Battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery. The electrode assembly comprises a battery cell main body, a first tab and a second tab, the battery cell main body is a cylinder, the polarity of the first tab is opposite to that of the second tab, the battery cell main body is provided with a first end face and a second end face which are oppositely arranged, and the first tab and the second tab are arranged on the side, away from the battery cell main body, of the first end face; the outer peripheral surface of the battery cell main body is coated with the insulating film, the thickness of the insulating film is greater than or equal to 0.04 mm and less than or equal to 0.1 mm, and the ratio of the size of the insulating film to the size of the battery cell main body is greater than or equal to 0.8 and less than or equal to 1 in the axial direction of the battery cell main body; the first collector plate is at least arranged on one side, deviating from the battery cell main body, of the first tab, and is provided with a first tab welding area connected with the first tab; the second collector plate is at least arranged on one side, deviating from the battery cell main body, of the second tab, and is provided with a second tab welding area connected with the second tab. The insulating film of the battery can play a role in protecting the electrode assembly.

Description

Technical Field

[0001] The present disclosure relates to the technical field of batteries, and in particular to a battery. Background Art

[0002] The positive and negative ears of the electrode assembly of the cylindrical battery are arranged on the same end face of the electrode assembly. The positive ear needs to be welded to the positive current collector plate, and the negative ear needs to be welded to the negative current collector plate. Therefore, there are requirements for the alignment of the positive ear with the positive current collector plate and the negative ear with the negative current collector plate. If the positive ear is not aligned with the positive current collector plate and the negative ear is not aligned with the negative current collector plate, the flow area of ​​the positive electrode and the flow area of ​​the negative electrode will be affected, and even cause a short circuit between the positive ear and the negative current collector plate and between the negative ear and the positive current collector plate.

[0003] However, the electrode assembly of the cylindrical battery is also configured as a cylinder, which is easy to rotate. Therefore, during welding, it is necessary to limit the rotation of the electrode assembly in the carrier. The limiting parts on the carrier will clamp or press the electrode assembly, causing damage to the electrode assembly.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0005] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned related technologies and provide a battery.

[0006] According to one aspect of the present disclosure, there is provided a battery, comprising:

[0007] The electrode assembly comprises a battery body, a first pole ear and a second pole ear, wherein the battery body is a column, the first pole ear and the second pole ear have opposite polarities, the battery body has a first end face and a second end face arranged opposite to each other, and the first pole ear and the second pole ear are arranged on a side of the first end face away from the battery body;

[0008] An insulating film is coated on the outer peripheral surface of the battery body, the thickness of the insulating film is greater than or equal to 0.04 mm and less than or equal to 0.1 mm, and in the axial direction of the battery body, the ratio of the size of the insulating film to the size of the battery body is greater than or equal to 0.8 and less than or equal to 1;

[0009] A first current collecting disk is at least arranged on a side of the first pole tab away from the battery body, the first current collecting disk has a first pole tab welding area, and the first pole tab welding area is connected to the first pole tab;

[0010] The second current collecting disk is at least arranged on a side of the second pole tab away from the battery body, and the second current collecting disk has a second pole tab welding area, and the second pole tab welding area is connected to the second pole tab.

[0011] In the battery disclosed in the present invention, the thickness of the insulating film is greater than or equal to 0.04 mm and less than or equal to 0.1 mm. In the axial direction of the battery body, the ratio of the size of the insulating film to the size of the electrode assembly is greater than or equal to 0.8 and less than or equal to 1. On the one hand, when the first pole ear is welded to the first collector disk and the second pole ear is welded to the second collector disk, the electrode assembly is clamped or pressed by the limiting member on the carrier to prevent rotation to ensure the alignment of the first pole ear with the first collector disk and the second pole ear with the second collector disk; and the insulating film can not only protect the electrode assembly, but also will not cause damage to the electrode assembly when the limiting member on the carrier clamps or presses the electrode assembly; and will not affect the space utilization of the battery shell to ensure the energy density of the battery. On the other hand, not only when the limiting member on the carrier clamps or presses the electrode assembly, the position of the limiting member corresponding to the electrode assembly is guaranteed to be covered with the insulating film, so that the insulating film can play a protective role; and will not affect the welding of the first pole ear with the first collector disk and the second pole ear with the second collector disk, and will not cause the first pole ear and the second pole ear to tear and break at the root.

[0012] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0014] Figure 1 It is a schematic diagram of the three-dimensional structure of an exemplary embodiment of the battery disclosed in the present invention.

[0015] Figure 2 for Figure 1 Schematic diagram of the cross-section of the battery.

[0016] Figure 3 for Figure 2 Schematic diagram of the three-dimensional structure of the first collecting plate.

[0017] Figure 4 for Figure 2 Schematic diagram of the three-dimensional structure of the second collecting plate.

[0018] Figure 5 It is a structural schematic diagram of the battery cell body in a flattened state.

[0019] Figure 6 It is a schematic diagram of the structure of the battery body and the insulating film.

[0020] Description of reference numerals:

[0021] 1. Battery housing; 11. Cover plate; 12. Side wall; 13. Bottom wall;

[0022] 2. Electrode assembly; 21. First pole ear; 22. Second pole ear; 23. Cell body; 231. First end face; 232. Second end face; 233. First pole piece; 234. Second pole piece; 235. Isolation film; 236. Positive pole piece tail end;

[0023] 3. Insulating film; 31. Overlapping area;

[0024] 4. First current collecting plate; 41. Connecting ring; 41a. Cover plate welding area; 42. Connecting tube; 43. Connecting plate; 43a. First pole ear welding area;

[0025] 5. Second current collecting plate; 51. First current collecting part; 51a. Second pole lug welding area; 52. Second current collecting part; 52a. Pole welding area;

[0026] 6. Battery pole;

[0027] X, axial direction; Y, circumferential direction. DETAILED DESCRIPTION

[0028] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0029] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on 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.

[0030] 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 "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0031] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. "And / or" is just a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0032] The present disclosure provides a battery according to an exemplary embodiment. Figure 1-Figure 6 As shown, the battery may include a first current collecting plate 4, a second current collecting plate 5, an electrode assembly 2 and an insulating film 3; the electrode assembly 2 may include a battery body 23, a first pole ear 21 and a second pole ear 22, the battery body 23 is a column, the first pole ear 21 and the second pole ear 22 have opposite polarities, the battery body 23 has a first end face 231 and a second end face 232 arranged oppositely, the first pole ear 21 and the second pole ear 22 are arranged on the side of the first end face 231 away from the battery body 23; the insulating film 3 is coated on the outer peripheral surface of the battery body 23, and the thickness of the insulating film 3 is greater than or equal to 0.04mm And is less than or equal to 0.1mm, in the axial direction X of the battery cell body 23, the ratio of the size of the insulating film 3 to the size of the battery cell body 23 is greater than or equal to 0.8 and less than or equal to 1; the first collecting disk 4 is at least arranged on the side of the first pole ear 21 away from the battery cell body 23, the first collecting disk 4 has a first pole ear welding area 43a, and the first pole ear welding area 43a is connected to the first pole ear 21; the second collecting disk 5 is at least arranged on the side of the second pole ear 22 away from the battery cell body 23, the second collecting disk 5 has a second pole ear welding area 51a, and the second pole ear welding area 51a is connected to the second pole ear 22.

[0033] The battery disclosed in the present invention, on the one hand, when the first pole ear 21 is welded to the first current collecting disk 4 and the second pole ear 22 is welded to the second current collecting disk 5, the electrode assembly 2 is clamped or pressed by the limiting member on the carrier to prevent rotation so as to ensure the alignment of the first pole ear 21 with the first current collecting disk 4 and the second pole ear 22 with the second current collecting disk 5; and the insulating film 3 can not only protect the electrode assembly 2, but also will not cause damage to the electrode assembly 2 when the limiting member on the carrier clamps or presses the electrode assembly 2; and will not affect the space utilization of the battery housing 1 to ensure the energy density of the battery. On the other hand, not only when the limiting member on the carrier clamps or presses the electrode assembly 2, the position of the limiting member corresponding to the electrode assembly 2 is guaranteed to be covered with the insulating film 3, so that the insulating film 3 can play a protective role; and will not affect the welding of the first pole ear 21 with the first current collecting disk 4 and the second pole ear 22 with the second current collecting disk 5, and will not cause the root of the first pole ear 21 and the second pole ear 22 to tear and break.

[0034] In this example embodiment, the battery may be a cylindrical battery, referring to Figure 1 As shown, the battery housing 1 can be set as a cylinder, that is, the battery housing 1 can include a cover plate 11 and a bottom wall 13 arranged opposite to each other, the cover plate 11 and the bottom wall 13 are both arranged in a circular shape, and a side wall 12 is connected between the cover plate 11 and the bottom wall 13, and the side wall 12 is arranged in a cylindrical shape. The side wall 12, the cover plate 11 and the bottom wall 13 surround and form a battery accommodation cavity. Of course, the battery can also be a regular pentagonal prism battery, a regular hexagonal prism battery, etc.

[0035] The battery housing 1 may be made of aluminum, steel or other metals and alloys. Of course, it may also be made of other materials, which will not be described here one by one.

[0036] In this example implementation, refer to Figure 2 As shown, an electrode assembly 2 is arranged in the accommodating cavity of the battery shell 1, and the electrode assembly 2 may include a battery body 23, a first pole ear 21 and a second pole ear 22, and the polarity of the first pole ear 21 is opposite to that of the second pole ear 22. The battery body 23 is set as a column, for example, the battery body 23 can be set as a cylinder adapted to the battery shell 1. The battery body 23 has a first end face 231 and a second end face 232, and the first end face 231 is arranged opposite to the second end face 232. The battery body 23 may include a first pole piece 233 and a second pole piece 234, and a separation film 235 arranged between the first pole piece 233 and the second pole piece 234. The battery body 23 may be formed by winding the first pole piece 233, the separation film 235 and the second pole piece 234 arranged in layers. Active material is coated on the first pole piece 233 and the second pole piece 234.

[0037] The first pole tab 21 is connected to the cell body 23, specifically, the first pole tab 21 is connected to the first pole piece 233; the first pole tab 21 is located at the first end surface 231 of the cell body 23 close to the cover plate 11. The second pole tab 22 is connected to the cell body 23, specifically, the second pole tab 22 is connected to the second pole piece 234; and the second pole tab 22 can be located on the same side of the cell body 23 as the first pole tab 21, that is, the second pole tab 22 can be located at the first end surface 231 of the cell body 23 close to the cover plate 11, so that the first pole tab 21 and the second pole tab 22 are arranged on the side of the first end surface 231 away from the cell body 23.

[0038] The first pole tab 21 may be a portion of the multi-layer first pole sheet 233 extending and protruding from the battery body 23, and being bent to the side of the first end face 231 of the battery body 23 away from the battery body 23 to form the first pole tab 21, so that the first pole tab 21 may include a multi-layer first pole tab sheet. The second pole tab 22 may be a portion of the multi-layer second pole sheet 234 extending and protruding from the battery body 23, and being bent to the side of the first end face 231 of the battery body 23 away from the battery body 23 to form the second pole tab 22, so that the second pole tab 22 may include a multi-layer second pole tab sheet.

[0039] It should be noted that the first pole tab 21 and the second pole tab 22 are conductive foil areas without active material coating, that is, no active material coating is coated on the first pole tab 21 and the second pole tab 22, and the first pole tab 21 and the second pole tab 22 are current collecting layers for transmitting current.

[0040] In this example implementation, refer to Figure 2 As shown, the battery pole 6 is insulated and connected to the cover plate 11. Specifically, a through hole is provided on the cover plate 11, and the battery pole 6 passes through the through hole and is riveted to the cover plate 11. An insulating member is provided between the battery pole 6 and the cover plate 11 to insulate the battery pole 6 from the cover plate 11.

[0041] In this example implementation, refer to Figure 2 As shown, a first current collecting plate 4 is provided on a side of the first pole tab 21 close to the cover plate 11, so that the first current collecting plate 4 is provided between the cover plate 11 and the electrode assembly 2. The first current collecting plate 4 has a cover plate welding area 41a and a first pole tab welding area 43a, the cover plate welding area 41a is connected to the cover plate 11, specifically, the cover plate welding area 41a is welded to the cover plate 11, so that a welding portion is provided between the cover plate welding area 41a and the cover plate 11; the first pole tab welding area 43a is connected to the first pole tab 21, specifically, the first pole tab welding area 43a is welded to the first pole tab 21, so that a welding portion is provided between the first pole tab welding area 43a and the first pole tab 21.

[0042] In this example implementation, refer to Figure 2 and Figure 3As shown, the first current collecting plate 4 may include a connecting ring 41, a connecting tube 42 and a connecting plate 43; the connecting ring 41 is set to be annular, so that the connecting ring 41 has an inner ring surface and an outer ring surface. The connecting ring 41 may include a cover plate welding area 41a, a part of the connecting ring 41 may be the cover plate welding area 41a, or the entire connecting ring 41 may be the cover plate welding area 41a, and the connecting ring 41 may be welded to the cover plate 11.

[0043] The connecting tube 42 is connected to the side of the connecting ring 41 close to the electrode assembly 2, and the connecting tube 42 is connected to the inner ring surface of the connecting ring 41. The connecting tube 42 is configured to be a semi-cylindrical shape, and the connecting tube 42 and the connecting ring 41 are smoothly connected.

[0044] The connection plate 43 is connected to the side of the connection tube 42 close to the electrode assembly 2, so that the height of the connection plate 43 is lower than the height of the connection ring 41; and the connection plate 43 is connected to the inner cylinder surface of the connection tube 42. The connection plate 43 is arranged in a fan ring shape, and the connection plate 43 may include a first pole lug welding area 43a, and a part of the connection plate 43 may be the first pole lug welding area 43a, or the entire connection plate 43 may be the first pole lug welding area 43a. The connection ring 41, the connection tube 42 and the connection plate 43 are arranged on the same central axis; and the connection plate 43 and the connection tube 42 are smoothly transitionally connected.

[0045] In this example implementation, refer to Figure 2 As shown, the battery may further include a second current collecting plate 5, the polarity of the second current collecting plate 5 being opposite to that of the first current collecting plate 4. For example, the first current collecting plate 4 may be a negative current collecting plate, and the second current collecting plate 5 may be a positive current collecting plate. Of course, the first current collecting plate 4 may also be a positive current collecting plate, and the second current collecting plate 5 may be a negative current collecting plate.

[0046] Reference Figure 4 As shown, the second current collecting plate 5 has a second pole tab welding area 51a and a pole welding area 52a. The second pole tab welding area 51a is connected to the second pole tab 22, specifically, the second pole tab welding area 51a is welded to the second pole tab 22, so that a welding portion is provided between the second pole tab welding area 51a and the second pole tab 22. The pole welding area 52a is connected to the battery pole 6, specifically, the pole welding area 52a is welded to the battery pole 6, so that a welding portion is provided between the pole welding area 52a and the battery pole 6.

[0047] The second current collecting plate 5 may include a first current collecting portion 51 and a second current collecting portion 52, wherein the first current collecting portion 51 is connected to the second current collecting portion 52. The first current collecting portion 51 is configured as a semicircular ring structure, that is, the first current collecting portion 51 is configured as a fan ring structure, and the second current collecting portion 52 is configured as a circular structure, and the second current collecting portion 52 is connected to the inner annular surface of the first current collecting portion 51 with a smaller radius.

[0048] Moreover, the second current collecting plate 5 needs to be connected to the battery pole 6. Specifically, the second current collecting part 52 is welded to the battery pole 6. Therefore, a protruding structure is provided on the second current collecting part 52. The protruding structure is provided in a cylindrical shape to cooperate with the cylindrical recessed structure on the battery pole 6.

[0049] In this exemplary embodiment, the insulating film 3 is coated on the outer peripheral surface of the battery cell body 23 , and the battery cell body 23 and the battery case 1 can be insulated and separated by the insulating film 3 ; and the insulating film 3 can protect the electrode assembly 2 .

[0050] The thickness of the insulating film 3 is greater than or equal to 0.04 mm and less than or equal to 0.1 mm. For example, the thickness of the insulating film 3 can be 0.042 mm, 0.045 mm, 0.047 mm, 0.05 mm, 0.053 mm, 0.055 mm, 0.058 mm, 0.06 mm, 0.062 mm, 0.065 mm, 0.067 mm, 0.07 mm, 0.073 mm, 0.075 mm, 0.078 mm, 0.08 mm, 0.082 mm, 0.085 mm, 0.087 mm, 0.09 mm, 0.093 mm, 0.095 mm, 0.098 mm, etc.

[0051] If the thickness of the insulating film 3 is too thin, the insulating film 3 will not be able to protect the electrode assembly 2. When the limiting member on the carrier clamps or presses the electrode assembly 2, the insulating film 3 will be damaged, causing damage to the electrode assembly 2.

[0052] If the thickness of the insulating film 3 is too thick, the insulating film 3 occupies a larger space inside the battery housing 1, which is not conducive to the space utilization of the battery housing 1 and is not conducive to improving the energy density of the battery.

[0053] The above numerical range not only enables the insulating film 3 to protect the electrode assembly 2, but also does not cause damage to the electrode assembly 2 when the limiting member on the carrier clamps or presses the electrode assembly 2; it also does not affect the space utilization of the battery casing 1, thereby ensuring the energy density of the battery.

[0054] Moreover, in the axial direction X of the battery cell body 23, the ratio of the size H1 of the insulating film 3 to the size H2 of the battery cell body 23 is greater than or equal to 0.8 and less than or equal to 1. For example, in the axial direction X of the battery cell body 23, the ratio of the size H1 of the insulating film 3 to the size H2 of the battery cell body 23 can be 0.82, 0.84, 0.855, 0.87, 0.89, 0.9, 0.93, 0.95, 0.97, 0.99, etc.

[0055] If the ratio of the size H1 of the insulating film 3 to the size H2 of the battery cell body 23 is too small, the area of ​​the battery cell body 23 covered by the insulating film 3 will be small. When the limiting piece on the carrier clamps or presses the battery cell body 23, the position of the limiting piece corresponding to the battery cell body 23 may not be covered by the insulating film 3, and the insulating film 3 will not play a protective role.

[0056] If the ratio of the size H1 of the insulating film 3 to the size H2 of the battery cell body 23 is too large, the insulating film 3 may stick to the first pole ear 21 and the second pole ear 22, affecting the welding of the first pole ear 21 and the second pole ear 22 and the collecting plate (the first collecting plate 4 and the second collecting plate 5); and the insulating film 3 will generate a pulling force on the first pole ear 21 and the second pole ear 22, which may cause the roots of the first pole ear 21 and the second pole ear 22 to be torn and broken.

[0057] The above numerical range not only ensures that when the limiting member on the carrier clamps or presses the battery cell body 23, the position of the limiting member corresponding to the battery cell body 23 is covered with the insulating film 3, so that the insulating film 3 can play a protective role; but also will not affect the welding of the first pole ear 21 and the second pole ear 22 to the collecting plate, and will not cause the root of the first pole ear 21 and the second pole ear 22 to be torn and broken.

[0058] In some example embodiments of the present disclosure, the ratio of the circumferential dimension of the insulating film 3 to the circumference of the battery cell body 23 is greater than or equal to 1 and less than or equal to 1.1. For example, the ratio of the circumferential dimension of the insulating film 3 to the circumference of the battery cell body 23 can be 1.02, 1.05, 1.06, 1.08, etc.

[0059] If the ratio of the circumferential dimension of the insulating film 3 to the circumference of the battery cell body 23 is too large, the overlapping area 31 of the insulating film 3 will be relatively large. When the battery cell body 23 expands during the battery charging and discharging process, the overlapping area 31 will exert excessive local restraint force on the battery cell body 23, resulting in uneven restraint force on various parts of the battery cell body 23, which is not conducive to the electrical performance of the battery.

[0060] If the ratio of the circumferential dimension of the insulating film 3 to the circumference of the battery cell body 23 is too small, the area of ​​the battery cell body 23 covered by the insulating film 3 is too small, and the outer circumferential surface of the battery cell body 23 may be covered neither by the insulating film 3 nor by the isolation film 235, thereby causing the insulation failure between the battery cell body 23 and the battery casing 1.

[0061] The above numerical range not only ensures that the local binding force of the overlapping area 31 on the battery cell body 23 is relatively uniform, which is beneficial to the electrical performance of the battery; but also the outer peripheral surface of the battery cell body 23 will not be covered by neither the insulating film 3 nor the isolation film 235, thereby ensuring the insulation effect between the battery cell body 23 and the battery casing 1.

[0062] It should be noted that, in the circumferential direction of the battery cell body 23, both the head and tail ends of the insulating film 3 can be set to be serrated. In this case, the serrations at the head end of the insulating film 3 and the serrations at the tail end of the insulating film 3 are interlocked, so that the ratio of the circumferential dimension of the insulating film 3 to the circumference of the battery cell body 23 is 1, that is, the insulating film 3 just surrounds the battery cell body 23. Of course, in some other exemplary embodiments of the present disclosure, the head and tail ends of the insulating film 3 can be set to be neat straight lines, and the straight lines can be parallel to the axial direction of the battery cell body or intersect with the axial direction of the battery cell body.

[0063] In some example embodiments of the present disclosure, the circumferential dimension of the insulating film 3 is less than or equal to the circumference of the battery cell body 23. When the circumferential dimension of the insulating film 3 is equal to the circumference of the battery cell body 23, the insulating film 3 just surrounds the electrode assembly 2. When the circumferential dimension of the insulating film 3 is less than the circumference of the battery cell body 23, the insulating film 3 does not surround the electrode assembly 2, and a gap is formed between the two ends of the insulating film 3. In this case, after the insulating film 3 is attached to the outer peripheral surface of the electrode assembly 2, the insulating film 3 does not form an overlapping area 31 domain. When the electrode assembly 2 expands during the battery charging and discharging process or the limiting member of the carrier clamps or presses the electrode assembly 2, there is no overlapping area 31 domain that causes excessive local restraint force on the electrode assembly 2, resulting in uneven restraint force on various parts of the electrode assembly 2, so as to ensure the electrical performance of the battery.

[0064] Moreover, when the circumferential dimension of the insulating film 3 is less than or equal to the circumference of the battery cell body 23, a gap is set between the two circumferential ends of the insulating film 3, but the width of the gap is different; the gap between the two circumferential ends of the insulating film 3 is arranged relative to the part of the isolation film 235 protruding from the first pole piece 233 and the second pole piece 234, so that the outer circumferential surface of the battery cell body 23 is insulated and wrapped to ensure the insulation effect between the battery cell body 23 and the battery casing 1.

[0065] In this example implementation, refer to Figure 2 As shown, in the axial direction X of the battery cell body, the distance L1 between the edge of the insulating film 3 close to the first end face 231 and the first end face 231 is greater than or equal to 0 and less than or equal to 15 mm. For example, the distance L1 between the edge of the insulating film 3 close to the first end face 231 and the first end face 231 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, and the like.

[0066] If the distance L1 between the edge of the insulating film 3 close to the first end surface 231 and the first end surface 231 is too small, the insulating film 3 may stick to the first pole lug 21 and the second pole lug 22, affecting the welding of the first pole lug 21 and the second pole lug 22 to the collecting plate; and the insulating film 3 will generate a pulling force on the first pole lug 21 and the second pole lug 22, which may cause the roots of the first pole lug 21 and the second pole lug 22 to be torn and broken.

[0067] If the distance L1 between the edge of the insulating film 3 close to the first end face 231 and the first end face 231 is too large, the insulating film 3 will not be able to protect the battery cell body 23, and the first pole piece 233 and the second pole piece 234 are not provided in a part of the first end of the battery cell body 23, resulting in the isolation film 235 lacking the support of the internal first pole piece 233 and the second pole piece 234, and the isolation film 235 is easily rolled inward or deformed, thereby causing the active material on the internal first pole piece 233 and the second pole piece 234 to fall off.

[0068] The above numerical range not only ensures that the insulating film 3 will not generate pulling force on the first pole ear 21 and the second pole ear 22, and will not cause the roots of the first pole ear 21 and the second pole ear 22 to be torn and broken; but also the insulating film 3 can play a role of fixing and supporting the isolation film 235, reducing or even avoiding the inward movement or deformation of the isolation film 235, thereby avoiding the falling of active materials on the first pole piece 233 and the second pole piece 234.

[0069] In this example implementation, refer to Figure 2 As shown, in the axial direction X of the battery cell body 23, the distance L2 between the edge of the insulating film 3 close to the second end face 232 and the second end face 232 is less than or equal to 2 mm. For example, the distance L2 between the edge of the insulating film 3 close to the second end face 232 and the second end face 232 can be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, etc.

[0070] If the distance L2 between the edge of the insulating film 3 close to the second end face 232 and the second end face 232 is large, the insulating film 3 cannot protect the bottom end of the electrode assembly 2. The electrode assembly 2 is installed into the battery casing 1 in a vertical shell-in manner. The bottom end of the electrode assembly 2 is easily hit and deformed when entering the shell; and the bottom end of the electrode assembly 2 is scratched against the battery casing 1, causing the isolation film 235 to fold and leak the first electrode sheet 233 and / or the second electrode sheet 234.

[0071] The above numerical range enables the insulating film 3 to protect the bottom end of the electrode assembly 2, preventing the bottom end of the electrode assembly 2 from being deformed by collision, and even if the bottom end of the electrode assembly 2 is scratched against the battery casing 1, the insulating film 235 will not be folded to leak out the electrode piece.

[0072] Reference Figure 5 As shown, in order to ensure the charging efficiency and service life of the battery, the area of ​​the negative electrode sheet (the second electrode sheet 234) is larger than the area of ​​the positive electrode sheet (the first electrode sheet 233); in order to ensure the insulation effect between the negative electrode sheet and the positive electrode sheet, the area of ​​the isolation film 235 is greater than or equal to the area of ​​the negative electrode sheet (the second electrode sheet 234). When the isolation film 235, the negative electrode sheet and the positive electrode sheet are in a flattened state, the positive projection of the negative electrode sheet on the isolation film 235 covers and is larger than the positive projection of the positive electrode sheet on the isolation film 235, and the isolation film 235 covers and is larger than the positive projection of the negative electrode sheet on the isolation film 235.

[0073] In this example implementation, refer to Figure 6 As shown, the figure only shows the structure of the tail end of the battery cell body 23 including the first pole piece 233, the isolation film 235 and the second pole piece 234, and a layer of the first pole piece 233, the isolation film 235 and the second pole piece 234 stacked at other positions are shown as a whole. The battery cell body 23 can be formed by winding the stacked first pole piece 233, the isolation film 235 and the second pole piece 234, that is, the battery cell body 23 may include the stacked first pole piece 233, the isolation film 235 and the second pole piece 234, the first pole piece 233, the isolation film 235 and the second pole piece 234 are wound so that the battery cell body 23 has a tail end. The following is an example of the first pole piece 233 being the positive pole piece and the second pole piece 234 being the negative pole piece. The battery cell body 23 has a positive electrode sheet tail end 236 , which refers to the end of the positive electrode sheet located outside the battery cell body 23 . For example, the positive electrode sheet tail end 236 may be 0.1-0.2 of the circumference of the battery cell body 23 .

[0074] The positive electrode sheet tail end portion 236 is arranged opposite to only one layer of insulating film 3 , that is, only one layer of insulating film 3 is arranged at the positive electrode sheet tail end portion 236 .

[0075] Since the negative electrode sheet exceeds the positive electrode sheet and the isolation film 235 exceeds the negative electrode sheet, two steps are formed by the positive electrode sheet and the negative electrode sheet at the tail end of the battery cell body 23, and the height of the step formed by the positive electrode sheet is relatively high. When the insulating film 3 has an overlapping area 31 (the overlapping area 31 is provided with two layers of insulating film 3), if the overlapping area 31 is arranged relative to the tail end 236 of the positive electrode sheet, resulting in the local thickness of the tail end 236 of the positive electrode sheet being too thick, then when the limiting part of the battery cell carrier presses against the electrode assembly 2 or when the battery cell body 23 expands at a later stage, the local pressure here will be too large, and the shear force generated at the step will cause the position corresponding to the tail end of the negative electrode sheet and the positive electrode sheet to fall off or even break.

[0076] Only one layer of insulating film 3 is provided at the tail end 236 of the positive electrode sheet, which will not cause the local thickness of the tail end 236 of the positive electrode sheet to be too thick. When the limiting part of the battery cell carrier presses against the electrode assembly 2 or the battery cell body 23 expands at a later stage, the local pressure at various parts of the battery cell body 23 is basically the same, and no shear force will be generated, which will cause the negative electrode sheet and the tail end of the positive electrode sheet to fall off or even break at the corresponding position.

[0077] In the circumferential direction of the battery cell body 23, the isolation membrane 235 extends beyond the first pole piece 233 and the second pole piece 234, and the ratio of the minimum dimension of the isolation membrane 235 extending beyond the first pole piece 233 and the second pole piece 234 to the circumference of the battery cell body 23 is greater than or equal to 0.5 and less than or equal to 4, so that the portion of the isolation membrane 235 extending beyond the first pole piece 233 and the second pole piece 234 can surround the battery cell body 23 with a number of turns greater than or equal to 0.5 and less than or equal to 4. For example, the ratio of the minimum dimension of the isolation membrane 235 extending beyond the first pole piece 233 and the second pole piece 234 to the circumference of the battery cell body 23 can be 0.8, 1, 1.2, 1.5, 1.7, 2, 2.3, 2.5, 2.8, 3, 3.2, 3.5, 3.7 and so on.

[0078] Since the negative electrode sheet exceeds the positive electrode sheet, the separator 235 exceeds the negative electrode sheet, and therefore, the minimum dimension of the separator 235 exceeding the first electrode sheet 233 and the second electrode sheet 234 refers to the dimension of the separator 235 exceeding the negative electrode sheet. Of course, in some other exemplary embodiments of the present disclosure, the minimum dimension of the separator 235 exceeding the first electrode sheet 233 and the second electrode sheet 234 may refer to the dimension of the separator 235 exceeding the positive electrode sheet.

[0079] If the ratio of the minimum dimension of the isolation film 235 beyond the first pole piece 233 and the second pole piece 234 to the circumference of the battery cell body 23 is too small, so that the minimum dimension of the isolation film 235 beyond the first pole piece 233 and the second pole piece 234 is too small, when the insulating film 3 is not set to one circle or more than one circle, it may cause a part of the battery cell body 23 to not be insulated and isolated from the battery casing.

[0080] If the ratio of the minimum size of the isolation film 235 exceeding the first electrode piece 233 and the second electrode piece 234 to the circumference of the battery cell body 23 is too large, the isolation film 235 will exceed the minimum size of the first electrode piece 233 and the second electrode piece 234 by too much, and the covering area of ​​the electrode assembly 2 will be too large and the local binding force will also be too large, resulting in the battery not being easy to expand during the later charging and discharging, affecting the charging and discharging effect.

[0081] In the circumferential direction of the battery cell body 23 , the ratio of the minimum dimension of the isolation film 235 extending beyond the first pole piece 233 and the second pole piece 234 to the circumference of the battery cell body 23 may be 1.

[0082] When the ratio of the minimum dimension of the isolation membrane 235 exceeding the first pole piece 233 and the second pole piece 234 to the circumference of the battery cell body 23 is greater than 1 or less than 1, a step will be formed on the end face of the isolation membrane 235. When the limiting part of the battery cell carrier presses against the electrode assembly 2 or the battery cell body 23 expands at a later stage, the shear force generated at the step will cause the first pole piece 233 and the second pole piece 234 to fall off or even break.

[0083] The elongation at break of the insulating film 3 is greater than or equal to 50%. For example, the elongation at break of the insulating film 3 can be 52%, 55%, 57%, 60%, 63%, 65%, 68%, 70%, etc. The elongation at break is the ratio of the displacement value of the sample when it is broken to the original length, expressed as a percentage (%). It has a large elongation at break, which indicates that the sample has a certain unidirectional elongation when it is impact-resistant and will not break immediately. The GB / T13542.2-2021 standard is a test method for thin films for electrical insulation. The elongation at break of the insulating film 3 can be measured by the method provided in this standard.

[0084] If the elongation at break of the insulating film 3 is too small, the insulating film 3 is easily torn apart by the shear force of the carrier clamping portion.

[0085] The above numerical range can ensure that the insulating film 3 is not easily torn apart by the shear force of the carrier clamping part.

[0086] The bonding strength between the insulating film 3 and the isolation film 235 is greater than or equal to 0.1N / mm. For example, the bonding strength between the insulating film 3 and the isolation film 235 can be 0.2N / mm, 0.5N / mm, 0.7N / mm, 1N / mm, 1.3N / mm, 1.5N / mm, 1.8N / mm, 2N / mm, 2.2N / mm, 2.5N / mm, 2.7N / mm, 3N / mm, 3.3N / mm, 3.5N / mm, 3.8N / mm, 4N / mm and the like.

[0087] If the bonding strength between the insulating film 3 and the isolation film 235 is too weak, when the carrier clamping part clamps the electrode assembly 2, the insulating film 3 and the isolation film 235 are easily misaligned and slipped, which may easily cause the insulating film 3 and the isolation film 235 to wrinkle, which is not conducive to ensuring the electrical performance of the battery.

[0088] The above numerical range can ensure the strong adhesion between the insulating film 3 and the isolation film 235, so that the insulating film 3 and the isolation film 235 will not be misaligned or slipped, and the insulating film 3 and the isolation film 235 will not be wrinkled, which is beneficial to ensuring the electrical performance of the battery.

[0089] The insulating film 3 and the isolation film 235 are bonded together by adhesive. Therefore, the bonding strength between the insulating film 3 and the isolation film 235 refers to the bonding strength of the adhesive between the insulating film 3 and the isolation film 235 .

[0090] Adhesive strength refers to the adhesive force on a unit adhesive surface, and the adhesive strength mainly includes the cohesive strength of the adhesive layer and the adhesive strength between the adhesive layer and the adhered surface. The current national standard for adhesive strength in my country is GB / T6328-2018 "Method for Determining Shear Strength of Synthetic Resin Adhesives". The adhesive strength between the insulating film 3 and the isolation film 235 can be measured by the method provided in this standard.

[0091] The "parallel" and "perpendicular" mentioned in this application can not only be completely parallel or perpendicular, but also can have a certain error; for example, if the angle between the two is greater than or equal to 0° and less than or equal to 5°, the two are considered to be parallel to each other; if the angle between the two is greater than or equal to 85° and less than or equal to 95°, the two are considered to be perpendicular to each other.

[0092] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A battery, characterized in that: include: An electrode assembly, comprising a cell body, a first pole ear and a second pole ear, wherein the cell body is a column, the first pole ear and the second pole ear have opposite polarities, the cell body has a first end face and a second end face that are oppositely arranged, and the first pole ear and the second pole ear are arranged on a side of the first end face that is away from the cell body; An insulating film is coated on the outer peripheral surface of the battery body, the thickness of the insulating film is greater than or equal to 0.04 mm and less than or equal to 0.1 mm, and in the axial direction of the battery body, the ratio of the size of the insulating film to the size of the battery body is greater than or equal to 0.8 and less than or equal to 1; A first current collecting disk, at least disposed on a side of the first pole tab away from the battery cell body, the first current collecting disk having a first pole tab welding area, the first pole tab welding area being connected to the first pole tab; The second current collecting disk is at least arranged on a side of the second pole tab away from the battery body, and the second current collecting disk has a second pole tab welding area, and the second pole tab welding area is connected to the second pole tab.

2. The battery according to claim 1, characterized in that The ratio of the circumferential dimension of the insulating film to the circumference of the battery cell body is greater than or equal to 1 and less than or equal to 1.

1.

3. The battery according to claim 1, characterized in that The circumferential dimension of the insulating film is less than or equal to the circumference of the battery cell body.

4. The battery according to claim 3, characterized in that The battery cell body includes a first pole piece, an isolation membrane and a second pole piece which are stacked. The first pole piece, the isolation membrane and the second pole piece are wound, and a gap between the circumferential ends of the insulating membrane is arranged opposite to a portion of the isolation membrane protruding from the first pole piece and the second pole piece.

5. The battery according to any one of claims 1 to 4, characterized in that: In the axial direction of the battery cell body, a distance between an edge of the insulating film close to the first end face and the first end face is greater than or equal to 0 and less than or equal to 15 mm.

6. The battery according to any one of claims 1 to 4, characterized in that: In the axial direction of the battery cell body, a distance between an edge of the insulating film close to the second end face and the second end face is less than or equal to 2 mm.

7. The battery according to any one of claims 1 to 4, characterized in that: The battery cell body is wound so as to have a positive electrode tail end portion, and the positive electrode tail end portion is arranged opposite to only one layer of the insulating film.

8. The battery according to any one of claims 1 to 4, characterized in that: The battery cell body is made by winding a first pole sheet, a separation membrane and a second pole sheet which are stacked in layers. In the circumferential direction of the battery cell body, the separation membrane extends beyond the first pole sheet and the second pole sheet. The ratio of the minimum dimension of the separation membrane extending beyond the first pole sheet and the second pole sheet to the circumference of the electrode assembly is greater than or equal to 0.5 and less than or equal to 4.

9. The battery according to claim 8, characterized in that The bonding strength between the insulating film and the isolation film is greater than or equal to 0.1 N / mm.

10. The battery according to any one of claims 1 to 4, characterized in that: The elongation at break of the insulating film is greater than or equal to 50%.

11. The battery according to any one of claims 1 to 4, characterized in that: The battery is a cylindrical battery.

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