CN220672808U - Multipolar ear pole piece, battery cell and lithium battery - Google Patents

Abstract

The utility model discloses a multi-lug pole piece, an electric core and a lithium battery, wherein the pole piece comprises a current collector and an active coating coated on the surface of the current collector, the coated area of the active coating is a coated area, the uncoated area is an empty foil area, and the empty foil area is provided with a plurality of die-cut lugs; the die-cutting lugs are arranged at intervals along the length direction of the current collector and are divided into a plurality of groups, and the number of each group of die-cutting lugs is at least two; the heights of the die-cut tabs of each group gradually decrease from the middle group to the two ends of the current collector. The utility model solves the problems that the multipolar lug structure is easy to block the central hole of the battery cell and cover the end face of the battery cell, so that the electrolyte injection is not smooth, thereby improving the electrolyte infiltration effect of the battery cell and simultaneously solving the problem of poor flatness of the multipolar lug structure after flattening.

Description

Multipolar ear pole piece, battery cell and lithium battery

Technical Field

The utility model relates to the technical field of lithium batteries, in particular to a multi-pole ear pole piece, an electric core and a lithium battery.

Background

The cylindrical battery is a common structural form of a lithium battery, and an electric core of the cylindrical battery is prepared by winding a pole piece; in order to lead out two electrodes of the battery, an empty foil area is generally arranged at the edge of the active coating of the pole piece, and a multi-pole ear structure is formed after the empty foil area is subjected to die cutting, so that the coiled multi-pole ear structure can be connected with structures such as a bus plate and a pole post to form the electrodes of the battery.

The application publication No. CN115377480A discloses a novel cylindrical lithium battery structure, which comprises a housin, electrode assembly's center is the centre bore, electrode assembly's upper portion draws positive pole multipolar ear and negative pole multipolar ear, positive pole multipolar ear distributes in the offside of centre bore and symmetric distribution with negative pole multipolar ear, electrode assembly's top is provided with the end cover, the end cover includes the main part, the utmost point post, insulating member, sealing member, the center of main part is provided with the through-hole, insulating member parcel utmost point post outer circumference surface, the utmost point post is located the through-hole, insulating member sealing post and end cover clearance, sealing member sealing main part is followed with the casing, the main part is connected to negative pole multipolar ear electricity, positive pole multipolar ear electricity is connected the utmost point post. Generally, the multipolar lug of the cylindrical lithium battery needs to be subjected to processes such as shaping, flattening and the like after being wound, can be firmly welded with a pole, and needs to be filled with liquid from a liquid filling hole during liquid filling.

The novel cylindrical lithium battery structure has the following defects:

firstly, positive electrode multipolar lugs and negative electrode multipolar lugs are generally manufactured through die cutting of empty foil areas of pole pieces, adjacent lugs are generally closely arranged and have no gaps after die cutting, the lugs can gather towards the middle of a battery cell after being flattened, so that the lugs easily block a central hole, and electrolyte is not smoothly discharged during liquid injection, as shown in figure 1;

secondly, after the tabs are flattened, the tabs are mutually overlapped, so that interference phenomenon exists among different tabs, and the flatness of the flattened end parts of the tabs cannot be ensured, and the welding of structures such as the tabs and the like is affected;

thirdly, because the tabs are densely arranged and have no gaps, the end parts of the wound battery cells are covered by the tabs completely, and the electrolyte infiltration is not facilitated, so that the electrolyte infiltration effect of the battery cells after the electrolyte injection is poor.

In view of this, improvements over existing multi-lug cylindrical batteries are needed.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model provides a multipolar ear pole piece, an electric core and a lithium battery, which are used for solving the problems that in the existing cylindrical lithium battery, a multipolar ear structure is easy to block a central hole of the electric core and cover the end face of the electric core, so that electrolyte injection is not smooth, thereby improving electrolyte infiltration effect of the electric core and simultaneously solving the problem of poor flatness after flattening of the pole ear caused by interference among the pole ears.

The utility model discloses a multi-lug pole piece, which comprises a current collector and an active coating coated on the surface of the current collector, wherein the coated area of the active coating is a coated area, the uncoated area is an empty foil area, and the empty foil area is provided with a plurality of die-cut lugs; the die-cutting lugs are arranged at intervals along the length direction of the current collector and are divided into a plurality of groups, and the number of each group of die-cutting lugs is at least two; the heights of the die-cut tabs of each group gradually decrease from the middle group to the two ends of the current collector.

Preferably, the interval between the adjacent die-cut tabs is 1-3 mm.

Preferably, a space is formed outside the die-cut tab at the end of the empty foil region, the space comprises a first space and a second space, the first space and the second space are respectively formed at two ends of the empty foil region, and the length of the first space is greater than that of the second space in the length direction of the current collector.

Preferably, the ratio of the length of the first vacancy to the length of the second vacancy is 3:1.

Preferably, the number of the die-cut tabs is an odd number, and the height of a group of die-cut tabs located at a middle position along the length direction of the current collector is the largest.

Preferably, the number of the die-cut tabs is an even number, and the heights of the two die-cut tabs located at the middle position along the length direction of the current collector are the largest.

Preferably, in the die-cut tab sequence groups adjacent to each other on the current collector and having sequentially increasing or decreasing heights, the difference between the heights of the die-cut tabs is equal.

The utility model discloses a battery cell, which comprises any one of the pole pieces and a diaphragm, wherein the diaphragm and the pole pieces are in a winding structure, the die-cutting pole lugs form a plurality of multi-pole lug structures, a first reserved space is positioned at the innermost ring of the winding structure, and a second reserved space is positioned at the outermost ring of the winding structure.

Preferably, the battery core has a central hole, each multipolar lug structure comprises an upper layer lug, a middle layer lug and a lower layer lug which are overlapped with each other, the height of the middle layer lug is maximum, the multipolar lug structure is folded to the central hole, and the end part of the middle layer lug is positioned outside the central hole.

The utility model discloses a lithium battery, which comprises any one of the battery cores.

The utility model has the beneficial effects that:

the electrode plates are provided with the die-cut electrode lugs with intervals, the lengths of the grouped die-cut electrode lugs are in an equal-difference array increment or decrement, so that after the electrode plates are wound to form the battery core, the formed multipole lug structure cannot extend to the central hole after being bent, the central hole of the battery core cannot be covered, gaps are reserved between the adjacent multipole lug structures, the adjacent multipole lug structures cannot overlap with each other, electrolyte can be smoothly discharged when electrolyte is poured, permeation and infiltration of the electrolyte are facilitated, and the multipole lug structures which are not overlapped with each other can ensure that the planeness of the flattened end part is good and the welding is convenient;

in a word, the utility model solves the problems that in the existing cylindrical lithium battery, the multipolar lug structure is easy to block the central hole of the battery core and cover the end face of the battery core, so that electrolyte injection is not smooth, thereby improving electrolyte infiltration effect of the battery core, and simultaneously solving the problem of poor flatness of the multipolar lug structure after flattening caused by interference among the multipolar lug structures.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

fig. 1 is a schematic diagram of a state in which a central hole of a battery cell is plugged by a tab in the background art;

FIG. 2 is a front view of the multipole ear pole piece of the present utility model;

FIG. 3 is a side view of the multipole ear pole piece of the present utility model;

fig. 4 is a schematic structural diagram of a battery cell according to the present utility model;

fig. 5 is a schematic diagram of a multi-tab structure of a cell.

Reference numerals illustrate: 1. a pole piece; 101. a current collector; 102. a reactive coating; 11. a coating zone; 12. an empty foil region; 1201. a first vacancy is left; 1202. second leaving a void; 121. die cutting the electrode lugs; 2. a battery cell; 21. a main body; 211. a central bore; 22. a multipolar ear structure; 221. upper layer electrode lugs; 222. middle layer tab; 223. and a lower tab.

Detailed Description

Various embodiments of the utility model are disclosed in the following drawings, in which details of the practice are set forth in the following description for the purpose of clarity. However, it should be understood that these practical details are not to be taken as limiting the utility model. That is, in some embodiments of the utility model, these practical details are unnecessary. Moreover, for the sake of simplicity of the drawing, some well-known and conventional structures and elements are shown in the drawings in a simplified schematic manner.

It should be noted that all directional indications such as up, down, left, right, front, and rear … … in the embodiments of the present utility model are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture such as that shown in the drawings, and if the particular posture is changed, the directional indication is changed accordingly.

In addition, the descriptions of the "first", "second", etc. in this application are for descriptive purposes only and are not intended to specifically indicate a sequential or a cis-position, nor are they intended to limit the utility model, but are merely intended to distinguish between components or operations described in the same technical term, and are not to be construed as indicating or implying a relative importance or implying that the number of technical features indicated is not necessarily limited. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

For a further understanding of the utility model, its features and advantages, reference is now made to the following examples, which are illustrated in the accompanying drawings in which:

referring to fig. 2 and 3, in order to disclose a multi-pole ear pole piece according to the present utility model, the pole piece 1 includes a current collector 101 and an active coating 102 coated on the surface of the current collector 101, wherein the current collector 101 is a strip-shaped metal foil, the active coating 102 is continuously coated along the length direction of the current collector 101, but an empty foil is remained at the edge of the current collector 101, so that the pole piece 1 is divided into a coating area 11 and an empty foil area 12 along the width direction thereof, the coating area 11 is an area provided with the active coating 102, and the empty foil area 12 is an exposed area of the metal foil.

Referring to fig. 2 and 3, the empty foil region 12 has a plurality of die-cut tabs 121, the die-cut tabs 121 are the empty foil of the current collector 101, which is formed by cutting through a die-cutting process, the die-cut tabs 121 are long, the long sides of the die-cut tabs 121 are the height thereof, the height direction of the die-cut tabs 121 is perpendicular to the length direction of the whole current collector 101, and spaces are provided between the adjacent die-cut tabs 121 along the length direction of the current collector 101, in this embodiment, the width of the spaces between the adjacent die-cut tabs 121 is 1-3 mm; the outside of the die-cut tab 121 at the end of the empty foil region 12 is a space, the space is formed by the two ends of the length direction of the coating region 11 exceeding the empty foil region 12, that is, a gap formed between the die-cut tab 121 at the end of the empty foil region 12 and the end of the coating region 11, the two spaces at the two ends of the empty foil region 12 are a first space 1201 and a second space 1202, respectively, the length of the first space 1201 is longer than the length of the second space 1202, and in this embodiment, the length ratio of the first space 1201 to the second space 1202 is 3:1 along the length direction of the current collector 101.

Referring to fig. 2 and 3, the die-cut tabs 121 are divided into a plurality of groups along the length direction of the current collector 101, the number of the die-cut tabs 121 of each group is at least two, and the number of the die-cut tabs 121 of each group is the same, in this embodiment, the die-cut tabs 121 of each group are provided with three, the three die-cut tabs 121 of each group are adjacently arranged, the heights of the three die-cut tabs 121 of each group are the same, among all the die-cut tabs 121 of each group, when the number of the die-cut tabs 121 of each group is an odd number, the height of one group of die-cut tabs 121 located at the middle position along the length direction of the current collector 101 is the largest, and when the number of the die-cut tabs 121 of each group is an even number, the heights of the two groups of die-cut tabs 121 located at the middle position along the length direction of the current collector 101 are gradually decreased from the middle group to the two ends of the current collector 101.

Referring to fig. 2 and 3, counting from a first space 1201 to a second space 1202, in the sequential groups of die-cut tabs 121 sequentially increasing in height, the heights of the die-cut tabs 121 between each group are equal differential series, i.e., the adjacent die-cut tab 121 groups have the same height increasing tolerance d1; in the die-cut tab 121 sequence group with sequentially decreasing heights along the length direction of the current collector 101, the heights of the die-cut tabs 121 are also in an arithmetic progression, that is, adjacent die-cut tab 121 groups have the same height decreasing tolerance d2, and d1=d2.

The utility model also discloses a battery cell, referring to fig. 4, the battery cell 2 comprises the pole piece 1, and further comprises a diaphragm (not shown in the figure), the pole piece 1 comprises a positive pole piece and a negative pole piece, the battery cell 2 is manufactured by winding after stacking the positive pole piece, the diaphragm, the negative pole piece, the diaphragm and the positive pole piece in sequence, a coating area 11 of the pole piece 1 and the diaphragm are wound to form a main body 21 of the battery cell 2, die-cut tabs 121 of an empty foil area 12 of the pole piece 1 are wound to form a multi-tab structure 22 of the battery cell 2, and in the winding structure, a first space 1201 of the pole piece 1 is positioned at the innermost ring, and a second space 1202 is positioned at the outermost ring.

Referring to fig. 4, the inner ring of the body 21 of the cell 2 has a central hole 211 disposed along an axial direction, the central hole 211 is a through hole for filling electrolyte, and the multipolar ear structures 22 are disposed on the end surface of the body 21 of the cell 2, and the multipolar ear structures 22 are uniformly arranged on the end surface of the body 21 of the cell 2 at equal intervals along a winding circumferential direction, and the multipolar ear structures 22 are bent toward the central hole 211 after being processed by a flattening process.

Referring to fig. 4 and 5, each of the multipolar tab structures 22 includes an upper tab 221, a middle tab 222 and a lower tab 223 overlapped with each other, the upper tab 221, the middle tab 222 and the lower tab 223 are each one die-cut tab 121 of the pole piece 1, in the winding structure, the surface of the lower tab 223 is closest to the end face of the main body 21, the middle tab 222 times, the distance between the surface of the upper tab 221 and the end face of the main body 21 is farthest, the height of the middle tab 222 is longer than the height of the upper tab 221 and the height of the lower tab 223, but the isolated end of the middle tab 222 is still located outside the central hole 211, so that the central hole 211 is not blocked by the multipolar tab structure 22, and the electrolyte is more smoothly poured; because the adjacent die-cut lugs 121 are spaced, gaps are formed between the bent multi-lug structures 22 formed after flattening, so that electrolyte permeation is facilitated, and interference phenomenon of mutual overlapping between the adjacent multi-lug structures 22 is avoided, and flatness of the end parts of the flattened multi-lug structures 22 is guaranteed.

The utility model also discloses a lithium battery, which comprises the battery core 2.

The implementation principle and the beneficial effects of the utility model are that the electrode plate 1 is provided with the die-cut electrode lugs 121 with intervals, and the heights of the die-cut electrode lugs 121 in groups are increased or decreased in an equal-difference array, so that after the electrode plate 1 is wound to form the battery core 2, the formed multipole lug structure 22 does not extend to the central hole 211 after being bent, thereby not covering the central hole 211 of the battery core 2, and the adjacent multipole lug structures 22 are provided with gaps and are not overlapped with each other, so that electrolyte can be smoothly discharged when electrolyte is poured, the permeation and infiltration of the electrolyte are facilitated, and the multipole lug structures 22 which are not overlapped with each other can ensure good flatness of the flattened end part and convenient welding;

in a word, the utility model solves the problems that in the existing cylindrical lithium battery, the multipolar lug structure 22 easily blocks the central hole 211 of the battery core 2 and covers the end face of the battery core 2, so that electrolyte injection is not smooth, thereby improving electrolyte infiltration effect of the battery core 2, and simultaneously solving the problem of poor flatness of the multipolar lug structure 22 after flattening caused by interference among the multipolar lug structures 22.

The above is merely an embodiment of the present utility model, and is not intended to limit the present utility model. Various modifications and variations of the present utility model will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, or the like, which is within the spirit and principles of the present utility model, should be included in the scope of the claims of the present utility model.

Claims (10)

1. The multi-lug pole piece is characterized in that the pole piece (1) comprises a current collector (101) and an active coating (102) coated on the surface of the current collector (101), a coated area of the active coating (102) is a coated area (11), an uncoated area is an empty foil area (12), and the empty foil area (12) is provided with a plurality of die-cut pole lugs (121);

the die-cutting lugs (121) are arranged at intervals along the length direction of the current collector (101), the die-cutting lugs (121) are divided into a plurality of groups, and the number of the die-cutting lugs (121) in each group is at least two;

the heights of the die-cut tabs (121) of each group gradually decrease from the middle group to the two ends of the current collector (101).

2. The multipole ear pole piece according to claim 1, characterized in that the spacing between adjacent die cut pole ears (121) is between 1 and 3 mm.

3. The multipole ear pole piece according to claim 1, characterized in that a void is provided on the outside of the die-cut pole piece (121) at the end of the empty foil region (12), the void comprises a first void (1201) and a second void (1202), the first void (1201) and the second void (1202) are provided at both ends of the empty foil region (12), respectively, and the length of the first void (1201) is greater than the length of the second void (1202) in the length direction of the current collector (101).

4. A multipole ear pole piece according to claim 3, characterized in that the ratio of the length of the first void (1201) to the length of the second void (1202) is 3:1.

5. The multi-tab pole piece of any one of claims 1-4, wherein the number of sets of die-cut tabs (121) is an odd number, and the height of a set of die-cut tabs (121) located at a central position along the length of the current collector (101) is the greatest.

6. The multi-tab pole piece of any one of claims 1-4, wherein the number of sets of die-cut tabs (121) is an even number, and the heights of two sets of die-cut tabs (121) located at intermediate positions along the length direction of the current collector (101) are the largest.

7. The multipole ear pole piece according to any of claims 1-4, characterized in that in the sequence of groups of die cut ears (121) adjacent to each other on the current collector (101) and of successively increasing or decreasing height, the difference in height of the die cut ears (121) between the groups is equal.

8. The battery cell is characterized in that the battery cell (2) comprises the pole piece (1) according to any one of claims 1-7, and further comprises a diaphragm, wherein the diaphragm and the pole piece (1) are in a winding structure, the die-cutting pole lugs (121) form a plurality of multipole lug structures (22), a first leaving empty space (1201) is positioned at the innermost ring of the winding structure, and a second leaving empty space (1202) is positioned at the outermost ring of the winding structure.

9. The cell of claim 8, wherein the cell (2) has a central hole (211), each of the multipolar tab structures (22) comprises an upper tab (221), a middle tab (222) and a lower tab (223) overlapping each other, the height of the middle tab (222) is the largest, the multipolar tab structure (22) is folded towards the central hole (211), and the ends of the middle tab (222) are located outside the central hole (211).

10. A lithium battery, characterized in that it comprises a cell (2) according to claim 8 or 9.