Battery cell, battery pack and vehicle

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell, a battery pack and a vehicle, the battery cell comprises a pole core and a filling unit, and the pole core comprises a flat area and a thinned area positioned at the end part of the flat area; the filling unit is arranged in the thinned area, and in the thickness direction perpendicular to the flat area, the ratio of the sum of the thickness of the filling unit and the thickness of the thinned area to the thickness of the flat area is 1: (0.90-1.05); the difference of migration paths of lithium ions in the thinned area and the flat area of the pole core in the battery cell is small, and the performance of the battery cell is good.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery cell, a battery pack and a vehicle. Background Art

[0002] Generally, a battery cell includes a jelly roll, an electrolyte and a housing; and the jelly roll includes a positive electrode sheet, a negative electrode sheet and a separator; for a battery cell, such as a blade battery cell, in order to improve the performance of the battery cell, a thinner area is formed at the edge part of the jelly roll, that is, a thinned area, and the other normal areas of the jelly roll are flat areas. Among them, the difference between the thinned area and the flat area of the jelly roll is formed due to the difference in the accumulated thickness of the thinned area and the flat area of the positive and negative electrode sheets. The purpose of the existence of the thinned area of the electrode sheet is to solve the "thick edge" phenomenon generated after the edge of the electrode sheet is coated during the coating stage due to the edge effect of the slurry during the coating process. Usually, the gasket of the coating equipment of the electrode sheet is functionally processed during the coating process, so that the electrode sheet has a thinned area after coating.

[0003] Since the physical thickness of the thinned area of the jelly roll is reduced, the thinned area of the jelly roll is not under pressure. These jelly roll structures with thinned areas may be looser than the flat areas, resulting in a longer or different migration path of Li+, which may increase the internal resistance of the battery, reduce the energy density and output power of the battery, and further reduce the comprehensive performance of the battery cell. Summary of the Utility Model

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide a battery cell, a battery pack and a vehicle, in which the difference in the lithium ion migration paths between the thinned area and the flat area of the jelly roll of the battery cell is small, and the performance of the battery cell is good.

[0005] To achieve the above purpose and other related purposes, the present utility model provides a battery cell, including:

[0006] A jelly roll, including a flat area and a thinned area located at the end of the flat area;

[0007] A filling unit, disposed in the thinned area, and along the thickness direction perpendicular to the flat area, the ratio of the sum of the thickness of the filling unit and the thinned area to the thickness of the flat area is 1: (0.90 - 1.05).

[0008] In an embodiment of the present utility model, the filling unit includes:

[0009] A heat dissipation shell, having a cavity inside, and one side of the heat dissipation shell is attached to the thinned area;

[0010] A heat dissipation medium, accommodated in the cavity.

[0011] In an embodiment of the present utility model, the heat dissipation medium includes:

[0012] Thermal conductive support framework;

[0013] Phase change filler, covering the outer surface of the thermal conductive support framework and / or filling the internal voids of the thermal conductive support framework.

[0014] In an embodiment of the present utility model, the thermal conductive support framework is made of graphite and / or carbon nanofibers and / or graphene materials.

[0015] In an embodiment of the present utility model, the phase change filler is paraffin, polyethylene glycol, phase change polyol and / or phase change polybasic acid.

[0016] In an embodiment of the present utility model, the thickness of the filling unit gradually increases from one end of the filling unit to the other end, and one side surface between the two ends of the filling unit is attached to the thinning area, and the other side surface is flush with the flat area.

[0017] In an embodiment of the present utility model, the battery cell further includes:

[0018] Tab, connected to the end of the thinning area of the electrode core;

[0019] Clamping assembly, connecting the filling unit, and the clamping assembly is detachably clamped to the tab;

[0020] Shell, at least the electrode core, the filling unit and the clamping assembly are received in the shell.

[0021] In an embodiment of the present utility model, the clamping assembly includes:

[0022] Card slot, connected to the filling unit on one side surface of the electrode core;

[0023] Card holder, connected to the filling unit on the other side surface of the electrode core; and the card slot and the card holder are configured to be able to be mutually engaged and at least be able to clamp and limit the bottom side of the tab between the card slot and the card holder.

[0024] In an embodiment of the present utility model, the card slot is provided with a protrusion, and the card holder is provided with a groove adapted to the protrusion.

[0025] To achieve the above and other related purposes, the present utility model provides a battery pack, including the battery cell described above.

[0026] To achieve the above and other related purposes, the present utility model provides a vehicle, including the battery pack described above.

[0027] In summary, in the present utility model, a filling unit is provided in the thinning area of the electrode core. Along the thickness direction perpendicular to the flat area, the ratio of the sum of the thickness of the filling unit and the thinning area to the thickness of the flat area is 1: (0.90 - 1.05), so that the thickness of the thinning area of the electrode core plus the filling unit is equivalent to the thickness of the flat area, thereby making the pressure on the thinning area and the flat area of the electrode core basically equal, and further reducing or decreasing the difference in the migration paths of Li+ in the thinning area and the flat area of the electrode core, and further improving the disadvantages such as the increase in the internal resistance of the battery cell, the reduction of the energy density and output power of the battery caused by this difference, thereby improving the performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 Exploded view of the structure of the electrode core and the filling unit of the battery cell in an embodiment of the present utility model;

[0030] Figure 2 Schematic diagram of the structure in which the electrode core and the filling unit of the battery cell in an embodiment of the present utility model are installed together;

[0031] Figure 3 Microstructure diagram of the filling unit in an embodiment of the present utility model;

[0032] Figure 4 Schematic diagram of the connection between the card slot of the clamping component and the filling unit in an embodiment of the present utility model;

[0033] Figure 5 Overall structure schematic diagram of the clamping component in an embodiment of the present utility model;

[0034] Figure 6 Schematic diagram of the structure in which the filling unit is arranged on the electrode core in an embodiment of the present utility model;

[0035] Element number description: Electrode core 1, flat area 11, thinning area 12, filling unit 2, heat dissipation shell 21, heat dissipation medium 22, heat conduction support framework 221, phase change filler 222, tab 3, clamping component 4, card slot 41, card holder 42, protrusion 411, groove 421. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following describes the implementation manners of the present utility model through specific examples. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present utility model. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. It should also be understood that the terms used in the embodiments of the present utility model are for describing specific implementation manners and not for limiting the protection scope of the present utility model. The test methods without specific conditions noted in the following embodiments are generally in accordance with conventional conditions or the conditions recommended by each manufacturer.

[0037] Please refer to Figures 1 to 6 . It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limited conditions under which the present utility model can be implemented. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope under which the present utility model can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present utility model can be implemented.

[0038] When the embodiments give numerical ranges, it should be understood that unless otherwise specified in the present utility model, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present utility model, based on the understanding of those skilled in the art of the prior art and the description of the present utility model, can also use any methods, devices, and materials of the prior art similar or equivalent to those described in the embodiments of the present utility model to implement the present utility model.

[0039] Please refer to Figures 1 - 3 , 6, the present utility model provides a battery cell, including a pole core 1 and a filling unit 2; the pole core 1 includes a flat area 11 and a thinned area 12 located at the end of the flat area 11;

[0040] The filling unit 2 is arranged in the thinned area 12, and along the thickness direction perpendicular to the flat area 11, the ratio of the sum of the thicknesses of the filling unit 2 and the thinned area 12 to the thickness of the flat area 11 is 1:(0.90 - 1.05).

[0041] It should be noted that Figure 6 The thickness difference between the thinned area 12 and the flat area 11 shown in Figure 6 is relatively large, just for the convenience of showing the thickness difference between the two. In fact, generally, the maximum thickness difference between the thinned area 12 and the flat area 11 of the electrode core 1 is only a few millimeters. The battery cell is the core component of the battery pack. A battery cell usually refers to a single electrochemical unit containing a positive electrode and a negative electrode. It is the basic unit for storing and releasing electrical energy. A battery cell generally includes an electrode core 1, an electrolyte, and a housing. The electrode core 1 includes a positive electrode sheet, a negative electrode sheet, a separator, and other structures. Among them, the positive and negative electrode sheets are the main sites for electrochemical reactions, the electrolyte provides a medium for ion transport, and the separator prevents the positive and negative electrode sheets from directly contacting to cause a short circuit and at the same time allows ions to pass through. The electrode core 1 includes a region with a relatively thin thickness and other regions with a normal thickness. The region with a relatively thin thickness is the thinned area 12, and the other regions with a normal thickness are the flat areas 11. The thickness difference between the thinned area and the normal area of each layer of electrode sheet is generally about ten-odd micrometers, and the thickness difference between the thinned area 12 and the flat area 11 of the electrode core 1 is accumulated by the thickness differences of the thinned areas of multiple electrode sheets. The thickness difference of the electrode core 1 is generally several millimeters; the thinned area 12 of the electrode core 1 is designed to optimize the battery performance. In the production of lithium-ion batteries, the coating of the positive and negative electrodes of the electrode core 1 is a key process step. The thinned area 12 specifically refers to the relatively thin area formed at the edge of these electrode cores 1. By optimizing these areas, the edge effect problem of lithium batteries can be effectively solved, and the capacity attenuation and life shortening phenomena during the charge and discharge cycles of the battery can be reduced. The hardness of the filling unit 2 is greater than the preset hardness, as long as it can meet the usage requirements. For example, the hardness of the filling unit 2 can make the thinned area 12 withstand the same pressure as the flat area 11 in the hot pressing process.

[0042] Due to the longer or different migration paths of Li+ caused by the thinned area 12 of the electrode core 1, this difference may increase the internal resistance of the battery, reduce the energy density and output power of the battery; for example, due to the difference in the migration rate of Li+, some regions may not be able to effectively participate in the electrochemical reaction, resulting in the actual available battery capacity being lower than the theoretical value, thereby reducing the battery capacity; for example, the uneven distribution of Li+ may increase the internal resistance of the battery, affecting the charge and discharge efficiency and output power of the battery; for example, in some extreme cases, the difference in the migration rate of Li+ may cause uneven deposition of lithium ions on the surface of the negative electrode, forming metallic lithium dendrites, piercing the separator, causing a short circuit, that is, the phenomenon of lithium plating; for example, due to the uneven migration of Li+, the active substances in some regions may be overused, accelerating the battery aging process, resulting in an accelerated decline in battery life; the problem of the difference in the migration rate of Li+ may affect the charging efficiency of the battery, increasing the energy loss during the charging process, thereby reducing the charging efficiency.

[0043] In view of the above problems, in this case, a filling unit 2 is provided in the thinning area 12 of the anode core 1. In the thickness direction perpendicular to the flat area 11, the sum of the thicknesses of the filling unit 2 and the thinning area 12 is close to or equal to the thickness of the flat area 11, so that the thickness of the thinning area 12 of the anode core 1 plus the filling unit 2 is equivalent to the thickness of the flat area 11. For example, the ratio of the sum of the thicknesses of the filling unit 2 and the thinning area 12 to the thickness of the flat area 11 is 1:0.90 or 1:0.95 or 1:1 or 1:1.05. Thus, the pressures on the thinning area 12 and the flat area 11 of the anode core 1 are basically equal, and further, the difference in the migration paths of Li+ between the thinning area 12 and the flat area 11 of the anode core 1 is reduced or decreased, thereby improving various drawbacks caused by this difference.

[0044] As an optional embodiment of this case, please refer to Figures 1 - 3 , 6, the filling unit 2 includes: a heat dissipation shell 21 and a heat dissipation medium 22;

[0045] A cavity is provided in the heat dissipation shell 21, and one side of the heat dissipation shell 21 is attached to the thinning area 12; the heat dissipation medium 22 is received in the cavity.

[0046] It should be noted that at least one of the heat dissipation shell 21 and the heat dissipation medium 22 is made of a hard material. For example, the heat dissipation shell 21 is a plastic with heat conduction properties. When the heat dissipation medium 22 is a hard material, the heat dissipation shell 21 can be a flexible material or a hard material. When the heat dissipation medium 22 is a flexible material, such as a fluid, the heat dissipation shell 21 must be a hard material, so that the filling unit 2 can withstand the corresponding pressure and is not easily deformed. The heat dissipation shell 21 can be an aluminum-plastic film, an aluminum shell, a steel shell, etc.; the heat dissipation medium 22 can be heat dissipation media such as distilled water, ethanol, heat-conducting silica gel, heat-conducting elastic rubber, phase change materials, etc. The heat dissipation medium 22 is preferably selected as a medium with good heat dissipation effect.

[0047] Furthermore, with the improvement of the fast charging performance of the battery cell, the problem of the temperature rise consistency inside the electrode core 1 of the battery cell becomes more prominent. The temperature rise difference at different positions inside the electrode core 1 can reach up to 30°C. In addition, for the blade battery cell, in the flat area 11 of the electrode core 1, which has a uniform thickness and usually undertakes the main electrochemical reaction, its consistency helps to achieve stable current output and heat distribution. In the thinned area 12 of the electrode core 1, this area is thinned by mechanical or chemical means to solve the edge effect caused by the slurry during the coating stage of the electrode sheet, but the heat conduction and dissipation may be affected due to the non-uniform thickness. Further analyzing the generation and accumulation of heat, due to the thicker material part of the flat area 11, heat may be generated uniformly therein but dissipated slowly, which can resist the rapid change of temperature to a certain extent and maintain relatively stable temperature control; while in the thinned area 12, although thinning can improve the local reaction efficiency, due to the reduction of materials, its ability to store and absorb heat is low, and it may overheat rapidly and increase in temperature quickly under high-power operations, especially during fast charging and discharging processes, resulting in inconsistent temperature rise between the flat area 11 and the thinned area 12 of the electrode core 1. This inconsistent temperature rise may lead to a decline in battery performance, shortened lifespan, and safety issues; for example, problems such as local overheating, uneven aging, lithium plating risk, and structural deformation. In this case, by setting the filling unit 2 as a structure with heat dissipation effect, the heat dissipation ability of the thinned area 12 is improved, and then the heat dissipation effect of the thinned area 12 tends to be consistent with that of the flat area 11, further optimizing or solving a series of drawbacks caused by the inconsistent temperature rise between the flat area 11 and the thinned area 12 of the electrode core 1.

[0048] As an optional embodiment of this case, please refer to Figures 1 - 3 , the heat dissipation medium 22 includes a heat-conducting support framework 221 and a phase change filler 222; the phase change filler 222 covers the outer surface of the heat-conducting support framework 221 and / or fills the internal voids of the heat-conducting support framework 221.

[0049] It should be noted that the heat-conducting support framework 221 may have voids inside. The heat-conducting support framework 221 is placed into the liquid phase-change filling material 222, so that the outer surface of the heat-conducting support framework 221 can adhere to and condense with the phase-change filling material 222, enabling the phase-change filling material 222 to form a coating on the outer surface of the heat-conducting support framework 221; the phase-change filling material 222 can also penetrate into the voids inside the heat-conducting support framework 221 and remain and condense in the voids inside the heat-conducting support framework 221. The use of the heat-conducting support framework 221 and the phase-change filling material 222 in the heat dissipation medium 22 can significantly improve the heat management efficiency, enhance the structural stability, and optimize the overall thermal performance of the material; specifically, using a material with a high thermal conductivity to construct the three-dimensional heat-conducting support framework 221 can effectively improve the overall heat conduction efficiency. Such a framework provides a direct and efficient transmission path for heat, thereby accelerating the conduction of heat from the high-temperature region to the low-temperature region; and the mechanical structure of the heat-conducting support framework 221 provides the necessary physical support to ensure the shape and size stability of the entire filling unit 2. The material of the phase-change filling material 222 is a phase-change material, and the phase-change material can absorb and release a large amount of thermal energy within a constant or narrow temperature range, which helps to absorb and reduce the temperature peak of the thinned area 12, so that the temperature rise of the thinned area 12 and the flat area 11 tends to be consistent.

[0050] As an optional embodiment of this case, please refer to Figures 1 - 3 , the heat-conducting support framework 221 is made of graphite and / or carbon nanofibers and / or graphene materials.

[0051] It should be noted that using graphite, carbon nanofibers, and graphene as the heat-conducting support framework 221 has the advantages of improving the thermal conductivity, enhancing the mechanical properties, and improving the morphological stability, etc.; for example, carbon nanofibers and graphene can form a three-dimensional network structure. This structure not only has good thermal conductivity itself, but also can effectively disperse heat, thereby reducing the formation of hot spots; and the addition of carbon nanofibers and graphene can significantly improve the mechanical strength and toughness of the material. If the heat-conducting support framework 221 uses metal or ceramic, not only the density is large, which will increase the weight of the battery cell, but also the mechanical properties are weaker compared with graphite, carbon nanofibers, and graphene. Therefore, the comprehensive performance of using graphite, carbon nanofibers, and graphene as the heat-conducting support framework 221 is better than using metal or ceramic. As Figure 3In the micrograph of the phase change composite material shown, the outermost is the heat dissipation shell 21, that is, the encapsulation material. In the cavity inside the encapsulation material, the rod-shaped ones are carbon nanofibers, the round-shaped ones are graphite, and the banana-shaped ones are graphene. The phase change material, such as paraffin wax, is in the gaps between the carbon nanofibers, graphite, and graphene. The above-mentioned rod shape, round shape, and banana shape are only for distinguishing and showing the distribution of carbon nanofibers, graphite, and graphene, and are not intended to limit the specific shapes of carbon nanofibers, graphite, and graphene. Among them, the graphene can specifically be graphene nanosheets.

[0052] As an optional embodiment of this case, the phase change filler 222 is paraffin wax and / or polyethylene glycol and / or phase change polyol and / or phase change polyacid.

[0053] As an optional embodiment of this case, please refer to Figures 1 - 4 Figures 6, the thickness of the filling unit 2 gradually increases from one end of the filling unit 2 to the other end, and one side surface between the two ends of the filling unit 2 is attached to the thinning area 12, and the other side surface is flush with the flat area 11, so as to realize the matching setting of the filling unit 2 and the thinning area 12.

[0054] As an optional embodiment of this case, please refer to Figures 1 - 2 Figures 4-5, the battery cell further includes a tab 3, a clamping assembly 4, and a housing; the tab 3 is connected to the end of the thinning area 12 of the electrode core 1;

[0055] The clamping assembly 4 is connected to the filling unit 2, and the clamping assembly 4 is detachably clamped to the tab 3; at least the electrode core 1, the filling unit 2, and the clamping assembly 4 are accommodated in the housing.

[0056] It should be noted that during the charging and discharging process of the battery, the active material in the thinned area 12 is prone to being subjected to relatively large stress, and the thinned area 12 helps to reduce this impact; the connection between the tab 3 and the thinned area 12 can reduce the risk of mechanical damage during the use of the battery, thereby improving the overall safety of the battery; the position of the tab 3 helps the thinned area 12 on the electrode core 1 at a relatively high temperature to dissipate heat, and further helps the heat dissipation of the entire battery cell; on the one hand, the clamping assembly 4 can fix the position of the filling unit 2, and on the other hand, since the clamping assembly 4 clamps the tab 3 and the filling unit 2 is attached to the electrode core 1, the clamping assembly 4 and the filling unit 2 cooperate to strengthen the connection between the tab 3 and the electrode core 1 to a certain extent, improve better connection stability, and prevent loosening of the connection due to vibration or impact during the use of the battery; and the clamping of the bottom side of the tab 3 by the clamping assembly 4 is also beneficial to the binding and shaping of the bottom side of the tab 3, avoiding or reducing the deformation of the tab 3 during use. The clamping assembly 4 can be a screw clamping mechanism, an eccentric clamping mechanism, or a wedge clamping mechanism. For example, the screw clamping mechanism pushes the clamping element by rotating the screw to fix the tab 3; the eccentric clamping mechanism realizes quick clamping and release by rotating an eccentric wheel or an eccentric shaft; the wedge clamping mechanism pushes the clamping element by the movement of the wedge to fix the tab 3. The electrode core 1, the filling unit 2, and the clamping assembly 4 are accommodated in the housing and dissipate heat outward through the housing. The material of the clamping assembly 4 can be polypropylene (PP) material, polyethylene terephthalate PET material, polyvinyl chloride PVC, etc.; the housing can be aluminum material, aluminum-plastic material, or other materials that meet the usage requirements.

[0057] As an optional embodiment of this case, please refer to Figures 1 - 2 Figs. 4-5, the clamping assembly 4 includes a clamping groove 41 and a clamping seat 42; the clamping groove 41 is connected to the filling unit 2 on one side surface of the electrode core 1;

[0058] the clamping seat 42 is connected to the filling unit 2 on the other side surface of the electrode core 1; and the clamping groove 41 and the clamping seat 42 are configured to be able to be mutually clamped and at least be able to clamp and limit the bottom side of the tab 3 between the clamping groove 41 and the clamping seat 42.

[0059] It should be noted that the inner side surface of the clamping groove 41 exactly fits and matches one side surface of the tab 3, and one side surface of the clamping seat 42 exactly matches and fits the other side surface of the tab 3, so as to be able to limit and flatten the relatively large side surface of the tab 3, avoid or reduce the occurrence of problems such as deformation or fracture of the bottom side of the tab 3, and is beneficial to strengthening the connectivity between the tab 3 and the electrode core 1.

[0060] As an optional embodiment of this case, please refer to Figures 1 - 2, 4-5, between the card slot 41 and the card holder 42, one of them is provided with a protrusion 411, and the other is provided with a groove 421. When the card slot 41 and the card holder 42 are engaged, the protrusion 411 and the groove 421 are exactly engaged and matched for limiting. On the one hand, it is beneficial to reduce the structural volume of the card slot 41 and the card holder 42 for engaging and limiting. On the other hand, it is convenient for the quick engaging connection between the card slot 41 and the card holder 42, which helps to improve the assembly efficiency.

[0061] The present utility model also provides a battery pack, including the battery cell as described above, so that the battery pack is also within the protection scope of this case.

[0062] The present utility model also provides a vehicle, including the battery pack as described above, so that the vehicle is also within the protection scope of this case.

[0063] In summary, the present utility model effectively overcomes some practical problems in the prior art, so it has high utilization value and practical significance.

[0064] The above embodiments only illustrate the principles and effects of the present utility model, rather than limiting the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A battery cell, characterized in that: include: A pole core, comprising a flat region and a thinned region at an end of the flat region; The filling unit is arranged in the thinning area, and along the thickness direction perpendicular to the flat area, the ratio of the sum of the thickness of the filling unit and the thinning area to the thickness of the flat area is 1:(0.90-1.05).

2. The battery cell according to claim 1, characterized in that: The filling unit comprises: A heat dissipation shell is provided with a cavity therein, and one side of the heat dissipation shell is arranged in contact with the thinned area; The heat dissipation medium is contained in the cavity.

3. The battery cell according to claim 2, characterized in that: The heat dissipation medium includes: Thermally conductive support frame; The phase change filler covers the outer surface of the thermal conductive support skeleton and / or fills the inner gap of the thermal conductive support skeleton.

4. The battery cell according to claim 3, characterized in that: The heat-conducting support skeleton is made of graphite and / or carbon nanofiber and / or graphene material.

5. The battery cell according to claim 3, characterized in that: The phase change filler is paraffin and / or polyethylene glycol and / or phase change polyol and / or phase change polyacid.

6. The battery cell according to claim 1, characterized in that: The thickness of the filling unit gradually increases from one end to the other end of the filling unit, and one side surface between the two ends of the filling unit is arranged in contact with the thinning area, and the other side surface is arranged flush with the flat area.

7. The battery cell according to claim 1, characterized in that: Also includes: A pole ear connected to the end of the thinned area of ​​the pole core; A clamping assembly connected to the filling unit, and the clamping assembly is detachably clamped and connected to the tab; A shell, in which at least the pole core, the filling unit and the clamping assembly are accommodated.

8. The battery cell according to claim 7, characterized in that: The clamping assembly comprises: A slot connected to the filling unit on one side of the pole core; The holder is connected to the filling unit on the other side of the pole core; and the slot and the holder are configured to be mutually engaged and at least clamp the bottom side of the pole ear between the slot and the holder.

9. A battery pack, characterized in that: A battery cell comprising the battery cell described in any one of claims 1 to 8.

10. A vehicle, characterized in that: A battery pack comprising the battery pack of claim 9.

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