Battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery. The battery comprises a battery shell and a battery cell, the battery shell comprises a metal shell and an insulating shell which are stacked, the metal shell and the insulating shell are of an integrally molded structure, the battery shell is provided with an inner side surface and an inner bottom surface, a transition surface is connected between the inner side surface and the inner bottom surface, the transition surface is an arc surface, and the central angle of the transition surface is alpha; the battery core is arranged in the battery shell, the insulating shell is closer to the battery core relative to the metal shell, the battery core comprises a main body part, the main body part comprises a first pole piece, an isolating membrane and a second pole piece which are laminated, the isolating membrane at least protrudes out of the first pole piece and the second pole piece at the end part close to the inner bottom surface, and the thickness of the isolating membrane is b; and the ratio of the central angle alpha of the transition surface to the thickness b of the isolating membrane is greater than or equal to 4.5 degrees / mu m and less than or equal to 16 degrees / mu m. The bent and wrinkled size of the isolating membrane of the battery is relatively small, so that the first pole piece and the second pole piece do not have the defects of material falling and short circuit.

Description

Technical Field

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

[0002] The battery casing may include a metal casing and an insulating casing. The relatively low strength of the insulating casing results in a relatively weak supporting strength for the battery cell, causing the isolation membrane at the bottom of the battery cell to be easily bent and wrinkled. When the isolation membrane is bent and wrinkled, the positive and negative electrode sheets are also bent and wrinkled, causing the positive and negative electrode sheets to easily fall off and short-circuit.

[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.

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

[0006] A battery shell, comprising a stacked metal shell and an insulating shell, wherein the metal shell and the insulating shell are an integrally formed structure, the battery shell has an inner side surface and an inner bottom surface, a transition surface is connected between the inner side surface and the inner bottom surface, the transition surface is an arc surface, and the center angle of the transition surface is α;

[0007] A battery cell is arranged in the battery shell, the insulating shell is arranged closer to the battery cell than the metal shell, the battery cell includes a main body, the main body includes a first pole piece, a separation membrane and a second pole piece which are stacked, the separation membrane protrudes from the first pole piece and the second pole piece at least at the end close to the inner bottom surface, the thickness of the separation membrane is b, and the ratio of the central angle α of the transition surface to the thickness b of the separation membrane is greater than or equal to 4.5° / μm and less than or equal to 16° / μm.

[0008] In the battery disclosed in the present invention, on the one hand, the insulating shell is arranged closer to the battery cell than the metal shell, and the insulating shell can increase the ability of the battery shell to resist corrosion by the electrolyte, and increase the insulation effect between the battery shell and the battery cell; on the other hand, the ratio of the central angle α of the transition surface to the thickness b of the isolation membrane is greater than or equal to 4.5° / μm and less than or equal to 16° / μm, which not only ensures that the size of the isolation membrane is small when bent and wrinkled, and will not cause the first pole piece and the second pole piece to bend and wrinkle, so that the first pole piece and the second pole piece will not drop out or short-circuit; but also ensures that the isolation membrane will not affect the overall energy density of the battery.

[0009] 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

[0010] 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.

[0011] Figure 1 It is a schematic diagram of the three-dimensional structure of an exemplary embodiment of the battery disclosed in the present invention.

[0012] Figure 2 A cross-sectional schematic diagram of an exemplary embodiment of a battery disclosed herein.

[0013] Figure 3 FIG. 4 is a cross-sectional schematic diagram of another exemplary embodiment of a battery disclosed herein.

[0014] Figure 4 It is a structural schematic diagram of the battery cell body in a flattened state.

[0015] Description of reference numerals:

[0016] 1. Battery shell; 11. Metal shell; 12. Insulating shell; 13. Inner side surface; 14. Transition surface; 15. Inner bottom surface; 16. Side plate; 17. Bottom wall plate;

[0017] 2. battery cell; 21. main body; 21a. first end surface; 21b. second end surface; 211. first pole piece; 212. isolation film; 213. second pole piece; 22. first pole ear; 23. second pole ear;

[0018] 3. Support plate;

[0019] 4. Cover plate; 5. First pole; 6. Second pole. DETAILED DESCRIPTION

[0020] Example embodiments will now be described more fully with reference to the accompanying drawings. However, 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 descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] The present disclosure provides a battery according to an exemplary embodiment. Figure 1-Figure 4 As shown, the battery may include a battery shell 1 and a battery cell 2; the battery shell 1 may include a metal shell 11 and an insulating shell 12 which are stacked, the metal shell 11 and the insulating shell 12 are an integrally formed structure, the battery shell 1 has an inner side surface 13 and an inner bottom surface 15, a transition surface 14 is connected between the inner side surface 13 and the inner bottom surface 15, the transition surface 14 is set as an arc surface, and the center angle of the transition surface 14 is α; the battery cell 2 is arranged in the battery shell 1, the insulating shell 12 is arranged closer to the battery cell 2 relative to the metal shell 11, the battery cell 2 includes a main body 21, the main body 21 includes a first pole piece 211, a separator 212 and a second pole piece 213 which are stacked, the separator 212 protrudes from the first pole piece 211 and the second pole piece 213 at least at the end close to the inner bottom surface 15, the thickness of the separator 212 is b, and the ratio of the center angle α of the transition surface 14 to the thickness b of the separator 212 is greater than or equal to 4.5° / μm and less than or equal to 16° / μm.

[0025] In the battery disclosed in the present invention, on the one hand, the insulating shell 12 is arranged closer to the battery cell 2 than the metal shell 11, and the insulating shell 12 can increase the ability of the battery shell 1 to resist corrosion by the electrolyte, and increase the insulation effect between the battery shell 1 and the battery cell 2; on the other hand, the ratio of the central angle α of the transition surface 14 to the thickness b of the isolation membrane 212 is greater than or equal to 4.5° / μm and less than or equal to 16° / μm, which not only ensures that the size of the isolation membrane 212 is small when bent and wrinkled, and will not cause the first pole piece 211 and the second pole piece 213 to bend and wrinkle, so that the first pole piece 211 and the second pole piece 213 will not drop out or short-circuit; but also ensures that the isolation membrane 212 will not affect the overall energy density of the battery.

[0026] In this example embodiment, the 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 five wall panels, and the five wall panels are respectively a bottom wall panel 17 and four side panels 16. The four side panels 16 are arranged opposite to each other in pairs; the four side panels 16 are connected end to end in sequence to form a rectangular cylindrical shape. A bottom wall panel 17 is connected to one side of the four side panels 16, so that the bottom wall panel 17 and the four side panels 16 surround to form a accommodating cavity. A cover plate 4 is connected to the other side opposite to the four side panels 16, and the opening of the battery housing 1 is sealed by the cover plate 4.

[0027] Of course, in some other example embodiments of the present disclosure, the bottom wall plate 17 and the cover plate 4 can be set to be circular, elliptical, trapezoidal, etc., and the side plate 16 can be set to one or more, and form a circular, elliptical, trapezoidal, etc. shape around, so that the battery housing 1 is formed into a cylindrical, elliptical column, prismatic, etc.

[0028] Reference Figure 2 and Figure 3As shown, the battery housing 1 may include a metal housing 11 and an insulating housing 12 which are stacked, so that the bottom wall plate 17 and the four side plates 16 of the battery housing 1 are all stacked structures including two layers of a metal layer and an insulating layer. The metal housing 11 and the insulating housing 12 are an integrally formed structure, that is, the metal housing 11 and the insulating housing 12 are formed by an integral forming process. For example, an insulating layer can be formed on a metal plate by bonding, coating, hot melting and other processes, and then the metal plate formed with the insulating layer is subjected to a stamping process or a stretching process, so that the metal plate formed with the insulating layer forms a battery housing 1 with a receiving cavity, that is, the metal plate forms the metal housing 11, and the insulating layer forms the insulating housing 12. The integrally formed structure is not to firstly form a metal housing 11 with a receiving cavity by a stamping process or a stretching process on the metal plate, and then form an insulating housing 12 on the metal housing 11 by bonding, coating, hot melting and other processes. The integrally formed structure makes the connection between the metal housing 11 and the insulating housing 12 tighter, and there is almost no gap between the metal housing 11 and the insulating housing 12. Moreover, the preparation process is relatively simple, which is conducive to improving efficiency.

[0029] The metal shell 11 may be an aluminum shell or an aluminum alloy shell, that is, the material of the metal shell 11 may be aluminum or an aluminum alloy, etc. Of course, it may also be other materials, which will not be described one by one here.

[0030] The material of the insulating shell 12 may be a polymer or a resin. For example, the material of the insulating shell 12 may be polyethylene, polytetrafluoroethylene, polypropylene, polyimide, polyethylene terephthalate, polycarbonate, and the like.

[0031] In this example implementation, refer to Figure 2 and Figure 3 As shown, a battery cell 2 is arranged in the accommodating cavity of the battery housing 1, and the battery cell 2 is arranged as a cuboid adapted to the battery housing 1, and the insulating housing 12 is arranged closer to the battery cell 2 than the metal housing 11, that is, the insulating housing 12 is arranged on the inner surface of the metal housing 11. The insulating housing 12 can increase the ability of the battery housing 1 to resist electrolyte corrosion, and increase the insulation effect between the battery housing 1 and the battery cell 2.

[0032] Reference Figure 2 and Figure 3As shown, the battery housing 1 has an inner side surface 13 and an inner bottom surface 15. Since the insulating housing 12 is arranged on the inner surface of the metal housing 11, the inner side surface 13 of the battery housing 1 refers to the side of the insulating layer of the side plate 16 away from the metal layer. Similarly, the inner bottom surface 15 of the battery housing 1 refers to the side of the insulating layer of the bottom wall plate 17 away from the metal layer. Since the battery housing 1 is formed by a stamping process or a stretching process, a transition surface 14 is connected between the inner side surface 13 and the inner bottom surface 15. The transition surface 14 is set as an arc surface, so that the inner side surface 13 and the inner bottom surface 15 can be smoothly transitioned and connected. The center angle of the transition surface 14 is α, that is, the center angle corresponding to the transition surface 14 is α.

[0033] The battery cell 2 may include a main body 21, a first pole ear 22 and a second pole ear 23. The main body 21 may include a first pole piece 211, a separator 212 and a second pole piece 213 arranged in layers, that is, the battery cell 2 may include a plurality of first pole pieces 211 and second pole pieces 213 arranged in layers (not shown in the figure), and a separator 212 arranged between the first pole piece 211 and the second pole piece 213. The battery cell 2 is a stacked type. The battery cell 2 may also be a wound type, and the stacked structure formed by the first pole piece 211, the separator 212 and the second pole piece 213 is wound to form a wound battery cell 2. Different active materials are coated on the first pole piece 211 and the second pole piece 213.

[0034] The polarity of the first electrode 211 is opposite to that of the second electrode 213. For example, the first electrode 211 can be a positive electrode and the second electrode 213 can be a negative electrode. Of course, the first electrode 211 can also be a negative electrode and the second electrode 213 can be a positive electrode.

[0035] Reference Figure 4 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 213) is larger than the area of ​​the positive electrode sheet (the first electrode sheet 211); in order to ensure the insulation effect between the negative electrode sheet and the positive electrode sheet, the area of ​​the isolation film 212 is greater than or equal to the area of ​​the negative electrode sheet (the second electrode sheet 213). When the isolation film 212, the negative electrode sheet and the positive electrode sheet are in a flattened state, the positive projection of the negative electrode sheet (the second electrode sheet 213) on the isolation film 212 covers and is larger than the positive projection of the positive electrode sheet (the first electrode sheet 211) on the isolation film 212, and the isolation film 212 covers and is larger than the negative electrode sheet (the second electrode sheet 213) on the isolation film.

[0036] In this example embodiment, the isolation membrane 212 protrudes beyond the first pole piece 211 and the second pole piece 213 at least at the end near the inner bottom surface 15. For example, the isolation membrane 212 may protrude beyond the first pole piece 211 and the second pole piece 213 only at the end near the inner bottom surface 15; or the isolation membrane 212 may protrude beyond the first pole piece 211 and the second pole piece 213 not only at the end near the inner bottom surface 15 but also at the end away from the inner bottom surface 15.

[0037] Since the insulating shell 12 has low strength and is easy to deform, it cannot provide good support for the battery cell 2, so that the isolation membrane 212 at the bottom of the battery cell 2 is easy to bend and wrinkle. When the isolation membrane 212 is bent and wrinkled, the first pole piece 211 and the second pole piece 213 are bent and wrinkled, making the first pole piece 211 and the second pole piece 213 prone to material falling off and short circuit.

[0038] In this example embodiment, the thickness of the isolation film 212 is b, and the ratio of the central angle α of the transition surface 14 to the thickness b of the isolation film 212 is greater than or equal to 4.5° / μm and less than or equal to 16° / μm. For example, the ratio of the central angle α of the transition surface 14 to the thickness b of the isolation film 212 can be 5° / μm, 5.5° / μm, 6° / μm, 6.5° / μm, 7° / μm, 7.5° / μm, 8° / μm, 8.5° / μm, 9° / μm, 9.5° / μm, 10° / μm, 10.5° / μm, 11° / μm, 11.5° / μm, 12° / μm, 12.5° / μm, 13° / μm, 13.5° / μm, 14° / μm, 14.5° / μm, 15° / μm, 15.5° / μm and so on.

[0039] If the ratio of the central angle α of the transition surface 14 to the thickness b of the isolation membrane 212 is too small, that is, the central angle α of the transition surface 14 is small and the thickness b of the isolation membrane 212 is thicker, the contact area between the battery cell 2 and the transition surface 14 is small due to the small central angle α of the transition surface 14, and the isolation membrane 212 is not easy to deform due to the thick thickness b of the isolation membrane 212, resulting in the isolation membrane 212 being too large and occupying a large space inside the battery, affecting the overall energy density of the battery.

[0040] If the ratio of the central angle α of the transition surface 14 to the thickness b of the isolation membrane 212 is too large, that is, the central angle α of the transition surface 14 is large and the thickness b of the isolation membrane 212 is thin, the contact area between the battery cell 2 and the transition surface 14 is large due to the large central angle α of the transition surface 14, and the interference size between the isolation membrane 212 and the transition surface 14 is large. In addition, due to the thin thickness of the isolation membrane 212, the strength is low and the size of the bending and wrinkling is large, which makes it difficult to provide stable support for the battery cell 2. The bent and wrinkled isolation membrane 212 drives the first pole piece 211 and the second pole piece 213 to bend and wrinkle, making the first pole piece 211 and the second pole piece 213 prone to material falling off and short circuit defects.

[0041] The above numerical range not only ensures that the isolation membrane 212 has a small size when bent and wrinkled, and will not cause the first pole piece 211 and the second pole piece 213 to bend and wrinkle, so that the first pole piece 211 and the second pole piece 213 will not fall off or short-circuit; but also ensures that the isolation membrane 212 will not affect the overall energy density of the battery.

[0042] In this example embodiment, the elastic modulus of the insulating shell 12 is greater than or equal to 1.1 Gpa and less than or equal to 8 Gpa. For example, the elastic modulus of the insulating shell 12 may be 1.3 Gpa, 1.5 Gpa, 1.8 Gpa, 2 Gpa, 2.2 Gpa, 2.5 Gpa, 2.7 Gpa, 3 Gpa, 3.3 Gpa, 3.5 Gpa, 3.8 Gpa, 4 Gpa, 4.2 Gpa, 4.5 Gpa, 4.7 Gpa, 5 Gpa, 5.3 Gpa, 5.5 Gpa, 5.8 Gpa, 6 Gpa, 6.2 Gpa, 6.5 Gpa, 6.7 Gpa, 7 Gpa, 7.3 Gpa, 7.5 Gpa, 7.8 Gpa and the like.

[0043] The elastic modulus can be regarded as an indicator to measure the ease with which a material undergoes elastic deformation. The larger its value, the greater the stress required to cause a certain elastic deformation of the material, that is, the greater the stiffness of the material, or the smaller the elastic deformation under a certain stress.

[0044] If the elastic modulus of the insulating shell 12 is too large, the rigidity of the insulating shell 12 is too large. When the battery shell 1 is formed by a stamping process or a stretching process, it is difficult for the insulating layer to form the insulating shell 12. Even if the insulating shell 12 is formed, the stress of the insulating shell 12 is relatively large, and even worse, cracks are directly generated in the insulating shell 12.

[0045] If the elastic modulus of the insulating shell 12 is too small, the rigidity of the insulating shell 12 is too small, and it is difficult to provide stable support for the battery cell 2, causing the isolation membrane 212 to bend and wrinkle. The bent and wrinkled isolation membrane 212 drives the first pole piece 211 and the second pole piece 213 to bend and wrinkle, making the first pole piece 211 and the second pole piece 213 prone to material falling off and short circuit.

[0046] The above numerical range not only ensures that the insulating shell 12 provides stable support for the battery cell 2 and prevents the isolation membrane 212 from bending and wrinkling, so as to ensure that the first pole piece 211 and the second pole piece 213 will not fall off or short-circuit; but also ensures that during the stamping or stretching process, the insulating layer can be easily deformed to form the insulating shell 12, and the performance of the insulating shell 12 is better.

[0047] In this example embodiment, the wall thickness H2 of the insulating housing 12 is greater than or equal to 0.04 mm and less than or equal to 0.15 mm. For example, the wall thickness H2 of the insulating housing 12 may be 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.14 mm, etc.

[0048] If the wall thickness H2 of the insulating shell 12 is too large, the thickness of the insulating layer required to form the insulating shell 12 is too large. When the battery shell 1 is formed by a stamping process or a stretching process, the insulating layer is difficult to form the insulating shell 12. Even if the insulating shell 12 is formed, the stress of the insulating shell 12 is relatively large, and even worse, cracks are directly generated in the insulating shell 12. Moreover, the insulating shell 12 occupies a large space inside the battery shell 1, which is not conducive to improving the energy density of the battery.

[0049] If the wall thickness H2 of the insulating shell 12 is too small, the thickness of the insulating layer required to form the insulating shell 12 is too small. When the battery shell 1 is formed by a stamping process or a stretching process, the insulating layer is easily damaged. In addition, when the battery cell 2 is loaded into the battery shell 1, the insulating shell 12 is also easily damaged by friction, which affects the corrosion resistance and insulation of the insulating shell 12.

[0050] The above numerical range not only ensures the corrosion resistance and insulation of the insulating shell 12, but also ensures that during the stamping or stretching process, the insulating layer can be easily deformed to form the insulating shell 12, and the performance of the insulating shell 12 is better and the energy density of the battery is guaranteed.

[0051] In this example embodiment, the thickness of the isolation film 212 is greater than or equal to 8μm and less than or equal to 20μm. For example, the thickness of the isolation film 212 can be 8.5μm, 9μm, 9.5μm, 10μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm, 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, and so on.

[0052] If the thickness of the isolation film 212 is too large, the isolation film 212 occupies a large space, which is not conducive to improving the energy density of the battery.

[0053] If the thickness of the isolation film 212 is too small, the isolation film 212 is prone to bending and wrinkling. The bent and wrinkled isolation film 212 drives the first pole piece 211 and the second pole piece 213 to bend and wrinkle, making the first pole piece 211 and the second pole piece 213 prone to material falling off and short circuit.

[0054] The above numerical range can not only avoid bending and wrinkling of the isolation film 212 as much as possible, so as to ensure that the first pole piece 211 and the second pole piece 213 will not fall off or short-circuit, but also ensure the energy density of the battery.

[0055] In this example embodiment, the central angle α of the transition surface 14 is greater than or equal to 90° and less than or equal to 150°. For example, the central angle α of the transition surface 14 can be 92°, 95°, 97°, 100°, 103°, 105°, 108°, 110°, 112°, 115°, 117°, 120°, 123°, 125°, 128°, 130°, 132°, 135°, 137°, 140°, 143°, 145°, 148°, etc.

[0056] If the central angle α of the transition surface 14 is too large, the contact area between the battery cell 2 and the transition surface 14 will be large, the interference size between the isolation membrane 212 and the transition surface 14 will be large, and the isolation membrane 212 will be bent and wrinkled to a large extent, making it difficult to provide stable support for the battery cell 2. The bent and wrinkled isolation membrane 212 will drive the first pole piece 211 and the second pole piece 213 to bend and wrinkle, making it easy for the first pole piece 211 and the second pole piece 213 to fall off and short-circuit.

[0057] If the central angle α of the transition surface 14 is too small, the contact area between the battery cell 2 and the transition surface 14 is small, and the isolation membrane 212 is not easy to deform, resulting in the isolation membrane 212 being too large and occupying a large space inside the battery, affecting the overall energy density of the battery.

[0058] The above numerical range not only ensures that the isolation membrane 212 has a small size when bent and wrinkled, and will not cause the first pole piece 211 and the second pole piece 213 to bend and wrinkle, so that the first pole piece 211 and the second pole piece 213 will not fall off or short-circuit; but also ensures that the isolation membrane 212 will not affect the overall energy density of the battery.

[0059] In this example embodiment, the ratio of the wall thickness H2 of the insulating shell 12 to the wall thickness H1 of the metal shell 11 is greater than or equal to 0.08 and less than or equal to 0.2. The ratio of the wall thickness H2 of the insulating shell 12 to the wall thickness H1 of the metal shell 11 can be 0.1, 0.12, 0.15, 0.17, etc.

[0060] If the ratio of the wall thickness H2 of the insulating shell 12 to the wall thickness H1 of the metal shell 11 is too large, the wall thickness H1 of the metal shell 11 is too small, resulting in too low strength of the battery shell 1; or the wall thickness of the insulating shell 12 is too large, resulting in a slow heat conduction rate between the battery cell 2 and the metal shell 11, which is not conducive to the heat dissipation of the battery cell 2.

[0061] If the ratio of the wall thickness H2 of the insulating shell 12 to the wall thickness H1 of the metal shell 11 is too small, the wall thickness H2 of the insulating shell 12 is too small, causing the insulating shell 12 to be easily damaged, thereby affecting the corrosion resistance and insulation of the insulating shell 12 .

[0062] The above numerical range not only ensures the strength of the battery shell 1 and the heat conduction rate between the battery cell 2 and the metal shell 11, which is beneficial to the heat dissipation of the battery cell 2; but also prevents the insulating shell 12 from being easily damaged, thereby ensuring the corrosion resistance and insulation of the insulating shell 12.

[0063] In this example implementation, refer to Figure 3 As shown, the battery may further include a support plate 3, which is disposed between the battery cell 2 and the inner bottom surface 15, and is used to support the battery cell 2; a ratio of a thickness H3 of the support plate 3 to a curvature radius R of the transition surface 14 is greater than or equal to 0.5 and less than or equal to 1, for example, a ratio of a thickness H3 of the support plate 3 to a curvature radius R of the transition surface 14 may be 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, and the like.

[0064] The support plate 3 can appropriately lift the battery cell 2 so that the battery cell 2 can avoid the transition surface 14, thereby preventing the isolation membrane 212 of the battery cell 2 close to the inner bottom surface 15 from interfering with the transition surface 14 and bending and wrinkling, thereby preventing the isolation membrane 212 from bending and wrinkling and causing the positive and negative electrodes to bend and wrinkle, thereby ensuring that the positive and negative electrodes are not prone to material shedding and short circuit defects.

[0065] The support plate 3 can provide a relatively flat base surface for the battery cell 2, so as to prevent the battery cell 2 from tilting and causing the separator 212 to bend and wrinkle, which in turn causes the positive and negative electrode sheets to bend and wrinkle, thereby ensuring that the positive and negative electrode sheets are not prone to material dropout and short circuit. In addition, the distance between each part of the battery cell 2 and the inner side surface 13 of the battery housing 1 is basically consistent, so as to ensure that the expansion space of each part of the battery cell 2 is consistent during the charging and discharging process.

[0066] If the ratio of the thickness H3 of the support plate 3 to the curvature radius R of the transition surface 14 is too small, the thickness H3 of the support plate 3 is too small, resulting in that the size of the battery cell 2 that can avoid the transition surface 14 is too small.

[0067] If the ratio of the thickness H3 of the support plate 3 to the curvature radius R of the transition surface 14 is too large, the thickness H3 of the support plate 3 is too large, and the space inside the battery housing 1 is too large, which is not conducive to improving the energy density of the battery.

[0068] The above numerical range not only ensures that the battery cell 2 can avoid the transition surface 14 and provide a relatively flat base surface for the battery cell 2 , but also does not affect the energy density of the battery.

[0069] When the curvature radius R of the transition surface 14 is constant, the thickness of the support plate 3 is proportional to the central angle α of the transition surface 14, that is, the central angle α of the transition surface 14 is set larger, so that the arc length from the inner side surface 13 to the inner bottom surface 15 of the transition surface 14 is longer, and the thickness H3 of the support plate 3 can be set thicker, so that the battery cell 2 can avoid the transition surface 14; the central angle α of the transition surface 14 is set smaller, so that the arc length from the inner side surface 13 to the inner bottom surface 15 of the transition surface 14 is shorter, and the thickness H3 of the support plate 3 can be set thinner, so that the battery cell 2 can avoid the transition surface 14.

[0070] In this example implementation, refer to Figure 2 and Figure 3 As shown, the main body 21 has a first end face 21a and a second end face 21b that are arranged opposite to each other, and the second end face 21b is closer to the inner bottom face 15 than the first end face 21a, that is, the first end face 21a can be the top face of the main body 21, and the second end face 21b can be the bottom face of the main body 21. One end of the main body 21 where the first end face 21a is arranged is the first end, and one end of the main body 21 where the second end face 21b is arranged is the second end.

[0071] The first electrode tab 22 and the second electrode tab 23 may be disposed on a side of the first end surface 21 a away from the main body 21 , that is, the first electrode tab 22 and the second electrode tab 23 are led out from the same side of the main body 21 .

[0072] Specifically, the first pole ear 22 is connected to the first pole piece 211, and the first pole ear 22 is located on the side of the first end face 21a away from the main body 21; a part of the first pole piece 211 may extend out of the main body 21 and be bent to the side of the first end face 21a away from the main body 21 to form the first pole ear 22.

[0073] The second pole ear 23 is connected to the second pole piece 213 and is located on the side of the first end face 21a away from the main body 21 . A portion of the second pole piece 213 may extend out of the main body 21 and bend to the side of the first end face 21a away from the main body 21 to form the second pole ear 23 .

[0074] It should be noted that the first pole tab 22 and the second pole tab 23 are conductive foil areas without active material coating, that is, no active material coating is coated on the first pole tab 22 and the second pole tab 23, and they are current collecting layers for transmitting current.

[0075] The first pole tab 22 is connected to the first pole 5, so that the first pole 5 forms the positive pole of the battery; the second pole tab 23 is connected to the second pole 6, so that the second pole 6 forms the negative pole of the battery.

[0076] The second electrode sheet 213 is a negative electrode sheet. At the second end near the inner bottom surface 15, the dimension H4 of the isolation membrane 212 extending beyond the negative electrode sheet is less than or equal to 1.6 mm. For example, the dimension H4 of the isolation membrane 212 extending beyond the negative electrode sheet may be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, etc.

[0077] If the isolation film 212 is too large beyond the size H4 of the negative electrode sheet, the strength of the isolation film 212 will be reduced, and the isolation film 212 will be easily bent and wrinkled. After the isolation film 212 is bent and wrinkled, the positive electrode sheet and the negative electrode sheet will bend and wrinkled, causing the positive electrode sheet and the negative electrode sheet to easily fall off and short-circuit.

[0078] The above numerical range can prevent the isolation film 212 from being easily bent or wrinkled, and will not cause the first pole piece 211 and the second pole piece 213 to bend or wrinkled, so that the first pole piece 211 and the second pole piece 213 will not fall off or short-circuit.

[0079] 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.

[0080] 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 modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes 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: A battery shell, comprising a stacked metal shell and an insulating shell, wherein the metal shell and the insulating shell are an integrally formed structure, the battery shell has an inner side surface and an inner bottom surface, a transition surface is connected between the inner side surface and the inner bottom surface, the transition surface is an arc surface, and the center angle of the transition surface is α; A battery cell is arranged in the battery shell, the insulating shell is arranged closer to the battery cell than the metal shell, the battery cell includes a main body, the main body includes a first pole piece, a separation membrane and a second pole piece which are stacked, the separation membrane protrudes from the first pole piece and the second pole piece at least at the end close to the inner bottom surface, the thickness of the separation membrane is b, and the ratio of the central angle α of the transition surface to the thickness b of the separation membrane is greater than or equal to 4.5° / μm and less than or equal to 16° / μm.

2. The battery according to claim 1, characterized in that The elastic modulus of the insulating shell is greater than or equal to 1.1 GPa and less than or equal to 8 GPa.

3. The battery according to claim 1, characterized in that The wall thickness of the insulating shell is greater than or equal to 0.04 mm and less than or equal to 0.15 mm.

4. The battery according to claim 1, characterized in that The thickness of the isolation film is greater than or equal to 8 μm and less than or equal to 20 μm.

5. The battery according to claim 1, characterized in that The central angle α of the transition surface is greater than or equal to 90° and less than or equal to 150°.

6. The battery according to claim 1, characterized in that The ratio of the wall thickness of the insulating shell to the wall thickness of the metal shell is greater than or equal to 0.08 and less than or equal to 0.

2.

7. The battery according to any one of claims 1 to 6, characterized in that: The battery also includes: A support plate is provided between the battery core and the inner bottom surface, and a ratio of a thickness of the support plate to a radius of curvature of the transition surface is greater than or equal to 0.5 and less than or equal to 1.

8. The battery according to claim 7, characterized in that The thickness of the support plate is proportional to the central angle α of the transition surface.

9. The battery according to any one of claims 1 to 6, characterized in that: The battery cell also includes a first pole ear and a second pole ear, the main body has a first end face and a second end face arranged opposite to each other, the second end face is closer to the inner bottom face than the first end face, and the first pole ear and the second pole ear are arranged on the side of the first end face away from the main body; the second pole sheet is a negative pole sheet, and at the end close to the inner bottom face, the isolation membrane exceeds the negative pole sheet by a size less than or equal to 1.6 mm.

10. The battery according to any one of claims 1 to 6, characterized in that: The metal shell is an aluminum shell or an aluminum alloy shell, and / or the insulating shell is made of a polymer or a resin.

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