Pole piece, pole core, battery and electric equipment

Abstract

The utility model discloses a pole piece, a pole core, a battery and electric equipment, at least one groove is formed on the pole piece, the groove is arranged on the surface of at least one side of the pole piece, the groove obliquely extends on the surface of one side of the pole piece, and the groove penetrates through the surfaces of two sides adjacent to two ends of the groove. An included angle alpha is formed between the center line of the groove and the edge, adjacent to the end of the center line, of the two side surfaces, and alpha is larger than 0 and smaller than 180 degrees and not equal to 90 degrees. Therefore, the pole piece is suitable for the battery, the groove is formed in the pole piece, and the inclined groove can form an exhaust channel under the condition of thermal runaway of the battery, so that gas generated by thermal runaway of the battery can be guided to be quickly exhausted to an anti-explosion valve through the groove, a flowing path of the thermal runaway gas on the surface of the pole piece is optimized, and the exhaust efficiency is improved; the pressure is quickly released, and the internal pressure accumulation is reduced, so that the explosion risk is reduced, and the safety and reliability of the battery are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a pole piece, a pole core, a battery and an electrical equipment. Background Art

[0002] In the prior art, when the position of thermal runaway of the battery is far from the position of the explosion-proof valve, the generated gas often causes the battery case to explode due to the unsmooth exhaust passage, which is dangerous. To solve this problem, the existing solutions will set multiple explosion-proof valves on the narrow side of the battery, and the multiple explosion-proof valves increase the material and manufacturing costs of the battery. 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 reason, the first object of the utility model is to provide a pole piece, which can improve the safety and reliability of the battery.

[0004] The second object of the utility model is to provide a pole core, which includes at least one positive pole piece, at least one negative pole piece and a separator, and the positive pole piece is the pole piece described in the above embodiments.

[0005] The third object of the utility model is to provide a battery, which includes a case, an explosion-proof valve and the pole core described in the above embodiments.

[0006] The fourth object of the utility model is to provide an electrical equipment, which includes the battery described in the above embodiments.

[0007] According to the pole piece of the first aspect embodiment of the utility model, at least one groove is formed on the pole piece, the groove is arranged on at least one side surface of the pole piece, the groove extends obliquely on the side surface of the pole piece, and the groove penetrates through the two side surfaces adjacent to the two ends of the groove. An included angle α is formed between the center line of the groove and the edge of the two side surfaces adjacent to the end of the center line, and the α satisfies: 0 < α < 180°, and α ≠ 90°.

[0008] According to the pole piece of the embodiment of the utility model, the pole piece is applicable to the battery. By arranging the groove on the pole piece, in the case of thermal runaway of the battery, the obliquely arranged groove can form an exhaust passage, which can guide the gas generated by the thermal runaway of the battery to quickly pass through the groove to the explosion-proof valve, optimize the flow path of the thermal runaway gas on the surface of the pole piece, improve the exhaust efficiency, quickly release the pressure, reduce the internal pressure accumulation, thereby reducing the explosion risk and improving the safety and reliability of the battery.

[0009] In some embodiments, the α further satisfies: 30° ≤ α ≤ 150°, and α ≠ 90°.

[0010] In some embodiments, there are multiple grooves, and the multiple grooves include a first groove and a second groove. The first groove and the second groove are disposed on two sides in the thickness direction of the pole piece, and at least a part of the projections of the first groove and the second groove on the pole piece do not coincide.

[0011] In some embodiments, the projections of the first groove and the second groove on the pole piece are perpendicularly arranged.

[0012] In some embodiments, the multiple first grooves and the multiple second grooves both include: at least one first sub - groove and at least one second sub - groove. The first sub - groove and the second sub - groove are disposed at two ends of the pole piece along the length direction of the pole piece, and the distance between the first sub - groove and the second sub - groove shows a decreasing trend from one end to the other end along the width direction of the pole piece; and / or the distance between the first sub - groove and the second sub - groove shows an increasing trend from the one end to the other end along the width direction of the pole piece.

[0013] In some embodiments, there are multiple first sub - grooves and multiple second sub - grooves. The distance between the center of the area where the multiple first sub - grooves are located and the center of the pole piece is L1, and the distance between the center of the area where the multiple second sub - grooves are located and the center of the pole piece is L2. The length of the pole piece is L, and L, L1, and L2 satisfy: 1 / 4L ≤ L1 ≤ 1 / 2L, 1 / 4L ≤ L2 ≤ 1 / 2L.

[0014] In some embodiments, the first sub - groove and the second sub - groove are symmetrically arranged along the length direction of the pole piece.

[0015] In some embodiments, the pole piece includes: a current collector and an active material layer. The active material layer is disposed on at least one side in the thickness direction of the current collector, and the groove is formed on the active material layer.

[0016] In some embodiments, the thickness of the active material layer is L3, and the depth of the groove is L4, and L3 and L4 satisfy: L4 ≤ L3.

[0017] In some embodiments, the width of the groove is L5, and L5 satisfies: 0.1mm ≤ L5 ≤ 0.3mm.

[0018] According to the pole core of the second - aspect embodiment of the present utility model, the pole core includes: at least one positive - pole piece, at least one negative - pole piece, and a separator. The separator is disposed between the adjacent positive - pole piece and negative - pole piece, and at least one of at least the positive - pole piece and the negative - pole piece is the pole piece according to the first - aspect embodiment of the present utility model.

[0019] In some embodiments, a groove of the electrode tab is provided on the negative electrode tab, the width of the groove of the negative electrode tab is L6, the width of the groove of the positive electrode tab is L5, and L5 and L6 satisfy: L6 ≤ L5 + 1 mm.

[0020] A battery according to an embodiment of the third aspect of the present invention includes: a housing, an explosion-proof valve, and a core. The explosion-proof valve is provided on the housing; the core is provided in the housing, the core and the housing define an exhaust passage, the exhaust passage communicates with the explosion-proof valve, and the core is the core according to the embodiment of the second aspect of the present invention.

[0021] In some embodiments, the housing includes adjacent first and second side surfaces, the area of the first side surface is less than or equal to the area of the second side surface; the explosion-proof valve is provided on the first side surface, the groove of the core is provided on a side of the electrode tab facing the second side surface, and the groove extends obliquely toward the explosion-proof valve.

[0022] In some embodiments, the cross-sectional area of the exhaust passage is S1, the sum of the cross-sectional areas of a plurality of grooves provided on the electrode tab of the core is S2, and S1 ≤ S2.

[0023] In some embodiments, the width of the groove is a, the depth of the groove is b, n grooves are formed on each electrode tab, each core includes m electrode tabs, the distance between the surface of the core adjacent to the explosion-proof valve and the side wall of the housing where the explosion-proof valve is provided is c, and the thickness of the core adjacent to the explosion-proof valve is h. Among them, the battery satisfies a × b × m × n ≥ 40% × c × h.

[0024] An electrical device according to an embodiment of the fourth aspect of the present invention includes the battery according to the embodiment of the third aspect of the present invention.

[0025] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 is a schematic diagram of a battery according to an embodiment of the present invention.

[0028] Figure 2 is a schematic diagram of an electrode tab according to an embodiment of the present invention.

[0029] Figure 3 isFigure 2 Enlarged schematic view of the P region in the middle.

[0030] Figure 4 It is a schematic cross-sectional view of the electrode core according to an embodiment of the present invention.

[0031] Figure 5 It is a schematic view of the electrode core according to an embodiment of the present invention.

[0032] Reference numerals:

[0033] 100, battery;

[0034] 10, electrode core; 11, positive electrode tab; 12, negative electrode tab; 13, separator; 14, tab.

[0035] 20, electrode tab; 21, groove; 22, first groove; 23, second groove; 24, first sub-groove; 25, second sub-groove; 26, current collector; 27, active material layer.

[0036] 30, housing; 31, explosion-proof valve.

[0037] A, width direction; B, length direction; C, thickness direction. Detailed implementation manners

[0038] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. Below, reference is made to Figures 1-5 Describe the electrode tab 20 according to an embodiment of the present invention.

[0039] Specifically, as Figures 1-5 shown, at least one groove 21 is formed on the electrode tab 20. The groove 21 is provided on at least one side surface of the electrode tab 20. The groove 21 extends obliquely on one side surface of the electrode tab 20, and the groove 21 penetrates through the two side surfaces adjacent to both ends of the groove 21. An included angle α is formed between the center line of the groove 21 and the edge adjacent to the end of the center line of the two side surfaces. α satisfies: 0 < α < 180°, and α ≠ 90°.

[0040] Combined with Figure 2, the electrode tab 20 is applicable to the battery 100. One end of the battery 100 is provided with an explosion-proof valve 31. Let the end where the explosion-proof valve 31 is located be one end of the electrode tab 20 in the width direction A. Let the electrode tab 20 have a width direction A, a length direction B, and a thickness direction C. One end of the groove 21 starts from one end of the electrode tab 20 along the width direction A, and the other end of the groove 21 extends obliquely along the width direction A of the electrode tab 20 towards the other end of the electrode tab 20. The groove 21 is formed by at least a part of the surface of the electrode tab 20 along the thickness direction C being recessed along the thickness direction C. The two end portions of the groove 21 penetrate through the electrode tab 20 and the two adjacent side surfaces of the two ends of the groove 21. The included angle between the center line of the groove 21 and the edges of the two side surfaces of the electrode tab 20 adjacent to the end portion of the center line of the groove 21 is α. The electrode tab 20 has two side surfaces along the width direction A. The two end portions of the center line of the groove 21 are respectively adjacent to the two side surfaces of the electrode tab 20 along the width direction A, and the two end portions of the groove 21 penetrate through the two side surfaces of the electrode tab 20 along the width direction A.

[0041] Among them, α satisfies: 0 < α < 180°, and α ≠ 90°, that is, the groove 21 is not perpendicular to the side of the electrode tab 20 along the width direction A, nor parallel to the side of the electrode tab 20 along the width direction A. When the battery 100 has a thermal runaway phenomenon, if α = 0° or 180°, then the groove 21 is parallel to the side of the electrode tab 20 along the width direction A where the explosion-proof valve 31 is provided, and the groove 21 cannot communicate with the explosion-proof valve 31 provided at one end of the electrode tab 20 in the width direction A. The gas generated by the thermal runaway cannot be directly discharged to the explosion-proof valve 31 through the groove 21, which is not conducive to shortening the exhaust path. If α = 90°, then when the groove 21 is perpendicular to the side of the electrode tab 20 along the width direction A, the groove 21 is provided on both side surfaces of the electrode tab 20, which easily leads to a relatively low structural strength at the groove 21 of the electrode tab 20, and phenomena such as fracture or bending are likely to occur. When α satisfies: 0 < α < 180°, it can be ensured that the groove 21 can effectively guide the gas flow towards the explosion-proof valve 31 during the thermal runaway of the battery 100, reduce the tortuosity of the gas discharge path, and improve the gas discharge efficiency.

[0042] According to the electrode tab 20 of the embodiment of the present invention, the electrode tab 20 is applicable to the battery 100. By providing the groove 21 on the electrode tab 20, in the case of thermal runaway of the battery 100, the obliquely arranged groove 21 can form an exhaust channel, which can guide the gas generated by the thermal runaway of the battery 100 to quickly pass through the groove 21 and be discharged to the explosion-proof valve 31, optimize the flow path of the thermal runaway gas on the surface of the electrode tab 20, improve the exhaust efficiency, quickly release the pressure, reduce the internal pressure accumulation, thereby reducing the explosion risk and improving the safety and reliability of the battery 100.

[0043] According to some embodiments of the present invention, as Figure 2 shown, α further satisfies: 30° ≤ α ≤ 150°, and α ≠ 90°.

[0044] When α further satisfies 30° ≤ α ≤ 150°, the groove 21 can effectively guide the gas generated during thermal runaway, making it flow along an inclined path towards the explosion-proof valve 31, so that the gas flow path can be smoother, reducing the resistance of gas flow, thereby accelerating the gas discharge speed, helping to timely release the pressure inside the battery 100, and preventing more serious explosion accidents.

[0045] Therefore, defining the range of the angle α formed between the center line of the groove 21 and the corresponding side can ensure that the groove 21 can effectively guide the gas towards the explosion-proof valve 31 during thermal runaway of the battery 100, reducing the tortuosity of the gas discharge path, improving the gas discharge efficiency. The appropriate angle can also ensure the structural strength of the electrode tab 20, reducing the risk of fracture or bending, ensuring that the electrode tab 20 has good structural integrity and mechanical properties, and extending the service life of the electrode tab 20.

[0046] According to some embodiments of the present invention, as Figures 2-4 shown, there are multiple grooves 21. The multiple grooves 21 include a first groove 22 and a second groove 23. The first groove 22 and the second groove 23 are provided on both sides of the electrode tab 20 in the thickness direction C. The projections of the first groove 22 and the second groove 23 on the electrode tab 20 do not completely overlap at least partially.

[0047] That is, grooves 21 are provided on both side surfaces of the electrode tab 20 along the thickness direction C. The two side surfaces of the electrode tab 20 along the thickness direction C are respectively a first surface and a second surface. The first groove 22 is formed on the first surface. The first groove 22 is recessed from at least a part of the first surface towards the side where the second surface is located along the thickness direction C of the electrode tab 20. The second groove 23 is recessed from at least a part of the second surface towards the side where the first surface is located along the thickness direction C of the electrode tab 20. The projections of the first groove 22 and the second groove 23 do not overlap, that is, the first groove 22 and the second groove 23 are not completely opposite in the thickness direction C of the electrode tab 20, which is beneficial to ensuring the structural strength of the electrode tab 20. In some embodiments, the projections of the first groove 22 and the second groove 23 on the electrode tab 30 intersect, that is, the projections of the first groove 22 and the second groove 23 along the thickness direction C of the electrode tab 30 partially overlap.

[0048] Therefore, the arrangement of the first groove 22 and the second groove 23 helps the heat transfer inside the battery 100, helps the heat to be evenly distributed, and improves the gas discharge efficiency. Through the different groove 21 layouts on both sides of the electrode tab 20, the gas generated inside can be more efficiently guided towards the explosion-proof valve 31, improving the safety performance of the battery 100, and ensuring the structural strength of the electrode tab 20, ensuring the reliability of the battery 100.

[0049] According to some embodiments of the present utility model, the projections of the first groove 22 and the second groove 23 on the pole piece 20 are perpendicularly arranged. Preferably, the included angle α formed between the center line of the first groove 22 and the corresponding side can be 45°, and the included angle α formed between the center line of the second groove 23 and the corresponding side can be 135°. Thus, the projections of the first groove 22 and the second groove 23 on the pole piece 20 are staggeredly perpendicular, which can reduce the strength weakening effect of a single groove 21 on the pole piece 20, ensure the overall mechanical strength and bending resistance of the pole piece 20, and form an exhaust channel, which helps to disperse and export the gas inside the battery 100, is conducive to the evacuation of the gas, improves the thermal management of the battery 100, and enhances the safety and service life of the battery 100.

[0050] According to some embodiments of the present utility model, as Figure 2 and Figure 3 shown, the multiple first grooves 22 and the multiple second grooves 23 both include: at least one first sub-groove 24 and at least one second sub-groove 25. The first sub-groove 24 and the second sub-groove 25 are arranged at both ends of the pole piece 20 along the length direction B of the pole piece 20, and the distance between the first sub-groove 24 and the second sub-groove 25 shows a decreasing trend from one end to the other along the width direction A of the pole piece 20. There is a certain distance between the first sub-groove 24 and the second sub-groove 25 along the length direction B of the pole piece 20. One end of the first sub-groove 24 and one end of the second sub-groove 25 are both arranged on the same side edge of the pole piece 20 along the width direction A, and the other end of the first sub-groove 24 and the other end of the second sub-groove 25 are inclined and extended towards each other along the length direction B of the pole piece 20.

[0051] Alternatively, the distance between the first sub-groove 24 and the second sub-groove 25 shows an increasing trend from one end to the other along the width direction A of the pole piece 20. One end of the first sub-groove 24 and one end of the second sub-groove 25 are both arranged on the same side edge of the pole piece 20 along the width direction A, and the other end of the first sub-groove 24 and the other end of the second sub-groove 25 are inclined and extended away from each other along the length direction B of the pole piece 20.

[0052] In some embodiments, among the multiple first grooves 22 on the first surface of the pole piece 20, one end of the first sub-groove 24 and the second sub-groove 25 is arranged at the end of the pole piece 20 along the width direction A where the explosion-proof valve 31 is provided, the distance between one end of the first sub-groove 24 and the second sub-groove 25 is smaller, and the distance between the other end of the first sub-groove 24 and the second sub-groove 25 is larger. Among the multiple second grooves 23 on the second surface of the pole piece 20, one end of the first sub-groove 24 and the second sub-groove 25 is arranged at the end of the pole piece 20 along the width direction A where the explosion-proof valve 31 is provided, the distance between one end of the first sub-groove 24 and the second sub-groove 25 is larger, and the distance between the other end of the first sub-groove 24 and the second sub-groove 25 is smaller.

[0053] Thus, the layout of the first sub-groove 24 and the second sub-groove 25 helps to improve the exhaust efficiency of the electrode sheet 20, takes into account the overall mechanical properties of the electrode sheet 20, and also helps to form a more uniform pressure distribution on the surface of the electrode sheet 20, ensuring the mechanical strength of the electrode sheet 20 to improve the durability of the battery 100.

[0054] According to some embodiments of the present invention, such as Figure 2 and Figure 3 shown, there are multiple first sub-grooves 24 and multiple second sub-grooves 25. The distance between the center of the region where the multiple first sub-grooves 24 are located and the center of the electrode sheet 20 is L1, and the distance between the center of the region where the multiple second sub-grooves 25 are located and the center of the electrode sheet 20 is L2. The length of the electrode sheet 20 is L, and L, L1, and L2 satisfy: 1 / 4L ≤ L1 ≤ 1 / 2L, 1 / 4L ≤ L2 ≤ 1 / 2L.

[0055] The center of the region where the multiple first sub-grooves 24 are located means that: if the number of the multiple first sub-grooves 24 is odd, the middle first sub-groove 24 is the center of the region where the multiple first sub-grooves 24 are located; if the number of the multiple first sub-grooves 24 is even, the symmetric center of the two middle first sub-grooves 24 is the center of the region where the multiple first sub-grooves 24 are located. The same applies to the center of the region where the multiple second sub-grooves 25 are located.

[0056] Along the length direction B of the electrode sheet 20, the distance between the center of the first sub-groove 24 region and the center of the electrode sheet 20 is L1, satisfying: 1 / 4L ≤ L1 ≤ 1 / 2L, that is, the first sub-groove 24 is located in the first half of the electrode sheet 20 along the length direction B. The distance between the center of the first sub-groove 21 region and the center of the electrode sheet 20 along the length direction B is greater than or equal to 1 / 4 of the length of the electrode sheet 20, and the center of the first sub-groove 24 region is not completely centered in the first half of the electrode sheet 20. The distance between the center of the first sub-groove 21 region and the center of the electrode sheet 20 along the length direction B is less than or equal to 1 / 2 of the length of the electrode sheet 20. The position constraint of the second sub-groove 25 is the same as that of the first group, and the second sub-groove 25 is positioned in the corresponding region in the second half of the electrode sheet 20 along the length direction B. Preferably, the distance L1 between the center of the first sub-groove 24 region and the center of the electrode sheet 20 is 1 / 3L, and the distance L2 between the center of the second sub-groove 25 region and the center of the electrode sheet 20 is 1 / 3L.

[0057] Thus, by defining the distances between the first sub-groove 24 and the second sub-groove 25 and the center of the pole piece 20, it can be ensured that whether it is the first sub-groove 24 or the second sub-groove 25, they are relatively evenly distributed within the main length range of the pole piece 20, avoiding stress concentration or functional imbalance that may be caused by extreme positions. At the same time, the explosion-proof valve 31 is located at the middle position of the pole piece 20 along the length direction B, and the first sub-groove 24 and the second sub-groove 25 are respectively arranged on both sides of the explosion-proof valve 31 along the length direction B. Defining the distance range between the first sub-groove 24 and the second sub-groove 25 and the center of the pole piece 20 ensures that the gas generated at each point on both sides of the explosion-proof valve 31 can be guided to the explosion-proof valve 31 through the groove 21, and shortens the exhaust guiding path, improving the exhaust efficiency.

[0058] According to some embodiments of the present invention, as Figure 2 shown, the first sub-groove 24 and the second sub-groove 25 are symmetrically arranged along the length direction B of the pole piece 20.

[0059] The symmetrical arrangement of the first sub-groove 24 and the second sub-groove 25 ensures the mechanical balance of the pole piece 20 in the length direction B, helps to reduce the phenomena of distortion or stress concentration caused by structural asymmetry, thereby improving the overall stability and service life of the pole piece 20. The symmetrical layout helps to form a more uniform distribution of the heat and gas generation areas during the operation of the battery 100. The symmetrical first sub-groove 24 and second sub-groove 25, as channels, can more efficiently guide heat and gas to the explosion-proof valves 31 or heat dissipation structures at both ends, improving the uniformity and efficiency of heat management and gas emission. The symmetrical design often simplifies the manufacturing process because a unified mold or processing procedure can be used to form the corresponding grooves 21, which is beneficial to improving production efficiency, reducing error rates, and at the same time reducing manufacturing costs.

[0060] Thus, the symmetrical arrangement of the first sub-groove 24 and the second sub-groove 25 along the length direction B of the pole piece 20 can improve the performance and safety of the battery 100, and also facilitate the improvement of the manufacturing convenience of the pole piece 20.

[0061] According to some embodiments of the present invention, as Figure 4 shown, the pole piece 20 includes: a current collector 26 and an active material layer 27. The active material layer 27 is provided on at least one side of the current collector 26 in the thickness direction C, and grooves 21 are formed on the active material layer 27.

[0062] The current collector 26 serves as the basic structure of the electrode sheet 20. The current collector 26 is mainly responsible for carrying current and is usually made of a material with good electrical conductivity and mechanical strength, such as copper or aluminum. The function of the current collector 26 is to provide an effective conduction path from the external circuit to the active material, ensuring the rapid transmission of charges, and at the same time supporting the entire structure of the electrode sheet 20. The active material layer 27 is directly coated or deposited on at least one side of the current collector 26. This layer of material usually contains active materials (such as lithium metal oxides or graphite in the lithium-ion battery 100) and conductive additives, aiming to increase the active area of the electrochemical reaction, thereby enhancing the electrochemical performance of the battery 100, such as increasing the energy density and power density.

[0063] In the front-end process of manufacturing the battery 100, copper-aluminum foil is usually used as the current collector 26. After coating the slurry containing the active material on it, it is then dried to form the active material layer 27, and then the electrode sheet 20 roll stock is made through a rolling process. According to the dimensions designed for different batteries 100, the roll stock will be cut into an appropriate width. Before or during the cutting of the roll stock, the active material layer 27 on both sides of the electrode sheet 20 can be cleaned by laser or the active material layer 27 on both sides of the extruded and sunken electrode sheet 20 can be processed by a metal knife die, so as to form multiple grooves 21 on the surface of the electrode sheet 20.

[0064] Thus, the grooves 21 are directly formed on the active material layer 27, which can protect the structural integrity of the current collector 26, avoid directly weakening the main structure for carrying current, and at the same time ensure that the grooves 21 can play a role in optimizing the gas discharge path without damaging the basic electrical conductivity and mechanical stability of the battery 100.

[0065] According to some embodiments of the present invention, as Figure 4 shown, the thickness of the active material layer 27 is L3, and the depth of the groove 21 is L4, and L3 and L4 satisfy: L4 ≤ L3.

[0066] Define the relationship between the thickness of the active material layer 27 and the depth of the groove 21, and ensure that the depth of the groove 21 does not exceed the thickness of the active material layer 27, which can ensure that even in the area of the groove 21, the active material layer 27 still has sufficient thickness to maintain good electrical conductivity, which is crucial for the smooth progress of the electrochemical reaction. Limiting the depth of the groove 21 not to exceed the thickness of the active material layer 27 helps to maintain the overall structural strength and stability of the electrode sheet 20. A reasonable design of the depth of the groove 21 can also optimize the effective exposure area of the active material, that is, the area where the electrochemical reaction occurs, which is beneficial to improving the energy density and power density of the battery 100. An overly deep groove 21 may weaken the mechanical strength of the electrode sheet 20 and increase the risk of breakage during the charge and discharge cycles of the battery 100. If the depth of the groove 21 is too shallow, when the battery 100 is charged and discharged, due to the influence of the formation of the SEI film or the intercalation and deintercalation of lithium ions from the negative electrode graphite, the electrode sheet 20 expands, resulting in the groove 21 being squeezed and blocked. If the groove 21 is designed too deep, it will cause the electrode sheet 20 to break at the groove 21. An appropriate depth of the groove 21 can increase the contact interface between the electrode material and the electrolyte without excessively reducing the total amount of active material actually participating in the reaction.

[0067] Thus, by defining the relationship between the thickness of the active material layer 27 and the depth of the groove 21, while ensuring the optimization of the performance of the battery 100, the manufacturability and the stability of the structure of the battery 100 can be ensured.

[0068] According to some embodiments of the present invention, such as Figure 4 shown, the width of the groove 21 is L5, and L5 satisfies: 0.1 mm ≤ L5 ≤ 0.3 mm.

[0069] If the width of the groove 21 is less than 0.1 mm, the width of the groove 21 is too small, and the processing difficulty of the groove 21 is too large, which will increase the production difficulty and production cost of the electrode sheet 20. If the width of the groove 21 is greater than 0.3 mm, the width of the groove 21 is too large, which is not conducive to the fine result control of the electrode sheet 20, and the overly wide groove 21 will also excessively cut the active material of the active material layer 27, resulting in a decline in the electrochemical performance of the battery 100.

[0070] Thus, defining the width range of the groove 21, within this range, the width of the groove 21 can effectively increase the specific surface area of the electrode material, thereby improving the efficiency of the electrochemical reaction. A suitable width of the groove 21 is also helpful for the thermal management inside the battery 100. By controlling the size of the groove 21, the heat distribution and heat dissipation efficiency inside the battery 100 can be affected, which helps to prevent local overheating and improve the safety of the battery 100.

[0071] According to the electrode core 10 of the second aspect embodiment of the present invention, such as Figure 4 and Figure 5As shown in the figure, the electrode core 10 includes: at least one positive electrode tab 11, at least one negative electrode tab 12, and a separator 13. The separator 13 is disposed between adjacent positive electrode tab 11 and negative electrode tab 12. At least one of the positive electrode tab 11 and the negative electrode tab 12 is an electrode tab 20 according to the embodiment of the first aspect of the present invention.

[0072] The electrode core 10 is composed of a plurality of stacked positive electrode tabs 11, negative electrode tabs 12, and separators 13. Both the positive electrode tab 11 and the negative electrode tab 12 are composed of a current collector 26 and an active material layer 27 coated on the current collector 26. The function of the separator 13 is to prevent direct contact between the positive and negative electrodes from causing a short circuit, while allowing lithium ions to pass through to complete the charge transfer during the charging and discharging processes. For the electrode core 10 composed of the positive electrode tab 11, the negative electrode tab 12, and the separator 13, positive and negative electrode leads 14 extend from both ends in the length direction B. The positive and negative electrode leads 14 are respectively connected to the positive and negative terminal assemblies, thereby realizing the output of current. To prevent the electrode core 10 from being scratched by the burrs at the shell opening or crushed by metal particles inside the shell when placed in the shell 30 and causing a short circuit, the electrode core 10 is wrapped with an insulating film. When grooves 21 are provided on both the positive electrode tab 11 and the negative electrode tab 12, the included angles of the grooves 21 on the two are different and not complementary to ensure the smoothness of the exhaust channel. If the included angles of the grooves 21 on the opposite positive electrode tab 11 and negative electrode tab 12 are the same or complementary, the adjacent two electrode tabs 20 are likely to have the situation of groove 21 embedding due to misalignment during lamination, resulting in the blockage of the exhaust channel.

[0073] For the electrode core 10 according to the embodiment of the present invention, through the application of a specially designed groove 21 structure on the positive electrode tab 11 or the negative electrode tab 12, combined with the use of the negative electrode material and the separator 13, the structure of the entire electrode core 10 is optimized. Grooves 21 are formed on the positive electrode tab 11 in the electrode core 10. The grooves 21 help to improve the thermal management ability of the electrode core 10, especially effectively guiding gas to discharge through the explosion-proof valve 31 in the case of thermal runaway, while ensuring the structural strength of the electrode tab 20 and the safety of the electrode core 10.

[0074] According to some embodiments of the present invention, as Figure 3 shown, grooves 21 of the electrode tab 20 are provided on the negative electrode tab 12. The width of the groove 21 of the negative electrode tab 12 is L6, and the width of the groove 21 of the positive electrode tab 11 is L5. L5 and L6 satisfy: L6 ≤ L5 + 1 mm.

[0075] The setting of the grooves 21 on the negative electrode tab 20 can further increase the cross-sectional area of the exhaust channel of the electrode core 10. However, considering the assembly accuracy of the mechanical handling equipment when the positive and negative electrode tabs 12 are stacked and assembled into the electrode core 10, there will be a dimensional error of ±0.5 mm in their relative positions. To ensure that the negative electrode tab 20 has sufficient lithium insertion positions, the width of the groove 21 of the negative electrode tab 20 needs to be less than or equal to the grooving width of the positive electrode tab 20 + 1 mm.

[0076] According to the battery 100 of the third aspect embodiment of the present utility model, as Figures 1-4 shown, it includes: a housing 30, an explosion-proof valve 31, and a core 10. The explosion-proof valve 31 is provided on the housing 30; the core 10 is provided inside the housing 30. The core 10 and the housing 30 define an exhaust passage, and the exhaust passage is communicated with the explosion-proof valve 31. The core 10 is the core 10 according to the second aspect embodiment of the present utility model.

[0077] The housing 30 serves as the external package of the battery 100, providing mechanical protection and sealing the internal components of the battery 100 to prevent external substances from invading. The explosion-proof valve 31 is installed on the housing 30. The explosion-proof valve 31 is provided at one end of the housing 30 along the width direction A, and the explosion-proof valve 31 is located at the middle position of the housing 30 along the length direction B. When the internal pressure of the battery 100 abnormally increases, the explosion-proof valve 31 can be opened in a timely manner to release excessive gas, prevent the battery 100 from exploding, and at the same time maintain the sealing performance of the battery 100 to avoid electrolyte leakage. There is a certain gap between both ends of the core 10 along the width direction A and the inner wall surfaces of both ends of the housing 30 along the width direction A. The gap is the exhaust passage defined by the core 10 and the housing 30. The exhaust passage is communicated with the groove 21. The exhaust passage is a gas flow path to ensure that the gas generated inside the battery 100 can be discharged to the explosion-proof valve 31 via the exhaust passage and the groove 21 and released to the external environment.

[0078] According to the battery 100 of the embodiment of the present utility model, by applying the core 10 in the above embodiment, the exhaust passage path inside the battery 100 can be effectively optimized, ensuring that the gas generated during the operation of the battery 100 can be effectively discharged, reducing the internal pressure accumulation, and improving the safety and reliability of the battery 100.

[0079] According to some embodiments of the present utility model, as Figure 4 shown, the housing 30 includes adjacent first and second side surfaces. The area of the first side surface is less than or equal to the area of the second side surface; the explosion-proof valve 31 is provided on the first side surface, and the groove 21 of the core 10 is provided on the side of the electrode plate 20 facing the second side surface, and the groove 21 extends obliquely towards the explosion-proof valve 31.

[0080] The first side surface is located on one side of the housing 30 along the width direction, and the explosion-proof valve 31 is provided on the first side surface. The second side surface is located on one side of the housing 30 along the thickness direction. The groove 21 extends obliquely towards the explosion-proof valve 31, which can effectively guide the gas generated inside the battery 100 to flow more smoothly towards the explosion-proof valve 31 through the groove 21. Thus, when the pressure increases, the gas can be released more quickly, reducing the risk of internal pressure accumulation.

[0081] According to some embodiments of the present utility model, the cross-sectional area of the exhaust passage is S1, and the sum of the cross-sectional areas of a plurality of grooves 21 provided on the electrode plate 20 of the electrode core 10 is S2, where S1 ≤ S2. In this application, the sum S2 of the cross-sectional areas of the plurality of grooves 21 being greater than or equal to the cross-sectional area S1 of the exhaust passage means that more gas can be quickly evacuated through the grooves 21, preventing the gas from clogging inside the electrode core 10, thereby effectively reducing the pressure inside the battery 100 and reducing the risk of thermal runaway.

[0082] According to some embodiments of the present utility model, as shown in the figure, the width of the groove 21 is a, the depth of the groove 21 is b, n grooves 21 are formed on each electrode plate 20, each electrode core 10 includes m electrode plates 20, and the sum of the cross-sectional areas of the plurality of grooves 21 is S2 = a × b × m × n; the distance between the surface of the electrode core 10 adjacent to the explosion-proof valve 31 and the side wall of the housing 30 where the explosion-proof valve 31 is provided is c, and the thickness of the electrode core 10 adjacent to the explosion-proof valve 31 is h, and the cross-sectional area S1 of the exhaust passage is S1 = c × h.

[0083] Moreover, a, b, m, n, and c need to satisfy: a × b × m × n ≥ 40% × c × h, and c can be 0.3 mm. By defining a × b × m × n ≥ 40% × c × h, a sufficient volume of the exhaust passage can be ensured, thereby ensuring the exhaust efficiency and exhaust effect. The plurality of grooves 21 are distributed in parallel. The width, depth, and number of the grooves 21 determine the cross-sectional area of the grooves 21, and thus determine the exhaust capacity of the grooves 21. The cross-sectional area of the grooves 21 and the cross-sectional area of the exhaust passage determine whether the gas can smoothly pass through the grooves 21 of the electrode core 10 and flow smoothly to the exhaust passage, and finally be discharged through the explosion-proof valve 31.

[0084] Thus, by defining the cross-sectional areas of the plurality of grooves 21 and the exhaust passage, it helps to optimize the gas discharge efficiency, helps to quickly release the pressure inside the battery 100, thereby enhancing the safety of the battery 100.

[0085] The electrical equipment according to the embodiment of the fourth aspect of the present utility model includes the battery 100 according to the embodiment of the third aspect of the present utility model described above.

[0086] According to the electrical equipment of the embodiment of the present utility model, the electrical equipment can be a vehicle, an energy storage system, etc. By applying the battery 100 in the above embodiments, the battery 100 includes the electrode plate 20 provided with the grooves 21, which can effectively improve the safety of the battery 100. The application of the battery 100 can improve the overall safety of the electrical equipment and effectively improve the user experience.

[0087] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0088] In the description of the present utility model, the "first feature" and "second feature" may include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more. In the description of the present utility model, the first feature being "above" or "below" the second feature may include the direct contact of the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. In the description of the present utility model, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature.

[0089] In the description of this specification, the description referring to terms such as "an embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0090] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A pole piece, characterized in that: At least one groove is formed on the pole piece, and the groove is arranged on at least one side surface of the pole piece. The groove extends obliquely on the one side surface of the pole piece, and the groove passes through the two side surfaces adjacent to the two ends of the groove. An angle α is formed between the center line of the groove and the edges in the two side surfaces and adjacent to the end of the center line, and α satisfies: 0<α<180°, and α≠90°.

2. The pole piece according to claim 1, characterized in that: The α further satisfies: 30°≤α≤150°, and α≠90°.

3. The pole piece according to claim 1, characterized in that: There are multiple grooves, including a first groove and a second groove. The first groove and the second groove are arranged on both sides of the pole piece in the thickness direction, and the projections of the first groove and the second groove on the pole piece at least partially do not overlap.

4. The pole piece according to claim 3, characterized in that: The projections of the first groove and the second groove on the pole piece are arranged vertically.

5. The pole piece according to claim 3, characterized in that: The plurality of first grooves and the plurality of second grooves each include: at least one first sub-groove; at least one second sub-groove, wherein the first sub-groove and the second sub-groove are arranged at two ends of the pole piece along the length direction of the pole piece, The distance between the first sub-groove and the second sub-groove decreases from one end to the other end along the width direction of the pole piece; and / or The distance between the first sub-groove and the second sub-groove increases from the one end to the other end along the width direction of the pole piece.

6. The pole piece according to claim 5, characterized in that: There are multiple first sub-grooves, and there are multiple second sub-grooves. The distance between the center of the area where the multiple first sub-grooves are located and the center of the pole piece is L1, and the distance between the center of the area where the multiple second sub-grooves are located and the center of the pole piece is L2. The length of the pole piece is L, and L, L1, and L2 satisfy: 1 / 4L≤L1≤1 / 2L, 1 / 4L≤L2≤1 / 2L.

7. The pole piece according to claim 5, characterized in that: The first sub-groove and the second sub-groove are symmetrically arranged along the length direction of the pole piece.

8. The pole piece according to any one of claims 1 to 7, characterized in that: The pole piece comprises: current collector; An active material layer is provided on at least one side of the current collector in a thickness direction, and the groove is formed on the active material layer.

9. The pole piece according to claim 8, characterized in that: The thickness of the active material layer is L3, the depth of the groove is L4, and L3 and L4 satisfy: L4≤L3.

10. The pole piece according to claim 8, characterized in that: The width of the groove is L5, and L5 satisfies: 0.1mm≤L5≤0.3mm.

11. A pole core, characterized in that: The pole core comprises: at least one positive electrode sheet and at least one negative electrode sheet; A diaphragm is provided between the adjacent positive electrode sheet and the negative electrode sheet, and at least one of the positive electrode sheet and the negative electrode sheet is a sheet according to any one of claims 1 to 10.

12. The pole core according to claim 11, characterized in that: The negative electrode plate is provided with a groove of the electrode plate, the width of the groove of the negative electrode plate is L6, the width of the groove of the positive electrode plate is L5, and L5 and L6 satisfy: L6≤L5+1mm.

13. A battery, characterized in that: include: case; An explosion-proof valve, the explosion-proof valve being arranged on the housing; A pole core, wherein the pole core is disposed in the shell, the pole core and the shell define an exhaust channel, the exhaust channel is connected to the explosion-proof valve, and the pole core is the pole core according to any one of claims 11-12.

14. The battery according to claim 13, characterized in that The housing comprises a first side surface and a second side surface that are adjacent to each other, and an area of ​​the first side surface is smaller than or equal to an area of ​​the second side surface; The explosion-proof valve is arranged on the first side surface, the groove of the pole core is arranged on the side of the pole piece facing the second side surface, and the groove extends obliquely toward the explosion-proof valve.

15. The battery according to claim 13, characterized in that The cross-sectional area of ​​the exhaust channel is S1, the sum of the cross-sectional areas of the plurality of grooves arranged on the pole piece of the pole core is S2, and S1≤S2.

16. The battery according to claim 13, characterized in that The width of the groove is a, the depth of the groove is b, n grooves are formed on each pole piece, each pole core includes m pole pieces, the distance between the surface of one side of the pole core adjacent to the explosion-proof valve and the side wall of the shell on which the explosion-proof valve is provided is c, and the thickness of the pole core adjacent to the side of the explosion-proof valve is h, wherein the battery satisfies a×b×m×n≥40%×c×h.

17. An electrical equipment, characterized in that: Comprising a battery according to any one of claims 13-16.

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