Battery cell and battery pack

Abstract

The utility model discloses a battery cell and a battery pack, and relates to the technical field of batteries. The battery core comprises a pole core and a bottom supporting plate, and the bottom supporting plate is arranged at the bottom of the pole core; the bottom supporting plate comprises a first plate body and a second plate body, the first plate body is arranged on at least part of the circumferential outer side of the second plate body in a surrounding mode, the first plate body is connected with the pole core, the second plate body makes contact with the pole core, and the porosity of the second plate body is larger than that of the first plate body. The bottom supporting plate is divided into two parts with different porosities, so that the first plate body surrounds at least part of the circumferential outer side of the second plate body, the first plate body is connected with the pole core, and the pole core is fixedly supported by the first plate body; meanwhile, the porosity of the second plate body is set to be larger than that of the first plate body, so that the second plate body can absorb impact energy through plastic deformation when being impacted. Therefore, the overall weight of the bottom supporting plate can be reduced while the bottom supporting plate supports the pole core, so that the weight of the battery cell is reduced; and the reliability and the safety of the battery cell can also be improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a battery cell and a battery pack. Background Technology

[0002] With the widespread application of batteries in mobile phones, digital products, laptops, drones, model aircraft, power tools, military industry, new energy vehicles, portable energy storage and medical equipment, the domestic battery industry has achieved rapid development.

[0003] The battery cell includes an electrode core and a base plate located at the bottom of the electrode core. The base plate is used to support and fix the electrode core. In related technologies, the base plate is too heavy and has poor shock absorption capacity, thus failing to provide adequate protection for the electrode core. Utility Model Content

[0004] This application aims to provide a battery cell and battery pack that can solve the problem in related technologies where the base plate is too heavy and has poor shock absorption capacity, thus failing to provide adequate protection for the battery core.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose a battery cell, comprising: an electrode core and a bottom support plate, wherein the bottom support plate is disposed at the bottom of the electrode core; the bottom support plate comprises a first plate body and a second plate body, the first plate body being disposed around at least a portion of the circumferential outer side of the second plate body, the first plate body being connected to the electrode core, the second plate body being in contact with the electrode core, and the porosity of the second plate body being greater than the porosity of the first plate body.

[0007] Optionally, the second plate comprises a homogenized lattice structure.

[0008] Optionally, the homogenized lattice structure of the second plate is one of the following: Diamond type, Double pyramid type, Octet type, or Star type lattice.

[0009] Optionally, the height direction of the battery cell is a first direction, and the orthographic projection of the second plate on a plane perpendicular to the first direction is located within the orthographic projection of the base plate on a plane perpendicular to the first direction.

[0010] Optionally, the thickness of the first plate is equal to the thickness of the second plate.

[0011] Optionally, the electrode core includes an electrode core body and an insulating film, the insulating film covering at least a portion of the outer peripheral surface of the electrode core body, and the first plate body being at least partially fixedly connected to the insulating film.

[0012] Optionally, the first plate has a plurality of hot-melt sections, which are arranged at intervals around the second plate, and the hot-melt sections are fixedly connected to the insulating film.

[0013] Optionally, the first plate and / or the second plate are provided with positioning holes, which are used to position the pole core.

[0014] Optionally, the battery cell further includes a housing and an explosion-proof valve. The housing has a receiving cavity, and the bottom support plate and the electrode core are both disposed in the receiving cavity. The bottom support plate is disposed between the electrode core and the bottom of the receiving cavity. The explosion-proof valve is installed in the housing and corresponds to the second plate.

[0015] And / or, the first plate and the second plate are integrally formed parts or separate formed parts.

[0016] Secondly, embodiments of this application provide a battery pack comprising: a battery cell as described in any of the preceding claims.

[0017] In embodiments of this application, the battery cell includes an electrode core and a base plate, with the base plate disposed at the bottom of the electrode core. The base plate includes a first plate and a second plate, with the first plate surrounding at least a portion of the second plate circumferentially outward. The first plate is connected to the electrode core, and the second plate is in contact with the electrode core. The porosity of the second plate is greater than that of the first plate. By dividing the base plate into two parts with different porosities, the first plate surrounds at least a portion of the second plate circumferentially outward. The first plate is connected to the insulating film of the electrode core, thereby providing a fixed support for the electrode core. Simultaneously, since a plate with a larger porosity has a greater compression capacity and a better ability to absorb impact energy, while a plate with a smaller porosity has higher strength, by setting the porosity of the second plate to be greater than that of the first plate, the second plate can absorb more impact energy through plastic deformation when subjected to impact, while ensuring the fixed support of the base plate for the electrode core and guaranteeing the support strength. In this way, while meeting the strength requirements of the bottom support plate for the electrode core, it can absorb more impact energy, thereby improving the reliability and safety of the battery cell.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is an exploded schematic diagram of a battery cell according to an embodiment of this application;

[0021] Figure 2 This is a structural schematic diagram of a first type of base plate according to an embodiment of this application;

[0022] Figure 3 According to the embodiments of this application Figure 2 An explosion diagram;

[0023] Figure 4 According to the embodiments of this application, along Figure 2 Sectional view of line AA in the middle;

[0024] Figure 5 This is a front view schematic diagram of the base plate according to an embodiment of this application;

[0025] Figure 6 This is a cross-sectional view of a second type of base plate according to an embodiment of this application;

[0026] Figure 7 This is a front view schematic diagram of a third type of base plate according to an embodiment of this application.

[0027] Figure label:

[0028] 10: Electrode core; 101: Electrode core body; 102: Insulating film; 11: Base plate; 111: First plate; 1111: Hot melt section; 112: Second plate; 113: Positioning hole; 13: Housing; 14: Top cover; 15: Connecting piece; 16: Top patch; X: First direction. Detailed Implementation

[0029] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0030] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0031] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0033] Before explaining the battery cells and battery packs provided in the embodiments of this application, the application scenarios of the battery cells and battery packs provided in the embodiments of this application will be specifically described:

[0034] In batteries (especially power batteries or large battery packs), batteries typically include electrode cores, casings, and a bottom support plate located between the electrode cores and the bottom of the casings. The bottom support plate is a key structural component that supports and protects the battery cells, and its function and structural design directly affect the battery's safety, thermal management performance, and overall mechanical strength.

[0035] In related technologies, the base plate is usually made of PP material or composite material in one piece, which is heavy and makes the whole battery heavy. It also has poor shock absorption capacity and cannot provide good protection for the electrode core.

[0036] Therefore, this application provides a battery cell and a battery pack. The following description, in conjunction with the accompanying drawings, details the battery cell and battery pack provided in this application through specific embodiments and application scenarios.

[0037] like Figure 1 and Figure 2As shown, according to some embodiments of this application, the battery cell includes an electrode core 10 and a bottom support plate 11. The bottom support plate 11 is disposed at the bottom of the electrode core 10. The bottom support plate 11 includes a first plate 111 and a second plate 112. The first plate 111 is disposed around at least a portion of the circumferential outer side of the second plate 112. The first plate 111 is connected to the electrode core 10, and the second plate 112 is in contact with the electrode core 10. The porosity of the second plate 112 is greater than that of the first plate 111.

[0038] In this embodiment, the base plate 11 is divided into two parts with different porosities. The first plate 111 surrounds at least a portion of the second plate 112 circumferentially outward. The first plate 111 is connected to the electrode core 10 to provide fixed support for the electrode core 10. Simultaneously, the porosity of the second plate 112 is set to be greater than that of the first plate 111, so that the second plate 112 can absorb impact energy through plastic deformation when subjected to impact. In this way, while satisfying the fixed support and strength requirements of the base plate 11 for the electrode core 10, more impact energy can be absorbed, improving the reliability and safety of the battery cell. Furthermore, the overall weight of the base plate 11 can be reduced, thereby reducing the weight of the battery cell.

[0039] In specific applications, the bottom support plate 11 is located at the bottom of the pole core 10, and the first plate 111 is connected to the pole core 10. Specifically, the connection can be achieved by hot-melt connection, bonding, ultrasonic welding, etc., so that the first plate 111 can be connected to the pole core 10 to provide support for the pole core 10. At the same time, the first plate 111 and the second plate 112 can protect the pole core 10, and the second plate 112 is more prone to plastic deformation, so the second plate 112 is more likely to absorb impact energy.

[0040] It should be noted that the aforementioned impact could be an external impact on the electrode core 10, or it could be gas escaping from the explosion-proof valve when the electrode core 10 experiences thermal runaway. The second plate 112 can absorb both external impacts on the electrode core 10 and impacts from the explosion-proof valve when the electrode core 10 experiences thermal runaway, thereby improving the safety and reliability of the battery cell. Simultaneously, because the second plate 112 is in contact with the electrode core 10 and has a large porosity, it can attenuate mechanical vibrations, thereby mitigating the vibration of the electrode core 10 and improving its reliability.

[0041] In some embodiments of this application, the second plate 112 comprises a homogenized lattice structure.

[0042] In this embodiment of the application, by setting the second plate 112 to include a homogenized lattice structure, the second plate 112 can have the physical characteristics of a homogenized lattice structure, thereby absorbing impact energy and improving the safety and reliability of the battery cell.

[0043] It should be explained that the second plate 112 can be made of homogenized plastic material or composite material, etc., with high porosity; or it can be made of high porosity plate material by additive manufacturing (AM), that is, 3D printing technology. For example, the second plate 112 is designed as a porous lattice structure with periodic or gradient split by homogenization lattice method, so that the second plate 112 has high porosity and suitable structural strength.

[0044] It should be noted that the homogenization lattice method is to form a specific lattice design through topology optimization and computational materials science methods. The aim is to optimize the porosity and arrangement of molecules inside the material without changing the structural shape, so that it has the mechanical properties of a uniform lattice structure throughout the entire volume.

[0045] The following is a brief description of the fabrication of the second plate 112 using 3D printing and homogenization lattice methods:

[0046] First, in the Ansys software's Workbench, define the specific structure and properties of a crystal lattice structure;

[0047] Secondly, multiple lattice structures are constructed into a second plate 112 by equivalent homogenization;

[0048] Next, the mechanical properties of the constructed second plate 112 are analyzed using simulation software;

[0049] Finally, the second plate 112 is manufactured by printing using 3D printing technology.

[0050] In some embodiments of this application, the homogenized lattice structure of the second plate 112 is one of the following: Diamond type, Doublepyramid type, Octet type, or Star type lattice.

[0051] In this embodiment of the application, by setting the homogenized lattice structure of the second plate 112 to one of the Diamond type, Double pyramid type, Octet type or Star type lattice, the second plate 112 can have the physical characteristics of the above-mentioned homogenized lattice structure, thereby absorbing energy shock and having corresponding structural strength, so as to improve the safety and reliability of the battery cell.

[0052] It should be noted that the unit cell structure of the homogenized lattice structure can be any type of unit cell structure, as detailed below:

[0053] The diamond-shaped structure is composed of multiple spherical structures and multiple connecting rods. Each face of the unit cell is on the same plane as a quarter-cut facet of a sphere, and the rods do not contact the unit cell faces or edges, but only serve to connect the spheres.

[0054] The double pyramid type is a structure consisting of two pyramids joined together by six hemispheres and multiple connecting rods. Each face of the unit cell is on the same plane as the cut surface of a hemisphere, and there are no connecting rods inside the structure.

[0055] The octet type is a unit cell structure based on the double pyramid type, with a 1 / 8 sphere designed at each corner of the cube. Each face of the unit cell is on the same plane as the cutting face of the 1 / 8 sphere. At the same time, each face is added with a 1 / 2 rod connecting the central hemisphere and the 1 / 8 sphere at the corner, and the cutting face of the rod is on the same plane as the face of the unit cell.

[0056] Star-type lattice, with a unit cell structure of a cube retaining only the frame. Inside the cube is a complete sphere, and at each corner of the cube is a 1 / 8 sphere connected to the central complete sphere by cylindrical rods. The facets of the 1 / 8 spheres are on the same plane as the unit cell facets.

[0057] Of course, it can also be a simple cubic lattice, a body-centered cubic lattice, a simple hexagonal lattice, etc., so that the second plate 112 can have the physical characteristics of a single-cell lattice structure and a certain porosity. Those skilled in the art can choose according to actual needs, and this application does not limit it.

[0058] In specific applications, the first plate 111 is disposed around at least a portion of the circumferential outer side of the second plate 112, such that the first plate 111 surrounds the entire outer periphery of the second plate 112. Figure 3 As shown; alternatively, there can be two first plates 111, with a second plate 112 sandwiched between the two first plates 111, and the first plates 111 can cover at least a portion of the circumferential edge of the second plate 112, such as... Figure 6 and Figure 7 As shown, this facilitates the connection between the first plate 111 and the pole core 10.

[0059] In some embodiments of this application, the porosity P of the second plate 112 satisfies: 20% ≤ P ≤ 90%.

[0060] In this embodiment of the application, by setting the porosity P of the second plate 112 within a reasonable range, the second plate 112 can absorb impact while ensuring its own structural strength.

[0061] It should be explained that when the porosity P of the second plate 112 is less than 20%, the overall weight of the second plate 112 will be large, making it impossible to achieve lightweighting, and it will also not be able to absorb impact well; while when the porosity P of the second plate 112 is greater than 90%, the overall structural strength of the second plate 112 will be poor, thus affecting the overall safety of the battery cell.

[0062] In specific applications, the porosity P of the second plate 112 can be set to any value or a range between two arbitrary values, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%.

[0063] In some embodiments of this application, the elastic modulus E of the second plate 112 satisfies: 3.4 × 10⁻⁶. 3 MPa≤E≤8×10 3 MPa.

[0064] In this embodiment of the application, by setting the elastic modulus E of the second plate 112 within a reasonable range, it is possible to ensure the overall rigidity of the second plate 112 while ensuring the buffering of the pole core 10.

[0065] It should be explained that when the elastic modulus E of the second plate 112 is less than 3.4 × 10⁻⁶, 3 When the elastic modulus E of the second plate 112 is too small at MPa, it makes the second plate 112 more prone to deformation, but its stiffness is insufficient, thus failing to provide good support for the pole core 10; while when the elastic modulus E of the second plate 112 is greater than 8 × 10 MPa... 3 When the elastic modulus E of the second plate 112 is too large at MPa, the second plate 112 will be unable to undergo effective plastic deformation, thus failing to absorb impact well.

[0066] In specific applications, the elastic modulus E of the second plate 112 can be set to: 3.4 × 10⁻⁶. 3 MPa, 4×10 3 MPa, 5×10 3 MPa, 6×10 3 MPa, 7×10 3 MPa, 8×10 3 Any value such as MPa or a range between two arbitrary values.

[0067] It should be noted that in actual design, the elastic modulus E of the second plate 112 can be set within the required range during equivalent homogenization using Ansys software. After the equivalent homogenization is completed, relevant experimental verification can be carried out through simulation.

[0068] In some embodiments of this application, the Poisson's ratio ν of the second plate 112 satisfies: 0.25≤ν≤0.35.

[0069] In this embodiment, by setting the Poisson's ratio ν of the second plate 112 within a reasonable range, it is possible to ensure that the second plate 112 can undergo sufficient plastic deformation to absorb the impact, while reducing the risk of the second plate 112 breaking due to deformation when bearing the pole core 10.

[0070] It should be explained that when the Poisson's ratio ν of the second plate 112 is less than 0.25, that is, when the Poisson's ratio ν of the second plate 112 is too small, the second plate 112 will not be able to undergo sufficient plastic deformation to absorb the impact; while when the Poisson's ratio ν of the second plate 112 is greater than 0.35, that is, when the Poisson's ratio ν of the second plate 112 is too large, the second plate 112 will break when bearing the pole core 10.

[0071] In specific applications, the Poisson's ratio ν of the second plate 112 can be set to any value or a range between two arbitrary values, such as 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35.

[0072] It should be noted that in actual design, the Poisson's ratio ν of the second plate 112 can be set within the required range during equivalent homogenization using Ansys software. After the equivalent homogenization is completed, relevant experimental verification can be carried out through simulation.

[0073] In some embodiments of this application, the shear modulus G of the second plate 112 satisfies: 2.7 × 10⁻⁶ 3 MPa≤G≤5×10 3 MPa.

[0074] In this embodiment of the application, by setting the shear modulus G of the second plate 112 within a reasonable range, it is possible to ensure the energy absorption capacity of the second plate 112 while reducing the possibility of structural instability or failure of the second plate 112.

[0075] It should be explained that when the shear modulus G of the second plate 112 is less than 2.7 × 10⁻⁶, 3 When the shear modulus G of the second plate 112 is too small (MPa), the second plate 112 is prone to large deformation, which can lead to structural instability or failure and fail to provide sufficient support for the pole core 10. Conversely, when the shear modulus G of the second plate 112 is greater than 5 × 10 MPa... 3 When the shear modulus G of the second plate 112 is too large at MPa, the second plate 112 has a low ability to absorb energy during deformation and is prone to brittle fracture.

[0076] In specific applications, the shear modulus G of the second plate 112 can be set to: 2.7 × 10⁻⁶. 3 MPa, 3×10 3 MPa, 3.5×10 3 MPa, 4×10 3 MPa, 4.5×10 3 MPa, 5×10 3 Any value such as MPa or a range between two arbitrary values.

[0077] like Figure 1 , Figure 3 and Figure 5 As shown, in some embodiments of this application, the height direction of the battery cell is the first direction X, and the orthographic projection of the second plate 112 on the plane perpendicular to the first direction X is located within the orthographic projection of the base plate 11 on the plane perpendicular to the first direction X.

[0078] In this embodiment of the application, by setting the orthographic projection of the second plate 112 on the plane perpendicular to the first direction X in the orthographic projection plane of the base plate 11 on the plane perpendicular to the first direction X, it is possible to ensure the effective absorption of impact energy by the base plate 11 while ensuring the reliability of the connection between the base plate 11 and the pole core 10.

[0079] like Figure 1 , Figure 3 and Figure 5 As shown, in some embodiments of this application, the height direction of the battery cell is the first direction X, and the orthographic projection area of ​​the second plate 112 on a plane perpendicular to the first direction X is S1mm. 2 The orthographic projection area of ​​the base plate 11 on a plane perpendicular to the first direction X is S2mm. 2 The condition is satisfied that 0.2 ≤ S1 / S2 ≤ 0.8.

[0080] In this embodiment of the application, by setting the ratio S1 / S2 between the orthogonal projection area S1 of the second plate 112 on the plane perpendicular to the first direction X and the orthogonal projection area S2 of the base plate 11 on the plane perpendicular to the first direction X within a reasonable range, it is possible to ensure the effective absorption of impact energy by the base plate 11 while ensuring the reliable connection between the base plate 11 and the pole core 10.

[0081] In specific applications, the first direction X specifically refers to the height direction of the battery cell, which is also the thickness direction of the base plate 11. The orthogonal projection area S1 of the second plate 112 on the plane perpendicular to the first direction X is the cross-sectional area of ​​the second plate 112 in the thickness direction. Similarly, the orthogonal projection area S2 of the base plate 11 on the plane perpendicular to the first direction X is the cross-sectional area of ​​the base plate 11 in the thickness direction.

[0082] It should be noted that when the ratio S1 / S2 between the projected area S1 of the second plate 112 on the plane perpendicular to the first direction X and the projected area S2 of the base plate 11 on the plane perpendicular to the first direction X is less than 0.2, that is, when the second plate 112 is too small, the contact area between the second plate 112 and the pole core 10 will be too small, thus preventing the second plate 112 from effectively absorbing impact energy. Conversely, when the ratio S1 / S2 between the projected area S1 of the second plate 112 on the plane perpendicular to the first direction X and the projected area S2 of the base plate 11 on the plane perpendicular to the first direction X is greater than 0.8, that is, when the second plate 112 is too large, the second plate 112 will occupy too much space on the base plate 11, thus leaving insufficient space for the first plate 111 to connect with the pole core 10, reducing the reliability of the connection.

[0083] In specific applications, the ratio S1 / S2 between the orthographic projection area S1 of the second plate 112 on the plane perpendicular to the first direction X and the orthographic projection area S2 of the base plate 11 on the plane perpendicular to the first direction X can be set to any value such as 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or a range between two arbitrary values.

[0084] like Figure 4 and Figure 6 As shown, in some embodiments of this application, the thickness of the base plate 11 is d, which satisfies: 0.15mm≤d≤0.3mm.

[0085] In this embodiment of the application, by setting the thickness d of the bottom support plate 11 within a reasonable range, the space occupied by the bottom support plate 11 in the height direction of the battery cell can be reduced while ensuring that the second plate 112 can effectively absorb the impact energy.

[0086] It should be explained that when the thickness d of the base plate 11 is less than 0.15mm, that is, when the thickness of the base plate 11 is too small, the base plate 11 cannot effectively absorb the impact energy, nor can it provide good support for the electrode core 10. When the thickness d of the base plate 11 is greater than 0.3mm, the base plate 11 will occupy too much space in the height direction of the cell, thus affecting the capacity of the cell at the same height.

[0087] In specific applications, the thickness d of the base plate 11 can be set to any value or a range between two arbitrary values, such as 0.15mm, 0.18mm, 0.20mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm, 0.3mm.

[0088] like Figure 4 and Figure 6 As shown, in some embodiments of this application, the thickness of the first plate 111 is equal to the thickness of the second plate 112.

[0089] In this embodiment of the application, by setting the thickness of the first plate 111 to be equal to the thickness of the second plate 112, it is easier to process and at the same time, the bottom support plate 11 can be flatter and can effectively support the pole core 10.

[0090] In specific applications, the first plate 111 in the base plate 11 can be circumferentially surrounding the second plate 112, such as... Figure 4 As shown; alternatively, two first plates 111 can sandwich a second plate 112 in between, such as... Figure 6 As shown; in both structures, the thickness of the first plate 111 and the second plate 112 are equal, so when the first plate 111 surrounds the outer circumference of the second plate 112, it is easy to process and the bottom plate 11 can be made flatter; when the second plate 112 is located between the two first plates 111, the structural strength of the bottom plate 11 can be guaranteed and it is easy to process.

[0091] It should be explained that the thickness of the first plate 111 is equal to the thickness of the second plate 112. For example, when the thickness d of the base plate 11 is 0.3 mm, and the first plate 111 surrounds the outer circumference of the second plate 112, the thickness of both the first plate 111 and the second plate 112 is 0.3 mm; when the second plate 112 is disposed between the two first plates 111, the thickness of both the first plate 111 and the second plate 112 is 0.1 mm.

[0092] like Figure 1 As shown, in some embodiments of this application, the electrode core 10 includes an electrode core body 101 and an insulating film 102. The insulating film 102 covers at least a portion of the outer peripheral surface of the electrode core body 101, and the first plate 111 is at least partially fixedly connected to the insulating film 102.

[0093] In this embodiment, the insulating film 102 covers at least a portion of the outer peripheral surface of the electrode core body 101, thereby insulating and isolating the electrode core body 101 while ensuring the sealing of the electrode core body 101; the first plate 111 is at least partially fixedly connected to the insulating film 102, thereby ensuring the stability of the support connection between the bottom support plate 11 and the electrode core 10.

[0094] In specific applications, the electrode core body 101 specifically refers to a wound core or a stacked electrode core, both of which include a positive electrode sheet, a negative electrode sheet, and a separator between the positive and negative electrode sheets for electrochemical reactions. The insulating film 102 is specifically a polyester film or a PET film, wrapped around the outer periphery of the electrode core body 101 to provide insulation for the electrode core body 101; exemplarily, the insulating film 102 is a Mylar film.

[0095] It should be noted that the first plate 111 is at least partially fixedly connected to the insulating film 102, which can be one of the fixed connection methods such as hot melt connection, bonding, ultrasonic welding, etc. Those skilled in the art can set it according to actual needs, and this application does not limit it.

[0096] It should be explained that the first plate 111 is generally made of PP material and is connected to the insulating film 102 by hot-melt connection, so that the pole core 10 can be stably in contact with the base plate 11. The base plate 11 can provide support for the pole core 10, thereby improving the stability and reliability of the connection.

[0097] like Figure 5 and Figure 7 As shown, in some embodiments of this application, the first plate 111 is provided with a plurality of hot-melt parts 1111, the plurality of hot-melt parts 1111 are arranged at intervals around the second plate 112, and the hot-melt parts 1111 are fixedly connected to the insulating film 102.

[0098] In this embodiment of the application, by providing a plurality of hot-melt parts 1111 on the first plate 111, and the plurality of hot-melt parts 1111 being arranged at intervals around the second plate 112, the hot-melt parts 1111 can be fixedly connected to the insulating film 102, thereby improving the stability and reliability of the connection.

[0099] In a specific application, the first plate 111 and the insulating film 102 are thermally fused together. Specifically, the thermally fused portion 1111 on the first plate 111 is thermally fused to the insulating film 102. For example, the thermally fused portion 1111 has a range of 2mm × 10mm. By applying a hot melt adhesive layer, heating and pressurizing, the thermally fused portion 1111 is bonded to the insulating film 102. After cooling and curing, a molecular-level bond is formed.

[0100] It should be noted that the number of hot melt sections 1111 can be set to any number, such as 3, 4, 5, 6, 7, or 8.

[0101] like Figure 2 , Figure 3 , Figure 5 and Figure 7As shown, in some embodiments of this application, the first plate 111 and / or the second plate 112 are provided with positioning holes 113, which are used to position the pole core 10.

[0102] In this embodiment of the application, positioning holes 113 are provided in the first plate 111 and / or the second plate 112 to position the pole core 10, thereby ensuring the accuracy of the installation and connection between the base plate 11 and the pole core 10, and thus ensuring the effective support of the base plate 11 for the pole core 10.

[0103] In specific applications, two positioning holes 113 can be provided, with the two positioning holes 113 being arranged opposite each other along the length direction of the base plate 11 to improve the connection accuracy between the base plate 11 and the pole core 10.

[0104] It should be explained that in practical applications, when the base plate 11 is installed to the bottom of the pole core 10, the installation position of the base plate 11 can be observed through the positioning hole 113 to see if it is in the preset installation position.

[0105] like Figure 6 and Figure 7 As shown, in some embodiments of this application, the second plate 112 forms a reinforcing rib structure in the base plate 11, thereby improving the structural strength of the base plate 11.

[0106] In specific applications, such as Figure 7 As shown in the dashed box portion, the shape of the second plate 112 is as shown in the dashed box portion. The second plate 112 is as follows: Figure 6 As shown, it is located between the two first plates 111, so that a reinforcing rib structure can be partially formed in the central region of the base plate 11, thereby improving the structural strength of the base plate 11.

[0107] like Figure 1 As shown, in some embodiments of this application, the battery cell also includes a housing 13 and an explosion-proof valve. The housing 13 has a receiving cavity, and the bottom support plate 11 and the electrode core 10 are both disposed in the receiving cavity. The bottom support plate 11 is disposed between the electrode core 10 and the bottom of the receiving cavity. The explosion-proof valve is installed in the housing 13 and corresponds to the second plate 112.

[0108] In this embodiment, by placing both the bottom support plate 11 and the electrode core 10 within the receiving cavity of the housing 13, the housing 13 can provide protection for the electrode core 10. Meanwhile, the explosion-proof valve corresponds to the second plate 112, so that when the battery cell experiences thermal runaway and the airflow in the explosion-proof valve rushes out, the second plate 112 can absorb the impact force of the airflow, reducing the impact on the battery cell.

[0109] like Figure 7As shown, in the central region of the base plate 11, the second plate 112 forms the area indicated by the dashed box. This area corresponds to the explosion-proof valve. When the battery cell experiences thermal runaway, the airflow can be absorbed by the second plate 112 to absorb part of the impact energy, thereby improving the reliability and safety of the battery cell.

[0110] like Figure 3 and Figure 6 As shown, in some embodiments of this application, the first plate 111 and the second plate 112 are integrally formed parts or separate formed parts.

[0111] In this embodiment of the application, by setting the first plate 111 and the second plate 112 as integral molded parts or separate molded parts, the processing flexibility of the base plate 11 can be improved, and reasonable selection can be made according to actual needs, thereby reducing the processing difficulty.

[0112] In specific applications, for example, the first plate 111 can be made of PP material, and the second plate 112 can be made of homogenized plastic material. The two can be separately molded and then welded together. Alternatively, the first plate 111 and the second plate 112 can be formed into parts with different porosities by using 3D printing technology or other methods, by combining different materials with the design.

[0113] In some embodiments of the application, a battery pack is also proposed, comprising the cells as described in any of the above embodiments.

[0114] In this embodiment, the battery cell includes an electrode core 10 and a base plate 11, with the base plate 11 disposed at the bottom of the electrode core 10. The base plate 11 includes a first plate 111 and a second plate 112. The first plate 111 surrounds at least a portion of the second plate 112 circumferentially outward. The first plate 111 is connected to the electrode core 10, and the second plate 112 is in contact with the electrode core 10. The porosity of the second plate 112 is greater than that of the first plate 111. By dividing the base plate 11 into two parts with different porosities, the first plate 111 surrounds at least a portion of the second plate 112 circumferentially outward, and the first plate 111 is connected to the electrode core 10, thereby providing a fixed support for the electrode core 10. Simultaneously, the porosity of the second plate 112 is set to be greater than that of the first plate 111 so that the second plate 112 can absorb impact energy through plastic deformation when subjected to impact. In this way, while ensuring the bottom support plate 11 supports the electrode core 10, the overall weight of the bottom support plate 11 can be reduced, thereby reducing the weight of the battery cell; and the reliability and safety of the battery cell can also be improved.

[0115] In specific applications, the battery pack can be any type of battery pack, such as cylindrical battery pack, square battery pack, pouch battery pack, or solid-state battery pack. Those skilled in the art can configure it according to actual needs, and this application does not impose any restrictions on it.

[0116] Other components of the battery cell according to the embodiments of this application, such as top cover 14, connecting piece 15, top patch 16, etc., are known to those skilled in the art and will not be described in detail here.

[0117] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0118] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, include: The electrode core (10) and the base plate (11) are disposed at the bottom of the electrode core (10). The base plate (11) includes a first plate (111) and a second plate (112). The first plate (111) is disposed around at least part of the circumferential outer side of the second plate (112). The first plate (111) is connected to the electrode core (10). The second plate (112) is in contact with the electrode core (10). The porosity of the second plate (112) is greater than that of the first plate (111).

2. The battery cell according to claim 1, characterized in that, The second plate (112) contains a homogenized lattice structure.

3. The battery cell according to claim 2, characterized in that, The homogenized lattice structure of the second plate (112) is one of the following: Diamond type, Double pyramid type, Octet type or Star type lattice.

4. The battery cell according to claim 1, characterized in that, The height direction of the battery cell is the first direction (X), and the orthographic projection of the second plate (112) on the plane perpendicular to the first direction (X) is located within the orthographic projection of the base plate (11) on the plane perpendicular to the first direction (X).

5. The battery cell according to any one of claims 1-4, characterized in that, The thickness of the first plate (111) is equal to the thickness of the second plate (112).

6. The battery cell according to any one of claims 1-4, characterized in that, The electrode core (10) includes an electrode core body (101) and an insulating film (102). The insulating film (102) covers at least a portion of the outer peripheral surface of the electrode core body (101), and the first plate (111) is at least partially fixedly connected to the insulating film (102).

7. The battery cell according to claim 6, characterized in that, The first plate (111) is provided with a plurality of hot melt parts (1111), and the plurality of hot melt parts (1111) are arranged at intervals around the second plate (112), and the hot melt parts (1111) are fixedly connected to the insulating film (102).

8. The battery cell according to claim 6, characterized in that, The first plate (111) and / or the second plate (112) are provided with positioning holes (113), which are used to position the pole core (10).

9. The battery cell according to claim 1, characterized in that, The battery cell also includes a housing (13) and an explosion-proof valve. The housing (13) has a receiving cavity. The bottom support plate (11) and the electrode core (10) are both disposed in the receiving cavity. The bottom support plate (11) is disposed between the electrode core (10) and the bottom of the receiving cavity. The explosion-proof valve is installed in the housing (13) and corresponds to the second plate (112). And / or, the first plate (111) and the second plate (112) are integrally formed parts or separate formed parts.

10. A battery pack, characterized in that, include: The battery cell as described in any one of claims 1-9.

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