CN220527152U - Battery cell - Google Patents

Abstract

The application provides a battery. The battery comprises a battery core and a shell, wherein the battery core is sequentially stacked or wound with a first pole piece, an isolating layer, a second pole piece, a first pole lug and a second pole lug, the first pole lug is provided with a first welding mark, and the second pole lug is provided with a second welding mark; the metal material of the first tab is the same as that of the shell, the first welding mark protrudes out of the surface of the first tab and faces the shell, the first welding mark is covered with uncovered adhesive paper, and the second welding mark is covered with adhesive paper. The battery that this application provided passes through the structure setting, on not producing safety hazard's basis, need not to adhere the gummed paper on first utmost point ear for battery collection discharge unit's volume is than the increase, also can increase the volume of collection discharge unit in the unit area promptly, thereby has improved the energy density of battery.

Description

Battery cell

Technical Field

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

Background

Along with the continuous progress of technological development, electronic products such as mobile phones, computers and flat panels are expected to be lighter and thinner, namely lighter in weight and thinner in thickness, and can be conveniently carried, so that higher requirements are put on batteries, and the improvement of energy density is also considered while quick charge is ensured.

Disclosure of Invention

In view of this, embodiments of the present application aim to provide a battery, on the basis of not creating a safety hazard, without adhering a gummed paper on the first tab, so that the volume ratio of the battery discharge collecting part is increased, that is, the volume of the discharge collecting part per unit area can be increased, thereby improving the energy density of the battery.

The application provides a battery, which comprises a battery cell and a shell wrapping the battery cell, wherein the battery cell comprises a first pole piece, an isolation layer, a second pole piece, a first pole lug and a second pole lug, wherein the first pole lug is provided with a first welding mark, and the second pole lug is provided with a second welding mark; wherein,

the metal material of the first tab is the same as that of the shell, the first welding mark protrudes out of the surface of the first tab and faces the shell, and the first welding mark is not covered with gummed paper.

In one possible embodiment, the case includes a first resin layer, a metal layer, and a second resin layer in this order in a thickness direction, and the projection height of the first solder is smaller than the sum of the thicknesses of the second resin layer and the metal layer.

In a possible embodiment, the first surface and the second surface of the second lug are both protruded with the second solder mark, and are both provided with adhesive papers covering the second solder mark.

In one possible embodiment, the projection height of the second solder mark on the second surface is smaller than the projection height of the second solder mark on the first surface; and/or the thickness of the gummed paper on the second surface is greater than or equal to the thickness of the gummed paper on the first surface; and/or the thickness of the gummed paper on the first surface is 10-100 micrometers, and the thickness of the gummed paper on the second surface is 10-100 micrometers.

In one possible embodiment, the projection of the gummed paper in the thickness direction does not overlap with the projection of the pole piece of the battery cell in the thickness direction.

In one possible implementation manner, the first pole piece, the isolation layer and the second pole piece are wound together, the outermost ring of the battery cell is a section of the first pole piece along the winding direction, and the tail end of the first pole piece is coated with ending glue; the tail end edge of the ending glue is located on a bending section of the battery cell closest to the tail end edge of the first pole piece.

In one possible embodiment, the first pole piece, the isolation layer and the second pole piece are wound together, the outermost ring of the battery cell is a section of the first pole piece along the winding direction, and the isolation layer has an extension section exceeding the tail end edge of the second pole piece; the tail end edge of the extension section is positioned on the bending section of the battery cell closest to the tail end edge of the first pole piece.

In one possible embodiment, the length of the extension is 5-20 mm.

In one possible embodiment, the two surfaces of the first pole piece are respectively provided with a first paste coating layer and a second paste coating layer, the two surfaces of the second pole piece are respectively provided with a third paste coating layer and a fourth paste coating layer, the first external paste coating layer of the first pole piece is opposite to the third paste coating layer of the second pole piece, and the second paste coating layer of the first pole piece is opposite to the fourth paste coating layer of the second pole piece.

In one possible embodiment, at the tail end of the second pole piece, the tail end of the fourth paste layer exceeds the tail end edge of the second paste layer opposite thereto by a length of 1 mm or more; and/or the tail end of the third paste coating layer exceeds the tail end edge of the first paste coating layer opposite to the tail end edge, and the exceeding length is more than or equal to 1 millimeter.

In one possible embodiment, the region of the first pole piece adjacent to the first pole lug is provided with an insulating layer, the second pole piece is adjacent to the edge of the paste coating layer of the second pole lug, and the projection in the thickness direction is located in the projection region of the insulating layer in the thickness direction.

According to the battery provided by the application, the first tab and the second tab are provided with welding marks, but the metal material of the first tab is the same as that of the shell, for example, when the shell is an aluminum plastic film, the material of the first tab is aluminum foil. Therefore, the first tab and the shell are in contact and cannot generate potential difference or electrochemical corrosion due to the fact that the metal materials of the first tab and the shell are the same, and therefore the first tab and the shell can be in contact and cannot generate safety hazards. Meanwhile, the first welding marks of the first electrode lugs are protruded on the surfaces of the first electrode lugs and face the shell, so that the first welding marks can not puncture the isolating layer on the battery cell even if adhesive paper is not attached, the safety problem of short circuit of the positive and negative electrode plates of the battery cell is avoided, the protruding height of the first welding marks is smaller than the thickness of the shell, and the shell can not be punctured. And glue paper is not pasted on the first tab, then compare with the battery of pasting glue paper on the first tab among the prior art, the battery that this application provided reduces overall thickness on the unchangeable basis of current collecting ability for battery collection discharge part's volume ratio increases, also can increase the volume of collection discharge part in the unit area promptly, thereby has improved the energy density of battery.

Drawings

Fig. 1 is a schematic diagram of a battery cell 1 according to an embodiment of the present application;

fig. 2 is a schematic cross-sectional view of a winding core structure of the battery cell 1 according to an embodiment of the present application;

fig. 3 is a schematic cross-sectional view of a stacked-core structure of the battery cell 1 according to an embodiment of the present application.

In fig. 1-3:

1. a battery cell; 2. a first tab; 3. a first solder printing; 4. a second lug; 5. a second solder printing; 6. glue paper; 7. an isolation layer; 8. a first pole piece; 9. a second pole piece; 10. ending glue; 11. an insulating layer.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Referring to fig. 1-3, an embodiment of the present application provides a battery, which includes a battery cell 1 and a housing wrapping the battery cell 1, wherein the battery cell 1 includes a first electrode tab 8, an isolation layer 7, a second electrode tab 9, and a first electrode tab 2 and a second electrode tab 4 stacked or wound in sequence. The isolating layer 7 may be a membrane or other insulating material layer. The first tab 2 is arranged on the first pole piece 8, and the second tab 4 is arranged on the second pole piece 9. The surface of the first tab 2 is formed with a first solder mark 3, and the surface of the second tab 4 is formed with a second solder mark 5, which is formed by soldering. For example, the first tab 2 includes a soft tab and a hard tab, where the soft tab and the hard tab are welded, a first weld 3 is formed, and where the soft tab and the hard tab of the second tab 4 are welded, a second weld 5 is formed. The metal material of the first tab 2 is the same as the metal material of the housing, for example, when the housing is an aluminum plastic film, the material of the first tab 2 is aluminum foil. Therefore, the first tab 2 and the shell are made of the same metal material, and the first tab 2 and the shell are contacted with each other without generating potential difference or electrochemical corrosion, so that the first tab 2 and the shell can be contacted without generating safety hazard. Meanwhile, the first welding marks 3 of the first electrode lugs 2 are arranged to protrude out of the surfaces of the first electrode lugs 2 and face the shell, so that the isolating layer 7 on the battery cell 1 can not be pierced even if the adhesive paper 6 is not attached to the first welding marks 3, and the safety problem of short circuit of the positive electrode plate and the negative electrode plate of the battery cell 1 is avoided. The protruding height of the first solder 3 is made smaller than the thickness of the housing, so that the housing is not pierced. Therefore, through the structural arrangement, the adhesive paper 6 covering the first welding mark 3 is not arranged on the first tab 2 in the application, and no safety problem is generated.

And glue paper 6 is not pasted on the first tab 2, then compare with the battery of pasting glue paper 6 on the first tab 2 among the prior art, the battery that this application provided has reduced whole thickness on the unchangeable basis of current collecting ability for battery collection discharge unit's volume ratio increases, also can increase the volume of collection discharge unit in the unit area promptly, increases the unit power collecting ability, thereby has improved the energy density of battery. The overall thickness of the battery is reduced, so that the battery is light and thin and convenient to set and apply; the adhesive paper 6 is not arranged on the first tab 2, so that the phenomenon that the adhesive paper 6 on the first tab 2 is adhered to the outermost layer of the battery cell 1 is avoided, and the flatness of the soft package of the battery cell 1 can be improved.

The metal material of the second tab 4 may be different from the metal material of the first tab 2, so that the second tab 4 may be provided with an adhesive tape 6 to cover the second solder mark 5, so as to avoid the potential difference generated by the contact between the second tab 4 and the housing, and also avoid the problem that the second solder mark 5 has burrs and may puncture the diaphragm or the housing.

The casing for wrapping the battery cell 1 may be an aluminum plastic film, and in some embodiments, the aluminum plastic film includes three composite layers of a first resin layer, a metal layer, and a second resin layer sequentially along the thickness direction. The protruding height of the first solder 3 (i.e., the height protruding from the surface of the first tab 2) is smaller than the sum of the thicknesses of the second resin layer and the metal layer. In this way, even if burrs exist on the first solder marks 3, the outer shell is not pierced.

As shown in fig. 1, the second tab 4 is in the form of a sheet, and both sides of the sheet are denoted as a first surface and a second surface, each of which is projected with the second solder mark 5, and each of which is provided with a gummed paper 6 covering the second solder mark 5. Thus, the protection can be fully realized.

Typically the hard tab is located on one side of the soft tab and therefore there is a height difference between the solder marks on the first and second surfaces. For example, the protruding height of the second solder marks 5 on the second surface is larger than the protruding height of the second solder marks 5 on the first surface. Thus, in some embodiments, the thickness of the gummed paper 6 on the second surface is equal to or greater than the thickness of the gummed paper 6 on the first surface. For example, it can also be said that the thickness of the first surface size 6 is smaller than the thickness of the second surface size 6. Because the height of the protrusion of the solder mark on the first surface is smaller, the gummed paper 6 attached to the surface can be thinner, so that the safety risk is avoided, the overall thickness of the battery core 1 can be further reduced, the total proportion of the current collecting substances is improved, and the volume of the current collecting substances in unit area is improved, namely the current collecting capacity and the energy density of the battery are improved.

In some embodiments, the thickness of the gummed paper 6 on the first surface of the second ear 4 is 10-100 microns, such as 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, 55 microns, 60 microns, 65 microns, 70 microns, 75 microns, 80 microns, 85 microns, 90 microns, 95 microns, 100 microns. The thickness of the gummed paper 6 on the second surface is 10-100 micrometers, for example 15 micrometers, 20 micrometers, 25 micrometers, 30 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, 50 micrometers, 55 micrometers, 60 micrometers, 65 micrometers, 70 micrometers, 75 micrometers, 80 micrometers, 85 micrometers, 90 micrometers, 95 micrometers, 100 micrometers.

The adhesive tape 6 on the second tab 4, whether the adhesive tape 6 on the first surface or the adhesive tape 6 on the second surface, may extend to the pole piece, for example, the tail end is stuck to the pole piece on the outermost layer of the battery cell 1, or may not extend to the pole piece, for example, the projection of the adhesive tape 6 in the thickness direction does not overlap with the projection of the pole piece in the thickness direction.

The first pole piece 8 comprises a first current collector, a first paste coating layer and a second paste coating layer which are positioned on two surfaces of the first current collector. The second electrode sheet 9 includes a second current collector, a third paste layer and a fourth paste layer on both surfaces of the second current collector. The battery cell 1 may be a stacked-core structure, for example, formed by stacking the first pole piece 8, the isolation layer 7 and the second pole piece 9 in sequence, or a rolled-core structure, for example, formed by winding the first pole piece 8, the isolation layer 7 and the second pole piece 9 together.

When the battery cell 1 is of a rolled core structure, the two surfaces of the current collector include a surface facing the center of the battery cell 1 and a surface facing the outside of the battery cell 1. The second paste layer of the first pole piece 8 may be a paste layer on the same current collector section, on the current collector surface facing or closer to the center of the cell 1, and also a paste layer closer to the center of the cell, while the first paste layer is a paste layer on the current collector surface facing the outside of the cell on the same current collector section, and also a paste layer farther from the center of the cell. Likewise, the third paste layer on the second pole piece 9 refers to the paste layer on the same section closer to the center of the battery cell, and the fourth paste layer refers to the paste layer on the same pole piece section farther from the center of the battery cell. The first paste layer of the first pole piece 8 is opposite to the third paste layer of the second pole piece 9 and is separated by the isolating layer 7, and the second paste layer of the first pole piece 8 is opposite to the fourth paste layer of the second pole piece 9 and is separated by the isolating layer 7.

In some embodiments, as shown in fig. 2, the second paste layer is on a side surface of the first current collector, extending from the leading edge of the first current collector to the trailing edge of the first current collector, which is also referred to as fully coated, the side surface of the first current collector being fully covered without uncoated areas. And the first paste layer extends from the leading edge to the trailing edge of the first current collector on the other side surface of the first current collector with a spacing from the trailing edge. That is, the other side surface of the first current collector, which has an uncoated region of the uncoated paste at the tail end, is not completely covered. Thus, in the wound cell 1, as shown in fig. 2, the tail end of the first pole piece 8 is used for ending, and the uncoated region forms the outer surface of the entire cell 1. And the head end of the first pole piece 8 is not provided with an uncoated area, so that the ratio of current collecting substances can be increased, and the energy density of the battery can be improved.

When the battery cell 1 is in a winding core structure, a plurality of annular ring segments are included along the winding direction, and the first pole piece 8 and the second pole piece 9 also include a plurality of annular ring segments. In some embodiments, the tail end of the first pole piece 8 forms the outermost ring of the battery cell 1, that is, the outermost ring of the battery cell 1 is a section of the first pole piece 8, which can also be said to use the tail end of the first pole piece 8 as the ending of the battery cell 1. The head end of the second pole piece 9 is used as the innermost ring of the battery cell 1. Along the winding direction, the annular ring section of the outermost ring of the battery core 1 is formed by the tail end of the first pole piece 8, so to speak, the tail end of the first pole piece 8 completely wraps the tail end of the second pole piece 9, or the last annular ring section of the first pole piece 8 wraps the last annular ring section of the second pole piece 9.

The tail end of the first pole piece 8 is stuck with ending glue 10, the ending glue 10 can be gummed paper, and the ending glue 10 sticks to the tail end edge of the first pole piece 8 to fix the first pole piece, so as to prevent winding from being scattered. The annular ring segment comprises a straight segment and a bending segment. In some embodiments, as shown in fig. 2, the tail edge of the ending glue 10 is located on a bending section (in the winding direction, the bending section closest to the tail edge of the first pole piece 8, also referred to as an arc surface, and the following description) of the cell 1 closest to the tail edge of the first pole piece 8. Thus, the ending glue 10 does not need to be too long and does not extend to the straight section of the battery cell 1, so that the duty ratio of non-current collecting substances can be reduced, and the energy density of the battery can be improved.

The separator 7 may be a membrane, at the end of which the membrane exceeds the end of the second pole piece 9 in the winding direction, i.e. the membrane has an extension beyond the end edge of the second pole piece 9 (e.g. at L1 in fig. 2, L1 in the drawing does not represent the length of the extension, but is only used to indicate the extension) to prevent shorting of the second pole piece 9 and the first pole piece 8. As shown in fig. 2, in some embodiments, the trailing edge of the extension of the diaphragm is located on the bent section of the cell 1 closest to the trailing edge of the first pole piece 8. In this way, the energy density of the battery can be increased as well.

The natural length of the extension of the membrane is at least 5 mm, and may be 5-20 mm, preferably 8-10 mm, e.g. 8 mm, 9 mm, 10 mm.

When the tail end of the first pole piece 8 is used as the tail end of the battery cell 1, the tail end of the fourth paste coating layer of the second pole piece 9 exceeds the tail end edge (shown as L2 in fig. 2) of the second paste coating layer of the first pole piece 8 opposite to the tail end, and the tail end of the third paste coating layer of the second pole piece 9 exceeds the tail end edge (shown as L3 in fig. 2) of the first paste coating layer of the first pole piece 8 opposite to the tail end. In this way, it is ensured that the paste layer of the second pole piece 9 exceeds the paste layer of the first pole piece 8, preventing lithium precipitation.

In some embodiments, the second pole piece 9 has a trailing edge of the fourth paste layer beyond the trailing edge of the second paste layer of the first pole piece 8 opposite thereto in the winding direction by a length of ∈1 mm. The tail edge of the third paste coating layer of the second pole piece 9 exceeds the tail edge of the first paste coating layer of the first pole piece 8 opposite to the tail edge, and the length of the tail edge exceeds more than or equal to 1 millimeter.

When the battery cell 1 is of a stacked-core structure, the first pole piece 8, the isolation layer 7, and the second pole piece 9 are stacked in order in the thickness direction, as shown in fig. 3. Wherein, the region of the first pole piece 8 near the first pole ear 2 is provided with an insulating layer 11, the second pole piece 9 is near the edge of the paste coating layer of the second pole ear 4, and the projection in the thickness direction is positioned in the projection region of the insulating layer 11 in the thickness direction.

The basic principles of the present application have been described above in connection with specific embodiments, however, it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are merely examples and not limiting, and these advantages, benefits, effects, etc. are not to be considered as necessarily possessed by the various embodiments of the present 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 intended to be limited to the details disclosed herein as such.

The components, arrangements, etc. referred to in this application are meant to be illustrative examples only and are not intended to require or imply that the connections, arrangements, configurations must be made in the manner shown in the drawings. These components, devices, may be connected, arranged, configured in any manner, as will be appreciated by those skilled in the art. 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 should also be noted that in the apparatus, devices of the present application, the components may be disassembled and/or assembled. Such decomposition and/or recombination should be considered as equivalent to 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" and "second" used in the descriptions of the embodiments of the present application are only used for clearly illustrating the technical solutions, and are not used to limit the protection 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 the 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.

The foregoing description of the preferred embodiments of the present utility model is not intended to limit the utility model to the precise form disclosed, and any modifications, equivalents, and alternatives falling within the spirit and principles of the present utility model are intended to be included within the scope of the present utility model.

Claims (11)

1. The battery is characterized by comprising a battery core and a shell wrapping the battery core, wherein the battery core comprises a first pole piece, an isolating layer, a second pole piece, a first pole lug and a second pole lug, wherein the first pole piece, the isolating layer and the second pole piece are sequentially stacked, the first pole lug is connected to the first pole piece, the second pole lug is connected to the second pole piece, the first pole lug is provided with a first welding mark, and the second pole lug is provided with a second welding mark; wherein,

the metal material of the first tab is the same as the metal material of the housing,

the first welding marks are protruded out of the surface of the first tab and face the shell, and the first welding marks are not covered with gummed paper.

2. The battery according to claim 1, wherein the case includes a first resin layer, a metal layer, and a second resin layer in this order in a thickness direction, and a projection height of the first solder is smaller than a sum of thicknesses of the second resin layer and the metal layer.

3. The battery of claim 1, wherein the first surface and the second surface of the second tab are each raised by the second solder and are each provided with a gummed paper covering the second solder.

4. The battery of claim 3, wherein the second solder bump height on the second surface is less than the second solder bump height on the first surface; and/or the number of the groups of groups,

the thickness of the gummed paper on the second surface is greater than or equal to the thickness of the gummed paper on the first surface; and/or the number of the groups of groups,

the thickness of the gummed paper on the first surface is 10-100 micrometers, and the thickness of the gummed paper on the second surface is 10-100 micrometers.

5. The battery of claim 3, wherein the thickness-wise projection of the gummed paper does not overlap with the thickness-wise projection of the pole piece of the cell.

6. The battery of claim 1, wherein the first pole piece, the isolation layer and the second pole piece are wound together, the outermost ring of the electric core is a section of the first pole piece along the winding direction, and a tail-end adhesive is attached to the tail end of the first pole piece;

the tail end edge of the ending glue is positioned on the bending section of the battery cell closest to the tail end edge of the first pole piece.

7. The battery of claim 1, wherein the first pole piece, the separator and the second pole piece are wound together, the outermost ring of the cell in the winding direction being a section of the first pole piece, the separator having an extension beyond the trailing edge of the second pole piece;

the tail end edge of the extension section is positioned on the bending section of the battery cell closest to the tail end edge of the first pole piece.

8. The battery of claim 7, wherein the extension has a length of 5-20 millimeters.

9. The battery of claim 1, wherein the two surfaces of the first pole piece have a first paste layer and a second paste layer, respectively, and the two surfaces of the second pole piece have a third paste layer and a fourth paste layer, respectively, the first paste layer of the first pole piece and the third paste layer of the second pole piece being opposite, and the second paste layer and the fourth paste layer of the second pole piece being opposite.

10. The battery of claim 9 wherein at the trailing end of the second pole piece, the trailing end of the fourth paste layer exceeds the trailing edge of the second paste layer opposite thereto by a length of ≡1 mm; and/or the number of the groups of groups,

the tail end of the third paste coating layer exceeds the tail end edge of the first paste coating layer opposite to the tail end edge, and the exceeding length is more than or equal to 1 millimeter.

11. The battery of claim 1, wherein an area of the first pole piece adjacent to the first tab is provided with an insulating layer, and the second pole piece is adjacent to an edge of the paste layer of the second tab, and a projection in a thickness direction is located in a projection area of the insulating layer in the thickness direction.