Battery cell

Abstract

The utility model relates to the technical field of batteries, and discloses a battery monomer. The single battery comprises a battery shell, a pole assembly and a battery cell, the battery shell comprises a shell metal layer and a shell insulating layer, the shell insulating layer is stacked on the surface of the shell metal layer, and the shell metal layer and the shell insulating layer are of an integrally formed structure; the pole component is fixed on the battery shell in an insulating manner; the battery cell is arranged in the battery shell, the battery cell comprises a body part and a tab part, the tab part is fixedly connected with the pole assembly, the tab part comprises at least two single tabs, the single tabs are provided with protruding parts, and the protruding parts are arranged in a protruding mode in the first direction perpendicular to the large surfaces of the single tabs; the size of the protruding part in the first direction is larger than or equal to 20 micrometers and smaller than or equal to 150 micrometers. According to the single battery, the strength of the single tab can be improved through the protruding part, and the bad tearing of the tab part under the action of the traction force of the pole column assembly is avoided, so that the electric connection strength is ensured; and gas generated during charging and discharging is easy to diffuse.

Description

Technical Field

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

[0002] At present, the battery shell may include a shell metal layer and a shell insulating layer, and the shell metal layer and the shell insulating layer are an integrally formed structure. The shell insulating layer can improve the electrochemical corrosion resistance of the battery shell; however, the strength of the battery shell is reduced and it is easy to deform. The pole assembly fixed to the battery shell will also be displaced. The pole assembly pulls the pole ear connected to it, thereby causing the pole ear to tear, causing the risk of electrical connection failure.

[0003] 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

[0004] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned related technologies and provide a battery cell.

[0005] According to one aspect of the present disclosure, there is provided a battery cell, comprising:

[0006] The battery shell comprises a shell metal layer and a shell insulating layer, wherein the shell insulating layer is stacked on the surface of the shell metal layer, and the shell metal layer and the shell insulating layer are an integrally formed structure;

[0007] A pole assembly, insulated and fixed to the battery housing;

[0008] A battery cell is arranged in a battery shell, the battery cell includes a main body and a pole ear portion, the pole ear portion is fixedly connected to the pole column assembly, the pole ear portion includes at least two single-piece pole ears, and a protrusion is arranged on the single-piece pole ear. The protrusion is protruded along a first direction perpendicular to the large surface of the single-piece pole ear, and the size of the protrusion in the first direction is greater than or equal to 20μm and less than or equal to 150μm.

[0009] In the battery cell disclosed in the present invention, on the one hand, a protrusion is provided on the single-piece pole ear, and the strength of the single-piece pole ear can be increased by the protrusion, thereby increasing the strength of the pole ear portion, avoiding the defect of the pole ear portion being torn under the pulling force of the pole column assembly, so as to ensure the electrical connection strength of the battery cell. On the other hand, the size of the protrusion in the first direction is greater than or equal to 20μm and less than or equal to 150μm, which not only ensures that the pole ear portion will not be torn under the pulling force of the pole column assembly; but also ensures that the pole ear portion will not occupy a large space inside the battery shell, which is conducive to improving the space utilization rate of the battery shell and the flow of the electrolyte, so that the gas generated during the charging and discharging of the battery cell is also easy to diffuse.

[0010] 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

[0011] 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.

[0012] Figure 1 It is a schematic diagram of the three-dimensional structure of an exemplary embodiment of a battery cell disclosed in the present invention.

[0013] Figure 2 for Figure 1 Schematic cross-sectional view of a battery cell.

[0014] Figure 3 It is a schematic diagram of the structure of a single-piece pole ear.

[0015] Figure 4 for Figure 2 Schematic diagram of the partial structure of the battery cell.

[0016] Figure 5 FIG. 1 is a cross-sectional schematic diagram of another exemplary embodiment of a battery cell according to the present disclosure.

[0017] Description of reference numerals:

[0018] 1. Battery housing; 11. Housing metal layer; 12. Housing insulation layer; 13. Cover plate; 14. Bottom wall plate; 15. Side plate;

[0019] 2. Pole assembly; 21. Battery pole; 22. Adapter;

[0020] 3. battery cell; 31. main body; 32. pole ear; 32a. first pole ear; 32b. second pole ear; 321. single-piece pole ear; 3211. protrusion;

[0021] 4. Welding part; 6. Insulation part;

[0022] X, width direction; Y, first direction. DETAILED DESCRIPTION

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The exemplary embodiment of the present disclosure provides a battery cell, referring to Figure 1-Figure 4As shown, the battery cell may include a battery case 1, a pole assembly 2 and a battery cell 3; the battery case 1 may include a shell metal layer 11 and a shell insulating layer 12, the shell insulating layer 12 is stacked on the surface of the shell metal layer 11, and the shell metal layer 11 and the shell insulating layer 12 are an integrally formed structure; the pole assembly 2 is insulated and fixed to the battery case 1; the battery cell 3 is arranged in the battery case 1, the battery cell 3 includes a main body 31 and a pole ear portion 32, the pole ear portion 32 is fixedly connected to the pole assembly 2, the pole ear portion 32 includes at least two single-piece pole ears 321, and a protrusion 3211 is arranged on the single-piece pole ear 321, the protrusion is protruding along a first direction Y perpendicular to the large surface of the single-piece pole ear, and the size of the protrusion in the first direction Y is greater than or equal to 20μm and less than or equal to 150μm.

[0028] The battery cell disclosed in the present invention, on the one hand, can increase the strength of the single-piece pole ear 321 through the protrusion 3211, thereby increasing the strength of the pole ear portion 32, avoiding the defect of the pole ear portion 32 being torn under the pulling force of the pole column assembly 2, so as to ensure the electrical connection strength of the battery cell. On the other hand, the size of the protrusion 3211 in the first direction Y is greater than or equal to 20μm and less than or equal to 150μm, which not only ensures that the pole ear portion 32 will not be torn under the pulling force of the pole column assembly 2; but also ensures that the pole ear portion 32 will not occupy a large space inside the battery housing 1, which is conducive to improving the space utilization of the battery housing 1 and the flow of the electrolyte, so that the gas generated during the charging and discharging of the battery cell is also easy to diffuse.

[0029] In this example embodiment, the single battery may be a quadrangular prism battery. Figure 1 As shown, the battery housing 1 of the quadrangular prism battery can be set to a rectangular parallelepiped structure. Specifically, the battery housing 1 may include six wall panels, which are a cover plate 13, a bottom wall plate 14 and four side plates 15. The four side plates 15 are arranged opposite to each other in pairs; the four side plates 15 are connected end to end in sequence to form a rectangular cylindrical shape. The bottom wall plate 14 is connected to one side of the four side plates 15, and the cover plate 13 is connected to the other side of the four side plates 15, so that the cover plate 13, the bottom wall plate 14 and the four side plates 15 surround to form a accommodating cavity.

[0030] Of course, in some other example embodiments of the present disclosure, the bottom wall plate 14 and the cover plate 13 can be set to be circular, elliptical, other polygonal, etc., and the side plate 15 can be set to one or more, and surround to form a cylinder, an elliptical cylinder, other polygonal cylinder, etc., so that the battery housing 1 is formed into a cylindrical shape, an elliptical cylinder shape, other polygonal cylinder shape, etc., so that the single battery is a cylindrical battery, an elliptical cylindrical battery, other polygonal prismatic battery, etc.

[0031] Reference Figure 2As shown, the battery shell 1 may include a shell metal layer 11 and a shell insulating layer 12, and the shell insulating layer 12 is stacked on the surface of the shell metal layer 11, so that the cover plate 13, the bottom wall plate 14 and the four side plates 15 of the battery shell 1 are all a stacked structure of at least two layers including the shell metal layer 11 and at least one layer of shell insulating layer 12.

[0032] It should be noted that the surface of the shell metal layer 11 may be not only the outer surface of the shell metal layer 11 , but also the inner surface of the shell metal layer 11 , or both the outer surface and the inner surface of the shell metal layer 11 .

[0033] The shell metal layer 11 and the shell insulating layer 12 are an integrally formed structure, that is, the shell metal layer 11 and the shell insulating layer 12 are formed by an integral forming process. For example, a layer of insulating film can be formed on a metal plate by bonding, coating, hot melting and other processes, and then the insulating film and the metal plate are simultaneously subjected to a stamping process or a stretching process, so that the insulating film and the metal plate form a battery shell 1 with a accommodating cavity, that is, the metal plate forms the shell metal layer 11, and the insulating film forms the shell insulating layer 12. The integrally formed structure is not to first form a shell metal layer 11 with a accommodating cavity by a stamping process or a stretching process on the metal plate, and then form a shell insulating layer 12 on the shell metal layer 11 by bonding, coating, hot melting and other processes. The integrally formed structure makes the connection between the shell metal layer 11 and the shell insulating layer 12 tighter, and there is almost no gap between the shell metal layer 11 and the shell insulating layer 12. Moreover, the preparation process is relatively simple, which is conducive to improving efficiency.

[0034] The material of the shell metal layer 11 can be stainless steel (SUS304), cold-rolled carbon steel (SPCC / SPCE), copper, titanium, nickel, chromium, aluminum or aluminum alloy, etc. Of course, it can also be other materials, which are not described here one by one.

[0035] In this example implementation, refer to Figure 2 As shown, the pole assembly 2 is insulated and fixed to the battery housing 1. Specifically, the pole assembly 2 can be insulated and fixed to the cover plate 13. The pole assembly 2 may include a battery pole 21 and an adapter 22. Two through holes are provided on the cover plate 13. The pole assembly 2 is provided with two. The two battery poles 21 pass through the two through holes one by one. An insulating member 6 is provided between the two battery poles 21 and the cover plate 13. The insulating member 6 is used to insulate and isolate the two battery poles 21 from the cover plate 13. The battery pole 21 may include a riveted portion, and the battery pole 21 is fixedly connected to the cover plate 13 by the riveted portion. The adapter 22 is provided in the battery housing 1, and the end surface of the battery pole 21 located in the battery housing 1 is welded to the adapter 22.

[0036] Of course, in some other exemplary embodiments of the present disclosure, the pole assembly 2 may not include the adapter plate 22 , but only include the battery pole 21 , and the battery pole 21 is directly welded to the pole ear portion 32 .

[0037] In this example implementation, refer to Figure 2 As shown, a battery cell 3 is arranged in the accommodating cavity of the battery housing 1 . The battery cell 3 is arranged as a rectangular parallelepiped adapted to the battery housing 1 . The battery cell 3 is the smallest unit for charging and discharging a single battery.

[0038] The battery cell 3 may include a body portion 31 and a pole ear portion 32; the body portion 31 may include a first pole piece, a separator and a second pole piece (not shown in the figure) arranged in layers, that is, the battery cell 3 may include a plurality of first pole pieces and second pole pieces arranged in layers, and a separator arranged between the first pole piece and the second pole piece, and the battery cell 3 is a layered type. The battery cell 3 may also be a wound type, and the layered structure formed by the first pole piece, the separator and the second pole piece is wound to form a wound type battery cell 3. Different active materials are coated on the first pole piece and the second pole piece.

[0039] The polarity of the first electrode is opposite to the polarity of the second electrode. For example, the first electrode can be a positive electrode and the second electrode can be a negative electrode. Of course, the first electrode can also be a negative electrode and the second electrode can be a positive electrode. The following description is based on the example that the first electrode is a positive electrode and the second electrode is a negative electrode.

[0040] The tab portion 32 may be a first tab 32a or a second tab 32b. The first tab 32a and the second tab 32b may be led out from the same side of the body portion 31 , for example, the first tab 32a and the second tab 32b may be led out from a first end surface of the body portion 31 .

[0041] Specifically, the first pole ear 32a is connected to the first pole piece, and the first pole ear 32a is located on the side of the first end surface away from the main body 31; a part of the first pole piece may extend out of the main body 31 and be bent to the side of the first end surface away from the main body 31 to form the first pole ear 32a.

[0042] The second pole ear 32b is connected to the second pole piece and is located on the side of the first end surface away from the main body 31. It can be a part of the second pole piece extending out of the main body 31 and bent to the side of the first end surface away from the main body 31 to form the second pole ear 32b.

[0043] It should be noted that the first electrode tab 32a and the second electrode tab 32b are conductive foil areas without active material coating, that is, no active material coating is coated on the first electrode tab 32a and the second electrode tab 32b, and they are current collecting layers for transmitting current.

[0044] The pole ear portion 32 is fixedly connected to the pole assembly 2; specifically, the first pole ear 32a is fixedly connected to one pole assembly 2, so that the pole assembly 2 forms the positive electrode of the battery cell; the second pole ear 32b is fixedly connected to another pole assembly 2, so that the pole assembly 2 forms the negative electrode of the battery cell.

[0045] In order to ensure the space utilization of the battery housing 1 and the energy density of the battery cell, the wall thickness of the battery housing 1 including the housing metal layer 11 and the housing insulation layer 12 is substantially the same as the wall thickness of the battery housing 1 including only the metal layer. Since the strength of the housing insulation layer 12 is relatively low, the strength of the battery housing 1 including the housing metal layer 11 and the housing insulation layer 12 is reduced and is easily deformed. The deformation of the battery housing 1 will cause the pole assembly 2 to be displaced, and the displacement of the pole assembly 2 will generate a pulling force on the pole ear portion 32 connected thereto, thereby causing the pole ear portion 32 to tear, causing the risk of electrical connection failure.

[0046] In this example implementation, refer to Figure 3 and Figure 4 As shown, a protrusion 3211 is provided on the monolithic pole tab 321, and the protrusion 3211 is provided protrudingly along a first direction Y, and the first direction Y is a direction perpendicular to the large surface of the monolithic pole tab 321, and the large surface of the monolithic pole tab 321 is the surface with the largest area of ​​the monolithic pole tab 321. Generally, after forming a battery cell, the large surface of the monolithic pole tab 321 is substantially parallel to the first end surface of the body portion 31.

[0047] The protrusion 3211 can increase the strength of the single-piece pole ear 321, thereby increasing the strength of the pole ear portion 32, avoiding the pole ear portion 32 from being torn under the pulling force of the pole assembly 2, thereby ensuring the electrical connection strength of the battery cell.

[0048] Moreover, the dimension H1 of the protrusion 3211 in the first direction Y is greater than or equal to 20μm and less than or equal to 150μm. For example, the dimension H1 of the protrusion 3211 in the first direction Y can be 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm, 130μm, 135μm, 140μm, or 145μm.

[0049] If the dimension H1 of the protrusion 3211 in the first direction Y is too large, the dimension of the single-piece pole ear 321 in the first direction Y is too large, resulting in the pole ear portion 32 occupying a larger space inside the battery housing 1, which is not conducive to improving the space utilization rate of the battery housing 1; moreover, the gas generated during the charging and discharging of the battery cell is not easy to diffuse, which is not conducive to the flow of the electrolyte.

[0050] If the dimension H1 of the protrusion 3211 in the first direction Y is too small, the protrusion 3211 will have little effect on increasing the strength of the single-piece pole ear 321 , and the pole ear 321 will still be torn under the pulling force of the pole assembly 2 , causing the risk of electrical connection failure.

[0051] The above numerical range not only ensures that the pole ear portion 32 will not be torn under the pulling force of the pole assembly 2; it also ensures that the pole ear portion 32 will not occupy a large space inside the battery shell 1, which is beneficial to improving the space utilization of the battery shell 1 and the flow of the electrolyte, so that the gas generated during the charging and discharging of the battery cell is also easy to diffuse.

[0052] In this example implementation, refer to Figure 3 and Figure 4 As shown, the ratio of the width K of the single-piece pole ear 321 to the dimension H1 of the protrusion 3211 in the first direction Y is greater than or equal to 150 and less than or equal to 4000. For example, the ratio of the width K of the single-piece pole ear 321 to the dimension H1 of the protrusion 3211 in the first direction Y can be 300, 500, 800, 1000, 1200, 1500, 1700, 2000, 2300, 2500, 2800, 3000, 3200, 3500, 3700, etc.

[0053] If the ratio of the width K of the single-piece pole ear 321 to the dimension H1 of the protrusion 3211 in the first direction Y is too large, so that when the width K of the single-piece pole ear 321 is wider, the dimension H1 of the protrusion 3211 in the first direction Y is smaller, resulting in the protrusion 3211 having little effect on increasing the strength of the single-piece pole ear 321. Under the pulling force of the pole assembly 2, the pole ear portion 32 will still be torn, causing the risk of electrical connection failure.

[0054] If the ratio of the width K of the single-piece pole ear 321 to the dimension H1 of the protrusion 3211 in the first direction Y is too small, when the width K of the single-piece pole ear 321 is narrow, the dimension H1 of the protrusion 3211 in the first direction Y is higher, resulting in poor flatness of the pole ear portion 32, affecting the welding between the pole ear portion 32 and the pole assembly 2, and making the welding between the pole ear portion 32 and the pole assembly 2 prone to cracking.

[0055] The above numerical range not only ensures that the pole ear portion 32 will not be torn under the pulling force of the pole assembly 2, but also ensures that the welding between the pole ear portion 32 and the pole assembly 2 will not be easily cracked.

[0056] It should be noted that the width direction X of the single-piece electrode tab 321 is parallel to the connection line L between the single-piece electrode tab 321 and the main body 31 .

[0057] In this example implementation, refer to Figure 3 and Figure 4 As shown, a plurality of protrusions 3211 are provided, and a distance S between two adjacent protrusions 3211 is greater than or equal to 0.01 mm and less than or equal to 5 mm. For example, the distance S between two adjacent protrusions 3211 may be 0.5 mm, 0.7 mm, 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.7 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.7 mm, and the like.

[0058] If the distance S between two adjacent protrusions 3211 is large, the protrusions 3211 will have little effect on increasing the strength of the single-piece pole ear 321. Under the pulling force of the pole assembly 2, the pole ear 32 will still be torn, causing the risk of electrical connection failure.

[0059] If the distance S between two adjacent protrusions 3211 is small, the flatness of the pole ear portion 32 is poor, which affects the welding between the pole ear portion 32 and the pole assembly 2 and makes the welding between the pole ear portion 32 and the pole assembly 2 easy to crack.

[0060] The above numerical range not only ensures that the pole ear portion 32 will not be torn under the pulling force of the pole assembly 2, but also ensures that the welding between the pole ear portion 32 and the pole assembly 2 will not be easily cracked.

[0061] The protrusion 3211 can be formed by stamping, and the protrusion 3211 can be set to a point shape, for example, it can be a spherical segment structure, or it can be set to an ellipsoidal segment structure; the protrusion 3211 can be set to an arc shape, that is, the positive projection of the protrusion 3211 on the pole ear portion 32 can be an arc shape.

[0062] In this example implementation, refer to Figure 2 As shown, the thickness H2 of the pole ear portion 32 is greater than or equal to 4 mm and less than or equal to 16 mm. For example, the thickness of the pole ear portion 32 can be 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, 15 mm, 15.5 mm, etc.

[0063] If the thickness H2 of the pole ear portion 32 is too small, even if the protrusion 3211 strengthens the strength of the single-piece pole ear 321 , the pole ear portion 32 may still be torn under the pulling force of the pole assembly 2 .

[0064] If the thickness H2 of the pole ear portion 32 is too large, the pole ear portion 32 occupies a larger space inside the battery housing 1, which is not conducive to improving the space utilization rate of the battery housing 1; moreover, the gas generated during the charge and discharge of the battery cell is not easy to diffuse, which is not conducive to the flow of the electrolyte.

[0065] The above numerical range not only ensures that the pole ear portion 32 will not be torn under the pulling force of the pole assembly 2; it also ensures that the pole ear portion 32 will not occupy a large space inside the battery shell 1, which is beneficial to improving the space utilization of the battery shell 1 and the flow of the electrolyte, so that the gas generated during the charging and discharging of the battery cell is also easy to diffuse.

[0066] In this example embodiment, the number of electrode sheets with the same polarity of the battery cell 3 is n, and the number of layers of the single-piece electrode sheet 321 included in the electrode ear portion 32 is greater than or equal to n, that is, the number of layers of the single-piece electrode sheet 321 included in the electrode ear portion 32 is greater than or equal to the number of electrode sheets with the same polarity of the battery cell 3. For example, the number of layers of the single-piece electrode sheet 321 included in the first electrode ear 32a is greater than or equal to the number of layers of the first electrode sheet, and the number of layers of the single-piece electrode sheet 321 included in the second electrode ear 32b is greater than or equal to the number of layers of the second electrode sheet.

[0067] Such an arrangement can increase the number of layers of the single-piece pole ear 321, thereby increasing the thickness of the pole ear portion 32, ensuring the strength of the pole ear portion 32, ensuring that the pole ear portion 32 will not be torn under the pulling force of the pole assembly 2; and ensuring the connection strength between the pole ear portion 32 and the pole assembly 2.

[0068] It should be noted that when the battery cell 3 is of a wound type, the number of electrode layers with the same polarity of the battery cell 3 refers to the number of first electrode layers or second electrode layers that are basically parallel to the large surface of the battery cell, and the large surface of the battery cell refers to the side with the largest area of ​​the battery cell.

[0069] Moreover, one electrode layer is connected to at least one single electrode ear 321 to ensure the uniformity of charging and discharging of the electrode.

[0070] In this example implementation, refer to Figure 2 As shown, the pole assembly 2 is welded to the pole ear portion 32. Therefore, the battery cell may further include a welding portion 4, which is disposed between a side of the pole assembly 2 close to the battery cell 3 and the pole ear portion 32. The ratio of the area of ​​the welding portion 4 to the area of ​​the pole ear portion 32 is greater than or equal to 0.4 and less than 1. For example, the ratio of the area of ​​the welding portion 4 to the area of ​​the pole ear portion 32 may be 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, and the like.

[0071] The area of ​​the welding portion 4 is set larger to increase the connection strength between the pole ear portion 32 and the pole assembly 2, to avoid failure of the welding portion 4 between the pole assembly 2 and the pole ear portion 32 when the pole assembly 2 is displaced due to deformation of the battery housing 1, thereby avoiding failure of the electrical connection between the pole assembly 2 and the pole ear portion 32.

[0072] In this example implementation, refer to Figure 2 As shown, the shell insulating layer 12 can be arranged on the outer surface of the shell metal layer 11, that is, the shell insulating layer 12 is arranged farther away from the battery cell 3 than the shell metal layer 11. The shell insulating layer 12 can increase the insulation effect between the battery shell 1 and other external components.

[0073] Of course, in some other exemplary embodiments of the present disclosure, reference Figure 5 As shown, the shell insulating layer 12 can be arranged on the inner surface of the shell metal layer 11, that is, the shell insulating layer 12 is arranged closer to the battery cell 3 relative to the shell metal layer 11. The shell insulating layer 12 can increase the ability of the battery shell 1 to resist electrolyte corrosion, and increase the insulation effect between the battery shell 1 and the battery cell 3.

[0074] In addition, in some other exemplary embodiments of the present disclosure, the shell insulating layer 12 can be provided on the inner surface and the outer surface of the shell metal layer 11, that is, the shell insulating layer 12 can be provided as two layers. The shell insulating layer 12 provided on the inner surface is the inner shell insulating layer, and the shell insulating layer 12 provided on the outer surface is the outer shell insulating layer. The inner shell insulating layer can increase the ability of the battery shell 1 to resist electrolyte corrosion, and increase the insulation effect between the battery shell 1 and the battery cell 3. The outer shell insulating layer can increase the insulation effect between the battery shell 1 and other external components.

[0075] The material of the shell insulating layer 12 may be an inorganic non-metallic material, for example, the material of the shell insulating layer 12 may be Al2O3, SiC, SiO2, etc.

[0076] The material of the shell insulating layer 12 can be a polymer or a resin. For example, the material of the shell insulating layer 12 can be polyethylene (PE), polytetrafluoroethylene (PTFE), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), LCP plastic material (LIQUID CRYSTAL POLYMER, also known as liquid crystal polymer), soluble polytetrafluoroethylene (PFA), acrylonitrile-butadiene-styrene copolymer (ABS), polyphenylene sulfide (PPS), etc.

[0077] In this example embodiment, the ratio of the wall thickness B1 of the shell insulation layer 12 to the wall thickness B2 of the shell metal layer 11 is greater than or equal to 0.3 and less than or equal to 5. For example, the ratio of the wall thickness B1 of the shell insulation layer 12 to the wall thickness B2 of the shell metal layer 11 can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, etc.

[0078] The thickness of the battery case 1 is already determined, that is, the sum of the wall thickness B1 of the shell insulating layer 12 and the wall thickness B2 of the shell metal layer 11 is determined; if the ratio of the wall thickness B1 of the shell insulating layer 12 to the wall thickness B2 of the shell metal layer 11 is too large, the wall thickness B2 of the shell metal layer 11 is too thin, affecting the strength of the battery case 1.

[0079] If the ratio of the wall thickness B1 of the shell insulating layer 12 to the wall thickness B2 of the shell metal layer 11 is too small, the wall thickness B1 of the shell insulating layer 12 is too thin, which affects the insulation effect of the shell insulating layer 12; the shell insulating layer 12 is easily damaged. Once the shell insulating layer 12 is damaged, it is easy to cause a short circuit between the battery cell 3 and the battery shell 1, causing self-discharge of the battery cell.

[0080] The above numerical range not only ensures the strength of the battery case 1, but also ensures the insulation effect of the case insulating layer 12. The case insulating layer 12 is not easily damaged, the battery cell 3 and the battery case 1 will not be short-circuited, and the battery cell will not self-discharge.

[0081] The wall thickness B1 of the shell insulation layer 12 is greater than or equal to 0.02 mm and less than or equal to 0.1 mm. For example, the wall thickness B1 of the shell insulation layer 12 can be 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, 0.05 mm, 0.055 mm, 0.06 mm, 0.065 mm, 0.07 mm, 0.075 mm, 0.08 mm, 0.085 mm, 0.09 mm, 0.095 mm, etc.

[0082] If the wall thickness B1 of the shell insulating layer 12 is too thin, the shell insulating layer 12 is easily damaged. Once the shell insulating layer 12 is damaged, it is easy to cause a short circuit between the battery cell 3 and the battery shell 1, causing the battery cell to self-discharge, and the insulation effect of the shell insulating layer 12 cannot be guaranteed.

[0083] If the wall thickness B1 of the shell insulating layer 12 is too thick, in order to ensure the strength of the battery shell 1, the thickness of the shell metal layer 11 cannot be thinner, so that the shell insulating layer 12 occupies a larger space inside the battery shell 1, affecting the space utilization of the battery shell 1 and the energy density of the battery cell.

[0084] The above numerical range not only ensures the insulation effect of the shell insulating layer 12, but also ensures that the shell insulating layer 12 does not occupy a large space inside the battery shell 1, which is beneficial to improving the space utilization of the battery shell 1 and the energy density of the battery cell.

[0085] 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.

[0086] 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 cell, characterized in that: include: A battery case, comprising a case metal layer and a case insulating layer, wherein the case insulating layer is stacked on the surface of the case metal layer, and the case metal layer and the case insulating layer are an integrally formed structure; A pole assembly, insulated and fixed to the battery housing; A battery cell is arranged in the battery shell, the battery cell includes a main body and a pole ear portion, the pole ear portion is fixedly connected to the pole column assembly, the pole ear portion includes at least two single-piece pole ears, and a protrusion is arranged on the single-piece pole ear. The protrusion is protruded along a first direction perpendicular to the large surface of the single-piece pole ear, and the size of the protrusion in the first direction is greater than or equal to 20μm and less than or equal to 150μm.

2. The battery cell according to claim 1, characterized in that: The ratio of the width of the single-piece tab to the dimension of the protrusion in the first direction is greater than or equal to 150 and less than or equal to 4000, and the width direction of the single-piece tab is parallel to the connection line between the single-piece tab and the main body.

3. The battery cell according to claim 1, characterized in that: The protrusions are provided in plurality, and the distance between two adjacent protrusions is greater than or equal to 0.01 mm and less than or equal to 5 mm.

4. The battery cell according to claim 1, characterized in that: The thickness of the pole ear portion is greater than or equal to 4 mm and less than or equal to 16 mm.

5. The battery cell according to claim 1, characterized in that: The number of electrode layers with the same polarity of the battery cell is n, and the number of layers of the single-piece electrode ears included in the electrode ear part is greater than or equal to n.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The battery cell further comprises: The welding portion is arranged between a surface of the pole assembly close to the battery core and the pole ear portion, and the ratio of the area of ​​the welding portion to the area of ​​the pole ear portion is greater than or equal to 0.4 and less than 1.

7. The battery cell according to any one of claims 1 to 5, characterized in that: The shell insulating layer is arranged on the inner surface and / or the outer surface of the shell metal layer.

8. The battery cell according to any one of claims 1 to 5, characterized in that: The ratio of the wall thickness of the shell insulating layer to the wall thickness of the shell metal layer is greater than or equal to 0.3 and less than or equal to 5.

9. The battery cell according to any one of claims 1 to 5, characterized in that: The wall thickness of the shell insulation layer is greater than or equal to 0.02 mm and less than or equal to 0.1 mm.

10. The battery cell according to any one of claims 1 to 5, characterized in that: The battery cell is a quadrangular prism battery.

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