Pole core, battery, battery pack and vehicle

Abstract

The utility model relates to the field of lithium battery production, in particular to a pole core, a battery, a battery pack and a vehicle, the pole core comprises dressing layers, diaphragm layers and tabs, the diaphragm layers and the dressing layers are alternately arranged, each tab comprises a tab exposure section and a tab insertion section connected with the tab exposure section, the tab insertion section is inserted into the dressing layers, and the diaphragm layers and the tab insertion sections are alternately arranged. The lengths of the exposed sections of the tabs are increased in a non-linear manner along a preset direction, the preset direction is a direction from the center of the pole core to two sides of the pole core, and the lengths of the inserted sections of the tabs are the same; the battery comprises a battery core top cover, a battery shell and a pole core, the center of the battery core top cover is flush with the center of the pole core, the upper surface of the battery core top cover is provided with a pole lug welding and printing area, and the exposed section of the pole lug is welded and printed in the pole lug welding and printing area. And the dressing layer, the diaphragm layer, the tab internally-inserted section and the tab exposed section in the shell are wrapped by the battery shell. According to the lithium ion battery, the quality of the pole core can be improved.

Description

Technical Field

[0001] The utility model relates to the field of lithium battery production, in particular to an electrode core, a battery, a battery pack and a vehicle. Background Art

[0002] At present, in the process of pre-welding the electrode tabs of common electrode cores, the heights of the positive and negative electrode tabs are the same, which makes the electrode tabs prone to tearing and elongation during the assembly process of the electrode core, resulting in a decrease in the quality of the electrode core. Therefore, how to improve the quality of the electrode core has become a technical problem to be solved urgently. Summary of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an electrode core, a battery, a battery pack and a vehicle, which can improve the quality of the electrode core.

[0004] To achieve the above object, a first aspect of an embodiment of the utility model provides an electrode core, which includes:

[0005] A dressing layer;

[0006] A separator layer, wherein the separator layer and the dressing layer are arranged alternately;

[0007] An electrode tab, wherein the electrode tab includes an electrode tab exposed section and an electrode tab inserted section connected to the electrode tab exposed section, the electrode tab inserted section is inserted into the dressing layer, the length of the electrode tab exposed section increases non-linearly along a preset direction, the preset direction is the direction from the center of the electrode core to both sides of the electrode core, and the lengths of the electrode tab inserted sections are the same.

[0008] According to some embodiments of the utility model, the preset direction includes a first direction and a second direction, and the increasing amplitude of the length of the electrode tab exposed section in the first direction is the same as the increasing amplitude of the length of the electrode tab exposed section in the second direction.

[0009] According to some embodiments of the utility model, the sum of the length of the electrode tab exposed section and the length of the electrode tab inserted section is less than or equal to 40 mm.

[0010] According to some embodiments of the utility model, the electrode tab includes a positive electrode tab and a negative electrode tab, the positive electrode tab is made of copper foil, and the negative electrode tab is made of aluminum foil.

[0011] According to some embodiments of the utility model, the dressing layer is divided into a positive electrode dressing layer and a negative electrode dressing layer arranged alternately with the positive electrode dressing layer, the positive electrode tab is inserted into the positive electrode dressing layer, and the negative electrode tab is inserted into the negative electrode dressing layer.

[0012] To achieve the above object, a second aspect of the embodiments of the present utility model provides a battery, comprising a cell top cover, a battery housing, and any one of the above-mentioned electrode cores. The cell top cover is flush with the center of the electrode core. An ear welding area is provided on the upper surface of the cell top cover, and the exposed section of the ear is welded to the ear welding area. The battery housing encloses the dressing layer, the separator layer, the inserted section of the ear, and the exposed section of the ear inside the housing.

[0013] According to some embodiments of the present utility model, the center of the ear welding area overlaps with the center of the upper surface of the cell top cover, and one end of the exposed section of the ear outside the battery housing overlaps with the center of the ear welding area.

[0014] According to some embodiments of the present utility model, the ear includes a positive ear and a negative ear. The positive ears and the negative ears are arranged alternately. The negative ear includes a first negative ear and a second negative ear. The exposed section of the first negative ear includes a first exposed section, a second exposed section, and a third exposed section. The front end of the first exposed section is flush with the center of the ear welding area, and the rear end of the first exposed section is flush with the end of the cell top cover close to the battery housing. The front end of the second exposed section is connected to the rear end of the first exposed section. The second exposed section is perpendicular to the battery housing and the rear end of the second exposed section is in contact with the surface of the battery housing. The front end of the third exposed section is connected to the rear end of the second exposed section. The third exposed section is perpendicular to the dressing layer and the rear end of the third exposed section is in contact with the surface of the dressing layer. The exposed section of the second negative ear adjacent to the first negative ear includes a fourth exposed section, a fifth exposed section, and a sixth exposed section. The fourth exposed section overlaps with the first exposed section. The front end of the fifth exposed section is connected to the rear end of the fourth exposed section. The fifth exposed section is obliquely in contact with the battery housing and the rear end of the fifth exposed section is in contact with the surface of the battery housing. The front end of the sixth exposed section is connected to the rear end of the fifth exposed section. The sixth exposed section is perpendicular to the dressing layer and the rear end of the sixth exposed section is in contact with the surface of the dressing layer. The length of the fourth exposed section is equal to the length of the first exposed section, and the length of the sixth exposed section is equal to the length of the third exposed section. The length of the first negative ear is equal to the sum of the lengths of the first exposed section, the second exposed section, and the third exposed section. The length of the second negative ear is equal to the sum of the lengths of the first exposed section, the fifth exposed section, and the third exposed section.

[0015] To achieve the above object, a third aspect of the embodiments of the present utility model provides a battery pack, comprising a battery pack housing and any one of the above-mentioned batteries. The battery pack housing is used to enclose the battery.

[0016] To achieve the above object, a fourth aspect of the embodiments of the present utility model provides a vehicle, including any one of the above battery packs.

[0017] In the present utility model, during the pre-welding process of the tab in the pole core assembly process, the tab of the pole core is cut, so that the length of the tab gradually increases along the direction from the center of the pole core to both sides of the pole core. Thus, when the positive tabs of the pole core are pressed together, the fitting positions of the endpoints of the positive tabs far from the pole core are consistent, and when the negative tabs of the pole core are pressed together, the fitting positions of the endpoints of the negative tabs far from the pole core are consistent, reducing the probability of tab tearing and tab redundancy during the pole core assembly process, thereby improving the quality of the pole core. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally denoted by similar reference numerals. In the drawings, the elements or parts do not necessarily draw to actual scale.

[0019] Figure 1 Schematic diagram of the structure of the electrode plate and the tab in the related art provided by the embodiments of the present utility model;

[0020] Figure 2 Schematic diagram of the cross-section of the negative electrode of the battery provided by the embodiments of the present utility model;

[0021] Figure 3 Schematic diagram of the cross-sectional structure of the pole core provided by the embodiments of the present utility model;

[0022] Figure 4 Schematic diagram of the cross-sectional structure of the battery provided by the embodiments of the present utility model;

[0023] Figure 5 Schematic diagram of the cross-section of the negative electrode of the battery provided by the embodiments of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will describe in detail the embodiments of the technical solutions of the present utility model with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present utility model, and thus are only examples and cannot be used to limit the protection scope of the present utility model.

[0025] It should be noted that unless otherwise specified, the technical terms or scientific terms used in the present utility model should have the ordinary meanings understood by those skilled in the art to which the present utility model belongs.

[0026] First, several nouns involved in the present utility model are analyzed:

[0027] Tab: A tab refers to the connecting part of the positive and negative electrodes of a battery, which is used to achieve the electrical connection of the battery. Under normal circumstances, both the positive and negative electrodes of the battery need to be connected to external devices or circuits to provide current output or receive external power charging. The tab can serve as the current transmission terminal of the battery and is connected to the external circuit through welding, crimping or other connection methods to achieve the electrical connection of the battery system. Tabs are usually made of metal materials with good electrical conductivity, such as copper, aluminum, etc. These materials can provide good current transmission performance and corrosion resistance to ensure the stable connection between the battery and the external circuit.

[0028] Dressing layer: The battery dressing layer refers to the positive and negative electrode plates inside the battery. The positive and negative electrode plates inside the battery are the sites for electrochemical reactions. They are separated by an electrolyte diaphragm, and electrochemical reactions occur therein to release or absorb electrical energy. In battery systems such as lithium-ion batteries, the positive electrode is generally composed of lithium-containing metal oxides, while the negative electrode is composed of carbon materials or lithium metal. These electrode plates can be connected to the outside of the battery through the electrolyte and the tabs to enable the normal operation of the battery.

[0029] Cell top cover: The cell top cover is an important part of the battery housing. It protects the internal components of the battery from external substances by enclosing the upper part of the battery, ensuring the safe operation of the battery. The cell top cover usually has electrode interfaces or connectors for connecting the positive and negative electrodes of the battery to external devices or circuits to achieve the electrical connection of the battery system. In some battery application scenarios, certain heat is generated during battery operation. The cell top cover is usually designed with heat dissipation holes or heat dissipation structures to facilitate the dissipation of the heat generated inside the battery to the external environment to ensure the stable working temperature of the battery.

[0030] Battery housing: The battery housing refers to the outer shell layer that wraps the entire battery. Its main functions are to protect the internal components of the battery, isolate the battery from the external environment, and provide support and fixation for the battery. The battery housing is usually made of materials such as metal or plastic.

[0031] In related technologies, such as Figure 1 , Figure 1 is a schematic cross-sectional view of the electrode core in related technologies. In order to maintain the stable connection of the battery and the smooth conduction of electric charges in the battery, it is usually necessary to press the positive tabs 1 in the electrode core together and press the negative tabs 2 in the electrode core together, as Figure 2 shown. Figure 2Pressing the negative electrode tabs 2 with the same height in the middle electrode core together easily causes the outer negative electrode tabs 5 far from the center 4 of the electrode core to be in a tight state, resulting in the tearing of the tabs of the battery, making the battery connection unstable and causing the battery to conduct charges smoothly. In addition, the center negative electrode tab 6 will be too long, resulting in the need to cut the center negative electrode tab 6 during the subsequent manufacturing process of the electrode core assembly, increasing the time of the electrode core assembly and reducing the efficiency of the electrode core assembly. In addition, the use of a battery with a long tab is likely to cause potential safety hazards.

[0032] The present utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present utility model provides an electrode core, a battery, a battery pack and a vehicle. By cutting the tabs of the electrode core during the pre-welding process of the tab assembly process of the electrode core, the length of the tabs gradually increases along the direction from the center of the electrode core to both sides of the electrode core, so as to ensure that when the positive electrode tabs of the electrode core are pressed together, the fitting positions of the endpoints of the positive electrode tabs far from the electrode core are consistent, and when the negative electrode tabs of the electrode core are pressed together, the fitting positions of the endpoints of the negative electrode tabs far from the electrode core are consistent, reducing the probability of tab tearing and tab elongation during the electrode core assembly process, thereby improving the quality of the electrode core.

[0033] Figure 3 It is a cross-sectional view of the electrode core 100 provided by the present utility model, as Figure 3 shown, the first aspect embodiment of the present utility model provides an electrode core 100, including a dressing layer 110, a separator layer 120 and tabs 130. Among them, the separator layer 120 and the dressing layer 110 are arranged alternately. The tabs 130 include a tab exposed section 131 and a tab inserted section 132 connected to the tab exposed section 131. The tab inserted section 132 is inserted into the dressing layer 110. The length of the tab exposed section 131 increases non-linearly along a preset direction, and the preset direction is the direction from the center 140 of the electrode core 100 to both sides of the electrode core 100, and the lengths of the tab inserted sections 132 are the same.

[0034] By cutting the tabs 130, the length of the tab exposed section 131 increases non-linearly along the direction from the center 140 of the electrode core 100 to both sides of the electrode core 100, reducing the probability of tab 130 tearing and tab 130 elongation in the electrode core 100. Such a design can reduce the cutting steps of the tab exposed section 131 in the subsequent processes of the electrode core 100 assembly process, thereby improving the assembly efficiency of the electrode core 100.

[0035] In some embodiments of the present utility model, the post - process includes tab 130 cutting and core 100 assembly: The tab 130 cutting is performed by trimming the over - long exposed tab segment 131, thereby maintaining the stable connection of the battery and the smoothness of the battery when conducting charges. When a core 100 of the present utility model is pre - welding the tab 130, the probability of the tab 130 being redundant during the assembly of the core 100 can be reduced, so that the trimming process of the exposed tab segment 131 during the tab 130 cutting can be omitted, and the assembly efficiency of the core 100 is improved.

[0036] The present utility model reasonably designs the length of the exposed tab segment 131 to ensure that the length of the exposed tab segment 131 increases non - linearly from the center 140 of the core 100 to both sides of the core 100, thereby reducing the probabilities of the tab 130 being redundant and the tab 130 being torn during the assembly of the core 100, improving the safety, reliability and performance of the core 100, and enhancing the quality and service life of the core 100. Specifically, it means:

[0037] (1) Strengthen the connection reliability of the core 100: By reasonably designing and controlling the length of the exposed tab segment 131, the risk of the tab 130 being torn can be reduced, ensuring a firm connection between the core 100 and external devices, reducing gaps and unstable factors, and improving the overall connection reliability.

[0038] (2) Reduce the failure probability of the core 100: By reasonably designing and controlling the length of the exposed tab segment 131, the redundancy of the tab 130 can be reduced, avoiding loosening, wear and breakage of the internal circuit connection part of the core 100, reducing the probability of the core 100 malfunctioning, and enhancing the stability and reliability of the core 100.

[0039] (3) Improve the performance of the core 100: Optimizing the length of the exposed tab segment 131 can reduce the resistance of the current - conducting path of the core 100, improve the efficiency of current transmission, enhance the performance of the core 100, reduce energy loss, and extend the working life of the core 100.

[0040] (4) Improve the safety level of the core 100: By reducing the length of the tab 130 at the center 140 of the core 100, the probability of the tab 130 being redundant is reduced, the safety risks such as short - circuit and overheating of the core 100 circuit can be reduced, the safety of the core 100 is improved, and potential accidents and damages can be reduced.

[0041] It should be noted that in some embodiments of the present utility model, to ensure the working efficiency, quality and service life of the core 100, the sum of the length of the exposed tab segment 131 of the longest tab 130 in the core 100 and the length of the inserted tab segment 132 is less than or equal to 40 mm.

[0042] In some embodiments of the present utility model, the separator layer 120 is a base film with a thickness of 9 microns, and both sides of the base film are coated with ceramics and polyvinylidene fluoride. Such a specific design of the separator layer 120, its size and composition are of great significance for improving the quality of the electrode core 100. By setting the separator layer 120 as a 9-micron base film, the resistance inside the electrode core 100 can be reduced, the resistance of electrons and ions during transmission between the positive and negative electrodes can be decreased, the charge and discharge efficiency of the electrode core 100 can be increased, the energy density of the electrode core 100 can be improved, and the electron transmission rate and ion diffusion rate of the electrode core 100 can also be increased, enabling the electrode core 100 to quickly respond to high-power demands, improving the power density of the electrode core 100, and enabling the electrode core 100 to adapt to the demands of higher power output. Further, by coating ceramics on both sides of the base film, the separator layer 120 can be effectively prevented from melting or deforming in a high-temperature environment, ensuring the safety and stability of the electrode core 100. In addition, the breakdown resistance of the separator layer 120 can be increased, the risk of perforation or breakdown of the separator layer 120 can be reduced, and thus the possibility of short circuit of the electrode core 100 can be decreased. By coating polyvinylidene fluoride on both sides of the base film, the chemical stability of the separator layer 120 can be improved, enabling the separator layer 120 to have good chemical corrosion resistance, and thus extending the service life of the separator layer 120.

[0043] As Figure 3 shown, in some embodiments, the center 140 of the electrode core 100 includes a first direction L1 and a second direction L2 in the directions on both sides of the electrode core 100. The increasing amplitude of the length of the exposed tab section 131 in the first direction L1 is the same as the increasing amplitude of the length of the exposed tab section 131 in the second direction L2, which can avoid the situation where the tab 130 is torn or the tab 130 is too long in the first direction L1 or the second direction L2 alone, causing inconvenience in tab 130 cutting, and thus reducing the assembly efficiency of the electrode core 100.

[0044] As Figure 3 shown, in some embodiments, the tab 130 includes a positive tab 133 and a negative tab 134. Among them, the positive tab 133 can be a copper foil, and the negative tab 134 can be an aluminum foil.

[0045] By reasonably selecting the materials of the positive tab 133 and the negative tab 134 of the present utility model, the safety, reliability and performance of the electrode core 100 can be improved, and the quality and service life of the electrode core 100 can be enhanced. Specifically, it means:

[0046] (1) Improving conductivity: The conductivity of copper is higher than that of aluminum. Therefore, using a copper foil for the positive tab 133 can provide better current transmission performance, reduce the resistance of the positive tab 133, and contribute to improving the discharge performance and charging efficiency of the electrode core 100.

[0047] (2) Improve thermal conductivity: Copper also has better thermal conductivity than aluminum. Using a copper foil for the positive electrode tab 133 helps to dissipate heat more effectively, preventing the core 100 from overheating due to heat accumulation during use, which could lead to a decline in the performance of the core 100 or pose a safety hazard.

[0048] (3) Improve electrochemical stability: Aluminum performs well in terms of electrochemical stability. As the material for the negative electrode tab 134, it can effectively reduce corrosion and oxidation inside the core 100, extending the service life of the core 100.

[0049] (4) Improve lightweight: Aluminum is relatively lighter than copper. Using an aluminum foil as the negative electrode tab 134 can reduce the overall weight of the core 100, helping to improve the energy density and power density of the core 100.

[0050] (5) Improve economy: Aluminum has a lower cost compared to copper. Using an aluminum foil as the negative electrode tab 134 can reduce the manufacturing cost of the core 100 and improve the economic applicability of the core 100.

[0051] In some embodiments of the present utility model, the dressing layer 110 is divided into a positive electrode dressing layer 111 and a negative electrode dressing layer 112 arranged alternately with the positive electrode dressing layer 111. The positive electrode tab 133 is inserted into the positive electrode dressing layer 111, and the negative electrode tab 134 is inserted into the negative electrode dressing layer 112. Among them, the thickness of a single-layer positive electrode dressing layer 111 is the first positive electrode thickness H11, the thickness of a single-layer negative electrode dressing layer 112 is the first negative electrode thickness H12, the thickness of a single-layer separator layer 120 is the second separator thickness H20, the thickness of a single-layer positive electrode tab 133 is the third positive electrode thickness H31, and the thickness of a single-layer negative electrode tab 134 is the third negative electrode thickness H32. It should be noted that the first positive electrode thickness H11 refers to half of the thickness of the positive electrode dressing layer 111, and the first negative electrode thickness H12 refers to half of the thickness of the negative electrode dressing layer 112.

[0052] In some embodiments of the present utility model, the positive electrode dressing layer 111 includes 94.5% lithium iron phosphate, 3.0% binder, and 2.5% conductive carbon black. The single-sided areal density of the positive electrode dressing layer 111 is 164 grams per cubic meter, and the tap density of the positive electrode dressing layer 111 is 2.5 grams per cubic centimeter. The negative electrode dressing layer 112 includes 94.0% artificial graphite, 2.5% binder, 2.0% dispersant, and 1.5% conductive carbon black. The single-sided areal density of the negative electrode dressing layer 112 is 76 grams per cubic meter, and the tap density of the negative electrode dressing layer 112 is 1.5 grams per cubic centimeter.

[0053] It should be understood that the component ratios of the above-mentioned positive electrode dressing layer 111 and the negative electrode dressing layer 112 are relatively optimal electrode sheet component ratio schemes in the present invention. Specifically, the component ratio of the positive electrode dressing layer 111 can be changed by adjusting the proportions of lithium iron phosphate, binder, and conductive carbon black, and the component ratio of the negative electrode dressing layer 112 can be changed by adjusting the proportions of artificial graphite, binder, dispersant, and conductive carbon black.

[0054] Figure 4 is a cross-sectional view of the battery during the battery assembly process provided by the present invention. As Figure 4 shown, the second aspect embodiment of the present invention provides a battery, including a battery cell top cover 200, a battery housing 300, and any one of the above-mentioned electrode cores 100. Among them, the battery cell top cover 200 is flush with the center 140 of the electrode core 100. The upper surface of the battery cell top cover 200 is provided with an ear welding area 210, and the exposed section 131 of the ear is welded to the ear welding area 210. The battery housing 300 wraps the dressing layer 110, the separator layer 120, the inserted section 132 of the ear, and the exposed section 131 of the ear inside the housing.

[0055] By making the battery cell top cover 200 flush with the center 140 of the electrode core 100, the ear welding area 210 is located at the center 140 position of the electrode core 100, which can ensure that when the positive electrode ears 133 of the electrode core 100 are pressed together, the fitting positions of the endpoints of the positive electrode ears 133 outside the battery housing 300 are consistent, and when the negative electrode ears 134 of the electrode core 100 are pressed together, the fitting positions of the endpoints of the negative electrode ears 134 outside the battery housing 300 are consistent, thus avoiding the situation of long ears 130 and improving the quality of the battery. It should be noted that in some embodiments of the present invention, the battery housing 300 is usually a metal housing. Preferably, the battery housing 300 can be an aluminum shell, which can reduce the weight of the battery and improve the anti-corrosion performance of the battery.

[0056] As Figure 4 shown, in some embodiments, the center of the ear welding area 210 overlaps with the center of the upper surface of the battery cell top cover 200, and one end of the exposed section 131 of the ear outside the battery housing 300 overlaps with the center of the ear welding area 210.

[0057] Figure 5 is a schematic cross-sectional view of one side of the battery provided by the present invention. As Figure 5As shown, the tab 130 includes a positive tab 133 and a negative tab 134. The positive tab 133 and the negative tab 134 are arranged alternately. The negative tab 134 includes a first negative tab 135 and a second negative tab 136. The tab exposed section 131 of the first negative tab 135 includes a first exposed section d1, a second exposed section d2, and a third exposed section d3. The front end of the first exposed section d1 is flush with the center of the tab welding mark area 210. The rear end of the first exposed section d1 is flush with one end of the cell top cover 200 close to the battery case 300. The front end of the second exposed section d2 is connected to the rear end of the first exposed section d1. The second exposed section d2 is perpendicular to the battery case 300 and the rear end of the second exposed section d2 is in contact with the surface of the battery case 300. The front end of the third exposed section d3 is connected to the rear end of the second exposed section d2. The third exposed section d3 is perpendicular to the dressing layer 110 and the rear end of the third exposed section d3 is in contact with the surface of the dressing layer 110. The tab exposed section 131 of the second negative tab 136 adjacent to the first negative tab 135 includes a fourth exposed section d4, a fifth exposed section d5, and a sixth exposed section d6. The fourth exposed section d4 overlaps with the first exposed section d1. The front end of the fifth exposed section d5 is connected to the rear end of the fourth exposed section d4. The fifth exposed section d5 is inclined to contact the battery case 300 and the rear end of the fifth exposed section d5 is in contact with the surface of the battery case 300. The front end of the sixth exposed section d6 is connected to the rear end of the fifth exposed section d5. The sixth exposed section d6 is perpendicular to the dressing layer 110 and the rear end of the sixth exposed section d6 is in contact with the surface of the dressing layer 110. The length of the fourth exposed section d4 is equal to the length of the first exposed section d1. The length of the sixth exposed section d6 is equal to the length of the third exposed section d3. The length of the tab exposed section 131 of the first negative tab 135 is equal to the sum of the lengths of the first exposed section d1, the second exposed section d2, and the third exposed section d3. The length of the tab exposed section 131 of the second negative tab 136 is equal to the sum of the lengths of the first exposed section d1, the fifth exposed section d5, and the third exposed section d3.

[0058] It should be noted that, as Figure 5As shown, the second exposed section d2 is vertically connected to the housing, and the fifth exposed section d5 is connected to the housing and is also connected to the second exposed section d2. Therefore, the battery housing 300 between the fifth exposed section d5, the second exposed section d2, and the first negative electrode tab 135 and the second negative electrode tab 136 can form a right triangle. Further, the length of the battery housing 300 between the first negative electrode tab 135 and the second negative electrode tab 136 is the same as the thickness of the electrode core 100 between the first negative electrode tab 135 and the second negative electrode tab 136. Among them, the thickness of the electrode core 100 between the first negative electrode tab 135 and the second negative electrode tab 136 includes one-half of the first thickness h1, the second thickness h2, the third thickness h3, the fourth thickness h4, the fifth thickness h5, the sixth thickness h6, the seventh thickness h7, the eighth thickness h8, and one-half of the ninth thickness h9. The first thickness h1 is the same as the ninth thickness h9, the second thickness h2 is the same as the eighth thickness h8, the third thickness h3 is the same as the seventh thickness h7, and the fourth thickness h4 is the same as the sixth thickness h6. Therefore, the length of the fifth exposed section d5 is related to the second exposed section d2, and the length of the fifth exposed section d5 is also related to the first thickness h1, twice the second thickness h2, twice the third thickness h3, twice the fourth thickness h4, and the fifth thickness h5.

[0059] Specifically, as Figure 5 shown,

[0060] Among them, K is a balance coefficient, and the balance coefficient is greater than or equal to 0.99 and less than or equal to 1.01.

[0061] In some embodiments, the first thickness h1 is the third negative electrode thickness H32, the second thickness h2 is the first negative electrode thickness H12, the third thickness h3 is the second separator thickness H20, the fourth thickness h4 is the first positive electrode thickness H11, and the fifth thickness h5 is the third positive electrode thickness H31.

[0062] In some embodiments of the present application, it should be noted that the length of the tab exposed section 131 is related to the thickness from the position of the tab exposed section 131 on the electrode core 100 to the center 140 of the electrode core 100. Therefore, the length of the tab exposed section 131 of each tab 130 is related to the thickness of the dressing layer 110 and the separator layer 120.

[0063] The third aspect embodiment of the present utility model provides a battery pack, including a battery pack housing and any one of the above batteries, wherein the battery pack housing is used to wrap the battery.

[0064] The third aspect embodiment of the present utility model provides a vehicle, including any one of the above battery packs, which can improve the endurance and response speed of the vehicle.

[0065] The present utility model provides an electrode core, a battery, a battery pack and a vehicle. By cutting the tabs of the electrode core during the pre-welding process of the tab assembly process of the electrode core, the length of the tabs gradually increases along the center of the electrode core towards both sides of the electrode core, so as to ensure that when the positive tabs of the electrode core are pressed together, the fitting positions of the ends of the positive tabs far from the electrode core are consistent, and when the negative tabs of the electrode core are pressed together, the fitting positions of the ends of the negative tabs far from the electrode core are consistent, reducing the probability of tab tearing and tab redundancy during the assembly process of the electrode core, thereby improving the quality of the electrode core.

[0066] As used in the specification of this application and the above-mentioned drawings, the terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that comprises a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0067] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or its similar expression means any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them. Although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present utility model, and they should all be covered by the scope of the claims and the specification of the present utility model.

Claims

1. A pole core, characterized in that: include: Dressing layer; A membrane layer; wherein the membrane layer and the dressing layer are arranged alternately; The pole ear; wherein the pole ear comprises an exposed section and an inserted section connected to the exposed section, the inserted section is inserted into the dressing layer, the length of the exposed section increases nonlinearly along a preset direction, the preset direction is the direction from the center of the pole core to both sides of the pole core, and the length of the inserted section is the same.

2. The pole core according to claim 1, characterized in that: The preset direction includes a first direction and a second direction, and the incremental length increment of the exposed section of the tab in the first direction is the same as the incremental length increment of the exposed section of the tab in the second direction.

3. The pole core according to claim 1, characterized in that: The sum of the length of the exposed section of the tab and the length of the inserted section of the tab is less than or equal to 40 mm.

4. The pole core according to claim 1, characterized in that: The electrode tabs include a positive electrode tab and a negative electrode tab, the positive electrode tab is copper foil, and the negative electrode tab is aluminum foil.

5. The pole core according to claim 4, characterized in that: The dressing layer is divided into a positive electrode dressing layer and a negative electrode dressing layer arranged alternately with the positive electrode dressing layer, the positive electrode tab is inserted into the positive electrode dressing layer, and the negative electrode tab is inserted into the negative electrode dressing layer.

6. A battery, characterized in that: It comprises a battery cell top cover, a battery shell and a pole core as claimed in any one of claims 1 to 5, wherein the battery cell top cover is flush with the center of the pole core, the upper surface of the battery cell top cover is provided with a pole lug welding area, the pole lug exposed section is welded on the pole lug welding area, and the battery shell wraps the dressing layer, the diaphragm layer, the pole lug inserted section and the pole lug exposed section in the shell.

7. The battery according to claim 6, characterized in that The center of the pole tab weld mark area overlaps with the center of the upper surface of the battery cell top cover, and the end of the pole tab exposed section outside the battery housing overlaps with the center of the pole tab weld mark area.

8. The battery according to claim 6, characterized in that The electrode tab comprises a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab are arranged alternately, the negative electrode tab comprises a first negative electrode tab and a second negative electrode tab, the electrode tab exposed section of the first negative electrode tab comprises a first exposed section, a second exposed section and a third exposed section, the front end of the first exposed section is flush with the center of the electrode tab welding area, the rear end of the first exposed section is flush with an end of the battery cell top cover close to the battery shell, the front end of the second exposed section is connected to the rear end of the first exposed section, the second exposed section is perpendicular to the battery shell and the rear end of the second exposed section is in contact with the surface of the battery shell, the front end of the third exposed section is connected to the rear end of the second exposed section, the third exposed section is perpendicular to the dressing layer and the rear end of the third exposed section is in contact with the surface of the dressing layer, the electrode tab outer section of the second negative electrode tab adjacent to the first negative electrode tab The exposed section includes a fourth exposed section, a fifth exposed section and a sixth exposed section, the fourth exposed section overlaps with the first exposed section, the front end of the fifth exposed section is connected to the rear end of the fourth exposed section, the fifth exposed section is obliquely connected to the battery shell and the rear end of the fifth exposed section is connected to the surface of the battery shell, the front end of the sixth exposed section is connected to the rear end of the fifth exposed section, the sixth exposed section is perpendicular to the dressing layer and the rear end of the sixth exposed section is connected to the surface of the dressing layer, the length of the fourth exposed section is equal to the length of the first exposed section, the length of the sixth exposed section is equal to the length of the third exposed section, the length of the first negative electrode ear is equal to the sum of the lengths of the first exposed section, the second exposed section and the third exposed section, and the length of the second negative electrode ear is equal to the sum of the lengths of the first exposed section, the fifth exposed section and the third exposed section.

9. A battery pack, characterized in that: It comprises a battery pack shell and a battery as claimed in any one of claims 6 to 8, wherein the battery pack shell is used to wrap the battery.

10. A vehicle, characterized in that: Comprising the battery pack as claimed in claim 9.

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