CN219800908U - Battery and battery pack - Google Patents

Abstract

The utility model relates to the technical field of batteries, and provides a battery and a battery pack. The battery includes: the two large surfaces in the battery cell are arranged along a first direction; the battery cell comprises a pole piece; the pole piece comprises an active material coating area; the active material coating area is divided into a central area and a peripheral area, the inner hole of the central area is smaller than the aperture of the inner hole of the peripheral area, and the aperture difference between the inner hole of the peripheral area and the inner hole of the central area is more than 0 and less than or equal to 100 mu m; the pole piece is provided with a center point, the center point is a diagonal intersection point of the projection of the active material coating area in a set plane, and the set plane is vertical to the first direction; the central area is elliptical, the long axis is a, and the short axis is b; the total length of the active material coated area was 2A and the total width was 2B, a, B, a and B satisfying: a/A is more than or equal to 0 and less than or equal to 0.954,0, B/B is more than or equal to 0.942. The battery can control the pole piece in the battery to have better performance in the early and later use stages by optimizing the structure of the battery.

Description

Battery and battery pack

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery and a battery pack.

Background

In the conventional battery, the expansion and deterioration of the large-surface center portion of the prismatic battery are generally most serious. Specifically, the material degradation, the gas production due to lack of liquid and the lithium precipitation of the central part are serious, after the pole piece is perforated, the electrolyte in the hole is abundant, the transmission of lithium ions and the optimization of the dynamic performance are facilitated in the early stage, but the side reaction of the electrolyte in the hole in the later stage is also more, so that the SEI (solid electrolyte interface) on the surface of the cathode material in the hole is continuously broken, grown and thickened, and the deterioration of the central part is aggravated.

Disclosure of Invention

The utility model provides a battery and a battery pack, wherein the battery can control the pole piece in the battery to have better performance in the early and later periods of use by optimizing the structure of the battery.

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

according to a first aspect of the present utility model, there is provided a battery comprising: the battery cell is provided with two large surfaces which are oppositely arranged, and the arrangement direction of the two large surfaces forms a first direction; the battery cell comprises a plurality of pole pieces which are stacked along the first direction; the pole piece comprises an active material coating area, and a hole extending along the first direction is formed in the active material coating area; the active material coating area is divided into a central area and a peripheral area which is arranged around the central area, the pore diameter of the inner pore of the central area is smaller than that of the inner pore of the peripheral area, and the pore diameter difference between the pore in the peripheral area and the pore in the central area is more than 0 mu m and less than or equal to 100 mu m;

the pole piece is provided with a center point, the center point is a diagonal intersection point of projection of the active material coating area in a set plane, and the set plane is perpendicular to the first direction; the central area is elliptical with the central point as the center, the long axis of the central area is a, and the short axis of the central area is b; the total length of the active material coating region is 2A, the total width of the active material coating region is 2B, and the a, B, a and B satisfy: a/A is more than or equal to 0 and less than or equal to 0.954,0, B/B is more than or equal to 0.942.

The battery provided by the utility model has the advantages that the aperture of the inner hole in the central area is smaller than that of the inner hole in the peripheral area, so that on one hand, the hole size in the peripheral area can be ensured to be enough to store rich electrolyte, the lithium ion transmission is facilitated, the dynamic performance is optimized, and the safety performance and the service life of the battery are improved; on the other hand, the structural design can enable the smaller-sized holes in the central area not to accumulate excessive electrolyte, so that the deterioration of the pole piece at the central part can be relieved, meanwhile, the smaller-sized holes in the central area can play a role in accommodating lithium dendrites, so that the lithium dendrites preferentially grow and deposit at the bottoms of the holes, the risk that the lithium dendrites puncture the diaphragm is reduced, and the safety performance and the service life of the battery are further improved.

In addition, in the battery provided by the utility model, the difference in pore diameter between the pores in the peripheral region and the pores in the central region is greater than 0 μm and less than or equal to 100 μm. The structure can avoid overlarge difference between the holes in the central area and the holes in the peripheral area, so that electrolyte stored in the holes in the central area is too little, and lithium ions are prevented from being transmitted in the central area and the dynamic performance of the battery core is reduced in the use process, or the electrolyte stored in the holes in the peripheral area is too much, so that negative influence is caused, and the service life and the safety performance of the battery are guaranteed.

According to a second aspect of the present utility model there is provided a battery pack comprising a battery as provided in any of the above first aspects.

In the battery pack provided by the utility model, the aperture of the inner hole of the central area is smaller than that of the inner hole of the peripheral area, so that on one hand, the hole size in the peripheral area can be ensured to be enough to store rich electrolyte, the lithium ion transmission is facilitated, the dynamic performance is optimized, and the safety performance and the service life of the battery are improved; on the other hand, the structural design can enable the smaller-sized holes in the central area not to accumulate excessive electrolyte, so that the deterioration of the pole piece at the central part can be relieved, meanwhile, the smaller-sized holes in the central area can play a role in accommodating lithium dendrites, so that the lithium dendrites preferentially grow and deposit at the bottoms of the holes, the risk that the lithium dendrites puncture the diaphragm is reduced, and the safety performance and the service life of the battery are further improved.

In addition, in the battery, the difference in pore diameter between the pores in the peripheral region and the pores in the central region is greater than 0 μm and less than or equal to 100 μm. The structure can avoid overlarge difference between the holes in the central area and the holes in the peripheral area, so that electrolyte stored in the holes in the central area is too little, and lithium ions are prevented from being transmitted in the central area and the dynamic performance of the battery core is reduced in the use process, or the electrolyte stored in the holes in the peripheral area is too much, so that negative influence is caused, and the service life and the safety performance of the battery are guaranteed.

Drawings

For a better understanding of the utility model, reference may be made to the embodiments illustrated in the following drawings. The components in the drawings are not necessarily to scale and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present utility model. In addition, the relevant elements or components may have different arrangements as known in the art. Furthermore, in the drawings, like reference numerals designate identical or similar parts throughout the several views. Wherein:

fig. 1 is a schematic structural diagram of a battery cell in a battery according to an embodiment of the present utility model;

FIG. 2 is a side view of an inner pole piece of the cell;

FIG. 3 is a schematic view of the surface active material coating area of the pole piece of FIG. 2;

FIG. 4 is a schematic view of a further configuration of the surface active material coating region of the pole piece of FIG. 2;

fig. 5 is a schematic structural diagram of the inner pole piece of the battery cell in fig. 1;

fig. 6 is a schematic structural diagram of an internal battery cell according to an embodiment of the present utility model;

fig. 7 is a schematic diagram of a second structure of the inner pole piece of the battery cell in fig. 1.

The reference numerals are explained as follows:

01. a battery cell; 100. a pole piece; 110. an active material coating region; 111. a central region; 112. a peripheral region; 120. a hole; 130. a carrier fluid; 200. a tab; s1, large surface.

Detailed Description

The technical solutions in the exemplary embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the exemplary embodiments of the present utility model. The example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present utility model, and it should be understood that various modifications and changes can be made to the example embodiments without departing from the scope of the utility model.

In the description of the present utility model, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance unless explicitly specified or limited otherwise; the term "plurality" refers to two or more than two; the term "and/or" includes any and all combinations of one or more of the associated listed items. In particular, references to "the/" object or "an" object are likewise intended to mean one of a possible plurality of such objects.

Unless specified or indicated otherwise, the terms "connected," "fixed," and the like are to be construed broadly and are, for example, capable of being fixedly connected, detachably connected, or integrally connected, electrically connected, or signally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the above terms in the present utility model can be understood by those skilled in the art according to the specific circumstances.

Further, in the description of the present utility model, it should be understood that the terms "upper", "lower", "inner", "outer", and the like in the exemplary embodiments of the present utility model are described in terms of the drawings, and should not be construed as limiting the exemplary embodiments of the present utility model. It will also be understood that in the context of an element or feature being connected to another element(s) "upper," "lower," or "inner," "outer," it can be directly connected to the other element(s) "upper," "lower," or "inner," "outer," or indirectly connected to the other element(s) "upper," "lower," or "inner," "outer" via intervening elements.

The embodiment of the utility model provides a battery. Fig. 1 is a schematic structural diagram of a battery cell in a battery according to an embodiment of the present utility model; FIG. 2 is a side view of an inner pole piece of the cell; FIG. 3 is a schematic view of the surface active material coating area of the pole piece of FIG. 2; fig. 4 is a schematic view of another structure of the surface active material coating area of the pole piece in fig. 2. Referring to the structure shown in fig. 1 to 4, a battery according to an embodiment of the present utility model includes: the battery cell 01 is shown in fig. 1, wherein the battery cell 01 is provided with two large surfaces S1 which are oppositely arranged, and the arrangement direction of the two large surfaces S1 forms a first direction; the battery cell 01 includes a plurality of pole pieces 100 (shown in fig. 2) stacked in a first direction; the pole piece 100 includes an active material coating region 110, and the active material coating region 110 is provided with a hole 120 extending along a first direction; as shown in fig. 2 and 3, the active material application region 110 is divided into a central region 111 and a peripheral region 112 disposed around the central region 111, the pore diameter of the pores 120 in the central region 111 is smaller than the pore diameter of the pores 120 in the peripheral region 112, and the pore diameter difference between the pores 120 in the peripheral region 112 and the pores 120 in the central region 111 is greater than 0 μm and equal to or less than 100 μm;

as shown in fig. 4, the pole piece 100 has a center point, which is a diagonal intersection of the projection of the active material coated area 110 in a set plane, which is perpendicular to the first direction; the center region 111 is an ellipse with the center point as the center, the major axis of the center region 111 is a, and the minor axis is b; the total length of the active material coated region 110 is 2A, and the total width of the active material coated region 110 is 2B, a, and B satisfy: a/A is more than or equal to 0 and less than or equal to 0.954,0, B/B is more than or equal to 0.942.

In the battery provided by the embodiment of the utility model, the battery cell 01 is provided with two large faces S1 which are arranged along the first direction. Specifically, the battery cell 01 is formed by stacking the pole pieces 100, and the large surface S1 of the pole piece 100 in the battery cell 01 is parallel to the large surface S1 of the battery cell 01. It should be understood that the large surface S1 refers to a surface having a larger area. The battery cell 01 is approximately provided with six sides, two large sides S1 and four sides, wherein the four sides are sequentially connected in a winding mode, and the area of the sides of the battery cell 01 is smaller than that of the large sides S1 of the battery cell 01.

In particular, pole piece 100 is rectangular in shape, having long sides (illustratively extending in a second direction perpendicular to the first direction) and short sides (illustratively extending in a third direction perpendicular to both the first and second directions); the pole piece 100 includes an active material coated region 110, the active material coated region 110 having a total length of 2A and a total width of 2B. Notably, by connecting the end points of the active material coated region 110 on the long side as well as the short side, a center point can be found at the center of the active material coated region 110. With continued reference to the structure shown in fig. 4, the active material application region 110 is divided into a central region 111 and a peripheral region 112, wherein the central region 111 is an ellipse centered on a central point, with a as the major axis and b as the minor axis; the peripheral region 112 is the region of the active material coated region 110 other than the central region 111.

In this embodiment, a, B, a, and B are set to satisfy: 0.ltoreq.a/a.ltoreq. 0.954,0.ltoreq.b/b.ltoreq.0.942 the central region 111 may be scaled reasonably according to the size of the active material coated region 110 so that the size of the active material coated region 110 is adapted to the partitioning of the central region 111 as well as the peripheral region 112, with different sizes of active material coated regions 110 being available for optimal effect by the structural design in the embodiments of the present utility model.

It should be noted that, by setting the aperture of the inner hole 120 of the central area 111 to be smaller than the aperture of the inner hole 120 of the peripheral area 112, the battery provided by the embodiment of the utility model can ensure that the size of the inner hole 120 of the peripheral area 112 is enough to store abundant electrolyte, help lithium ion transmission, optimize dynamic performance, and improve the safety performance and service life of the battery; on the other hand, the structural design can ensure that the smaller-sized holes 120 in the central region 111 cannot accumulate excessive electrolyte, so that the deterioration of the pole piece 100 at the central part can be relieved, and meanwhile, the smaller-sized holes 120 in the central region 111 can play a role in accommodating lithium dendrites, so that the lithium dendrites preferentially grow and deposit at the bottoms of the holes 120, the risk that the lithium dendrites puncture the diaphragm is reduced, and the safety performance and the service life of the battery are further improved.

In addition, in the battery provided by the embodiment of the utility model, the difference in the aperture between the aperture 120 in the peripheral region 112 and the aperture 120 in the central region 111 is greater than 0 μm and less than or equal to 100 μm. The arrangement can avoid too large difference between the holes 120 in the central region 111 and the holes 120 in the peripheral region 112, so that the electrolyte stored in the holes 120 in the central region 111 is too small, and the lithium ions are prevented from being transported in the central region 111 and the dynamic performance of the battery core 01 is reduced in the using process, or the electrolyte stored in the holes 120 in the peripheral region 112 is too much, so that negative influence is caused, and the service life and the safety performance of the battery are ensured.

In one embodiment, the difference in pore size between the pores 120 in the peripheral region 112 and the pores 120 in the central region 111 is between 5 μm and 90 μm.

In this embodiment, the range of the difference between the pore diameter of the pore 120 in the peripheral region 112 and the pore diameter of the pore 120 in the central region 111 is further optimized to better avoid the problem that too much difference between the pore diameter of the pore 120 in the central region 111 and the pore diameter of the pore 120 in the peripheral region 112 causes too little electrolyte to be stored in the pore 120 in the central region 111, which results in the blocking of lithium ion transmission in the central region 111 and the decrease of dynamic performance of the battery core 01 during the use process, or causes too much electrolyte to be stored in the pore 120 in the peripheral region 112, which results in negative effects, and further ensures the service life and the safety performance of the battery.

In the case where the difference in the aperture of the aperture 120 in the peripheral region 112 and the aperture 120 in the central region 111 is specifically set, the difference in the aperture may be set to one of the following values.

5μm、10μm、20μm、30μm、40μm、50μm、60μm、70μm、80μm、90μm。

In preparing the apertures 120 in the central region 111 and the apertures 120 in the peripheral region 112, the different apertures between the two may be achieved in a variety of ways, this configuration. Specifically, at least one of the following forms is adopted.

Embodiment one: in the initial punching, i.e., in the central region 111 and the peripheral region 112, holes 120 of different diameters are punched.

Embodiment two: in the initial punching, holes 120 having the same aperture are punched in the central region 111 and the peripheral region 112. Thereafter, with the peripheral region 112 having a larger binding force than the central region 111, the pore diameter of the pores 120 in the central region 111 is compressed by the expansion force of the active material application region 110 in the planar direction (which is parallel to the second direction and the third direction).

In one embodiment, the hole depth of the holes 120 in the central region 111 is greater than the hole depth of the holes 120 in the peripheral region 112.

It should be noted that, the expansion of the active material coating region 110 in the peripheral region 112 is smaller than that in the middle region, so that the adjacent pole pieces 100 are not easy to lack of liquid, and the depth of the inner hole 120 in the peripheral region 112 can be set to be small, so that the active material coating region 110 is prevented from being removed to form a hole 120 structure in an excessive size on the premise of helping lithium ion transmission and optimizing the dynamic performance, thereby ensuring the overcurrent capacity of the active material coating region 110 and improving the structural performance of the battery.

In one embodiment, the difference in hole depth between the holes 120 in the central region 111 and the holes 120 in the peripheral region 112 is greater than 0 μm and less than or equal to 80 μm. The arrangement of the structure can avoid too large aperture difference between the holes 120 in the central area 111 and the peripheral area 112, so that too little electrolyte can be stored in the holes 120 in the central area 111, which results in blocked lithium ion transmission and reduced dynamic performance of the battery core 01 in the central area 111 in the use process, or too much electrolyte can be stored in the holes 120 in the peripheral area 112, which results in negative effects, and the service life and safety performance of the battery can be improved.

In the case where the hole depth difference between the holes 120 in the peripheral region 112 and the holes 120 in the central region 111 is specifically set, the hole depth difference may be set to one of the following values.

0.1μm、0.5μm、1μm、5μm、10μm、20μm、30μm、40μm、50μm、60μm、70μm、80μm。

In one embodiment, the hole density of the holes 120 in the central region 111 is equal to the hole density of the holes 120 in the peripheral region 112. This structural arrangement can improve the uniformity of pole piece 100 for ease of manufacture.

It will be appreciated that the density of holes is the number of holes per square, the greater the density, the longer the production time.

In one embodiment, with continued reference to the structure shown in fig. 2, the pole piece 100 further includes a carrier 130, and the active material coating region 110 is disposed on at least one side of the carrier 130 along a first direction; as shown in fig. 5, along the length direction of the pole piece 100, the end of the carrier fluid 130 not covered by the active material coating region 110 forms a tab 200;

the hole density of the holes 120 in the peripheral region 112 is greater than the hole density of the holes 120 in the remaining peripheral region 112 in the range of 0 to 20mm (exemplary L range as in fig. 5) from the tab 200.

It should be noted that, the current density near the tab 200 is large, lithium is more easily separated, and the risk of shorting in the overlapping area near the tab 200 is also larger, so the hole density of the inner hole 120 of the peripheral area 112 in the range of 0-20 mm from the tab 200 is set to be greater than the hole density of the inner hole 120 of the remaining peripheral area 112, so that deposition and accommodation of metallic lithium can be facilitated, so that lithium dendrites preferentially grow and deposit at the bottom of the hole 120, and the risk of piercing the diaphragm by the lithium dendrites is reduced, thereby further improving the safety performance and the service life of the battery.

It will be appreciated that in cell design, if the negative electrode does not receive lithium ions, the lithium ions may precipitate on the surface of the negative electrode, form lithium dendrites, pierce the separator, cause internal shorting in the cell, and cause thermal runaway. Therefore, in designing lithium batteries, the negative electrode often needs to be overdesigned to avoid such situations. One way of overdesign the negative electrode is Overhang. Overhang refers to that the negative electrode sheet 100 is longer than the positive electrode sheet 100 in the length direction (i.e., the second direction).

In one embodiment, the cell 01 is a lamination stack. It will be appreciated that the lamination stack is formed by a plurality of stacks of strips of material including the separator and pole pieces 100.

When specifically set, it is possible to set: the hole density of the inner holes 120 of the peripheral region 112 is greater than that of the inner holes 120 of the remaining peripheral region 112 in a range of 4-18 mm from the tab 200. In this embodiment, the range of the region with larger hole density is further narrowed, so that the lamination structure of the electric core 01 can be adapted to facilitate deposition and accommodation of metallic lithium, so that lithium dendrites preferentially grow and deposit at the bottom of the holes 120, and the risk that the lithium dendrites puncture the separator is reduced, so as to further improve the safety performance and service life of the battery.

In one embodiment, as shown in fig. 6 and 7, the cell 01 is a jellyroll structure. It will be appreciated that the core structure is formed from a web of material formed by a winding process, the web of material including the separator and pole piece 100. It will be appreciated that the web of material is initially formed into a cylindrical shape as shown in fig. 6, and then is pressed by pressure in the direction of the arrow to form a rectangular cell 01 as shown in fig. 1. It is noted that, after the winding core structure is extruded, as shown in fig. 6 and 7, along the width direction (i.e., the third direction) of the pole piece 100, the bending of the adjacent pole piece 100 large surface and the pole piece 100 large surface in the cell 01 at the junction forms an R angle (the R angle is exemplary, and the R angle is within the range of the dashed line frame in fig. 6 and 7), and the R angle is the area with radian formed after the columnar winding core structure is extruded.

It should be appreciated that, since the winding core structure, after being extruded as shown in fig. 6, is located in the first direction near the area where the large surface of the adjacent pole pieces 100 and the large surface of the pole pieces 100 are joined in the cell 01, the lamination tightness between the pole pieces 100 is smaller than that of other areas, and thus the electrolyte can be more easily filled between the adjacent pole pieces 100, when the holes 120 above the active material coating area 110 are specifically located, it is possible to provide: the peripheral region 112 is not provided with holes 120 at the corresponding R angular positions; alternatively, the apertures 120 of the peripheral region 112 disposed in the corresponding R angular position are smaller than the apertures of the apertures 120 disposed in the remaining peripheral region 112.

It should be noted that, by the structural arrangement, the active material coating region 110 can be prevented from being removed to form the pore 120 structure in excessive size on the premise of helping lithium ion transmission and optimizing dynamic performance, so as to ensure the overcurrent capacity of the active material coating region 110 and improve the structural performance of the battery.

Notably, the pole pieces 100 within the cell 01 include two pole pieces 100 of opposite polarity, and the two pole pieces 100 of opposite polarity are separated by a separator. When one pole piece 100 is positive, the other pole piece 100 is negative.

Since the negative electrode tab 100 in the battery is more likely to cause a problem of lithium precipitation, the negative electrode tab 100 is preferably provided with the above-described structure.

It should be noted that, in the embodiment of the present utility model, the hole 120 is a blind hole 120, and the hole 120 may be manufactured by mechanical extrusion or laser ablation, which will not be described in detail.

In a second aspect, embodiments of the present utility model provide a battery pack. The battery pack comprises a battery as provided in any of the above-described first aspects.

It should be noted that, in the battery pack provided by the embodiment of the present utility model, the aperture of the inner hole 120 of the central area 111 is smaller than the aperture of the inner hole 120 of the peripheral area 112, so that on one hand, the size of the hole 120 in the peripheral area 112 can be ensured to be enough to store abundant electrolyte, thereby helping lithium ion transmission and optimizing dynamic performance, and improving the safety performance and service life of the battery; on the other hand, the structural design can ensure that the smaller-sized holes 120 in the central region 111 cannot accumulate excessive electrolyte, so that the deterioration of the pole piece 100 at the central part can be relieved, and meanwhile, the smaller-sized holes 120 in the central region 111 can play a role in accommodating lithium dendrites, so that the lithium dendrites preferentially grow and deposit at the bottoms of the holes 120, the risk that the lithium dendrites puncture the diaphragm is reduced, and the safety performance and the service life of the battery are further improved.

In the battery, the difference in the pore diameter between the pores 120 in the peripheral region 112 and the pores 120 in the central region 111 is greater than 0 μm and 100 μm or less. The arrangement can avoid too large difference between the holes 120 in the central region 111 and the holes 120 in the peripheral region 112, so that the electrolyte stored in the holes 120 in the central region 111 is too small, and the lithium ions are prevented from being transported in the central region 111 and the dynamic performance of the battery core 01 is reduced in the using process, or the electrolyte stored in the holes 120 in the peripheral region 112 is too much, so that negative influence is caused, and the service life and the safety performance of the battery are ensured.

In one embodiment, the battery pack is a battery module or a battery pack.

The battery module includes a plurality of batteries, and the battery module can also include end plate and curb plate, and end plate and curb plate are used for fixed a plurality of batteries. The battery module may further include a bracket to which the battery may be fixed.

The battery pack comprises a plurality of batteries and a box body, wherein the box body is used for fixing the plurality of batteries.

The battery pack includes a plurality of batteries, and the plurality of batteries are disposed in the case. Wherein, a plurality of batteries can be installed in the box after forming the battery module. Or, a plurality of batteries can be directly arranged in the box body, namely, the plurality of batteries do not need to be grouped, and the plurality of batteries are fixed by the box body.

Other embodiments of the utility model will be apparent to those skilled in the art from consideration of the specification and practice of the utility model disclosed herein. This utility model is intended to cover any variations, uses, or adaptations of the utility model following, in general, the principles of the utility model and including such departures from the present disclosure as come within known or customary practice within the art to which the utility model pertains. The specification and example embodiments are to be considered exemplary only, with a true scope and spirit of the utility model being indicated by the following claims. It is to be understood that the utility model is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the utility model is limited only by the appended claims.

Claims (10)

1. A battery, comprising: the battery cell is provided with two large surfaces which are oppositely arranged, and the arrangement direction of the two large surfaces forms a first direction; the battery cell comprises a plurality of pole pieces which are stacked along the first direction; the pole piece comprises an active material coating area, and a hole extending along the first direction is formed in the active material coating area; the active material coating area is divided into a central area and a peripheral area which is arranged around the central area, the pore diameter of the inner pore of the central area is smaller than that of the inner pore of the peripheral area, and the pore diameter difference between the pore in the peripheral area and the pore in the central area is more than 0 mu m and less than or equal to 100 mu m;

the pole piece is provided with a center point, the center point is a diagonal intersection point of projection of the active material coating area in a set plane, and the set plane is perpendicular to the first direction; the central area is elliptical with the central point as the center, the long axis of the central area is a, and the short axis of the central area is b; the total length of the active material coating region is 2A, the total width of the active material coating region is 2B, and the a, B, a and B satisfy: a/A is more than or equal to 0 and less than or equal to 0.954,0, B/B is more than or equal to 0.942.

2. The battery of claim 1, wherein the pore size difference between the pores in the peripheral region and the pores in the central region is 5 μm to 90 μm.

3. The battery of claim 2, wherein the hole depth of the central region hole is greater than the hole depth of the peripheral region hole.

4. The battery of claim 3, wherein the difference in pore depth between the pores in the central region and the pores in the peripheral region is greater than 0 μm and less than or equal to 80 μm.

5. The cell of claim 3, wherein the hole density of the central region holes is equal to the hole density of the peripheral region holes.

6. The battery of claim 5, wherein the pole piece further comprises a carrier fluid, the active material coating region being disposed on at least one side of the carrier fluid along the first direction; along the length direction of the pole piece, the end part of the current carrier body, which is not covered by the active material coating area, forms a pole lug;

the hole density of the inner holes of the peripheral area in the range of 0-20 mm away from the tab is greater than that of the inner holes of the rest peripheral area.

7. The battery of claim 6, wherein the cells are laminated structures; and the hole density of the inner holes of the peripheral area in the range of 4-18 mm away from the tab is greater than that of the inner holes of the rest peripheral area.

8. The battery of claim 6, wherein the battery cell is in a coiled core structure, and the adjacent pole piece large faces in the battery cell and the bending of the pole piece large faces at the joint part form an R angle along the width direction of the pole piece;

the peripheral region is not provided with the hole at the position corresponding to the R angle; alternatively, the apertures of the holes provided in the peripheral region in the corresponding R angular position are smaller than the apertures of the holes provided in the remaining peripheral region.

9. The battery of any one of claims 1-8, wherein the pole piece is a negative polarity pole piece.

10. A battery comprising a battery as claimed in any one of claims 1 to 9.