CN219371301U

CN219371301U - Cylindrical battery

Info

Publication number: CN219371301U
Application number: CN202320549203.0U
Authority: CN
Inventors: 孙倩倩; 张璐璐
Original assignee: China Innovation Aviation Technology Group Co ltd
Current assignee: China Innovation Aviation Technology Group Co ltd
Priority date: 2023-03-20
Filing date: 2023-03-20
Publication date: 2023-07-18
Anticipated expiration: 2033-03-20

Abstract

The disclosure relates to the technical field of batteries, and discloses a cylindrical battery; the cylindrical battery includes a winding core and an insulating film; the winding core comprises a main body part and a pole ear part; the insulating film is at least coated on the circumferential outer surface of the winding core, the insulating film is arranged into an integral structure, the insulating film comprises a first part and a second part which are connected into a whole, the first part covers at least part of the main body part, and the second part covers at least part of the lug part. The cylindrical battery increases the strength of the insulating film and the connection strength between the insulating film and the winding core; the risk of insulation failure between the winding core and the battery shell is avoided; the charge and discharge efficiency of the cylindrical battery is ensured; and simultaneously, the insulation effect of the main body part and the lug part is ensured.

Description

Cylindrical battery

Technical Field

The disclosure relates to the technical field of batteries, and in particular relates to a cylindrical battery.

Background

Along with the global energy crisis, the original energy consumption structure is gradually changed worldwide, and the energy is more reasonably and effectively utilized. Lithium ion batteries with the advantages of high energy density, long cycle life, green pollution-free property and the like have become one of the necessary choices of the future automobile industry, large energy storage and the like.

However, the insulation film arrangement of the current cylindrical battery is not reasonable.

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the present disclosure and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The purpose of the present disclosure is to overcome the unreasonable disadvantage of the insulating film arrangement in the related art, and provide a cylindrical battery with a reasonable insulating film arrangement.

According to one aspect of the present disclosure, there is provided a cylindrical battery including:

a winding core comprising a main body part and a pole ear part;

the insulation film is at least coated on the circumferential outer surface of the winding core, the insulation film is of an integrated structure, the insulation film comprises a first part and a second part which are connected into a whole, the first part covers at least part of the main body part, and the second part covers at least part of the lug part.

According to the cylindrical battery disclosed by the utility model, on one hand, the insulating film is arranged into an integrated structure, so that the strength of the insulating film is increased, and the connecting strength between the insulating film and the winding core is improved because the bonding area between the insulating film and the winding core is larger; on the other hand, the risk of insulation failure between the winding core and the battery shell, which is caused by the possibility of a gap between at least two separately arranged insulating films, is avoided; on the other hand, the pretightening force of the insulating film on the winding core is basically consistent, the expansion of the pole piece part is ensured, and enough space is provided for lithium ion shuttle so as to ensure the charge and discharge efficiency of the cylindrical battery; on the other hand, only one insulating film is needed to be adhered, so that the assembly efficiency of the cylindrical battery can be improved; the first part covers at least part of the main body part, the second part covers at least part of the lug part, the first part and the second part can be respectively arranged, and meanwhile, the insulation effect of the main body part and the lug part is ensured.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. It will be apparent to those of ordinary skill in the art that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived from them without undue effort.

Fig. 1 is a schematic perspective view of an example embodiment of a cylindrical battery of the present disclosure.

Fig. 2 is a schematic cross-sectional view of a first example embodiment of a cylindrical battery of the present disclosure.

Fig. 3 is a schematic cross-sectional view of a second example embodiment of a cylindrical battery of the present disclosure.

Fig. 4 is a schematic cross-sectional view of a third example embodiment of a cylindrical battery of the present disclosure.

Reference numerals illustrate:

1. a battery case; 11. a top plate; 12. a bottom plate; 13. a side plate;

2. a winding core; 21. a main body portion; 211. a first end face; 212. a second end face; 22. a tab portion; 221. a first tab; 222. a second lug;

3. an insulating film; 31. a first portion; 32. a second portion; 321. a first sub-portion; 322. a second sub-portion;

4. a collecting tray; 51. a positive electrode post; 52. a negative electrode column;

z, third direction.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus detailed descriptions thereof will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another component, these terms are used in this specification for convenience only, such as in terms of the orientation of the examples described in the figures. It will be appreciated that if the device of the icon is flipped upside down, the recited "up" component will become the "down" component. When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

The terms "a," "an," "the," "said" and "at least one" are used to indicate the presence of one or more elements/components/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. in addition to the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and do not limit the number of their objects.

In the present application, unless explicitly specified and limited otherwise, the term "coupled" is to be construed broadly, and for example, "coupled" may be either fixedly coupled, detachably coupled, or integrally formed; can be directly connected or indirectly connected through an intermediate medium. "and/or" is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or may mean: a alone, both a and a alone, and both. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The present disclosure provides a cylindrical battery, which may include a winding core 2 and an insulating film 3, as shown with reference to fig. 1 to 4; the winding core 2 may include a main body portion 21 and a tab portion 22; the insulating film 3 is at least coated on the circumferential outer surface of the winding core 2, the insulating film 3 is provided as an integral structure, the insulating film 3 comprises a first part 31 and a second part 32 which are connected integrally, the first part 31 covers at least part of the main body part 21, and the second part 32 covers at least part of the tab part 22.

According to the cylindrical battery disclosed by the disclosure, the strength of the insulating film 3 with an integrated structure is stronger, and the bonding area between the insulating film 3 and the winding core 2 is larger, so that the connection strength between the insulating film 3 and the winding core 2 is improved; the risk of insulation failure between the winding core 2 and the battery shell 1, which is caused by the possible existence of a gap between at least two insulation films 3 which are arranged in a split manner, is avoided; in addition, the pretightening force of the insulating film 3 on the winding core 2 is basically consistent, the expansion of the pole piece part is ensured, and enough space is provided for lithium ion shuttle so as to ensure the charge and discharge efficiency of the cylindrical battery; furthermore, only one insulating film 3 is needed to be adhered, so that the assembly efficiency of the cylindrical battery can be improved; the first portion 31 covers at least part of the main body portion 21, the second portion 32 covers at least part of the tab portion 22, and the first portion 31 and the second portion 32 can be provided separately while ensuring the insulating effect of the main body portion 21 and the tab portion 22.

In the present exemplary embodiment, referring to fig. 1, a cylindrical battery may include a battery case 1, and the battery case 1 may be provided as a cylinder, that is, the battery case 1 may include two end plates disposed opposite to each other, the two end plates being a top plate 11 and a bottom plate 12, respectively, the top plate 11 and the bottom plate 12 being provided as circles, a side plate 13 being connected between the top plate 11 and the bottom plate 12, the side plate 13 being provided as a cylinder. The side plates 13, the top plate 11 and the bottom plate 12 surround the accommodation chamber forming a cylindrical battery.

A battery cell and an electrolyte are provided in the battery case 1, and the battery cell may include a winding core 2 and an insulating film 3 coated at least on the circumferential outer surface of the winding core 2.

Referring to fig. 2-4, the winding core 2 may include a main body portion 21 and a tab portion 22. The winding core 2 is a winding core 2, so that the winding core 2 forms a substantially cylindrical structure; that is, the main body 21 has a substantially cylindrical structure, the main body 21 has a first end surface 211 and a second end surface 212 that are disposed opposite to each other, the first end surface 211 and the second end surface 212 are disposed substantially in parallel, and the first end surface 211 and the second end surface 212 are disposed substantially in parallel with the two end plates (the top plate 11 and the bottom plate 12) of the battery case 1.

The winding core 2 may be a unit formed by winding a laminated structure, which may include a first electrode sheet, a separator, and a second electrode sheet that are laminated in this order, and when the first electrode sheet is a positive electrode sheet, the second electrode sheet is a negative electrode sheet. Namely, the first pole piece, the second pole piece opposite to the first pole piece and the isolating film arranged between the first pole piece and the second pole piece are wound to obtain the winding type winding core 2. Of course, the polarities of the first pole piece and the second pole piece may be interchanged, i.e. the first pole piece may be a negative pole piece and the second pole piece may be a positive pole piece. The first and second pole pieces are coated with an active substance. The following description will take the first pole piece as the positive pole piece and the second pole piece as the negative pole piece as an example.

The circumferential outer surface of the winding core 2 refers to a substantially cylindrical outer surface of the winding core 2.

Referring to fig. 2 and 3, the tab portion 22 may include a first tab 221 and a second tab 222, and the first tab 221 and the second tab 222 may extend from opposite sides of the body portion 21 of the winding core 2. The first tab 221 is connected to the main body 21, specifically, the first tab 221 is connected to the first pole piece, and the first tab 221 is located at a side of the first end surface 211 facing away from the main body 21; a part of the first pole piece extends to protrude from the main body 21, and is bent to a side of the first end surface 211 away from the main body 21 to form a first pole ear 221; in this case, the first tab 221 may cover the first end surface 211 entirely, or may cover a part of the first end surface 211.

The second tab 222 is connected to the main body 21, specifically, the second tab 222 is connected to the second plate, and the second tab 222 is located on a side of the second end surface 212 facing away from the main body 21, and may be a portion of the second plate extending to protrude from the main body 21 and being bent to a side of the second end surface 212 facing away from the main body 21 to form the second tab 222; in this case, the second tab 222 may cover the second end surface 212 entirely or may cover a part of the second end surface 212.

Of course, the first tab 221 may be connected to the second tab, and the second tab 222 may be connected to the first pole piece.

The tab portion 22 is a conductive foil region where no active material coating is provided, that is, the first tab 221 and the second tab 222 are not coated with an active material coating, and the tab portion 22 is a current collecting layer for transmitting current.

Referring to fig. 2 and 3, the insulating film 3 is coated on at least the circumferential outer surface of the winding core 2, that is, the insulating film 3 is coated on at least the substantially cylindrical outer surface of the winding core 2.

If the insulating film 3 is provided as at least two parts provided separately, one part is for covering at least part of the main body portion 21 and the other part is for covering at least part of the tab portion 22; since the entire side surface of the winding core 2 needs to be insulated from the battery case 1, a gap cannot be provided between at least two parts of the insulating films provided separately, and if a gap exists, insulation failure between the winding core 2 and the battery case 1 is likely to occur. However, due to the problems of process errors and equipment precision, it is impossible to completely align at least two parts of the insulating films separately disposed, i.e., there is no gap between at least two parts of the insulating films separately disposed, nor there is an overlapping region; therefore, in order to ensure the insulation effect between the winding core 2 and the battery case 1, a part of overlapped area is arranged between at least two parts of insulation films which are separately arranged, so that the thickness of the insulation film in the overlapped area is thicker, and the utilization rate of the internal space of the cylindrical battery is affected; moreover, the insulating film has larger pretightening force on the winding core 2 in the overlapped area, which is not beneficial to the expansion of the first pole piece and the second pole piece, and can not provide enough space for lithium ion shuttle.

In order to solve the above technical problem, the insulating film 3 is provided as an integral structure, and the insulating film 3 may include a first portion 31 and a second portion 32 integrally connected, i.e., the insulating film 3 is formed as a single piece, instead of a structure in which the first portion 31 and the second portion 32 are formed separately and then integrally connected by adhesive or other connection means. The first portion 31 covers at least part of the main body portion 21 and the second portion 32 covers at least part of the tab portion 22.

By the arrangement, the strength of the insulating film 3 is increased, and the bonding area between the insulating film 3 and the winding core 2 is larger, so that the connection strength between the insulating film 3 and the winding core 2 is improved; the risk of insulation failure between the winding core 2 and the battery shell 1, which is caused by the possible existence of a gap between at least two insulation films 3 which are arranged in a split manner, is avoided; and moreover, the pretightening force of the insulating film 3 on the winding core 2 is basically consistent, the expansion of the first pole piece and the second pole piece is ensured, and enough space is provided for lithium ion shuttle so as to ensure the charge and discharge efficiency of the cylindrical battery.

Specifically, referring to fig. 2 and 3, in the case where the first tab 221 and the second tab 222 extend from opposite sides of the main body portion 21 of the winding core 2, the second portions 32 are provided in two, and two second portions 32 are connected to opposite sides of the first portion 31, one second portion 32 being for covering at least part of the first tab 221 and the other second portion 32 being for covering at least part of the second tab 222.

In some example embodiments of the present disclosure, referring to fig. 2, neither the first tab 221 nor the second tab 222 is electrically connected to the battery case 1, for example, a first through hole may be provided on the top plate 11 of the battery case 1, the cylindrical battery may further include a positive electrode post 51 penetrating the first through hole, and the positive electrode post 51 may be connected with the first tab 221 to form a positive electrode of the cylindrical battery.

A second through hole may be provided on the bottom plate 12 of the battery case 1, and the cylindrical battery may further include a negative electrode post 52, where the negative electrode post 52 penetrates through the second through hole, and the negative electrode post 52 may be connected with the second tab 222 to form a negative electrode of the cylindrical battery.

In this case, one second portion 32 may be used to cover one side of the first tab 221 near the side plate 13, and since one side of the first tab 221 near the end plate also needs to be connected to the positive electrode post 51, it is not necessary to cover the insulating film 3 for insulation. Similarly, another second portion 32 may be used to cover a side of the second tab 222 near the side plate 13, and since a side of the second tab 222 near the end plate is also required to be connected to the negative post 52, it is not required to cover the insulating film 3 for insulation.

Since the first tab 221 and the second tab 222 covered by the two second portions 32 are the same in scope; thus, the heights of the two second portions 32 in the third direction Z may be substantially the same, the third direction Z coinciding with the axial direction of the cylindrical cells, which are perpendicular to the top plate 11 and the bottom plate 12, i.e. the third direction Z is perpendicular to the top plate 11 and the bottom plate 12.

The above-mentioned errors are not completely the same, but have a certain error, and the error ranges are different depending on the equipment and the production process, and therefore, the errors are considered to be the same within the error ranges of the equipment and the production process.

Further, since both the first tab 221 and the second tab 222 need to be insulated from the battery case 1, the second portion 32 covering the first tab 221 protrudes from the first tab 221 in the third direction Z, that is, the distance H1 between the top plate 11 and the side of the second portion 32 covering the first tab 221 near the top plate 11 is smaller than the distance H2 between the top plate 11 and the side of the first tab 221 near the top plate 11. The second portion 32 covering the second tab 222 protrudes from the second tab 222, i.e. the distance H3 between the side of the second portion 32 covering the second tab 222 close to the base plate 12 and the base plate 12 is smaller than the distance H4 between the side of the second tab 222 close to the base plate 12 and the base plate 12. Thereby securing the insulating effect of the first tab 221 and the second tab 222 with the battery case 1.

Alternatively, the second portion 32 covering the first tab 221 is flush with the first tab 221, i.e., the distance H1 between the side of the second portion 32 covering the first tab 221 adjacent to the top plate 11 and the top plate 11 is equal to the distance H2 between the side of the first tab 221 adjacent to the top plate 11 and the top plate 11. The second portion 32 covering the second tab 222 is flush with the second tab 222, i.e. the distance H3 between the side of the second portion 32 covering the second tab 222 adjacent to the base plate 12 and the base plate 12 is equal to the distance H4 between the side of the second tab 222 adjacent to the base plate 12 and the base plate 12. Thereby securing the insulating effect of the first tab 221 and the second tab 222 with the battery case 1.

In other example embodiments of the present disclosure, the first tab 221 or the second tab 222 may be electrically connected with the battery case 1, i.e., one of the first tab 221 and the second tab 222 is electrically connected with the battery case 1, and the other is not electrically connected with the battery case 1; for example, referring to fig. 3, a first through hole may be provided in the top plate 11 of the battery case 1, and the cylindrical battery may further include a positive electrode post 51, the positive electrode post 51 penetrating through the first through hole, and the positive electrode post 51 may be connected with the first tab 221 to form the positive electrode of the cylindrical battery. While the second tab 222 is connected to the battery case 1 to form the negative electrode of the cylindrical battery, specifically, the second tab 222 is connected to the bottom plate 12 to form the negative electrode of the cylindrical battery.

In this case, the two second portions 32 may be a first sub-portion 321 and a second sub-portion 322. The first sub-portion 321 is used to cover the first tab 221 that is not electrically connected to the battery case 1, and the first sub-portion 321 may be used to cover a side surface of the first tab 221 near the side plate 13, and since a side surface of the first tab 221 near the end plate is also required to be connected to the positive electrode post 51, the cover insulating film 3 is not required to perform insulation. The second sub-portion 322 covers the second tab 222 electrically connected to the battery case 1, and the second sub-portion 322 may be used to cover a side of the second tab 222 near the side plate 13, and since a side of the second tab 222 near the end plate is also required to be connected to the bottom plate 12, it is not required to cover the insulating film 3 for insulation.

Of course, the positive electrode post 51 may be connected to the second tab 222 to form a positive electrode of the cylindrical battery, and the first tab 221 may be connected to the bottom plate 12 to form a negative electrode of the cylindrical battery. In this case, the first sub-portion 321 is for covering the second tab 222 that is not electrically connected to the battery case 1, and the second sub-portion 322 is for covering the first tab 221 that is electrically connected to the battery case 1.

However, since the second sub-portion 322 covers the second tab 222 electrically connected to the battery case 1, the insulation requirement between the second tab 222 and the side plate 13 of the battery case 1 is not high, and the height H5 of the second sub-portion 322 in the third direction Z is smaller than the height H6 of the first sub-portion 321 in the third direction Z.

Further, since the polarity of the first tab 221 is opposite to that of the battery case 1, insulation is required between the first tab 221 and the battery case 1, and thus, in the third direction Z, the first sub-portion 321 protrudes from the first tab 221 that is not electrically connected to the battery case 1, that is, the distance H7 between the top plate 11 and the side of the first sub-portion 321 near the top plate 11 is smaller than the distance H2 between the top plate 11 and the side of the first tab 221 near the top plate 11. Of course, in other example embodiments of the present disclosure, in the case where the second tab 222 is not electrically connected with the battery case 1, the first sub-portion 321 protrudes from the second tab 222 that is not electrically connected with the battery case 1 in the third direction Z.

Referring to fig. 4, in some example embodiments of the present disclosure, the first tab 221 and the second tab 222 may extend from the same side of the body portion 21 of the winding core 2. Specifically, the first tab 221 is connected to the main body 21, specifically, the first tab 221 is connected to the first pole piece, and the first tab 221 is located on a side of the first end surface 211 facing away from the main body 21; a part of the first pole piece extends to protrude from the main body 21, and is bent to a side of the first end surface 211 away from the main body 21 to form a first pole ear 221; in this case, the first tab 221 may cover a portion of the first end surface 211.

The second tab 222 is connected to the main body 21, specifically, the second tab 222 is connected to the second tab, and the second tab 222 is located on a side of the first end surface 211 facing away from the main body 21, and may be a portion of the second tab extending and protruding from the main body 21, and is bent to a side of the first end surface 211 facing away from the main body 21 to form the second tab 222; in this case, the second tab 222 may cover a portion of the second end face 212.

The second tab 222 and the first tab 221 are insulated from each other, and specifically, the insulation between the second tab 222 and the first tab 221 may be achieved by providing an insulating member between the second tab 222 and the first tab 221, or the insulation between the second tab 222 and the first tab 221 may be achieved by providing a space between the second tab 222 and the first tab 221.

The first tab 221 and the second tab 222 extend from the same side of the main body 21, so that the overall space utilization rate inside the battery can be improved, and the first tab 221 and the second tab 222 can be respectively connected with the positive electrode post 51 and the negative electrode post 52 located at the same side of the battery case 1, that is, the first tab 221 and the second tab 222 are not electrically connected with the battery case 1; or, the first tab 221 or the second tab 222 is electrically connected with the battery case 1, for example, the first tab 221 and the second tab 222 are correspondingly connected with the battery case 1 and the electrode post respectively, and the battery case 1 is used as an electrode leading-out end of a battery, so that connection during subsequent battery grouping can be facilitated, the area of the battery case 1 is relatively large, and a reliable overcurrent area during battery grouping can be ensured, so that the overall charge and discharge rate of the battery is ensured.

In this case, the second portion 32 is provided in one, and the second portion 32 covers both the first tab 221 and the second tab 222, and in order to secure the insulating effect between the first tab 221 and the second tab 222 and the battery case 1, the second portion 32 protrudes from the first tab 221 and the second tab 222 in the third direction Z; that is, the distance H1 between the side of the second portion 32 close to the top plate 11 and the top plate 11 is smaller than the distance H2 between the side of the first tab 221 close to the top plate 11 and the top plate 11, and at the same time, the distance H1 between the side of the second portion 32 close to the top plate 11 and the top plate 11 is smaller than the distance H8 between the side of the second tab 222 close to the top plate 11 and the top plate 11.

The first tab 221 and the second tab 222 may be multiple, and the first tab 221 and the second tab 222 may be staggered, so as to ensure insulation performance between the first tab 221 and the second tab 222. Alternatively, the first tab 221 and the second tab 222 may be one.

Further, the resistivity of the second portion 32 is greater than the resistivity of the first portion 31; resistivity (Resistivity) is a physical quantity representing the resistance characteristics of various substances, and is made of a material having a length of 1m and a cross-sectional area of 1m ² Is equal in value to the resistivity of the conductor of such a material. It reflects the property of a substance to hinder the current flow, and it is not only related to the kind of substance, but also affected by external factors such as temperature, pressure and magnetic field. Thus, the resistivity of the first portion 31 and the second portion 32 is a comparison in the case where external factors such as temperature, pressure, and magnetic field are the same.

Since the current needs to be transmitted through the first tab 221 and the second tab 222, and the volumes of the first tab 221 and the second tab 222 are smaller and the resistance is larger, the insulation requirements of the first tab 221 and the second tab 222 are larger; the outside of the main body 21 is also provided with a barrier film for insulation, and thus, the insulation requirement of the main body 21 is small. The insulation failure between the first tab 221 and the second tab 222 and the battery case 1 is more likely. The second portion 32 covering the tab portion 22 has a higher resistivity than the first portion 31 covering the winding core 2, and can ensure the insulation requirements of both the main body portion 21 and the tab portion 22.

In addition, in other exemplary embodiments of the present disclosure, the thickness of the second portion 32 may be greater than the thickness of the first portion 31, for example, the second portion 32 may be made of the same material as the first portion 31, that is, the resistivity of the second portion 32 is equal to the resistivity of the first portion 31, the thicker second portion 32 may meet the higher insulation requirement of the tab portion 22, and the thinner first portion 31 may meet the insulation requirement of the main body portion 21; moreover, the first part 31 with smaller thickness occupies smaller space in the battery shell 1, improves the space utilization rate of the battery, provides enough space for the expansion of the first pole piece and the second pole piece, and also provides enough space for the lithium ion shuttle so as to ensure the charge and discharge efficiency of the battery.

One surface of the insulating film 3 is a flat surface, the other surface is a stepped surface, and one side of the flat surface is bonded to the winding core 2.

The insulating films 3 having different thicknesses may be formed by different numbers of coating and drying, i.e., the region where the second portion 32 is formed may be subjected to a plurality of coating and drying. The insulating film 3 having a different thickness may be formed by imprinting with a mold having a different thickness in two regions.

Of course, on the basis that the resistivity of the second portion 32 is greater than that of the first portion 31, the thickness of the second portion 32 may be greater than that of the first portion 31, so as to further ensure a higher insulation requirement of the tab portion 22.

Still further, in further example embodiments of the present disclosure, the second portion 32 covers not only at least a portion of the tab portion 22, but the second portion 32 may also cover at least a portion of the body portion 21. The ratio of the height of the portion of the second portion 32 covering the main body portion 21 in the third direction Z to the height of the main body portion 21 is 0.01 or more and 0.3 or less, for example, the ratio of the height of the portion of the second portion 32 covering the main body portion 21 in the third direction Z to the height of the main body portion 21 may be 0.04, 0.08, 0.12, 0.17, 0.23, 0.28, or the like.

Since there is always a certain error in the equipment and the manufacturing process, it is difficult for the second portion 32 to just cover the tab portion 22 without covering the main body portion 21, and if the second portion 32 is provided in a structure just covering only the tab portion 22, an error in which the second portion 32 does not cover the desired tab portion 22 easily occurs during the manufacturing and bonding process of the insulating film 3, resulting in poor insulation of the tab portion 22. The second portion 32 is provided so as to cover not only at least part of the tab portion 22 but also at least part of the main body portion 21, and even if errors occur in the manufacturing and bonding processes, the second portion 32 covers the desired tab portion 22, ensuring the insulating effect of the tab portion 22.

Note that, in the case where the first tab 221 is connected to the positive electrode post 51, the first tab 221 may be connected to the positive electrode post 51 through the current collecting plate 4; when the second tab 222 is connected to the positive electrode post 51, the second tab 222 may be connected to the positive electrode post 51 through the current collecting plate 4.

The references to "parallel", "perpendicular" in this application are not entirely parallel, perpendicular, but rather are to some degree of error; for example, the included angle between the two is greater than or equal to 0 ° and less than or equal to 5 °, i.e. the two are considered to be parallel to each other; the included angle between the two is more than or equal to 85 degrees and less than or equal to 95 degrees, namely the two are considered to be mutually perpendicular.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A cylindrical battery, comprising:

a winding core comprising a main body part and a pole ear part;

2. The cylindrical battery of claim 1, wherein the body portion has oppositely disposed first and second end faces, and the tab portion comprises:

the first tab is connected to the main body part and is positioned at one side of the first end face away from the main body part;

the second lug is connected to the main body part and is positioned at one side of the second end face, which is away from the main body part.

3. The cylindrical battery of claim 2, wherein the second portion is provided in two and is connected to opposite sides of the first portion, the cylindrical battery further comprising:

the battery shell, the core is located in the battery shell, first utmost point ear with the second utmost point ear with the battery shell does not electrically connect, two the second part is highly the same in the third direction, the third direction with the axial of cylinder battery is unanimous.

4. The cylindrical battery of claim 3, wherein in the third direction, the second portion covering the first tab protrudes from the first tab, and the second portion covering the second tab protrudes from the second tab; or, the second part covering the first tab is flush with the first tab, and the second part covering the second tab is flush with the second tab.

5. The cylindrical battery of claim 2, wherein the second portion is provided in two and is connected to opposite sides of the first portion, the cylindrical battery further comprising:

the winding core is arranged in the battery shell, and the first tab or the second tab is electrically connected with the battery shell; the two second parts are a first sub-part covering at least part of the first tab or at least part of the second tab not electrically connected to the battery case, and a second sub-part covering at least part of the first tab or at least part of the second tab electrically connected to the battery case.

6. The cylindrical battery of claim 5, wherein a height of the second sub-portion in a third direction is less than a height of the first sub-portion in the third direction, the third direction being coincident with an axial direction of the cylindrical battery.

7. The cylindrical battery of claim 1, wherein the body portion has oppositely disposed first and second end faces, and the tab portion comprises:

the second lug is connected to the main body part and is positioned at one side of the first end face, which is away from the main body part, and the second lug and the first lug are arranged in an insulating way.

8. The cylindrical battery of claim 7, wherein the cylindrical battery further comprises:

the battery shell, the said core is located in the said battery shell, the said first tab and said second tab are not connected electrically with the said battery shell, or, the said first tab or said second tab is connected electrically with the said battery shell; in a third direction, the second part protrudes from the first tab and the second tab, and the third direction is consistent with the axial direction of the cylindrical battery.

9. The cylindrical battery of any one of claims 1-8, wherein the resistivity of the second portion is greater than the resistivity of the first portion.

10. The cylindrical battery of any one of claims 1-8, wherein the thickness of the second portion is greater than the thickness of the first portion.

11. The cylindrical battery of any one of claims 1-8, wherein the second portion further covers at least a portion of the body portion.

12. The cylindrical battery according to claim 11, wherein a ratio of a height of a portion of the second portion covering the main body portion in the third direction to a height of the main body portion is 0.01 or more and 0.3 or less.