Square aluminum shell battery with large capacity and high heat dissipation performance

Abstract

The utility model discloses a square aluminum shell battery with large capacity and high heat dissipation performance, which comprises a square aluminum shell, two battery cells connected in parallel, a heat-conducting partition plate, a heat-conducting buffer layer, a positive electrode cover plate, a negative electrode cover plate and an insulating part, the square aluminum shell is of an integrally formed structure, the interior is hollow, the end of the square aluminum shell is open, and bottom plates are respectively and fixedly arranged on two narrow walls of the square aluminum shell; vent holes are evenly formed in the bottom plate, the heat conduction partition plate is placed between the two battery cells connected in parallel, the heat conduction buffer layer is placed between the battery cells and the square aluminum shell so that impact force outside the battery cells can be buffered through the heat conduction buffer layer, and the positive electrode cover plate is installed at the opening position of the end, close to the positive electrode lug, of the square aluminum shell. Structural parts are reduced, and the proportion of energy storage elements is increased, so that the mass energy density of the battery is improved, the liquid injection efficiency of the battery is greatly improved, and heat generated by the lithium battery is dissipated; the external impact force is buffered, a part of deformation generated by the battery cell is absorbed, the influence on the lithium battery is reduced, and the possibility of explosion is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to a square aluminum-cased battery with high capacity and high heat dissipation performance. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage industries, the demand for power batteries has also increased. Based on the battery casing, power batteries are generally divided into steel-cased power batteries and aluminum-cased power batteries. Among them, square aluminum-cased batteries are widely used due to their compact structure and high assembly efficiency. However, existing technologies still face the following bottlenecks: In traditional single-cell structure designs, limited by the upper limit of single-cell capacity, conventional parallel connection schemes require the addition of multiple connecting components (such as adapter plates, busbars, etc.), resulting in an excessively high proportion of inactive materials and significantly reducing the mass energy density of the battery system. Furthermore, in existing electrolyte injection processes, limited by the small diameter of the injection holes, the electrolyte wetting efficiency is low, and the injection process takes 6-8 hours, severely impacting production efficiency. In addition, during battery operation, internal heat accumulation is a significant problem. Traditional closed-shell structures lack effective heat dissipation channels, and when the temperature gradient exceeds 5°C / cm, it easily triggers the risk of thermal runaway. In terms of mechanical safety protection, the traditional aluminum shell thickness is mostly 0.2mm-0.5mm. The thinness of the shell directly affects the overall pressure resistance of the square battery, making the aluminum shell prone to deformation, the battery easily damaged, affecting the safety of use, and also affecting the quality of the product.

[0003] As described in prior art, CN222190913U provides a battery pack including a cooling component, electrical components, and a first battery pack. The first battery pack includes a plurality of first battery cells, each having dimensions in three directions and stacked in the first direction. The cooling component is at least abutted against the outer side of the first battery cells in the first battery pack in the second direction. The electrical components are at least located on the outer surface of the top surface of the first battery cells in the first battery pack in the third direction. By providing cooling plates on both sides of the battery cells, the cooling contact area is increased, improving heat dissipation efficiency. Furthermore, by connecting the bottoms of the first and second battery cells to form a double-row battery pack structure, the packing method is optimized, thereby increasing the energy density of the battery pack.

[0004] As described in prior art 2, CN206364128U provides a square aluminum-cased lithium-ion battery, comprising a square aluminum casing, a cell, terminals, a cover plate, connecting tabs, and tabs. The tabs on both sides of the cell are connected to the cover plate via connecting tabs, and the terminals penetrate the cover plate and extend to the connecting tabs. Its advantages are that, with accurate positioning during welding, it reduces the risk of air leakage from the cover plate and improves production efficiency; it also effectively controls the height of the cell after connection with the cover plate, preventing the tabs from being damaged by compression when the cell is inserted into the casing.

[0005] As described in prior art (CN119275412A), a heat insulation structure for a square aluminum-cased battery sandwich layer includes a heat insulation frame and a heat insulation plate. A heat insulation plate is connected to one side of the heat insulation frame, and a heat-conducting plate is connected to the other side. The heat-conducting plate has evenly distributed circular heat-conducting holes. Internal frames are connected to both sides of the heat insulation frame, and each internal frame contains heat-conducting components. This solution utilizes the heat insulation frame, heat insulation plate, and heat-conducting plate in conjunction to form a basic heat insulation structure. The heat insulation plate and heat-conducting plate are distributed on both sides of the heat insulation frame, separating multiple square aluminum-cased batteries. The heat insulation plate provides insulation, and the heat-conducting plate and heat-conducting holes further facilitate heat conduction, increasing the contact area with air and rapidly dissipating the heat generated during the operation of the square aluminum-cased battery, thus helping to extend its service life.

[0006] As described in prior art (CN217641694U), a square aluminum-cased battery cell structure with side-out tabs includes a battery cell and a battery cell housing. Each end of the top of the battery cell has a busbar, which includes a horizontal section at the top of the cell. This horizontal section connects to either the positive or negative tab at the top of the cell. The outward-facing end of the horizontal section is bent downwards to form a vertical section covering the side of the battery cell. The bottom end of the vertical section is bent outwards to form a horizontal busbar extension. The battery cell housing encloses the battery cell, and the housing has an extension hole for the busbar extension to extend outwards. This square aluminum-cased battery cell structure with side-out tabs improves the flatness of the upper and lower surfaces of the battery cell housing, enabling compatibility with the battery cell, top cover, and cooling plate.

[0007] As described in prior art (CN117748036A), a square aluminum casing for a lithium battery includes an outer shell and retaining strips. Several retaining strips surround the outer side of the outer shell, providing initial protection for the lithium battery. Anti-collision strips inside the outer shell separate the lithium battery from the outer shell, preventing heat buildup from affecting the battery's operation and making it safer during use. When the outer shell is impacted, the anti-collision strips mitigate the impact, reducing damage to the lithium battery and extending its lifespan. The retaining strips, in conjunction with limiting rods, reinforce the outer shell, enhancing its strength and pressure resistance, thereby further protecting the lithium battery and improving its operational stability.

[0008] The existing technology has the following disadvantages: 1) The additional structural components such as the adapter and busbar occupy space and increase weight in the existing technology, which significantly reduces the mass energy density of the battery system; 2) The existing technology has the problem of secondary sealing reliability. The process of sealing the injection hole by reducing the diameter is prone to micro-cracks due to thermal stress, and the probability of leakage is as high as 0.3% - 0.5%; 3) The existing technology is highly dependent on external factors and requires an additional liquid cooling system, which increases the overall weight and energy consumption of the battery pack.

[0009] In response to the above technical solutions, the industry urgently needs to develop a new battery structure that can improve energy density while achieving synergistic improvements in liquid injection efficiency and thermo-mechanical coupling safety protection.

[0010] Therefore, a square aluminum-cased battery with high capacity and excellent heat dissipation performance is needed. Utility Model Content

[0011] To address the problems of the existing technology, this invention provides a high-capacity, high-heat-dissipation square aluminum-cased battery. The aim is to achieve direct parallel connection of two cells by welding their tabs to the same cover plate, reducing structural components and increasing the proportion of energy storage elements, thereby improving the battery's mass energy density. Simultaneously, the increased diameter of the electrolyte injection hole significantly improves the battery's electrolyte injection efficiency, and vent holes on the base plate dissipate the heat generated by the lithium battery. Furthermore, this invention uses a thermally conductive buffer layer to cushion external impacts, absorbing some of the cell deformation and reducing the impact on the lithium battery, thus decreasing the possibility of explosion.

[0012] To achieve the above objectives, this utility model provides the following technical solution: a large-capacity, high-heat-dissipation square aluminum-cased battery, comprising a square aluminum casing, two parallel-connected battery cells, a thermally conductive separator, a thermally conductive buffer layer, a positive electrode cover, a negative electrode cover, and insulating components. The square aluminum casing is an integrally formed structure, hollow inside, and open at both ends. A base plate is fixedly installed on each of the two narrow walls of the square aluminum casing, and ventilation holes are evenly distributed on the base plate. One end of each of the two parallel-connected battery cells is provided with a positive electrode tab, and the other end is provided with a negative electrode tab. A tab and a thermally conductive separator are placed between two parallel cells. A thermally conductive buffer layer is placed between the cells and the square aluminum shell to buffer the impact force from the outside of the cells. A positive cover plate is installed at the open end of the square aluminum shell near the positive tab, and a negative cover plate is installed at the open end of the square aluminum shell near the negative tab. Insulating parts are provided on the side of the positive cover plate facing the positive tab and the side of the negative cover plate facing the negative tab to insulate the two parallel cells from the positive and negative cover plates.

[0013] Preferably, the vents are distributed in rows and columns at equal intervals.

[0014] Preferably, high-temperature tape is applied to the four corners of the two parallel cells.

[0015] Preferably, the positive electrode cover plate is provided with a positive electrode post, a liquid injection hole and a positive electrode mark "+", the positive electrode post is welded to the positive electrode tabs of two parallel cells, and the liquid injection hole is located between the positive electrode post and the positive electrode mark "+".

[0016] Preferably, the diameter of the injection hole is 3mm, the channel of the injection hole has a stepped structure, and the injection hole is sealed with a sealing pin.

[0017] Preferably, the sealing pin is made of elastic rubber, which is used to make an interference fit with the injection hole.

[0018] Preferably, the negative electrode cover plate is provided with a negative electrode post, an explosion-proof valve and a negative electrode marking "-", the negative electrode post is welded to the negative electrode tabs of two parallel cells, and the negative electrode marking "-" is located between the negative electrode post and the explosion-proof valve.

[0019] Preferably, the two parallel cells are configured with a positive electrode tab and a negative electrode tab at the same end. An electrode cover plate is provided at the open end of the square aluminum shell near the electrode tab of the cell. A positive electrode post, a negative electrode post, a liquid injection hole, an explosion-proof valve, and a positive electrode marking "+" and a negative electrode marking "-" are respectively located on both sides of the electrode cover plate on the side facing the electrode tab.

[0020] In summary, this invention provides a high-capacity, high-heat-dissipation square aluminum-cased battery. By directly connecting two parallel cells by welding their tabs to the same cover plate, this invention reduces structural components and increases the proportion of energy storage elements, thereby improving the battery's mass energy density and doubling its capacity. In this invention, the increased diameter of the injection hole significantly improves the battery's injection efficiency. Ventilation holes on the bottom plate allow for heat dissipation from the lithium battery. Furthermore, the thermally conductive buffer layer cushions external impacts, absorbs some of the cell deformation, reduces the impact on the lithium battery, and decreases the possibility of explosion.

[0021] It can support the battery cell and evenly dissipate the heat released by the lithium battery; the thermally conductive separator and thermally conductive buffer layer structure can play a certain role in buffering and supporting; the whole square aluminum shell battery solution customized for the above scheme includes the positive electrode cover plate, negative electrode cover plate, liquid injection hole, and the connection method between the positive and negative electrode tabs and the positive and negative electrode posts, etc. Attached Figure Description

[0022] Figure 1 An exploded view of a square aluminum-cased battery;

[0023] Figure 2 This is a three-dimensional view of the base plate;

[0024] Figure 3 This is a schematic diagram of the positive electrode cover plate.

[0025] Figure 4 A schematic diagram of the negative electrode cover plate;

[0026] Figure 5 An exploded view of a square aluminum-cased battery according to another embodiment of this application;

[0027] In the picture: Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] like Figures 1 to 5 As shown:

[0030] This utility model is a high-capacity, high-heat-dissipation square aluminum-cased battery. It comprises six main components: a square aluminum casing 1, two parallel-connected battery cells 2, a thermally conductive separator 3, a thermally conductive buffer layer 4, a positive electrode cover 5, an electrode cover 6, and an insulating component 7. The square aluminum casing 1 is a one-piece molded structure, hollow inside with open ends. A base plate 11 is fixedly installed on each of the two narrow walls of the square aluminum casing 1. Vent holes 12 are provided on the base plate 11, with equal row and column spacing between the vent holes 12. The vent holes 12 dissipate the heat generated by the lithium battery, and the evenly spaced vent holes evenly dissipate the heat, making the lithium battery more stable during use, preventing excessive temperature from affecting its operation, and effectively improving the stability of the lithium battery.

[0031] Two parallel-connected battery cells 2 are respectively provided with positive electrode tabs 21 and negative electrode tabs 22 at both ends, and high-temperature tape is attached to the four corners of the two parallel-connected battery cells 2. A thermally conductive partition 3 is placed between the two parallel-connected battery cells 2, which can block the heat released to the outside when the battery cell thermally runs away, and play a certain role in buffering and supporting.

[0032] The thermally conductive buffer layer 4 is placed between the two parallel battery cells 2 and the square aluminum shell 1. The thermally conductive buffer layer 4 can buffer the external impact force, absorb some of the deformation generated by the battery cells, reduce the impact on the lithium battery, reduce the possibility of explosion, and at the same time assist the battery cells in exchanging heat with the outside, thereby effectively improving the service life of the lithium battery.

[0033] An example is provided where a square aluminum shell 1 has an internally hollow structure with open openings at its opposite ends, as shown below:

[0034] The positive electrode cover 5 is installed at one open end of the square aluminum shell 1 to seal the square aluminum shell 1. An insulating component 7 is provided below it. The insulating component 7 can prevent the two parallel cells 2 from directly contacting the positive electrode cover 5 and short-circuiting.

[0035] The positive electrode cover 5 is provided with a positive electrode post 51, an injection hole 52, and a positive electrode marking "+". The positive electrode post 51 is welded to the positive electrode tabs 21 of the two parallel cells 2. The injection hole 52 is located between the positive electrode post 51 and the positive electrode marking "+". The injection hole 52 has a diameter of 3mm, which is a large size and will significantly improve the battery's electrolyte filling efficiency. The injection hole 52 has a stepped structure, and the injection hole 52 is sealed with a sealing pin 53. The sealing pin is made of elastic rubber, and its elasticity allows for an interference fit with the injection hole 52. This structure is not affected by thermal expansion and contraction or vibration, effectively preventing battery leakage.

[0036] The negative electrode cover 6 is installed at the open end of the square aluminum shell 1 to seal the square aluminum shell 1, and an insulating component 7 is installed below it. The negative electrode cover is provided with a negative electrode post 61, an explosion-proof valve 62 and a negative electrode marking "-". The negative electrode post 61 is welded to the negative electrode tabs 22 of the two parallel cells 2. The negative electrode marking "-" is located between the negative electrode post 61 and the explosion-proof valve 62. The explosion-proof valve 62 can minimize the risk of product runaway under extreme conditions.

[0037] An example is provided where a square aluminum shell 1 has an internal hollow structure and an open end on one side, as shown below:

[0038] The square aluminum-cased battery has a positive electrode tab 21 and a negative electrode tab 22 located at the same end of the two parallel cells 2. The square aluminum casing 1 has an open end with an electrode cover plate 41 near the electrode tab of the cell 2. The electrode cover plate 41 has a positive electrode post 51, a negative electrode post 61, an injection hole 52, an explosion-proof valve 62, and positive electrode markings "+" and negative electrode markings "-" located on both sides of the electrode cover plate 41.

[0039] The embodiments described in this utility model are for illustrative purposes only and do not constitute a limitation on the scope of the claims. Other substantially equivalent substitutions that can be conceived by those skilled in the art are all within the protection scope of this utility model.

Claims

1. A square aluminum-cased battery with high capacity and high heat dissipation performance, characterized in that, The device includes a square aluminum shell (1), two parallel battery cells (2), a thermally conductive partition (3), a thermally conductive buffer layer (4), a positive electrode cover (5), a negative electrode cover (6), and an insulating component (7). The square aluminum shell (1) is an integrally formed structure with a hollow interior and an open end. A base plate (11) is fixedly installed on each of the two narrow walls of the square aluminum shell (1). Ventilation holes (12) are evenly distributed on the base plate (11). One end of each of the two parallel battery cells (2) is provided with a positive electrode tab (21), and the other end is provided with a negative electrode tab (22). The thermally conductive partition (3) is placed between the two parallel battery cells (2) to provide thermal buffering. Layer (4) is placed between the cell (2) and the square aluminum shell (1) so that the thermally conductive buffer layer (4) can buffer the impact force outside the cell (2). The positive cover plate (5) is installed at the open end of the square aluminum shell (1) near the positive electrode tab (21), and the negative cover plate (6) is installed at the open end of the square aluminum shell (1) near the negative electrode tab (22). Insulators (7) are provided on the side of the positive cover plate (5) facing the positive electrode tab (21) and the side of the negative cover plate (6) facing the negative electrode tab (22) to insulate the two parallel cells (2) from the positive cover plate (5) and the negative cover plate (6).

2. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 1, characterized in that, The ventilation holes (12) are distributed in rows and columns at equal intervals.

3. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 1, characterized in that, High-temperature tape is attached to the four corners of the two parallel cells (2).

4. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 1, characterized in that, The positive electrode cover plate (5) is provided with a positive electrode post (51), an injection hole (52) and a positive electrode mark "+". The positive electrode post (51) is welded to the positive electrode tabs (21) of two parallel cells (2). The injection hole (52) is located between the positive electrode post (51) and the positive electrode mark "+".

5. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 4, characterized in that, The injection hole (52) has a diameter of 3 mm. The channel of the injection hole (52) has a stepped structure. The injection hole (52) is sealed with a sealing nail (53).

6. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 5, characterized in that, The sealing pin (53) is made of elastic rubber and uses its elasticity to make an interference fit with the injection hole (52).

7. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 1, characterized in that, The negative electrode cover plate is provided with a negative electrode post (61), an explosion-proof valve (62) and a negative electrode mark "-". The negative electrode post (61) is welded to the negative electrode tabs (22) of two parallel cells (2). The negative electrode mark "-" is located between the negative electrode post (61) and the explosion-proof valve (62).

8. A square aluminum-cased battery with high capacity and high heat dissipation performance according to claim 1, characterized in that, Two parallel cells (2) are configured with a positive electrode tab (21) and a negative electrode tab (22) at the same end. An electrode cover plate (41) is provided at the end of the square aluminum shell (1) near the electrode tab of the cell (2). A positive electrode post (51), a negative electrode post (61), an injection hole (52), an explosion-proof valve (62) are provided on the side of the electrode cover plate (41) facing the electrode tab. The positive electrode mark "+" and the negative electrode mark "-" are located on both sides of the electrode cover plate (41).

Images