S3/S4 < 1, has the following relationship, S3 satisfies 6 mm.ltoreq.S3.ltoreq.200mm; and/or S4 satisfies 6mm < S4 < 300mm.

So set up, in the electric core of common specification, when one type of utmost point ear 21 and two type of utmost point ears 22 accord with above-mentioned condition, when guaranteeing to avoid contact between the pole piece of first utmost point ear 2 and opposite polarity, compromise the area of the welded zone 203 between the biggest utmost point ear 2 and the mass flow body of improvement.

In another embodiment, in the MD direction of the first pole piece, the spacing distance between the first type tab 21 and the second type tab 22 is L1, and L1 satisfies 3 mm.ltoreq.L1.ltoreq.100 mm. Through verification, in the battery cell with common specification, the spacing distance between the first type tab 21 and the second type tab 22 is selected in the range for further design, so that a reasonable battery cell design scheme can be obtained.

In another embodiment, the first type tabs 21 and the second type tabs 22 are alternately arranged along the winding direction of the battery core, the spacing distance between the first type tabs 21 and the second type tabs 22 adjacently arranged in the MD direction of the first pole piece is L1, and the length of the second pole piece 4 in the MD direction of the second pole piece is L2, where L1 and L2 satisfy 1.2l2 < L1.

So set up, after first pole piece, second pole piece stack, in the MD direction of pole piece, second utmost point ear 4 is in between two adjacent first utmost point ears 2, designs to 1.2L2 < L1, can prevent that the opposite first utmost point ear 2 of polarity from contacting with second utmost point ear 4.

In another embodiment, the first tab 2 is welded with the first current collector 1, and the welding area 203 is formed on the first tab 2, the edge of the first current collector 1 is located in the edge of the diaphragm 5, and the diaphragm 5 completely covers the welding area 203 of the first tab 2. In general, the edges of the separator 5 are beyond the edges of the first current collector 1 and the second current collector 3 in the TD direction of the pole piece. This arrangement ensures that when all the first tabs 2 are assembled together and slightly bent, the welding area 203 between the first tab 2 and the first current collector 1 will not be in contact with the second current collector 3 to short-circuit.

In another embodiment, in the winding direction of the battery cell, the width of the battery cell is a, the thickness of the battery cell is B, the length of the connection portion 202 of the one-type tab 21 is S3, and the length of the connection portion 202 of the two-type tab 22 is S4; wherein S3 satisfies 5% of (A+B) less than or equal to S3 less than or equal to 60% of A+B; and/or S4 satisfies 50% ((a+b) < S4 +.90% () a+b).

So set up, when one type of utmost point ear 21 and two types of utmost point ears 22 accords with above-mentioned condition, can guarantee to maximize and utilize the welding space, improve the welded zone 203 area between first utmost point ear 2 and the first electric current collector 1 as far as possible, simultaneously, can guarantee again that the electric core is gone into behind the shell, first utmost point ear 2 does not interfere with the battery case and leads to the security risk.

After the winding of the battery core is completed, all the first tabs 2 need to be conducted with an external electric appliance in a switching mode. When the battery is actually produced, one battery cell or a plurality of battery cells are generally adopted to form the battery, so as to meet the design requirement.

Based on the above-mentioned battery cells, the embodiment of the application also provides a battery, which comprises a plurality of the above-mentioned battery cells, wherein the first electrode lugs 2 of the adjacent battery cells are electrically conducted, and the second electrode lugs 4 of the adjacent battery cells are electrically conducted. The battery has the above-mentioned battery core, so the beneficial effects brought by the battery core are referred to above, and will not be described herein.

In another embodiment, between two adjacent electric cells, all the first lugs 2 of each electric cell are equalized to the first switching sheet 6, and all the second lugs 4 of each electric cell are equalized to the second switching sheet 7; welding and forming welding marks 8 between the first tab 2 and the first switching sheet 6 and between the second tab 4 and the second switching sheet 7; i.e. four solder marks 8 are formed between the two cells.

In another embodiment, the solder mark 8 is completely located in the edge of the first tab 2 or the second tab 4, and the distance between the edge of the solder mark 8 and the outer edge of either side of the first tab 2 or the second tab 4 is greater than or equal to 0.5mm and less than or equal to 5mm.

The arrangement is that the distance between the welding mark 8 and the first tab 2 is at least 0.5mm, so that the position deviation possibly generated by the welding process can be accommodated, and the welding to the position beyond the first tab 2 is prevented; the distance between the welding mark 8 and the first tab 2 is controlled to be not more than 5mm, so as to ensure that the first tab 2 and the switching piece have enough welding area.

In another embodiment, the first tab 2 and the second tab 4 are glued with adhesive paper, the adhesive paper completely covers all the solder marks 8, and the adhesive paper partially or completely covers the first tab 2 and the second tab 4. So set up, when two electric cores of adjustment are in the position side by side, the adhesive tape prevents to weld the uneven surface of seal 8 and damage electric core structure.

The basic principles of the present application have been described above in connection with specific embodiments, but it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are merely examples and not intended to be limiting, and these advantages, benefits, effects, etc. are not to be construed as necessarily possessed by the various embodiments of the application. Furthermore, the specific details disclosed herein are for purposes of illustration and understanding only, and are not intended to be limiting, as the application is not necessarily limited to practice with the above described specific details.

The block diagrams of the devices, apparatuses, devices, systems referred to in the present application are only illustrative examples and are not intended to require or imply that the connections, arrangements, configurations must be made in the manner shown in the block diagrams. As will be appreciated by one of skill in the art, the devices, apparatuses, devices, systems may be connected, arranged, configured in any manner. Words such as "including," "comprising," "having," and the like are words of openness and mean "including but not limited to," and are used interchangeably therewith. The terms "or" and "as used herein refer to and are used interchangeably with the term" and/or "unless the context clearly indicates otherwise. The term "such as" as used herein refers to, and is used interchangeably with, the phrase "such as, but not limited to.

It is also noted that in the apparatus, devices and methods of the present application, the components or steps may be disassembled and/or assembled. Such decomposition and/or recombination should be considered as equivalent aspects of the present application.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

It should be understood that the terms "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are used for more clearly describing the technical solutions, and are not intended to limit the scope of the present application.

The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit embodiments of the application to the form disclosed herein. Although a number of example aspects and embodiments have been discussed above, a person of ordinary skill in the art will recognize certain variations, modifications, alterations, additions, and subcombinations thereof.

Claims

1. The battery cell is characterized by comprising a first pole piece, a diaphragm (5) and a second pole piece which are laminated and wound, wherein the polarity of the first pole piece is opposite to that of the second pole piece, the first pole piece comprises a first current collector (1) and a first tab (2), the second pole piece comprises a second current collector (3) and a second tab (4), the first current collector (1) is a composite current collector, the second current collector (3) is a metal current collector, the number of the first tabs (2) is n, and the number of the second tabs (4) is m; wherein n and m satisfy:

n＞m；

And/or 2*m-1.ltoreq.n.ltoreq.2.m+1.

2. The cell of claim 1, wherein the cell comprises a plurality of conductive traces,

The first current collector (1) comprises a supporting layer and a conductive layer, wherein the conductive layer is positioned on at least one side surface of the supporting layer;

The first tab (2) comprises a main body part (201) and a connecting part (202), and the connecting part (202) is connected with the conductive layer;

Wherein, in the MD direction of the first pole piece, the length of the connecting part (202) of the first pole lug (2) is larger than the length of the main body part (201) of the first pole lug (2).

3. The battery cell according to claim 2, wherein the first tab (2) includes a one-type tab (21) and a two-type tab (22), a plurality of the one-type tabs (21) and a plurality of the two-type tabs (22) are alternately distributed along an MD direction of the first pole piece, and in the MD direction of the first pole piece, a length of the main body portion (201) of the one-type tab (21) is S1, a length of the main body portion (201) of the two-type tab (22) is S2, a length of the connection portion (202) of the one-type tab (21) is S3, and a length of the connection portion (202) of the two-type tab (22) is S4; wherein,

S2＞S1；

Or s2=s1, and S4 > S3.

4. A cell according to claim 3, wherein in the MD direction of the first pole piece, the spacing distance between the first-type tab (21) and the second-type tab (22) which are adjacently arranged is L1, and in the MD direction of the second pole piece, the lengths of the second tabs (4) are L2, L1, L2 satisfy 1.2×l2 < L1.

5. A cell according to claim 3, wherein the spacing distance between the one-type tab (21) and the two-type tab (22) in the MD direction of the first pole piece is L1, L1 satisfying 3mm +.l1 +.100 mm.

6. The cell according to claim 2, characterized in that the first tab (2) is welded to the first current collector (1) and a welding zone (203) is formed on the first tab (2), the edge of the first current collector (1) is located in the edge of the diaphragm (5), and the diaphragm (5) completely covers the welding zone (203).

7. A battery comprising a plurality of cells according to any one of claims 1-6, wherein electrical conduction is provided between adjacent first tabs (2) of said cells and between adjacent second tabs (4) of said cells.

8. The battery according to claim 7, characterized in that between two adjacent cells, all the first tabs (2) of each cell are voltage-equalized to a first switching tab (6) and all the second tabs (4) of each cell are voltage-equalized to a second switching tab (7);

Welding marks (8) are formed between the first tab (2) and the first switching piece (6) and between the second tab (4) and the second switching piece (7).

9. The battery according to claim 8, wherein the solder mark (8) is located entirely within the edge of the first tab (2) or the second tab (4), and the distance between the edge of the solder mark (8) and the outer edge of either side of the first tab (2) or the second tab (4) is 0.5mm or more and 5mm or less.

10. The battery according to claim 8, characterized in that the first tab (2) and the second tab (4) are glued with a glue, which completely covers all the solder marks (8).