CN219800907U - Anode plate, battery cell and battery - Google Patents

Abstract

The utility model discloses an anode sheet, a battery cell and a battery, wherein the anode sheet comprises: the anode plate comprises at least one corner region and a plurality of non-corner regions, wherein the corner regions and the non-corner regions are alternately distributed, a protruding part is arranged on one side of the corner region along the thickness direction of the anode plate, and the protruding part protrudes relative to the anode plate; after the anode sheet is wound, the corner region can be located at a corner of the anode sheet after the anode sheet is wound, and the protruding portion can be located at a side of the anode sheet toward the winding center. Because the bulge is located towards one side of the winding center of the anode strip after the anode strip is wound, then, along the thickness direction of the anode strip, the top end of the bulge can be propped against the diaphragm, and the height of the bulge also determines the distance between the anode strip and the diaphragm in the corner area, so that the distance between the anode strip and the diaphragm in the corner area can be enlarged, the mobility of electrolyte in the corner area is increased, the transmission resistance of lithium ions is reduced, and the lithium precipitation phenomenon of the anode strip is relieved.

Description

Anode plate, battery cell and battery

Technical Field

The utility model relates to the technical field of battery manufacturing, in particular to an anode plate, a battery core and a battery.

Background

The winding process is used as the most commonly used manufacturing method in the production of lithium ion batteries, so that the battery cells can be manufactured in large quantities, the production efficiency is high, and the cost is lower. In the related art, a plurality of corners can appear on the anode sheet after winding, and mutual extrusion between the anode sheet and the diaphragm can appear on one side of the corner towards the winding center of the anode sheet, so that the anode sheet at the corner is not in good contact with electrolyte, and therefore, the phenomenon of lithium precipitation occurs at the corner. In addition, in the cyclic expansion process, the side of the corner, which faces the winding center of the anode sheet, is extruded by the anode sheets at the two sides, so that the lithium precipitation phenomenon is more obvious. In the process of separating out lithium on the anode sheet, the metal lithium is gradually accumulated from the anode sheet towards the separator, and finally contacts with the separator and punctures the separator, so that the battery is invalid.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides the anode sheet, which can relieve the lithium precipitation phenomenon of the anode sheet.

The utility model also provides a battery cell with the anode sheet.

The utility model also provides a battery with the battery cell.

An anode sheet according to an embodiment of the first aspect of the present utility model, which can be wound with a separator and a cathode sheet to form a cell, includes:

the anode plate comprises at least one corner region and a plurality of non-corner regions, wherein the corner regions and the non-corner regions are alternately distributed, a protruding part is arranged on one side of each corner region along the thickness direction of the anode plate, and the protruding part protrudes relative to the anode plate;

after the anode sheet is wound, the corner region can be located at a corner of the anode sheet, and the protruding portion can be located at one side of the anode sheet facing the winding center.

The anode sheet provided by the embodiment of the utility model has at least the following beneficial effects: because the bulge is located towards one side of the winding center of the anode strip after the anode strip is wound, then, along the thickness direction of the anode strip, the top end of the bulge can be propped against the diaphragm, and the height of the bulge also determines the distance between the anode strip and the diaphragm in the corner region (namely, the distance between the anode strip and the diaphragm is the height of the bulge), so that the distance between the anode strip and the diaphragm in the corner region can be enlarged, the extrusion between the anode strip and the diaphragm in the corner region is further relieved, the mobility of electrolyte in the corner region is increased, the transmission resistance of lithium ions is reduced, and the lithium precipitation phenomenon of the anode strip is relieved.

According to some embodiments of the utility model, the recess is disposed at one side of the corner region, and the recess can face away from a winding center of the cell after the anode sheet is wound.

According to some embodiments of the utility model, the recess extends in a width direction of the anode sheet;

or the corner region is provided with a plurality of concave parts which are distributed at intervals along the width direction of the anode sheet.

According to some embodiments of the utility model, the corner region is provided with a protrusion protruding with respect to a side surface of the anode tab, the protrusion being provided at one side of the corner region, the protrusion being capable of being directed toward a winding center of the battery cell after the anode tab is wound.

According to some embodiments of the utility model, the protruding portion extends in a width direction of the anode sheet;

alternatively, the corner region includes a plurality of protruding portions, and the plurality of protruding portions are arranged at intervals in the width direction of the anode sheet.

According to some embodiments of the utility model, the corner region includes a plurality of the protruding portions, and the protruding portions are spaced apart along the length direction of the anode sheet so that a gap is provided between top ends of two adjacent protruding portions after the anode sheet is wound.

According to some embodiments of the utility model, the recess is recessed inward such that a side of the anode sheet facing away from the recess protrudes outward to form the protrusion.

According to some embodiments of the utility model, the corner region is provided with a plurality of the protruding portions and a plurality of the recessed portions, the plurality of protruding portions and the recessed portions being spaced apart along a length direction of the anode sheet.

According to some embodiments of the utility model, the non-corner regions are planar on opposite sides in the thickness direction of the anode sheet.

A cell according to an embodiment of the second aspect of the present utility model includes:

the anode sheet;

a cathode sheet;

a separator, wherein the anode sheet, the separator and the cathode sheet are stacked and wound along the thickness direction of the anode sheet;

wherein the corner region is located at a corner position of the battery cell.

The battery cell provided by the embodiment of the utility model has at least the following beneficial effects: the anode sheet capable of relieving the lithium precipitation phenomenon of the anode sheet is adopted in the embodiment, and the failure of the battery cell can be avoided.

According to an embodiment of the third aspect of the present utility model, a battery includes:

the shell is internally provided with an inner cavity, and electrolyte is poured into the inner cavity;

the battery cell is accommodated in the inner cavity.

The battery cell provided by the embodiment of the utility model has at least the following beneficial effects: the embodiment adopts the battery cell with lower failure risk, thereby prolonging the service life of the battery.

Additional aspects and advantages of the utility model 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 utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic view of an anode sheet according to an embodiment of the present utility model;

fig. 2 is a schematic structural diagram of a battery cell and a battery according to an embodiment of the utility model;

FIG. 3 is an enlarged schematic view of FIG. 2A;

FIG. 4 is a schematic view of a portion of a corner region according to one embodiment of the present utility model;

FIG. 5 is a schematic plan view of an anode sheet facing a winding center side in one embodiment of the present utility model;

FIG. 6 is a schematic plan view of an anode sheet facing away from the center of winding in one embodiment of the present utility model;

FIG. 7 is a schematic plan view of an anode sheet facing a winding center side in one embodiment of the present utility model;

fig. 8 is a schematic plan view of a side of an anode sheet facing away from a winding center in one embodiment of the present utility model.

Reference numerals: anode tab 100, corner region 110, non-corner region 120, protrusion 200, recess 300, separator 400, cathode tab 500, cell 600, battery 700, housing 710, and interior cavity 720.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present utility model and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, the meaning of a number is one or more, the meaning of a number is two or more, and greater than, less than, exceeding, etc. are understood to exclude the present number, and the meaning of a number is understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

In the description of the present utility model, the descriptions of the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., 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 utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Referring to fig. 1 to 3, an anode sheet 100 according to an embodiment of the first aspect of the present utility model, the anode sheet 100 includes: at least one corner region 110 and a plurality of non-corner regions 120, the corner regions 110 and the non-corner regions 120 being alternately arranged, a protrusion 200 being provided at one side of the corner region 110 in a thickness direction of the anode sheet 100, and the protrusion 200 protruding with respect to the anode sheet 100; wherein, after the anode tab 100 is wound, the corner region 110 can be located at a corner of the anode tab 100, and the protrusion 200 can be located at a side of the anode tab 100 toward the winding center.

Since the protrusion 200 is located at a side toward the winding center of the anode sheet 100 after the anode sheet 100 is wound, the top end of the protrusion 200 can be abutted against the separator 400 in the thickness direction of the anode sheet 100 (refer to fig. 3), thereby expanding the space between the anode sheet 100 and the separator 400 in the corner region 110, thereby relieving the extrusion between the anode sheet 100 and the separator 400 in the corner region 110, increasing the fluidity of the electrolyte in the corner region 110, reducing the transmission resistance of lithium ions, and thus relieving the lithium precipitation phenomenon of the anode sheet 100.

Further, after the anode sheet 100 is wound, since the protrusion 200 faces the winding center of the cell 600 after the anode sheet 100 is wound, it can be understood that purple specks are generated when the lithium intercalation space on the anode sheet 100 is insufficient, and the purple specks are evolved into lithium, and by providing the protrusion 200, the surface area of the anode sheet 100 facing the winding center of the cell 600 is enlarged, so that the side of the corner region 110 facing the winding center of the cell 600 can provide more lithium intercalation space (i.e. graphite), thereby reducing the generation of purple specks.

In some preferred embodiments, the length of the corner region 110 is 2mm along the length direction of the anode sheet 100, and it is understood that taking the length of the corner region 110 to be 2mm can ensure that the overall thickness of the battery cell 600 is not affected after the anode sheet 100 is wound, and can also slow down the lithium precipitation phenomenon at the corner region 110.

In some embodiments, referring to fig. 5, the protrusion 200 extends in the width direction of the anode sheet 100; alternatively, referring to fig. 7, the corner region 110 includes a plurality of protrusions 200, and the plurality of protrusions 200 are arranged at intervals in the width direction of the anode sheet 100.

The present embodiment enables the anode tab 100 to more uniformly absorb lithium ions in the width direction of the anode tab 100 at the corner region 110 after winding by extending the protrusion 200 in the width direction of the anode tab 100 or by distributing a plurality of protrusions 200 at intervals in the width direction of the anode tab 100.

In some embodiments, referring to fig. 3 and 7, the corner region 110 includes a plurality of protrusions 200, and the plurality of protrusions 200 are spaced apart in the length direction of the anode sheet 100 such that a gap is provided between top ends of two adjacent protrusions 200 after the anode sheet 100 is wound. So arranged, after the anode tab 100 is wound, the phenomenon of mutual extrusion between adjacent protrusions 200 along the length direction of the anode tab 100 can be prevented, thereby preventing lithium precipitation between adjacent protrusions 200 due to mutual extrusion.

It should be noted that, after the anode sheet 100 is wound, at the corner of the anode sheet 100, one side of the corner region 110 away from the winding center of the cell 600 (i.e., the outer ring surface of the anode sheet 100) will be in a stretched state (i.e., one side of the anode sheet 100 toward the winding center of the cell 600 is pressed against each other, one side of the anode sheet 100 away from the winding center of the cell 600 is stretched), resulting in a more dispersed amount of graphite on the outer ring surface of the anode sheet 100, so that the rate of absorbing lithium ions by the outer ring surface of the anode sheet 100 is lower than the rate of absorbing lithium ions by the other side of the corner region 110, thereby resulting in a shortage of cell balance (i.e., CB value) of the cell 600 at the outer ring surface of the anode sheet 100 at the later stage of the cycle.

Thus, in some embodiments, referring to fig. 4, the corner region 110 is provided with a recess 300, the recess 300 being provided at one side of the corner region 110, the recess 300 being capable of facing away from the winding center of the cell 600 after the anode sheet 100 is wound.

In this embodiment, the recess 300 is disposed, so that when the anode sheet 100 is wound, the side of the corner region 110 away from the winding center of the cell 600 is stretched more obviously in the stretching process, and the bottom wall of the recess 300 is stretched less, so that after the anode sheet 100 is wound, graphite can still gather on the bottom wall of the recess 300, thereby reducing free lithium ions generated on the outer ring surface of the anode sheet 100.

It is understood that when the free lithium ions are less (i.e., the concentration of lithium ions in the electrolyte is lower), the rate of precipitation of metal lithium on the side of the anode sheet 100 toward the winding center of the cell 600 at the corner region 110 can be effectively reduced, thereby further alleviating the phenomenon of precipitation of lithium on the anode sheet 100.

Further, in some embodiments, referring to fig. 6, the recess 300 extends in the width direction of the anode sheet 100; or, referring to fig. 8, the corner region 110 is provided with a plurality of depressions 300, and the plurality of depressions 300 are spaced apart in the width direction of the anode sheet 100.

It can be appreciated that since the recess 300 extends in the width direction of the anode tab 100 or the plurality of recesses 300 are spaced apart in the width direction of the anode tab 100, the outer circumferential surface of the anode tab 100 absorbs lithium ions more uniformly in the width direction of the anode tab 100 after the anode tab 100 is wound.

In some embodiments, referring to fig. 4, the recess 300 is recessed inward such that a side of the anode sheet 100 facing away from the recess 300 protrudes outward to form the protrusion 200.

In this embodiment, the protruding portion 200 and the recessed portion 300 are simultaneously disposed in the corner region 110, it can be understood that the protruding portion 200 faces the winding center of the anode sheet 100 after the anode sheet 100 is wound, so that the phenomenon of lithium precipitation can be alleviated, the recessed portion 300 can slowly analyze the phenomenon of lithium after the anode sheet 100 is wound and is opposite to the winding center of the anode sheet 100, and the protruding portion 200 and the recessed portion 300 are combined and applied to the corner region 110, so that an overlapping effect can be generated, and the anode sheet 100 can better slowly analyze the phenomenon of lithium.

Further, the recess 300 is recessed inward such that the anode sheet 100 protrudes outward from one side of the recess 300 to form the protrusion 200 (i.e., in the form of embossing), so that the occupation space of the protrusion 200 and the recess 300 in the length direction or the width direction of the anode sheet 100 can be reduced; it will be appreciated that the embossing is more convenient for the production of the protruding portion 200 and the recessed portion 300, and reduces the difficulty of production.

In some preferred embodiments, the distance between the top end of the protrusion 200 and the anode tab 100 in the thickness direction of the anode tab 100 is maintained between 40 μm and 70 μm, thereby ensuring that the protrusion of the protrusion 200 with respect to the anode tab 100 does not affect the width of the cell 600.

Further, in some embodiments, referring to fig. 4, 7 to 8, the corner region 110 is provided with a plurality of protrusions 200 and a plurality of depressions 300, and the plurality of protrusions 200 and depressions 300 are spaced apart along the length direction of the anode sheet 100.

The plurality of protruding portions 200 and recessed portions 300 which are distributed at intervals are arranged in the length direction of the anode sheet 100, so that the surface area of the corner region 110 is larger than the surface area of the corner region 110 in the case that only the protruding portions 200 extend along the length direction of the anode sheet 100, the corner region 110 has more lithium intercalation vacancies, and meanwhile, the concentration of lithium ions in the electrolyte can be reduced more rapidly.

In some embodiments, referring to fig. 1, in the thickness direction of the anode sheet 100, both opposite sides of the non-corner region 120 are planar.

In this embodiment, the protruding portion 200 is only disposed at the corner region 110 of the anode sheet 100, and the non-corner region 120 is not provided with the protruding portion 200, so that the thickness of the anode sheet 100 after being wound can be effectively reduced, and the thickness of the winding core can be further reduced.

The present utility model also proposes a battery cell 600 according to an embodiment of the second aspect, referring to fig. 3, the battery cell 600 comprising: the anode sheet 100, the cathode sheet 500, and the separator 400 described above, the anode sheet 100, the separator 400, and the cathode sheet 500 are stacked and wound in the thickness direction of the anode sheet 100; wherein corner regions 110 are located at corner positions of cell 600.

During the process of lithium separation, the anode sheet 100 will gradually accumulate lithium metal from the anode sheet 100 toward the separator 400 until contacting the separator 400 and piercing the separator 400 to contact the cathode sheet 500, resulting in failure of the cell 600.

The present embodiment adopts the anode sheet 100 capable of alleviating the lithium precipitation phenomenon of the anode sheet 100, so as to reduce the failure risk of the battery cell 600.

The present utility model also proposes a battery 700 of an embodiment of a third aspect, referring to fig. 3, the battery 700 comprising: the housing 710 and the battery cell 600 described above, the housing 710 has an inner cavity 720, the electrolyte is poured into the inner cavity 720, and the battery cell 600 is accommodated in the inner cavity 720, and the battery cell 600 with a low failure risk is adopted in this embodiment, so that the service life of the battery 700 is prolonged.

The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model. Furthermore, embodiments of the utility model and features of the embodiments may be combined with each other without conflict.

Claims (10)

1. An anode sheet capable of being wound with a separator and a cathode sheet to form a cell, comprising:

the anode plate comprises at least one corner region and a plurality of non-corner regions, wherein the corner regions and the non-corner regions are alternately distributed, a protruding part is arranged on one side of each corner region along the thickness direction of the anode plate, and the protruding part protrudes relative to the anode plate;

after the anode sheet is wound, the corner region can be located at a corner of the anode sheet, and the protruding portion can be located at one side of the anode sheet facing the winding center.

2. The anode sheet according to claim 1, wherein the protruding portion extends in a width direction of the anode sheet;

alternatively, the corner region includes a plurality of protruding portions, and the plurality of protruding portions are arranged at intervals in the width direction of the anode sheet.

3. The anode sheet according to claim 1 or 2, wherein the corner region includes a plurality of the protruding portions, the plurality of protruding portions being spaced apart in a length direction of the anode sheet such that a gap is provided between top ends of two adjacent protruding portions after the anode sheet is wound.

4. The anode tab of claim 1, wherein the corner region is further provided with a recess portion disposed on a side of the anode tab facing away from the protrusion portion.

5. The anode sheet according to claim 4, wherein the recess portion extends in a width direction of the anode sheet;

or the corner region is provided with a plurality of concave parts which are distributed at intervals along the width direction of the anode sheet.

6. The anode sheet according to claim 4 or 5, wherein the concave portion is concave inward so that a side of the anode sheet facing away from the concave portion protrudes outward to form the convex portion.

7. The anode sheet according to claim 6, wherein the corner region is provided with a plurality of the convex portions and a plurality of the concave portions, the plurality of the convex portions and the concave portions being spaced apart in a length direction of the anode sheet.

8. The anode sheet according to claim 1, wherein the opposite sides of the non-corner region are planar in the thickness direction of the anode sheet.

9. The electric core, its characterized in that includes:

the anode sheet of any one of claims 1 to 8;

a cathode sheet;

a separator, wherein the anode sheet, the separator and the cathode sheet are stacked and wound along the thickness direction of the anode sheet;

wherein the corner region is located at a corner position of the battery cell.

10. A battery, comprising:

the shell is internally provided with an inner cavity, and electrolyte is poured into the inner cavity;

the battery cell of claim 9, the battery cell being housed within the internal cavity.