Pole piece, pole core, battery and power equipment
By setting foil on the tab and fixing it through welding, the thickness of the tab is increased to reduce resistance, which solves the problem of excessive tab temperature rise during fast charging of the power battery and improves the fast charging capability of the battery.
Patent Information
- Application Number
- CN202422349775.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2034-09-25
AI Technical Summary
When the power battery is fast charged, the temperature of the tab rises too high, affecting the fast charging capability of the battery.
A foil is arranged on the tab and fixedly connected to the tab through a first weld mark and a second weld mark, thereby increasing the thickness of the tab to reduce resistance and lower temperature rise.
By increasing the thickness of the tab, the heat generated under the same current is reduced, the fast charging capability of the battery is improved, and the excessive temperature rise of the tab is avoided.
Smart Images
Figure CN223321278U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of batteries, and in particular, to a pole piece, a pole core, a battery, and a power device. Background Art
[0002] As the fast-charging capabilities of power batteries improve, excessive temperature rise during fast charging is becoming a major obstacle. In related technologies, the tabs, as the area with the weakest current capacity in the entire battery, often experience the highest temperature rise during fast charging, impacting the battery's fast-charging capabilities. Utility Model Content
[0003] The purpose of the present disclosure is to provide a pole piece, a pole core, a battery and a power device to solve the technical problem of excessive temperature rise of the pole tab during fast charging of the battery.
[0004] In order to achieve the above-mentioned purpose, the present disclosure provides a pole piece, including a current collector and a dressing layer stacked on a portion of the surface of the current collector, the portion of the end of the current collector exposed from the dressing layer forms a pole ear, and a foil is provided on the pole ear, wherein the pole ear and the foil are adhered to and fixedly connected to each other by a first weld mark and a second weld mark, the first weld mark and the second weld mark extend in parallel, the extension direction of the first weld mark and the second weld mark is perpendicular to the direction in which the pole ear protrudes from the dressing layer, and the first weld mark and the second weld mark are spaced apart along the direction in which the pole ear protrudes from the dressing layer.
[0005] Optionally, the first weld mark and the second weld mark are arranged on the foil, and the first weld mark is located on a side of the second weld mark facing the dressing layer.
[0006] Optionally, a distance between an edge of the foil facing the dressing layer and an edge of the dressing layer facing the foil is 0 mm to 1.5 mm.
[0007] Optionally, a distance between an edge of the first weld mark facing the dressing layer and an edge of the dressing layer facing the foil is 1.5 mm to 2.5 mm.
[0008] Optionally, an edge of one end of the foil facing away from the dressing layer coincides with an edge of one end of the tab facing away from the dressing layer.
[0009] Optionally, a distance between an edge of the second weld mark facing away from the dressing layer and an edge of the tab facing away from the dressing layer is 2 mm to 5 mm.
[0010] Optionally, along the direction in which the tab protrudes from the dressing layer, the width of the first weld mark is 2 mm to 6 mm, and the width of the second weld mark is 2 mm to 6 mm.
[0011] Optionally, the width of the first weld mark is the same as the width of the second weld mark.
[0012] Optionally, the thickness of the foil is less than the thickness of the dressing layer.
[0013] Optionally, the foil has a thickness of 0.003 mm to 0.015 mm.
[0014] Optionally, the first weld mark and the second weld mark are formed by ultrasonic rolling welding.
[0015] Optionally, the foil is copper foil or aluminum foil.
[0016] On the basis of the above technical solution, the present disclosure further provides a pole core, comprising a plurality of stacked pole pieces, wherein the pole pieces are the pole pieces in the above technical solution.
[0017] On the basis of the above technical solution, the present disclosure further provides a battery, comprising a shell and a pole core arranged in the shell, wherein the pole core is the pole core in the above technical solution.
[0018] On the basis of the above technical solution, the present disclosure further provides a power device, comprising the battery in the above technical solution.
[0019] Through the above technical solution, the pole piece provided by the present disclosure includes a foil arranged on the pole ear. Through the first weld print and the second weld print, the entire foil can be completely attached and fixed to the surface of the pole ear. Since the foil can pass current, the foil attached to the surface of the pole ear is equivalent to increasing the thickness of the pole ear, so that the cross-sectional area of the pole ear is increased and the resistance is reduced. When the same current flows through, the pole ear generates less heat and the temperature rise is smaller. Similarly, under the same temperature rise, the pole ear with the foil attached can allow a larger current to pass. Without violating the trend of gradually reducing the thickness of the current collector in the related art, the thickness of the pole ear is increased by the foil. When the pole piece is used in a battery, the fast charging capability of the battery can be improved, while avoiding excessive temperature rise of the pole ear during fast charging. The pole core provided by the present disclosure has the same technical effect as the pole piece in the above technical solution. In order to avoid unnecessary repetition, it will not be repeated here. The battery provided by the present disclosure has the same technical effect as the pole core in the above technical solution. In order to avoid unnecessary repetition, it will not be repeated here. The power equipment provided by the present disclosure has the same technical effects as the battery in the above technical solution, and in order to avoid unnecessary repetition, it will not be described here.
[0020] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:
[0022] Figure 1 This is a schematic diagram of the structure of the pole piece in a specific embodiment of the present disclosure;
[0023] Figure 2 yes Figure 1 Exploded diagram;
[0024] Figure 3 yes Figure 1 A partial enlarged view of point A in the middle;
[0025] Figure 4 is a partial cross-sectional view of a pole piece in a specific embodiment of the present disclosure;
[0026] Figure 5 is a partial top view of a pole piece in a specific embodiment of the present disclosure;
[0027] Figure 6 It is a schematic structural diagram of the pole core in a specific embodiment of the present disclosure.
[0028] Description of Reference Numerals
[0029] 1-pole, 10-ear, 11-current collector, 12-dressing layer, 13-foil,
[0030] 21-first weld mark, 22-second weld mark,
[0031] 3-pole core. DETAILED DESCRIPTION
[0032] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.
[0033] In this disclosure, unless otherwise indicated, directional terms generally refer to the control box provided herein under normal use. "Inside" and "outside" can refer to the inside and outside of the corresponding component's outline or its location inside or outside the environment, depending on the specific context. Additionally, when the following description refers to the accompanying drawings, unless otherwise indicated, identical numbers in different drawings represent identical or similar elements. Terms such as "first" and "second" used in this disclosure are intended to distinguish one element from another and do not convey sequentiality or importance.
[0034] According to a specific embodiment of the present disclosure, a pole piece 1 is provided, referring to Figures 1 to 5 As shown, the electrode 1 may include a current collector 11 and a dressing layer 12 stacked on the surface of the current collector 11 .
[0035] Taking the application of the electrode 1 in a lithium-ion battery as an example, the current collector 11 is mainly used for electron transmission. The current collector 11 can provide a conductive channel for electrons so that the current can flow smoothly between the positive and negative electrodes. The current collector 11 in this embodiment can be made of copper foil or aluminum foil commonly used in the field. In a lithium-ion battery, it usually includes a electrode 1 as a positive electrode and a electrode 1 as a negative electrode. The current collector 11 on the electrode 1 as the positive electrode can be aluminum foil, and the current collector 11 on the electrode 1 as the negative electrode can be copper foil. If the aluminum foil is used as the negative electrode, when the negative electrode potential is less than 1.0V, the current collector 11 on the electrode 1 as the negative electrode is embedded with lithium to form a lithium-aluminum alloy.
[0036] The dressing layer 12 is also called battery slurry. It can be set on a single side surface of the current collector 11 along the thickness direction, or on both side surfaces of the current collector 11 along the thickness direction. The dressing layer 12 affects the capacity and cycle performance of the lithium-ion battery. At the same time, the thickness of the dressing layer 12 is related to the capacity and internal resistance and other properties of the lithium-ion battery. In a lithium-ion battery, the dressing layer 12 on the electrode 1 as the positive electrode can be called the positive electrode dressing. The positive electrode dressing is usually made of a mixture of lithium compounds and conductive materials. Its main function is to release positive charges to the outside. The positive electrode dressing can be made of lithium cobalt oxide, ternary materials or lithium iron phosphate commonly used in the field. The dressing layer 12 on the electrode 1 as the negative electrode can be called the negative electrode dressing. The negative electrode dressing can be made of graphite materials commonly used in the field. Its main function is to release negative charges to the outside. Due to the special properties of lithium-ion batteries, the negative electrode dressing generally needs to have certain diffusivity and reversibility to ensure rapid conduction and recycling of charges.
[0037] refer to Figures 1 to 5 As shown, the dressing layer 12 is superimposed on part of the surface of the current collector 11, and the end of the current collector 11 exposed from the dressing layer 12 forms a pole tab 10. The surface of the pole tab 10 can be fitted and fixed with a foil 13. Specifically, the pole tab 10 and the foil 13 can be fitted and fixed to each other by a first weld mark 21 and a second weld mark 22. The first weld mark 21 and the second weld mark 22 extend in parallel, and the extension direction of the first weld mark 21 and the second weld mark 22 is perpendicular to the direction in which the pole tab 10 protrudes from the dressing layer 12. The first weld mark 21 and the second weld mark 22 are spaced apart along the direction in which the pole tab 10 protrudes from the dressing layer 12 to ensure that the entire foil 13 can be completely fitted and fixed to the surface of the pole tab 10.
[0038] Through the above technical solution, the pole piece 1 provided by the present disclosure includes a foil 13 provided on the pole tab 10. Through the first weld mark 21 and the second weld mark 22, the entire foil 13 can be completely adhered and fixed to the surface of the pole tab 10. Since the foil 13 can pass current, the foil 13 adhered to the surface of the pole tab 10 is equivalent to increasing the thickness of the pole tab 10, so that the cross-sectional area of the pole tab 10 is increased and the resistance is reduced. Under the same current, the pole tab 10 generates less heat and has a smaller temperature rise. Similarly, under the same temperature rise, the pole tab 10 attached with the foil 13 can allow a larger current to pass through. Without violating the trend of gradually reducing the thickness of the current collector 11 in the related art, the thickness of the pole tab 10 is increased by the foil 13. When the pole piece is used in a battery, the fast charging capability of the battery can be improved, while avoiding excessive temperature rise of the pole tab during fast charging.
[0039] It should be noted that the aforementioned foil 13 refers to a thin metal sheet (e.g., aluminum foil, copper foil, etc.) that has the ability to conduct current. Furthermore, on the same electrode 1, if the current collector 11 is copper foil, the foil 13 can also be copper foil, and if the current collector 11 is aluminum foil, the foil 13 can also be aluminum foil.
[0040] refer to Figure 3 and Figure 5 As shown, the first weld mark 21 and the second weld mark 22 are both provided on the foil 13. The first weld mark 21 can be close to the end of the foil 13 facing the dressing layer 12 to ensure that the end of the foil 13 facing the dressing layer 12 is kept in contact with the tab 10. The second weld mark 22 can be close to the end of the foil 13 facing away from the dressing layer 12 to ensure that the end of the foil 13 facing away from the dressing layer 12 is kept in contact with the tab 10. That is, the foil 13 has a first end face facing the dressing layer 12 and a second end face facing away from the dressing layer 12. Along the direction in which the tab 10 protrudes from the dressing layer 12, the distance between any position in the first weld mark 21 and the first end face is smaller than the distance between any position in the first weld mark 21 and the second end face, and the distance between any position in the second weld mark 22 and the second end face is smaller than the distance between any position in the second weld mark 22 and the first end face. Under the fixing action of the first weld mark 21 and the second weld mark 22, the foil 13 can be attached to the tab 10 as closely as possible along the direction of current flow on the electrode 1 (i.e., the direction extending from the dressing layer 12 toward the tab 10), thereby increasing the current carrying capacity of the tab 10. In addition, the second weld mark 22 can prevent the tab 10 from folding during the lamination process and facilitate the welding of the tab 10 to the battery cover.
[0041] refer to Figure 4 and Figure 5As shown, the distance D between the edge of one end of the foil 13 facing the dressing layer 12 and the edge of the dressing layer 12 facing the foil 13 can be 0mm to 1.5mm. If D is less than 0mm, that is, a portion of the foil 13 is inserted into the dressing layer 12, it will not only cause the pole piece 1 to be scrapped by drawing during die-cutting, but also cause the foil 13 to contact the dressing layer 12 when the tab 10 is bent, thereby affecting the use of the battery. If D is greater than 1.5mm, that is, the distance between the edge of the end of the foil 13 close to the dressing layer 12 and the dressing layer 12 is too large, so that the area with a larger cross-sectional area on the tab 10 is reduced compared to the entire tab 10, and the effect of the foil 13 will also be difficult to exert. Therefore, D is in the range of 0 mm to 1.5 mm, which can allow the foil 13 to be as close to the dressing layer 12 as possible without contacting the dressing layer 12, thereby increasing the proportion of the area with a larger cross-sectional area on the tab 10 compared to the entire tab 10, and can also prevent the foil 13 from being inserted into the dressing layer 12, causing the pole piece 1 to be drawn and scrapped during die-cutting.
[0042] refer to Figure 5 As shown, the distance C between the edge of the first weld mark 21 facing the dressing layer 12 and the edge of the dressing layer 12 facing the foil 13 is 1.5 mm to 2.5 mm. If C is less than 1.5 mm, that is, the first weld mark 21 is too close to the dressing layer 12, the first weld mark 21 may fall outside the foil 13, causing perforation or even rupture of the single-layer tab 10. If C is greater than 2.5 mm, that is, the first weld mark 21 is too far from the dressing layer 12, the end of the foil 13 facing the dressing layer 12 may not be attached to the surface of the tab 10, reducing the temperature reduction effect of the foil 13 on the tab 10. Therefore, C is within the range of 1.5 mm to 2.5 mm. This can prevent the first weld mark 21 from falling on the portion of the tab 10 not attached to the foil 13, causing the tab 10 to rupture, and can also prevent the end of the foil 13 facing the dressing layer 12 from tilting up, which would reduce the temperature reduction effect of the foil 13 on the tab 10.
[0043] Table 1 shows the relationship between the temperature difference between the tab 10 without the foil 13 and the tab 10 with the foil 13 (hereinafter referred to as the temperature reduction effect of the foil 13 on the tab 10) and the C value when the same current flows through the electrode 1.
[0044] Table 1
[0045]
[0046] As can be seen from Table 1, the smaller the C value, that is, the closer the first weld mark 21 is to the dressing layer 12, the more significant the temperature reduction effect of the foil 13 on the tab 10. When the C value is greater than 2.5 mm, that is, the distance between the first weld mark 21 and the dressing layer 12 is greater than 2.5 mm, the temperature reduction effect of the foil 13 on the tab 10 decreases.
[0047] refer to Figures 1 to 3 As shown, the edge of one end of the foil 13 facing away from the dressing layer 12 can overlap with the edge of one end of the tab 10 facing away from the dressing layer 12, and the edges on both sides of the foil 13 can also overlap with the edges of the tab 10, so as to maximize the proportion of the area with a larger cross-sectional area on the tab 10 compared to the entire tab 10 without the foil 13 exceeding the tab 10.
[0048] The distance between the edge of the second weld mark 22 facing away from the dressing layer 12 and the edge of the end of the tab 10 facing away from the dressing layer 12 can be 2 mm to 5 mm. Figure 5 As shown, the distance B between the edge of the second weld mark 22 facing away from the dressing layer 12 and the dressing layer 12 is, and the distance A that the tab 10 extends out of the dressing layer 12 is. The relationship between A and B can be: A-5≤B≤A-2. This ensures the reliability of the connection between the end of the foil 13 facing away from the dressing layer 12 and the tab 10 support, while also preventing the second weld mark 22 from landing on the portion of the tab 10 not attached to the foil 13, which could cause the tab 10 to break. In addition, the distance A that the tab 10 extends out of the dressing layer 12 is positively correlated with the thickness of the electrode core 3 described below. The thicker the electrode core 3 and the greater the number of electrode sheets 1 that need to be stacked, the longer the distance the tab 10 extends out of the dressing layer 12, ensuring that the tabs 10 of multiple electrode sheets 1 can be connected together.
[0049] refer to Figure 5 As shown, along the direction in which the tab 10 protrudes from the dressing layer 12, the width E of the first weld mark 21 and the second weld mark 22 can be 2 mm to 6 mm, respectively. For ease of processing, the width E of the first weld mark 21 and the width E of the second weld mark 22 can be the same. When E is less than 2 mm, that is, when the weld mark width is too narrow, it is easy to cause the connection between the tab 10 and the foil 13 to fail, and then cause the foil 13 to be lifted from the tab 10, affecting the temperature reduction effect of the foil 13 on the tab 10. When E is greater than 6 mm, that is, when the weld mark width is too wide, it may make the tab 10 difficult to bend, affecting its assembly. Therefore, E is within the range of 2 mm to 6 mm. This can prevent the weld mark from being too narrow, which may affect the connection reliability between the tab 10 and the foil 13, and can also prevent the weld mark from being too wide, which may make the tab 10 difficult to bend during assembly.
[0050] The thickness of the foil 13 may be less than the thickness of the dressing layer 12. Figure 6 As shown, when the electrode 1 is used in a battery, multiple electrode sheets 1 need to be stacked to form a pole core 3. If the thickness of the foil 13 is greater than or equal to the thickness of the dressing layer 12, it will affect the stacking of the electrode 1, thereby affecting the strength of the pole core 3.
[0051] The thickness of the foil 13 can be 0.003 mm to 0.015 mm. Specifically, when the thickness of the foil 13 is less than 0.003 mm, that is, when the foil 13 is thin, the cross-sectional area of the tab 10 cannot be effectively increased. When the thickness of the foil 13 is greater than 0.015 mm, that is, when the foil 13 is thick, the temperature reduction effect of the foil 13 on the tab 10 is no longer significantly improved. Therefore, considering the cost, processability, and the temperature reduction effect of the foil 13 on the tab 10, the thickness of the foil 13 can be set to 0.003 mm to 0.015 mm.
[0052] Since the tab 10 and the foil 13 are both sheet-like structures, the first weld mark 21 and the second weld mark 22 can be formed by ultrasonic rolling welding. During ultrasonic rolling welding, the foil 13 and the tab 10 can be clamped by two rollers and welded together when the rollers move.
[0053] On the basis of the above technical solution, the present disclosure also provides a pole core 3, referring to Figure 6 As shown, the pole core 3 may include a plurality of stacked pole pieces 1, which may be Figures 1 to 5 The pole piece shown in .
[0054] Through the above technical solution, the pole core 3 provided by the present disclosure has the same technical effect as the pole piece 1 in the above technical solution. In order to avoid unnecessary repetition, it will not be described here.
[0055] On the basis of the above technical solution, the present disclosure further provides a battery, comprising a shell and a pole core 3 arranged in the shell. The pole core 3 can be as described in the above technical solution. Figure 6 The pole core 3 is shown.
[0056] Through the above technical solution, the battery provided by the present disclosure has the same technical effect as the pole core 3 in the above technical solution. In order to avoid unnecessary repetition, it will not be described here.
[0057] On the basis of the above technical solution, the present disclosure further provides a power device, comprising the battery in the above technical solution.
[0058] Through the above technical solution, the power equipment provided by the present disclosure has the same technical effect as the battery in the above technical solution. In order to avoid unnecessary repetition, it will not be described here.
[0059] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.
[0060] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.
[0061] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.
Claims
1. A pole piece, characterized in that: The device comprises a current collector and a dressing layer stacked on a portion of the surface of the current collector, wherein the portion of the end of the current collector exposed from the dressing layer is formed into a tab, and a foil is provided on the tab. In which, the tab and the foil are adhered to each other and fixedly connected by a first weld mark and a second weld mark, the first weld mark and the second weld mark extend in parallel, the extension direction of the first weld mark and the second weld mark is perpendicular to the direction in which the tab protrudes from the dressing layer, and the first weld mark and the second weld mark are spaced apart along the direction in which the tab protrudes from the dressing layer.
2. The pole piece according to claim 1, characterized in that: The first weld mark and the second weld mark are arranged on the foil, and the first weld mark is located on a side of the second weld mark facing the dressing layer.
3. The pole piece according to claim 2, characterized in that: The distance between the edge of the foil facing the dressing layer and the edge of the dressing layer facing the foil is 0 mm to 1.5 mm.
4. The pole piece according to claim 3, characterized in that: The distance between the edge of the first weld mark facing the covering layer and the edge of the covering layer facing the foil is 1.5 mm to 2.5 mm.
5. The pole piece according to claim 2, characterized in that: An edge of one end of the foil facing away from the dressing layer coincides with an edge of one end of the tab facing away from the dressing layer.
6. The pole piece according to claim 5, characterized in that: The distance between the edge of the second weld mark facing away from the dressing layer and the edge of the tab facing away from the dressing layer is 2 mm to 5 mm.
7. The pole piece according to claim 1, characterized in that: Along the direction in which the tab protrudes from the dressing layer, the width of the first weld mark is 2 mm to 6 mm, and the width of the second weld mark is 2 mm to 6 mm.
8. The pole piece according to claim 7, characterized in that: The width of the first weld mark is the same as the width of the second weld mark.
9. The pole piece according to claim 1, characterized in that: The thickness of the foil is less than the thickness of the dressing layer.
10. The pole piece according to any one of claims 1 to 9, characterized in that: The thickness of the foil is 0.003 mm to 0.015 mm.
11. The pole piece according to any one of claims 1 to 9, characterized in that: The first weld mark and the second weld mark are formed by ultrasonic rolling welding.
12. The pole piece according to any one of claims 1 to 9, characterized in that: The foil is copper foil or aluminum foil.
13. A pole core, characterized in that: The invention comprises a plurality of stacked pole pieces, wherein the pole pieces are the pole pieces according to any one of claims 1 to 12.
14. A battery, characterized in that: It comprises a shell and a pole core arranged in the shell, and the pole core is the pole core according to claim 13.
15. A power equipment, characterized in that: Including the battery according to claim 14.