Tab and tab connecting structure
By designing a heat dissipation section and a conductive adhesive connection structure on the tabs, the problem of poor heat dissipation caused by welding burrs was solved, achieving better heat dissipation and conductivity, and improving battery performance and safety.
Patent Information
- Application Number
- CN202422779531.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2034-11-14
AI Technical Summary
Burrs generated during the welding of the electrode tabs can lead to poor heat dissipation, affecting battery performance and potentially causing lithium plating.
Design a tab structure that includes a conductive part and a heat dissipation part along the width direction to increase the heat dissipation area, and connect it to the current collector through conductive adhesive to avoid the generation of welding burrs.
Improve the heat dissipation capacity of the tabs to prevent damage to the active materials due to excessive temperature, enhance conductivity, and improve battery energy density and stability.
Smart Images
Figure CN223693326U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field, specifically, relate to a tab and tab connecting structure. BACKGROUND
[0002] The tab is usually made of metal material, and the tab is welded with the current collector inside the battery, so that the tab is conductive with the electrode assembly inside the battery, thereby achieving the purpose of transmitting current.
[0003] However, the tab connected by welding will generate burrs in welding, which needs to be pasted with adhesive paper. The pasting of adhesive paper will affect the heat dissipation of the tab. After the heat dissipation of the adhesive paper, the bonding effect will be poor, and the adhesive paper itself is not conducive to the heat dissipation of the tab. Therefore, the thermal expansion at the tab is larger, and the structure of the surrounding active material is also damaged more, which is easy to cause lithium precipitation.
[0004] Therefore, it is urgent to invent a tab and a tab connecting structure. UTILITY MODEL CONTENT
[0005] One of the purposes of the utility model is to provide a tab, which is provided with a heat dissipation part to accelerate the heat dissipation of the tab, prevent the damage of heat to the structure of the active material around the tab, and improve the conductivity of the tab.
[0006] To solve the above technical problems, the application adopts the following technical solutions:
[0007] A tab is provided, which comprises a conductive part and a heat dissipation part extending along the width direction of the conductive part. The width of the heat dissipation part is W, and the width of the conductive part is S, which satisfies 1.5S < W < 2S.
[0008] Specifically, the heat dissipation part is arranged on the top of the conductive part.
[0009] Specifically, the shape of the heat dissipation part is rectangular.
[0010] Specifically, the heat dissipation part and the conductive part are integrally formed.
[0011] The utility model has the beneficial effects that the application improves the heat dissipation capacity of the tab by setting the heat dissipation part to prevent the damage of high temperature of the tab to the active material. Due to the setting of the heat dissipation part, the width of the tab is increased, and the contact area with the active material is also increased, thereby improving the conductivity of the tab.
[0012] The second purpose of the utility model is to provide a tab connecting structure, which comprises a current collector, an active material layer and conductive glue, and is used for connecting the above-mentioned tab. The tab is connected with the current collector through the conductive glue.
[0013] Specifically, the current collector is provided with a coated area and a blank foil area on at least one side in the thickness direction of the current collector, the active material layer is arranged on the coated area, the blank foil area is provided with a tab slot, the tab is arranged in the tab slot, and the conductive adhesive is arranged on the bottom and side of the tab slot.
[0014] Specifically, when the tab is arranged in the tab slot, the conductive adhesive fills the tab slot.
[0015] Specifically, the thickness of the active material layer is D, the sum of the thickness of the conductive adhesive on the bottom of the tab slot and the thickness of the tab is d, and they satisfy -3 μm < D-d < 3 μm.
[0016] Specifically, the shape of the tab slot is matched with the shape of the tab.
[0017] Specifically, the thickness of the conductive adhesive layer formed by the conductive adhesive is between 1 μm and 20 μm. BRIEF DESCRIPTION OF DRAWINGS
[0018] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:
[0019] Figure 1 It is a structural schematic view of the embodiment of the present application;
[0020] Figure 2 It is a front view of the tab of the present application;
[0021] Figure 3 It is a top view of the tab of the present application;
[0022] Figure 4 It is a side view of the tab of the present application,
[0023] Figure 5 It is a perspective view of the tab of the present application.
[0024] Wherein: 1-conductive part; 2-heat dissipation part; 3-current collector; 4-active material layer; 5-tab slot; 51-conductive adhesive; 52-conductive adhesive layer. DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the present application will be described clearly and completely in the embodiments of the present application in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application. Unless otherwise defined, all the technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application.
[0026] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.
[0027] The present application discloses the above with preferred embodiments, but is not intended to limit the claims, and any person skilled in the art can make several possible changes and modifications without departing from the concept of the present application, therefore the protection scope of the present application should be limited by the scope defined by the claims of the present application.
[0028] When the tab is connected to the current collector of the battery by welding, many burrs will be generated, which are easy to pierce the diaphragm of the battery and cause short circuit of the battery if not treated, so it is necessary to paste adhesive tape at the position of the tab welding to protect the diaphragm from being pierced by the burrs, however, the adhesive tape will affect the heat dissipation of the tab, and the adhesive tape will cause the bonding effect to be poor after being heated, and the adhesive tape itself is also not conducive to the heat dissipation of the tab, so the thermal expansion of the tab at the position is larger, and the structure of the surrounding active material is also damaged more, which is easy to cause lithium precipitation.
[0029] Therefore, the present application changes the shape of the tab to increase the heat dissipation area of the tab, so as to enhance the heat dissipation effect of the tab, reduce the accumulation of heat, and reduce the influence of temperature on the active material around the tab.
[0030] Embodiment 1
[0031] As Figures 1-4As shown, this application provides an electrode tab, including a conductive part 1 and a heat dissipation part 2 extending along the width direction of the conductive part 1. The width of the heat dissipation part 2 is W and the width of the conductive part 1 is S, which satisfy 1.5S < W < 2S. By providing a wider heat dissipation part 2, the surface area of the electrode tab can be increased, thus increasing the heat dissipation area. The heat of the conductive part 1 can be conducted to the heat dissipation part 2 for heat dissipation, preventing the electrode tab from overheating and damaging the active material around the electrode tab. When the heat dissipation part 2 comes into contact with the active material, it can conduct electrons in the active material to the conductive part 1. The heat dissipation part 2 can also undertake part of the conductive function, increasing the conductivity of the electrode tab.
[0032] Preferably, the heat dissipation part 2 is disposed on the top of the conductive part 1. The top of the conductive part 1 is the part away from the current collector 3 after the conductive part 1 is connected to the current collector 3. When the tab is not covered with adhesive tape, placing the heat dissipation part 2 on the top of the conductive part 1 is beneficial for the electrolyte inside the battery to conduct convective heat exchange with the heat dissipation part 2, thereby increasing the heat dissipation effect of the heat dissipation part 2. Furthermore, placing the heat dissipation part 2 on the top of the conductive part 1 is beneficial for the installation of the tab, making it easier to match the shape of the tab groove 5 with the tab. Also, since placing the heat dissipation part 2 on the top of the conductive part 1 makes it easier to keep the tab flat, it reduces the accumulation of electrolyte and prevents the active material from expanding unevenly and being subjected to uneven stress due to the accumulation of electrolyte, which ultimately leads to lithium plating and capacity decay.
[0033] Preferably, the heat dissipation part 2 is rectangular. The shape of the heat dissipation part 2 can be selected from various shapes as long as the heat dissipation part 2 has a wider width to increase the heat dissipation of the electrode tab. For example, a circle or triangle can be selected. Among them, choosing a rectangle is simpler to manufacture and has a better heat dissipation effect.
[0034] Preferably, the heat dissipation part 2 and the conductive part 1 are integrally formed. Integral forming can reduce the contact thermal resistance and conductive resistance between the heat dissipation part 2 and the conductive part 1, and increase the heat dissipation capacity and conductivity of the tab.
[0035] Implementation Method 2
[0036] like Figure 1 As shown, this application also provides a tab connection structure, including a current collector 3, an active material layer 4, and a conductive adhesive 51, for connecting the aforementioned tabs. The tabs are connected to the current collector 3 through the conductive adhesive 51. The conductive adhesive 51 needs to have both adhesive and conductive effects, so that the tabs can be bonded to the current collector 3 through the conductive adhesive 51 and can also achieve electrical connection through the conductive adhesive 51.
[0037] When the tab is connected to the current collector 3 by welding, it is necessary to paste adhesive tape on the tab, and the adhesive tape occupies a certain space, reducing the energy density of the battery. In addition, since the tab needs to be welded, a certain redundant position needs to be left for the empty foil area left by the tab welding to prevent the active material coating from being affected during welding. In order to prevent the welding from affecting the active material, the active material cannot be coated on both sides of the tab welding area of the current collector 3, which reduces the energy density of the battery. In addition, the empty foil area between the tab and the active coating will form a thickness difference. In the slot position area without the tab, the empty foil and the active coating will also form a thickness difference, which will reduce the flatness of the tab position, and the electrolyte will easily accumulate in the thickness difference area, and the adhesive tape will be repeatedly soaked in the electrolyte, thereby causing the adhesive effect of the adhesive tape to deteriorate. After the adhesive effect of the adhesive tape deteriorates, it will easily affect the protective effect of the adhesive tape, and even cause black spots and lithium precipitation in the negative plate area opposite to the tab position.
[0038] Therefore, the application connects the tab and the current collector 3 by using conductive adhesive 51. Since this connection method does not require welding, it will not produce burrs and the use of adhesive tape can be omitted. Since welding connection is not required, there is no need to worry about the impact of the welding process on the active material, so the slot position of the tab can be set smaller and the size of the tab can be adapted. Only one side of the current collector 3 and the tab needs to be provided with an empty foil, and the other side does not need to be provided with an empty foil. More active material is set to improve the energy density of the battery. However, since the tab is closer to the active material of the battery, the heat of the tab is more likely to affect the active material, causing damage to the active material. Therefore, the tab used in the application is provided with a heat dissipation structure to quickly dissipate the heat of the tab and prevent the temperature of the tab from being too high to affect the active material around the tab. In addition, the tab used in the application has better heat dissipation effect and better conductivity effect, which can prevent the conductive adhesive 51 from increasing the resistance between the tab and the current collector 3 and causing the conductivity effect of the tab to decrease.
[0039] Preferably, the current collector 3 is provided with a coated area and an empty foil area on at least one side in the thickness direction of the current collector 3, the active material layer 4 is arranged on the coated area, the empty foil area is provided with a tab slot 5, the tab is arranged in the tab slot 5, and the conductive adhesive 51 is arranged on the bottom and the side of the tab slot 5. From the perspective of heat insulation, the conductive adhesive 51 arranged on the bottom and the side of the tab slot 5 can prevent the heat of the tab from being directly conducted to the active material, and the heat is first conducted from the tab to the conductive adhesive 51 and then from the conductive adhesive 51 to the active material. The conductive adhesive 51 plays a role of heat insulation, which can reduce the influence of the temperature of the tab on the active material. By arranging the conductive adhesive 51 on the bottom and the side of the tab slot 5, the adhesion to the tab can be increased, and the tab can be fixed in all directions, which is beneficial to improve the fixing effect of the tab. The stable connection between the tab and the current collector 3 can be achieved by adhesion. After the connection mode between the tab and the current collector 3 is changed, the connection between the tab and the current collector 3 is not stable. In addition, the tab adhesive arranged on the side of the tab slot 5 can fill the gap between the tab and the tab slot 5, reduce the accumulation of electrolyte in the gap, and reduce the utilization rate of electrolyte. When charging and discharging, soaking in more electrolyte can easily cause the charging and discharging rates to be inconsistent, the expansion of the active material to be inconsistent, and the structure of the active material to be damaged, which can cause the capacity of the battery to decrease and even cause lithium precipitation. Preferably, when the tab is arranged in the tab slot 5, the conductive adhesive 51 fills the tab slot 5, so that there is no gap between the tab and the tab slot 5, and the problem of inconsistent expansion of the tab to damage the structure of the active material is not easy to occur. In addition, the gap is filled with conductive adhesive 51, which enhances the electrical contact, improves the electrical conductivity, and reduces the contact resistance.
[0040] As shown in the figure, preferably, the thickness of the active material layer 4 is D, and the sum of the thickness of the conductive adhesive 51 at the bottom of the tab slot 5 and the thickness of the tab is d. They satisfy -3 μm < D-d < 3 μm. In order to keep the tab and the active material flat and prevent the electrolyte from accumulating in the tab slot 5 to increase the utilization rate of the electrolyte, the thickness of the active material layer 4 is set to be similar to the thickness of the tab plus the thickness of the conductive adhesive 51, and the error is set in the above range, which is good and easy to achieve.
[0041] Preferably, the shape of the tab slot 5 is matched with the shape of the tab. Since the connection mode between the tab and the current collector 3 is changed, in order to maximize the arrangement of the active material and increase the energy density of the battery, the shape of the tab slot 5 is matched with the shape of the tab. For example, when a tab with a heat dissipation structure is used, the active material is thinned at the tab slot 5, the thickness of the thinning is the thickness of the heat dissipation structure, and a slot position with a size similar to that of the conductive part 1 is arranged. Finally, the tab is installed in the tab slot 5.
[0042] Preferably, the conductive adhesive 51 forms a conductive adhesive layer 52 with a thickness of 1-20 μm. When the thickness of the conductive adhesive layer 52 is too small, the viscosity is not enough, and when the thickness of the conductive adhesive layer 52 is too large, the resistance increases, and more space is occupied. In the scope of the present application, the thickness of the conductive adhesive layer 52 is appropriate.
[0043] The above description shows and describes several preferred embodiments of the present application, but as previously mentioned, the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the present application, by the above teachings or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the scope of the appended claims of the present application.
Claims
1. A tab, characterized by: The conductive part (1) and the heat dissipation part (2) extend along the width direction of the conductive part (1), the width of the heat dissipation part (2) is W, the width of the conductive part (1) is S, and they satisfy 1.5S < W < 2S.
2. The tab of claim 1, wherein: The heat dissipation part (2) is arranged on the top of the conductive part (1).
3. The tab of claim 1 wherein: The heat dissipation part (2) is rectangular.
4. The tab of claim 1 wherein: The heat dissipation part (2) and the conductive part (1) are integrally formed.
5. A tab connecting structure characterized by: The current collector (3), the active material layer (4) and the conductive adhesive (51) are used to connect the tab as claimed in any one of claims 1-4, and the tab is connected with the current collector (3) through the conductive adhesive (51).
6. The tab connection structure according to claim 5, wherein: The current collector is provided with a coated area and a blank foil area on at least one side in the thickness direction of the current collector, the active material layer (4) is arranged on the coated area, the blank foil area is provided with a tab slot (5), the tab is arranged in the tab slot (5), and the conductive adhesive (51) is arranged on the bottom and the side of the tab slot (5).
7. The tab connection structure according to claim 6, wherein: When the tab is arranged in the tab slot (5), the conductive adhesive (51) fills the tab slot (5).
8. The tab connection structure according to claim 7, wherein: The thickness of the active material layer (4) is D, the sum of the thickness of the conductive adhesive (51) on the bottom of the tab slot (5) and the thickness of the tab is d, and they satisfy -3 μm < D-d < 3 μm.
9. The tab connection structure according to claim 8, wherein: The shape of the tab slot (5) is matched with the shape of the tab.
10. The tab connection structure according to claim 7, wherein: The thickness of the conductive adhesive layer (52) formed by the conductive adhesive (51) is between 1 μm and 20 μm.