Square battery cell based on heat conducting plate
By combining heat-conducting plates and winding processes, the problems of complex manufacturing and poor heat dissipation of square lithium batteries have been solved, achieving efficient heat dissipation and low-cost production, and improving battery performance and safety.
Patent Information
- Application Number
- CN202423311364.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing square lithium batteries suffer from problems such as complex manufacturing, high cost, poor heat dissipation, uneven temperature, and low production efficiency, especially poor alignment and slow production speed of long stacked cells.
The heat-conducting plate design includes an evaporation section and a condensation section. The condensation section extends outside the core to improve heat dissipation and is combined with the core through a winding process. Combined with the liquid-absorbing core layer and shell structure, heat dissipation and structural stability are ensured.
It improves the heat dissipation performance and production efficiency of square batteries, reduces manufacturing costs, extends battery life, and enhances battery safety and energy density.
Smart Images
Figure CN223941833U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium battery technology, and in particular to a square battery cell based on a heat-conducting plate. Background Technology
[0002] Square lithium batteries are the mainstream batteries in electric vehicles. A typical square lithium battery is rectangular in shape, containing two flat, elliptical cores wound side-by-side along the battery's height. The outer casing is usually a stamped aluminum shell, with the positive and negative terminals and pressure relief valve located at the top. Square lithium batteries have relatively high energy density, storing more energy in the same volume. However, the flat, elliptical cores present challenges in manufacturing, including complex tension control and poor alignment, hindering production efficiency and cost reduction. Furthermore, they suffer from poor heat dissipation, with a 10-20°C temperature difference between the internal and external temperatures, requiring a more complex thermal management system to ensure stable operation and reducing cycle life. As an upgrade to this existing technology, the blade-type square lithium battery significantly extends the cell length, reaching 960mm or even longer, resulting in higher energy density, better heat dissipation, higher space utilization, and improved safety. However, its long stacked wafers and long stacked cores manufacturing method has problems such as poor alignment, slow production speed and low yield, which is not conducive to improving battery production efficiency and reducing manufacturing costs.
[0003] Therefore, this application is submitted. Utility Model Content
[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a square battery cell based on a heat-conducting plate.
[0005] To achieve the above objectives, the main technical solutions adopted by this utility model include:
[0006] A square battery cell based on a heat-conducting plate includes a heat-conducting plate and a racetrack-shaped core. The heat-conducting plate includes an evaporation section located inside the core and a condensation section located outside the core. The condensation section is located at one end or opposite ends of the evaporation section, and the evaporation section and the condensation section are an integral structure. The total height of the condensation section is 1%-20% of the core height, specifically 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%. %, 16%, 17%, 18%, 19%, 20%, etc.; the heat-conducting plate is arranged in a ring from the inside out: coolant, liquid-absorbing core layer and shell layer. The innermost layer of the heat-conducting plate is coolant, which can be methanol, ethanol, ethane, acetone, toluene, etc. The next outermost layer is liquid-absorbing core layer, and the outermost layer is shell layer, which can be copper, aluminum, stainless steel, alloy steel, carbon steel, etc.; in order to prevent short circuits inside the square battery cell, an insulating coating is provided on the outer surface of the heat-conducting plate. The insulating coating can be polyester layer, polypropylene layer, polyimide layer, etc.
[0007] Heat dissipation principle: The evaporation section of the heat-conducting plate is in direct contact with the core to transfer the heat generated by the cell to the heat-conducting plate. The condensation section of the heat-conducting plate is connected to the battery cover. On the one hand, the condensation section contacts the battery cover to dissipate heat, ensuring the temperature consistency between the cell and the casing. On the other hand, the condensation section is directly exposed to the air for heat dissipation, resulting in a more significant heat dissipation effect. Theoretically, the longer the condensation section, the better the heat dissipation effect of the square cell. However, the longer the condensation section extends beyond the core, the more unreasonable the structure of the square cell becomes, which will adversely affect the energy density of the square cell and subsequent assembly. This utility model has confirmed through several experiments that when the total height of the condensation section is 1%-20% of the core height, the heat-conducting plate has both good heat dissipation capacity and can control the adverse effects on the square cell structure within an acceptable range. The resulting square cell based on the heat-conducting plate has good electrochemical performance and high safety. More importantly, it has a simple structure, is easy to control, and is easy to produce, which helps to improve the production efficiency of square lithium batteries and reduce the manufacturing cost of square lithium batteries. It should be noted that:
[0008] (1) The specific structure of the heat-conducting plate is not limited. It can be a plate structure with a square cross-section, a plate structure with a rounded square cross-section, or a plate structure with an elliptical cross-section.
[0009] (2) The condensation section can be located at one end of the evaporation section or at both ends of the evaporation section. In short, the heat-conducting plate extends out of the core at only one end, and the height of the extended part is 1%-20% of the core height. Alternatively, both ends can extend out of the core, and the total height of the extended part is 1%-20% of the core height. In terms of the adverse effects on the square cell structure, it is preferable to extend a portion of each end of the heat-conducting plate out of the core.
[0010] (3) In actual production, the core is directly wound around the heat-conducting plate through the winding process. The fit between the core and the heat-conducting plate is higher, and the space utilization rate inside the square cell can also be improved.
[0011] Preferably, the liquid-absorbing core layer is selected from one of the following: powder sintered liquid-absorbing core, metal wire mesh liquid-absorbing core, axial groove liquid-absorbing core, and composite liquid-absorbing core.
[0012] The coolant wick layer requires high permeability and high thermal conductivity to uniformly distribute the coolant, provide heat conduction channels, and improve heat transfer efficiency. Powder sintered coolant wicks, wire mesh coolant wicks, axial groove coolant wicks, and composite coolant wicks are all existing technologies.
[0013] Preferably, the assembly also includes an aluminum shell, an insulating film, a positive electrode cover plate, a negative electrode cover plate, a positive electrode insulating sheet, a negative electrode insulating sheet, a positive electrode adapter piece, a negative electrode adapter piece, a positive electrode current collector, and a negative electrode current collector; the positive electrode cover plate and the negative electrode cover plate have the same length, width, and height and are sequentially marked as L2, T2, and H2, respectively, where L2, T2, and H2 satisfy the following conditions: 10mm≤L2≤300mm, 10mm≤T2≤200mm, and 1≤H2≤10mm. For example, L2 can specifically be 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, or 90mm. The available sizes are 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 300mm, etc. T2 sizes can be 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, etc. The diameters of the electrodes are 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, etc., while H2 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc. Necessary structural components are provided on the positive and negative electrode covers, such as an injection hole, negative electrode post, and pressure relief valve on the negative electrode cover. For example, a positive electrode post is provided on the positive electrode cover plate. At least one of the positive electrode cover plate and the negative electrode cover plate has a through groove that matches the structure of the condensation section. The groove opening extends along its height direction to form a contact cavity. The height of the contact cavity is marked as L3, where 1mm≤L3≤10mm. Specifically, L3 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc.
[0014] If one end of the heat-conducting plate extends beyond the core, a through groove is provided on the cover plate corresponding to that extended end; if both ends of the heat-conducting plate extend beyond the core, through grooves are provided on both the positive and negative electrode cover plates. The heat-conducting plate transfers heat to the cover plate through contact with the through groove, and then dissipates heat to the outside through the cover plate. Therefore, the thickness of the cover plate determines the effective contact area for heat dissipation between the heat-conducting plate and the cover plate. The thicker the cover plate, the larger the effective contact area for heat dissipation, and the better the heat dissipation effect. However, the cover plate increases the cell mass and occupies valuable space, thus reducing the energy density of the square cell. To address this, this invention extends the slot along its height in a square shape to form a contact cavity. This contact cavity is an integral structure with the cover plate. The heat-conducting plate contacts its inner wall within this contact cavity and then transfers heat to the cover plate. This increases the effective contact area for heat dissipation and improves the heat dissipation effect without increasing the thickness of the cover plate.
[0015] During assembly, the insulating film is wrapped around the core, which lies flat inside the aluminum shell and is a single-cavity, single-core structure. The aluminum shell adapts to the core, which not only reduces design difficulty but also effectively suppresses its expansion, increases battery energy density, and extends cycle life. The core's tabs are connected to the current collector, the current collector to the adapter plate, and the adapter plate to the cover plate's electrode post using existing technologies such as laser welding and riveting. One or both ends of the heat-conducting plate pass through the slot on the cover plate and are exposed to form a condensation section. The heat-conducting plate and the slot are connected by laser welding.
[0016] Preferably, the ratio of the surface area S1 of the heat-conducting plate to the surface area S2 of the aluminum shell satisfies: 0 < S1 / S2 ≤ 0.3, and the ratio of the energy W of the square battery cell to the surface area S1 of the heat-conducting plate satisfies: 0 < W / S1 ≤ 0.1.
[0017] To achieve good heat dissipation, the heat-conducting plate needs to effectively transfer the heat generated inside the square battery cell to the outside. This usually requires the heat-conducting plate to have a sufficiently large surface area to facilitate adequate heat exchange with the external environment. There is also a close relationship between the surface area of the heat-conducting plate, the surface area of the aluminum casing, and the energy of the square battery cell. A larger surface area of the aluminum casing is more conducive to heat dissipation, and higher battery energy typically generates more heat. Considering both heat dissipation and heat generation, this invention finds that when 0 < S1 / S2 ≤ 0.3 and 0 < W / S1 ≤ 0.1, the heat-conducting plate can dissipate the heat generated by the square battery cell to the maximum extent in a timely manner, ensuring the uniformity of temperature inside and outside the square battery cell, and ensuring the safe and stable operation of the battery.
[0018] Preferably, the core includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet includes a positive current collector and a positive active material layer. A region I on the positive current collector is not coated with the positive active material layer, and region I forms the positive electrode tab. The negative electrode sheet includes a negative current collector and a negative active material layer. A region II on the negative current collector is not coated with the negative active material layer, and region II forms the negative electrode tab. The separator is attached to both sides of the positive and negative electrode sheets. The stacked negative electrode sheet, separator, positive electrode sheet, and separator are wound on a heat-conducting plate to form a racetrack-shaped core. The positive electrode tab, the... The negative electrode tabs are located at both ends of the core. Multiple notches are cut at intervals on both Region I and Region II. After the multiple notches are superimposed, two oppositely arranged fan-shaped grooves are formed at both ends of the core. The angle of the fan shape is 10°-180°. The radius of the rounded corner of the arc segment adjacent to the fan shape is marked as R2. The length, height, thickness and radius of the rounded corner of the core are marked as L5, H4 and T5 in sequence. R2, L5, H4 and T5 satisfy: 0mm≤R2≤100mm, 10mm≤L5≤300mm, 10mm≤H4≤2000mm, 10mm≤T5≤200mm.
[0019] During electrolyte injection, the positive and negative electrode plates can quickly absorb the electrolyte through two pairs of grooves, improving the speed, consistency, and uniformity of electrolyte penetration and absorption, shortening the injection time, increasing the cycle life of lithium batteries, and improving lithium battery production capacity. Furthermore, the pair of grooves positioned opposite each other on the same end can effectively eliminate the stress generated during tab folding. This not only helps reduce the defect rate on the production line caused by tab folding, improving production efficiency and product quality, but also has a positive impact on improving battery performance, enhancing battery safety, and extending battery life.
[0020] In addition, both the positive and negative tabs are preferably retained. The design of all tabs helps to enhance the current carrying capacity, improve power density and rate performance, and ensure safety.
[0021] Preferably, the length, height, and thickness of the heat-conducting plate are marked as L6, H5, and T6 in sequence, and L6, H5, and T6 satisfy the following conditions: 10mm≤L6≤300mm, 10mm≤H5≤2050mm, and 1mm≤T6≤20mm.
[0022] Preferably, the aluminum shell is a one-piece molded square aluminum shell with rounded corners. The thickness of the aluminum shell is marked as T4, and the radius of the rounded corners is marked as R3. T4 and R3 satisfy: 0.2mm≤T4≤8mm, 1mm≤R3≤5mm.
[0023] Preferably, the positive current collector and the negative current collector have the same length, width and height, and are marked as L4, T3 and H3 in sequence. L4, T3 and H3 satisfy: 10mm≤L4≤300mm, 10mm≤T3≤200mm, 1mm≤H3≤5mm.
[0024] Preferably, the length, height, thickness, and corner radius of the square battery cell are marked as L1, H1, T1, and R1 in sequence, and D1, L1, H1, T1, and R1 satisfy the following: 1mm≤D1≤50mm, 10mm≤L1≤300mm, 10mm≤H1≤2000mm, 10mm≤T1≤200mm, and 1mm≤R1≤5mm.
[0025] Preferably, the condensing section is located at opposite ends of the evaporating section, and the condensing section at each end of the evaporating section has the same height, which is D2, where 0.5mm≤D2≤25mm.
[0026] This invention provides a square battery cell based on a heat-conducting plate, which improves the heat dissipation effect of the square battery cell, expands the heat dissipation methods of the square battery cell, and has a simple structure and is easy to manufacture. Compared with the prior art, it also has the following beneficial effects:
[0027] (1) The design of the heat-conducting plate not only improves the heat dissipation effect of the square battery cell, but also facilitates the production of the square battery cell. The process of directly winding the heat-conducting rod results in a higher degree of fit between the core and the heat-conducting rod, which increases the internal space utilization of the battery cell and reduces the winding arc of the core, thereby reducing the control difficulty of the winding process, improving production efficiency, and reducing production costs.
[0028] (2) The core is laid flat in the aluminum shell and is single-cavity single-core. On the one hand, it reduces the design difficulty of the core and improves the space utilization of the shell. On the other hand, the inner shell is adapted to the core, which can effectively suppress cell expansion, improve the energy density of lithium battery and extend the cycle life of lithium battery.
[0029] (3) The design structure of the cell with all tabs significantly enhances the overcurrent capacity, which helps to improve the rate performance of the battery and ensure the safety of the lithium battery.
[0030] (4) The resulting square cells can meet the system integration requirements, which helps to build battery packs and improve the overall energy density of battery packs. Attached Figure Description
[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 This is one embodiment of the square battery cell based on a heat-conducting plate according to this utility model;
[0033] Figure 2 for Figure 1 Exploded view;
[0034] Figure 3 for Figure 2 Schematic diagram of the structure of the heat-conducting plate;
[0035] Figure 4 for Figure 3 A sectional view;
[0036] Figure 5 for Figure 2 Schematic diagram of the structure of the core;
[0037] Figure 6 for Figure 5 A sectional view;
[0038] Figure 7 for Figure 2 Schematic diagram of the positive electrode cover plate;
[0039] Figure 8 for Figure 2 Schematic diagram of the structure of the negative electrode cover plate;
[0040] Figure 9 for Figure 2 Schematic diagram of the positive electrode current collector;
[0041] Figure 10 for Figure 2 Top view of the aluminum shell.
[0042] In the diagram: 1. Core; 2. Heat-conducting plate; 3. Aluminum shell; 4. Insulating film; 5. Positive electrode cover plate; 6. Negative electrode cover plate; 7. Positive electrode insulating sheet; 8. Negative electrode insulating sheet; 9. Positive electrode adapter plate; 10. Negative electrode adapter plate; 11. Positive electrode current collector; 12. Negative electrode current collector; 13. Groove. Detailed Implementation
[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0044] It should be noted that any components or structures not described in detail below employ conventional techniques in this field.
[0045] Example 1
[0046] like Figures 1-10 As shown: A square battery cell based on a heat-conducting plate with an energy of 320Ah includes: a heat-conducting plate 2, a racetrack-shaped core 1, an aluminum shell 3, an insulating film 4, a positive electrode cover plate 5, a negative electrode cover plate 6, a positive electrode insulating sheet 7, a negative electrode insulating sheet 8, a positive electrode adapter sheet 9, a negative electrode adapter sheet 10, a positive electrode current collector 11, and a negative electrode current collector 12;
[0047] The core 1 includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet includes a positive current collector and a positive active material layer. Region I, where the positive active material layer is not coated, forms the positive electrode tab. The negative electrode sheet includes a negative current collector and a negative active material layer. Region II, where the negative active material layer is not coated, forms the negative electrode tab. The separator is attached to both sides of the positive and negative electrode sheets. The stacked positive electrode sheet, separator, and negative electrode sheet are wound onto the heat-conducting plate 2. A runway-shaped core 1 is wound around, with the positive and negative electrode tabs located at both ends of the core 1. Multiple notches are cut at intervals in both regions I and II. After the multiple notches are superimposed, two oppositely arranged fan-shaped grooves 13 are formed at both ends of the core 1. The angle of the fan shape is 30°, and the radius of the rounded corner R2 of the arc segment adjacent to the fan shape is 50mm. The length L5, height H4, thickness T5, and radius of the rounded corner R2 of the core 1 are 150mm, 240mm, 25mm, and 10mm, respectively.
[0048] The length L6, height H5, and thickness T6 of the heat-conducting plate 2 are 100mm, 275mm, and 3mm respectively. The heat-conducting plate 2 is arranged in a ring from the inside to the outside as follows: methanol coolant, metal wire mesh liquid absorber, and shell layer. The outer surface of the heat-conducting plate 2 is provided with a polyester insulating coating. The heat-conducting plate 2 is divided into an evaporation section and a condensation section in terms of height. The evaporation section is located inside the core 1, and the condensation section is located at the top of the evaporation section and extends outward from the core 1. The height of the condensation section is 10% of the height of the core 1, that is, D1 is 25mm. The aluminum shell 3 is a one-piece square aluminum shell. The length, height, and width of the inner cavity of the square aluminum shell are 150mm, 250mm, and 27mm respectively. The corners of the square aluminum shell are rounded. The thickness T4 of the aluminum shell 3 is 0.6mm, and the radius of the rounded arc R1 is 3mm.
[0049] Insulating film 4 is a polyester insulating film;
[0050] The positive electrode cover plate 5 and the negative electrode cover plate 6 have the same length L2, width T2, and height H2, which are 150mm, 25mm, and 2mm respectively. Both the positive electrode cover plate 5 and the negative electrode cover plate 6 have through slots that match the structure of the condensation section. The slot opening on the positive electrode cover plate 5 extends along its height direction to form a contact cavity, and the height L3 of the contact cavity is 5mm. The thickness of the positive electrode insulating sheet 7 is 1mm, and the specifications of the negative electrode insulating sheet 8 are the same as those of the positive electrode insulating sheet 7. The thickness of the positive electrode adapter sheet 9 is 1mm, and the specifications of the negative electrode adapter sheet 10 are the same as those of the positive electrode adapter sheet 9. The length L4, width T3, and height H3 of the positive electrode current collector 11 are 150mm, 25mm, and 1mm respectively, and the specifications of the negative electrode current collector 12 are the same as those of the positive electrode current collector 11.
[0051] Example 2
[0052] Compared to Example 1, the heat-conducting plate 2 has an evaporation section in the middle, and condensation sections of equal height are provided at both ends of the evaporation section. The two condensation sections extend from the through slots of the positive electrode cover plate 5 and the negative electrode cover plate 6, respectively. The total height of the condensation sections is 5% of the height of the core 1, that is, the height of each condensation section is 12.5 mm. Everything else is the same as in Example 1.
[0053] Example 3
[0054] Compared to Example 1, the slot opening on the positive electrode cover plate 5 does not have a contact cavity. Everything else remains the same as in Example 1.
[0055] Example 4
[0056] Compared to Example 1, the height L3 of the contact cavity is 1 mm. Everything else remains the same as in Example 1.
[0057] Example 5
[0058] Compared to Example 1, the height L3 of the contact cavity is 10 mm. Everything else remains the same as in Example 1.
[0059] Example 6
[0060] Compared to Example 1, the height of the condensation section is 1% of the height of the core 1, i.e., D1 is 2.5 mm. All other dimensions remain the same as in Example 1.
[0061] Example 7
[0062] Compared to Example 2, the height of the condensation section is 20% of the height of the core 1, i.e., D1 is 50 mm. All other dimensions remain the same as in Example 1.
[0063] Comparative Example 1
[0064] Compared to Example 1, the heat-conducting plate 2 is replaced with a mandrel that only serves a supporting function to facilitate the winding of the core 1. Everything else remains the same as in Example 1.
[0065] Comparative Example 2
[0066] Compared to Example 1, the height of the heat-conducting plate 2 is the same as the height of the core 1, meaning that the entire heat-conducting plate 2 is located inside the core 1. Everything else remains the same as in Example 1.
[0067] Temperature measurements were performed on the square cells obtained in Examples 1-7 and Comparative Example 1, as well as on existing conventional square lithium batteries (Peng Hui Energy 320Ah square cells, hereinafter referred to as "existing" in the table). During the measurements, the cells were charged and discharged at 0.5C at 25°C for 120 minutes to fully charge and 250 minutes to discharge. During this period, the temperature (°C) at the positive electrode tab was collected at regular intervals using thermocouples. The results are as follows:
[0068]
[0069] As shown in Table 1:
[0070] (1) From the comparison of the test results of Example 1, Comparative Example 1 and Comparative Example 2, it can be seen that: by setting a heat-conducting plate 2 inside the core 1 and having one end of the heat-conducting plate 2 extend out of the core 1 to form a condensation section (Example 1), the present invention can significantly improve the heat dissipation effect compared with not setting a heat-conducting plate 2 (Comparative Example 1) or although a heat-conducting plate 2 is set, the heat-conducting plate 2 is completely located inside the core 1 (Comparative Example 2).
[0071] (2) A comparison between Example 1 and Example 2 shows that, for the same height, a condensation section located at both ends of a square battery cell has better heat dissipation than one located at only one end of the square battery cell. A comparison between Example 1 and Examples 3, 4, and 5 shows that the height of the contact cavity within a certain range, such as 1-5 mm, has a positive impact on heat dissipation. Within this range, a higher contact cavity height is more conducive to improving heat dissipation; however, if it exceeds this range, such as 10 mm, it will degrade the heat dissipation performance. A comparison between Example 1 and Examples 6 and 7 shows that a higher condensation section is more conducive to improving heat dissipation.
[0072] (3) As can be seen from the comparison between Examples 1-7 and the prior art, the square battery cell based on the heat-conducting plate proposed in this utility model does have better heat dissipation performance than the prior art.
[0073] In summary, the square battery cell based on a heat-conducting plate proposed in this invention has a faster cooling speed and better heat dissipation effect, which can ensure that the battery temperature remains constant and can operate for a long time, effectively extending the battery cell's lifespan and helping to improve battery safety. More importantly, it helps to reduce the difficulty of production operations, improve battery production efficiency, and reduce manufacturing costs.
[0074] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions, and variations to the above embodiments within the scope of the present invention. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.
Claims
1. A square battery cell based on a heat-conducting plate, characterized in that, The device includes a heat-conducting plate (2) and a racetrack-shaped core (1). The heat-conducting plate (2) includes an evaporation section located inside the core (1) and a condensation section located outside the core (1). The condensation section is located at one end or opposite ends of the evaporation section and the evaporation section and the condensation section are an integrated structure. The total height of the condensation section is 1%-20% of the height of the core (1). The heat-conducting plate (2) is provided with a coolant, a liquid-absorbing core layer and a shell layer in sequence from the inside to the outside. The outer surface of the heat-conducting plate (2) is provided with an insulating coating.
2. The square battery cell according to claim 1, characterized in that, The liquid-absorbing core layer is selected from one of the following: powder sintered liquid-absorbing core, metal wire mesh liquid-absorbing core, axial groove liquid-absorbing core, and composite liquid-absorbing core.
3. The square battery cell according to claim 1, characterized in that, It also includes an aluminum shell (3), an insulating film (4), a positive electrode cover plate (5), a negative electrode cover plate (6), a positive electrode insulating sheet (7), a negative electrode insulating sheet (8), a positive electrode adapter piece (9), a negative electrode adapter piece (10), a positive electrode current collector (11), and a negative electrode current collector (12). The positive electrode cover plate (5) and the negative electrode cover plate (6) have the same length, width, and height and are marked as L2, T2, and H2 in sequence. L2, T2, and H2 satisfy: 10mm≤L2≤300mm, 10mm≤T2≤200mm, and 1≤H2≤10mm. At least one of the positive electrode cover plate (5) and the negative electrode cover plate (6) is provided with a through groove that matches the structure of the condensation section. The groove opening extends along its height direction to form a contact cavity. The height of the contact cavity is marked as L3, and 1mm≤L3≤10mm.
4. The square battery cell according to claim 3, characterized in that, The ratio of the surface area S1 of the heat-conducting plate (2) to the surface area S2 of the aluminum shell (3) satisfies: 0 < S1 / S2 ≤ 0.3, and the ratio of the energy W of the square battery cell to the surface area S1 of the heat-conducting plate (2) satisfies: 0 < W / S1 ≤ 0.
1.
5. The square battery cell according to claim 1, characterized in that, The core (1) includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet includes a positive current collector and a positive active material layer. There is a region I on the positive current collector that is not coated with the positive active material layer, and region I forms a positive electrode tab. The negative electrode sheet includes a negative current collector and a negative active material layer. There is a region II on the negative current collector that is not coated with the negative active material layer, and region II forms a negative electrode tab. The separator is attached to both sides of the positive electrode sheet and the negative electrode sheet. The stacked negative electrode sheet, the separator, the positive electrode sheet, and the separator are wound on a heat-conducting plate (2) to form a racetrack-shaped core (1). The positive electrode tab and the negative electrode tab are... Located at both ends of the core (1); multiple notches are cut at intervals on both regions I and II. After the multiple notches are superimposed, two oppositely arranged and fan-shaped grooves (13) are formed at both ends of the core (1). The angle of the fan shape is 10°-180°. The radius of the rounded corner of the arc segment adjacent to the fan shape is marked as R2. The length, height, thickness and radius of the rounded corner of the core (1) are marked as L5, H4 and T5 in sequence. R2, L5, H4 and T5 satisfy: 0mm≤R2≤100mm, 10mm≤L5≤300mm, 10mm≤H4≤2000mm, 10mm≤T5≤200mm.
6. The square battery cell according to claim 1, characterized in that, The length, height and thickness of the heat-conducting plate (2) are marked as L6, H5 and T6 in sequence. L6, H5 and T6 satisfy: 10mm≤L6≤300mm, 10mm≤H5≤2050mm, 1mm≤T6≤20mm.
7. The square battery cell according to claim 3, characterized in that, The aluminum shell (3) is a square aluminum shell formed in one piece. The corners of the square aluminum shell are rounded. The thickness of the aluminum shell (3) is marked as T4, and the radius of the rounded arc is marked as R3. T4 and R3 satisfy: 0.2mm≤T4≤8mm, 1mm≤R3≤5mm.
8. The square battery cell according to claim 3, characterized in that, The positive current collector (11) and the negative current collector (12) have the same length, width and height, and are marked as L4, T3 and H3 in sequence. L4, T3 and H3 satisfy: 10mm≤L4≤300mm, 10mm≤T3≤200mm, 1mm≤H3≤5mm.
9. The square battery cell according to any one of claims 1-8, characterized in that, The condensation section is located at one end of the evaporation section. The height of the condensation section is D1. The length, height, thickness, and corner radius of the square battery cell are marked as L1, H1, T1, and R1 in sequence. D1, L1, H1, T1, and R1 satisfy the following conditions: 1mm≤D1≤50mm, 10mm≤L1≤300mm, 10mm≤H1≤2000mm, 10mm≤T1≤200mm, and 1mm≤R1≤5mm.
10. The square battery cell according to any one of claims 1-8, characterized in that, The condensing section is located at opposite ends of the evaporating section. The condensing section at each end of the evaporating section has the same height, which is D2, and 0.5mm≤D2≤25mm.