A reinforced case structure for a cylindrical battery, a cylindrical battery, and a battery module

Abstract

The application belongs to the technical field of cylindrical batteries, and discloses a reinforced shell structure for a cylindrical battery, the cylindrical battery and a battery module. The reinforced shell structure comprises a cylindrical battery shell for accommodating the battery cell of the cylindrical battery. The shell cylinder wall of the cylindrical battery shell is integrally formed with an outwardly protruding outer protruding reinforcing band. The outer protruding reinforcing band is correspondingly formed with a composite gas guiding groove in communication with the inside of the cylindrical battery on the inner side of the shell cylinder wall. The outer protruding reinforcing band comprises at least one annular outer protruding reinforcing band or spiral outer protruding reinforcing band extending along the circumference of the cylindrical battery shell. The outer protruding reinforcing band can form a structure similar to a reinforcing rib, and can circumferentially or spirally support the shell cylinder wall, which is beneficial to dispersing the internal expansion pressure of the cylindrical battery and external assembly and stacking pressure. Meanwhile, the outer protruding reinforcing band has the functions of gas collection and exhaust, and can improve the anti-deformation ability, pressure resistance stability and exhaust performance of the cylindrical battery shell.

Description

Technical Field

[0001] This invention belongs to the field of cylindrical battery technology, and specifically relates to a reinforced shell structure for cylindrical batteries, a cylindrical battery, and a battery module. Background Technology

[0002] The rapid development of power storage applications has placed higher demands on battery performance, and electrochemical battery cells are gradually evolving towards larger capacity and larger size. In recent years, cylindrical batteries, with their advantages of high process maturity, good heat dissipation performance, and flexible modular assembly, have begun to be used in energy storage systems with capacities of hundreds of ampere-hours and even higher. Compared with traditional small cylindrical batteries (such as 18650 and 21700 models), manufacturing large-capacity, large-size cylindrical batteries for energy storage can significantly increase battery capacity and improve the integration efficiency of energy storage systems, but it also poses more severe challenges to their structural strength and internal environmental management.

[0003] Currently, conventional cylindrical battery casings are typically smooth, thin-walled cylindrical structures. This structure is prone to deformation when faced with the significant radial stress inside large-size batteries and the external stacking and assembly pressures. This deformation not only compresses the internally wound or stacked electrode arrays, leading to safety hazards such as active material stripping and internal short circuits, but also alters the spacing between electrodes, affecting lithium-ion migration and accelerating battery performance degradation. Furthermore, during battery cycling, especially after high-rate charging and discharging or long-term use, electrode materials inevitably decompose, generating gas. Traditional small cylindrical batteries produce relatively little gas, which can easily accumulate at the top of the battery and be discharged through a pressure relief valve. However, in large-size cylindrical batteries, the length of the wound electrodes increases significantly, and the internal spatial structure becomes more complex. The generated gas struggles to migrate to the top through the narrow space in the high-viscosity electrolyte, instead tending to remain trapped in the narrow gaps between the wound electrode layers, forming localized gas stagnation zones. Gas retention increases battery internal resistance, leading to intensified polarization and decreased charge / discharge efficiency. It also hinders the electrolyte's wetting of the electrode materials in the retention area, resulting in uneven utilization of active materials and accelerated local aging. Furthermore, long-term gas retention may accumulate pressure, posing a threat to casing sealing and safety.

[0004] In existing technologies, the problem of casing strength is usually solved by increasing the casing wall thickness or using higher strength materials, but this sacrifices the battery's energy density and increases manufacturing costs. Improving gas expulsion requires complex electrode designs or the addition of extra gas-conducting components, which further complicates the manufacturing process and reduces reliability. Therefore, how to enhance the deformation resistance of cylindrical battery casings caused by increases in size and capacity, and how to effectively manage the large amount of gas generated inside the battery, are key issues in the development of large-capacity, large-size cylindrical batteries for energy storage. Summary of the Invention

[0005] The purpose of this invention is to propose a reinforced shell structure for cylindrical batteries, a cylindrical battery and a battery module, in order to solve the technical problems of poor deformation resistance and inability to channel gas generated inside the battery in existing cylindrical batteries.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a reinforced casing structure for a cylindrical battery, comprising: Cylindrical battery casing, used to house the cells of a cylindrical battery; The cylindrical battery casing has an integrally formed outer reinforcing band protruding outward from the outer side of the cylindrical battery casing. The outer reinforcing band forms a composite air-guiding groove communicating with the inside of the cylindrical battery on the inner side of the casing wall. The convex reinforcing strip includes at least one annular or spiral convex reinforcing strip extending circumferentially along the cylindrical battery casing.

[0007] A further improvement of the present invention is that it further includes: The upper end cover is sealed to the upper end of the cylindrical battery casing; A top cavity is formed between the cylindrical battery casing and the upper end cover, located above the battery cell. The upper end cover is provided with a pressure relief valve that communicates with the top cavity.

[0008] A further improvement of the present invention is that the annular convex reinforcing band is connected to the top cavity through an internal air guide groove provided on the inner wall of the shell cylinder; The spiral outward reinforcing strip connects to the top cavity through an internal air guide groove provided on the inner wall of the shell cylinder, or the top end of the spiral outward reinforcing strip directly connects to the top cavity.

[0009] A further improvement of the present invention is that the internal air guide groove is a straight groove or a helical groove.

[0010] A further improvement of the present invention is that the convex reinforcing strip includes at least one annular convex reinforcing strip and at least one spiral convex reinforcing strip. The annular convex reinforcing strip forms an annular composite air guiding groove on the inner side of the shell wall, and the spiral convex reinforcing strip forms a spiral composite air guiding groove on the inner side of the shell wall. The annular composite air guiding groove and the spiral composite air guiding groove are interconnected, and the top end of the spiral air guiding groove is connected to the top cavity.

[0011] A further improvement of the present invention is that multiple annular convex reinforcing strips are provided, and the multiple annular convex reinforcing strips are distributed at intervals along the axial direction of the cylindrical battery casing; the axial distance between two adjacent annular convex reinforcing strips is 1 / 5 to 1 / 3 of the height of the cylindrical battery casing.

[0012] A further improvement of the present invention is that the annular convex reinforcing strip is arranged in a continuous annular shape along the circumference of the cylindrical battery casing, or in an arc shape along the circumference of the cylindrical battery casing.

[0013] A further improvement of the present invention is that the spiral convex reinforcing strip extends continuously along the outer periphery of the cylindrical battery casing, and the spiral angle of the spiral convex reinforcing strip is 10° to 60°.

[0014] A further improvement of the present invention is that the depth of the composite air guiding groove is 0.5 to 3.0 times the thickness of the shell wall, and the ratio of the depth of the composite air guiding groove to the width of the groove is 1:1.

[0015] A further improvement of the present invention is that the inner surface of the composite air guide groove is provided with at least one of a metal coating, a ceramic coating, or a polymer coating.

[0016] A further improvement of the present invention is that the cylindrical battery casing is made of aluminum alloy.

[0017] A further improvement of the present invention is that the outer diameter of the cylindrical battery casing is greater than or equal to 50 mm.

[0018] Secondly, the present invention provides a cylindrical battery, including a reinforced outer casing structure for a cylindrical battery and a battery cell disposed within the reinforced outer casing structure; the rated capacity of the cylindrical battery is greater than or equal to 50Ah.

[0019] Thirdly, the present invention provides a battery module comprising a plurality of cylindrical batteries arranged side by side; the convex reinforcing strips of adjacent cylindrical batteries are staggered to avoid each other.

[0020] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a reinforced casing structure for cylindrical batteries. An outwardly protruding reinforcing strip is integrally formed on the casing wall of the cylindrical battery, creating a rib-like structure that provides circumferential or helical support to the casing wall. This helps disperse internal expansion pressure and external assembly / stacking pressure, reducing the risk of localized bulging, denting, or instability deformation of the casing wall and improving the deformation resistance and pressure stability of the cylindrical battery casing. Simultaneously, a composite gas-guiding groove is formed on the inner side of the casing wall, communicating with the interior of the cylindrical battery. This allows the same integrally formed structure to serve both casing reinforcement and gas guidance functions. Gas generated inside the cylindrical battery can enter the composite gas-guiding groove, reducing the phenomenon of gas stagnating between the cell and the casing or in localized areas of the cell. This improves the gas distribution around the cell and reduces the adverse effects of localized gas accumulation on electrolyte wetting, cell internal resistance, and casing safety. Using an annular convex reinforcing strip can significantly improve the circumferential stiffness and radial expansion resistance of the casing wall. Using a spiral convex reinforcing strip can simultaneously provide structural constraints in both the radial and axial directions of the casing wall, and cause the corresponding composite gas-guiding grooves to tend to extend along the casing's axial direction. Therefore, this structure achieves a synergistic improvement in casing structural strength and internal gas-guiding capacity without relying solely on increasing the casing wall thickness, which is beneficial for balancing the safety, energy density, and manufacturing cost of cylindrical batteries.

[0021] Furthermore, this invention provides a sealed upper cover at the top of the cylindrical battery casing and forms a top cavity above the battery cell. This provides a relatively concentrated collection space for the gas generated inside the cylindrical battery, reducing the phenomenon of gas being directly trapped around the battery cell or in narrow gaps inside the cell. The upper cover is equipped with a pressure relief valve communicating with the top cavity, allowing the gas collected in the top cavity to be discharged through the valve when the internal pressure of the cylindrical battery reaches a set condition. This establishes a pressure relief path from inside the battery to the top cavity and then to the pressure relief valve, which helps reduce the risk of casing deformation, seal failure, or safety accidents caused by continuous increase in internal battery pressure, thereby improving the pressure relief reliability and safety of the cylindrical battery.

[0022] Furthermore, this invention, by providing an internal gas guide groove on the inner wall of the casing, connects the composite gas guide groove formed on the inner side of the annular convex reinforcing strip with the top cavity, allowing the gas collected in the annular composite gas guide groove to be directionally transported to the upper part of the cylindrical battery along the internal gas guide groove. This structure overcomes the problem that closed annular grooves mainly extend circumferentially and are difficult to transport gas to the top cavity independently. It allows the annular composite gas guide groove to function as a gas collection structure, and the internal gas guide groove to function as an axial transport structure, thus forming a continuous gas transmission path of circumferential collection—axial discharge—top pressure relief. This improves the gas guiding effectiveness of the groove corresponding to the annular convex reinforcing strip and reduces gas retention around the annular groove or the battery cell.

[0023] Furthermore, the composite gas-guiding groove formed on the inner side of the spiral outward reinforcing strip of this invention itself has a structural characteristic of gradually extending along the axial direction of the cylindrical battery casing. By connecting the spiral outward reinforcing strip to the top cavity through the internal gas-guiding groove, or by directly connecting the top end of the spiral outward reinforcing strip to the top cavity, the gas entering the spiral composite gas-guiding groove can be continuously guided to the top cavity. The method of connecting through the internal gas-guiding groove allows for flexible placement of the gas outlet based on the positions of the upper end cap, the rolled edge sealing structure, and the pressure relief valve; the method of directly connecting the top end of the spiral outward reinforcing strip to the top cavity reduces intermediate gas-guiding structures, shortens the gas flow path, reduces flow resistance, and simplifies the internal gas-guiding structure of the casing. Both of these methods improve the efficiency and reliability of the migration of gas generated inside the cylindrical battery to the top cavity.

[0024] Furthermore, when the internal air guide groove is set as a straight groove, it can form an axial air guide channel with a shorter path and a clear direction, which helps to reduce the flow resistance of gas from the composite air guide groove to the top cavity and facilitates the processing and forming of the shell. When the internal air guide groove is set as a helical groove, it can increase the intersection range of the internal air guide groove and the annular composite air guide groove or spiral composite air guide groove distributed along the circumference of the shell, making it easier for gas generated or collected at different circumferential positions to enter the internal air guide groove, and can avoid the air guide structure from being excessively concentrated in a single axial position on the shell wall, which is beneficial to balance the uniformity of the shell's stress and the gas guiding capacity.

[0025] Furthermore, this invention simultaneously incorporates annular and spiral convex reinforcing strips, enabling the cylindrical battery casing to possess both circumferential and spiral reinforcement functions. The annular convex reinforcing strip enhances the casing's circumferential stiffness and radial expansion resistance, while the spiral convex reinforcing strip improves the overall stability of the casing under radial, axial, and combined loads. The annular composite gas-guiding groove formed inside the annular convex reinforcing strip collects gas from different circumferential positions within the cylindrical battery, while the spiral composite gas-guiding groove formed inside the spiral convex reinforcing strip transports the collected gas axially upwards along the casing. By connecting the annular and spiral composite gas-guiding grooves and ensuring the top of the spiral composite gas-guiding groove connects to the top cavity, a composite gas-guiding network is formed, where gas from multiple circumferential collection points converges into the spiral gas-guiding channel and is then transported to the top cavity. Therefore, this structure not only improves the multi-directional load-bearing capacity of the cylindrical battery casing but also enhances the collection and transport efficiency of dispersed gas, achieving synergistic cooperation between the casing reinforcement structure and the internal gas-guiding structure.

[0026] Furthermore, by arranging multiple annular convex reinforcing strips at intervals along the axial direction of the cylindrical battery casing, this invention creates multiple circumferential load-bearing zones at different heights of the casing wall. This allows for segmented bearing and dispersion of internal pressure and external assembly loads, reducing the risk of localized stress concentration and bulging deformation in the middle or ends of the casing wall. Limiting the axial spacing between adjacent annular convex reinforcing strips to 1 / 5 to 1 / 3 of the cylindrical battery casing height helps achieve a balance between the number of reinforcing strips, overall casing rigidity, processing difficulty, and effective casing volume. This spacing avoids excessive spacing between reinforcing strips, which could lead to a lack of support in some areas of the casing wall, and also avoids overly dense reinforcement strips, which could increase casing weight, processing complexity, or occupy internal space, resulting in a more uniform deformation resistance along the axial direction of the casing.

[0027] Furthermore, when the annular convex reinforcing strip of the present invention is continuously arranged in a ring along the circumference of the cylindrical battery casing, it can form a complete closed circumferential reinforcing structure, providing more uniform support to the casing wall in the entire circumferential direction, which is beneficial to improving the overall circumferential stiffness and radial expansion resistance of the casing. When the annular convex reinforcing strip is arc-shaped along the circumference of the cylindrical battery casing, it can provide targeted reinforcement in local high-stress areas of the casing wall, and retain non-protruding areas between adjacent arc-shaped reinforcing structures, which helps to reduce the impact of the convex structure on battery assembly, spacing between adjacent batteries, and heat dissipation channels. At the same time, the arc-shaped arrangement also facilitates staggered arrangement according to the position of adjacent cells in the battery module, improving the flexibility of structural design.

[0028] Furthermore, this invention enables the spiral convex reinforcing strip to extend continuously along the outer circumference of the cylindrical battery casing, forming a continuous spiral reinforcing path on the casing wall. This reduces localized weak areas caused by interruptions in the reinforcing structure, thus improving the overall stability of the casing under radial expansion, axial compression, and torsional loads. Limiting the helix angle of the spiral convex reinforcing strip to 10°–60° balances both circumferential reinforcement and axial extension components. When the helix angle is within this range, the spiral convex reinforcing strip provides effective radial constraint to the casing while ensuring sufficient axial extension of the corresponding spiral composite gas-guiding groove. This facilitates the gradual guidance of gas to the upper part of the cylindrical battery, achieving both structural reinforcement and gas flow guidance effects.

[0029] Furthermore, this invention limits the depth of the composite gas-guiding groove to 0.5 to 3.0 times the thickness of the shell wall, enabling the convex reinforcing strip to have a certain protrusion height and moment of inertia, thereby improving the structural rigidity of the shell wall. Simultaneously, it creates a gas-guiding space within the shell with actual gas-accommodating and transporting capabilities. Limiting the ratio of the composite gas-guiding groove's depth to its width to (0.5 to 3):1 helps avoid insufficient reinforcement and gas-guiding volume due to excessively shallow or wide grooves, and also avoids difficulties in forming, localized stress concentration, or increased gas flow resistance due to excessively deep or narrow grooves. Thus, a good balance is achieved between shell reinforcement strength, gas-guiding smoothness, internal space occupancy, and processing feasibility.

[0030] Furthermore, the present invention provides at least one of a metal coating, a ceramic coating, or a polymer coating on the inner surface of the composite gas-guiding groove. This improves the smoothness and surface properties of the groove's inner surface, reduces the adhesion resistance encountered by bubbles or gas flowing along the composite gas-guiding groove, and helps improve gas migration efficiency. The coating also isolates the electrolyte, reaction byproducts, and the casing substrate material, reducing the risk of corrosion or chemical erosion in the composite gas-guiding groove area. In particular, the composite gas-guiding groove may undergo localized plastic deformation during stamping or roll forming; applying a suitable coating can improve the corrosion resistance and long-term structural stability of this area, extending the service life of the cylindrical battery casing.

[0031] Furthermore, the cylindrical battery casing of this invention is made of aluminum alloy. This utilizes the low density, good thermal conductivity, and ease of stamping or roll forming of aluminum alloy to reduce the weight of the cylindrical battery casing, increase the battery's mass energy density, and facilitate the transfer of heat generated by the battery cell. Aluminum alloy has good plasticity, making it easy to integrally form annular or spiral convex reinforcing strips on the casing wall, reducing the need for additional reinforcing components and welded connections. The convex reinforcing strips compensate for the relatively insufficient rigidity of the thin-walled aluminum alloy casing, thus balancing lightweight design, thermal conductivity, machinability, and structural strength.

[0032] Furthermore, when multiple cylindrical battery cells are assembled side by side into a battery module, the annular reinforcing strips on the cylindrical wall of each cell are staggered by 10 to 45 degrees in the circumferential direction to avoid direct overlap and compression of the convex parts of adjacent cells. Attached Figure Description

[0033] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the single-ring outward convex reinforcing strip structure shown in Example 1.

[0034] Figure 2 This is a partial detailed schematic diagram of the annular convex reinforcing strip shown in Example 1.

[0035] Figure 3 This is a schematic diagram of the multi-turn distributed reinforcement strip structure shown in Example 2.

[0036] Figure 4 This is a schematic diagram of the spiral reinforcing strip structure shown in Example 3.

[0037] Figure 5 This is a schematic diagram of the circumferentially misaligned battery arrangement structure within the module shown in Example 4.

[0038] Figure 6 This is a schematic diagram of the axially misaligned battery arrangement structure within the module shown in Example 4.

[0039] In the figure, 1 Cylindrical battery casing, 2 Circular convex reinforcing strip, 3 Inside the battery, 4 Groove opening, 5 Annular groove, 6 Shell wall, 7 First annular convex reinforcing band, 8 Second annular convex reinforcing band, 9 The third annular convex reinforcing band, 10-spiral convex reinforcing band, 11-discontinuous annular convex reinforcing band. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0041] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0042] Example 1 Please see Figure 1-2 As shown, this embodiment of the invention provides a reinforced casing structure for a cylindrical battery, including a cylindrical battery casing 1; the cylindrical battery casing 1 is made of aluminum alloy; an annular convex reinforcing band 2 is provided in the middle of the casing wall 6 of the cylindrical battery casing 1. The annular convex reinforcing band 2 is continuously distributed in a ring around the outer periphery of the casing wall 6, with an outward convex height of about 0.8 mm and a width of 4 mm; a corresponding annular groove 5 is formed on the inner side of the annular convex reinforcing band 2, and the depth of the annular groove 5 is twice the wall thickness of the casing wall 6; the groove opening 4 of the annular groove 5 faces the battery interior 3. The cross-section of the annular convex reinforcing band 2 is arc-shaped. The annular convex reinforcing band 2 can divide the casing wall 6 into upper and lower stress zones. When radial expansion pressure is generated inside the battery cell or external assembly clamping force is generated, the casing wall 6 can effectively disperse stress concentration, so that the deformation of the cylinder expands from a single point to a planar deformation, thereby improving the anti-expansion strength of the casing.

[0043] For example, the cross-sectional shape of the annular groove 5 can be, in addition to, an arc shape, an inverted U shape or an inverted V shape, or a combination thereof.

[0044] For example, the depth of the annular groove 5 is 0.5 to 3.0 times the thickness of the shell wall 6, and the ratio of the depth of the annular groove 5 to the width of the groove opening 4 is (0.5 to 3): 1.

[0045] For example, the inner surface of the annular groove 5 is provided with one or more of a metal coating, a ceramic coating, or a polymer coating to reduce the flow resistance of gas in the channel and improve the corrosion resistance of the shell at the groove.

[0046] For example, the annular convex reinforcing band 2 is connected to the top cavity of the cylindrical battery through an internal air guide groove (not shown) provided on the inner wall of the housing cylinder wall 6.

[0047] Example 2 Please see Figure 3 As shown, this embodiment of the invention provides a reinforced outer shell structure for cylindrical batteries, which, based on embodiment 1, includes multiple annular convex reinforcing strips 2.

[0048] For example, it specifically includes three annular convex reinforcing bands 2: a first annular convex reinforcing band 7 located on the upper part of the shell wall 6, a second annular convex reinforcing band 8 located in the middle part of the shell wall 6, and a third annular convex reinforcing band 9 located on the lower part of the shell wall 6. The first annular convex reinforcing band 7, the second annular convex reinforcing band 8, and the third annular convex reinforcing band 9 are equidistantly distributed, with a spacing of approximately 1 / 5 to 1 / 3 of the total height of the shell; preferably, the spacing can be 1 / 5, 1 / 4, or 1 / 3.

[0049] This multi-ring distribution design creates multiple load-bearing zones along the long axis of the cylinder, which can uniformly decompose the combined stress caused by cell expansion, stacking and pressing, and external impact. Finite element simulation analysis shows that the cylinder with multi-ring reinforcing strip structure reduces the maximum strain by about 35% when subjected to the same internal pressure, while effectively suppressing local bulging deformation at the ends of the cylinder, thus meeting the strength requirements of cylindrical battery casings with an outer diameter of not less than 100 mm.

[0050] For example, the present invention may provide two or more annular outward convex reinforcing strips 2 on the shell wall 6; the annular outward convex reinforcing strips 2 may be arranged at equal intervals or at non-equal intervals.

[0051] Example 3 Please see Figure 4 As shown, this embodiment of the invention provides a reinforced shell structure for cylindrical batteries. Compared to embodiment 1, the annular convex reinforcing strip 2 is configured as a spiral, forming a spiral convex reinforcing strip 10. The spiral convex reinforcing strip 10 is continuously arranged in a spiral shape along the shell wall 6; the spiral convex reinforcing strip 10 forms continuous spiral convex ribs on the surface of the shell, with corresponding spiral groove channels formed on its inner side. When subjected to force, the spiral convex reinforcing strip 10 can simultaneously provide radial support and axial torsional reinforcement, enabling the shell to maintain overall stability under complex loads. Because the spiral connection structure of the spiral convex reinforcing strip 10 is interconnected, the yielding mode of the shell changes from local circumferential expansion to spiral extension deformation, thereby achieving stress redistribution and improving the deformation resistance limit. In addition, this structure can provide additional support at the top rolled edge, improving the end sealing strength.

[0052] For example, the spiral convex reinforcing band 10 extends continuously along the outer periphery of the cylindrical battery casing 1, and the spiral angle of the spiral convex reinforcing band 10 is 10° to 60°.

[0053] Example 4 This invention provides a reinforced casing structure for a cylindrical battery, including at least one annular convex reinforcing strip 2 as described in embodiment 1 and at least one spiral convex reinforcing strip 10 as described in embodiment 3. The annular convex reinforcing strip 2 forms an annular composite air-guiding groove on the inner side of the casing wall 6, and the spiral convex reinforcing strip 10 forms a spiral composite air-guiding groove on the inner side of the casing wall 6. The annular composite air-guiding groove and the spiral composite air-guiding groove are interconnected, and the top end of the spiral air-guiding groove is connected to the top cavity of the cylindrical battery.

[0054] Example 5 Please see Figures 5 to 6 As shown, this embodiment of the invention provides a battery module in which, when multiple cylindrical battery cells are assembled side by side, the outwardly convex reinforcing strips of each housing wall 6 are intermittently annularly convex reinforcing strips 11, staggered from each other by 20° to 40° in the circumferential direction. This staggered arrangement prevents the intermittently annularly convex reinforcing strips 11 between adjacent batteries from directly contacting each other, thereby avoiding local contact stress concentration and uneven stacking gaps. Furthermore, the position and height of the intermittently annularly convex reinforcing strips 11 can be adjusted (e.g., by adjusting the height of the strips). Figure 6 As shown, an axially staggered layout is formed, which improves the overall force balance and space utilization of the module, improves the battery module stacking density and heat dissipation uniformity, and maintains the stability and safety of the assembly structure.

[0055] This invention, by incorporating an annular convex reinforcing strip on the outer periphery of the cylindrical battery casing, effectively disperses localized stress concentrations caused by internal gas expansion, volume deformation, external stacking, and assembly pressure. This significantly enhances the casing's resistance to deformation and pressure stability, preventing the wound cells from being squeezed and deformed, and preventing the peeling of active materials, thereby improving the battery's cycle stability and lifespan consistency. Simultaneously, the groove formed by the convex reinforcing strip inside the casing, between it and the upper end cap, constitutes a gas guiding channel and buffer cavity, directionally guiding and accommodating the gas generated inside the battery, alleviating gas stagnation, and improving battery performance. Furthermore, when cylindrical batteries with this structure are assembled into modules, the corresponding arrangement not only reduces mutual interference between individual cells but also increases the stacking density of the battery modules, optimizing space utilization.

[0056] Compared to traditional designs that simply rely on thickened walls, the reinforcing strip structure described in this invention maintains high energy density and lightweight advantages while ensuring strength, and provides additional safety redundancy for cylindrical batteries. This structure improves casing strength, manufacturability, and module assembly compatibility, making it suitable for the reliable and safe operation requirements of large-capacity energy storage cylindrical batteries.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application and not to limit them. Although the embodiments of this application have been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the embodiments of this application. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the embodiments of this application should be covered within the protection scope of the claims of the embodiments of this application.

Claims

1. A reinforced casing structure for cylindrical batteries, characterized in that, include: Cylindrical battery casing (1) for accommodating the cells of a cylindrical battery; The cylindrical wall (6) of the cylindrical battery housing (1) is integrally formed with an outwardly protruding reinforcing strip that protrudes outward from the cylindrical battery housing (1). The outwardly protruding reinforcing strip forms a composite air-guiding groove that communicates with the inside of the cylindrical battery on the inner side of the cylindrical wall (6). The convex reinforcing strip includes at least one annular convex reinforcing strip (2) extending circumferentially along the cylindrical battery housing (1), and / or at least one spiral convex reinforcing strip (10) extending spirally along the outer periphery of the cylindrical battery housing (1).

2. The reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, Also includes: The upper end cover is sealed to the upper end of the cylindrical battery casing (1); The cylindrical battery casing (1) and the upper end cover form a top cavity above the battery cell, and the upper end cover is provided with a pressure relief valve that communicates with the top cavity.

3. The reinforced casing structure for a cylindrical battery according to claim 2, characterized in that, The annular convex reinforcing strip (2) is connected to the top cavity through an internal air guide groove provided on the inner wall of the shell cylinder wall (6).

4. The reinforced casing structure for a cylindrical battery according to claim 2, characterized in that, The spiral outward reinforcing strip (10) is connected to the top cavity through an internal air guide groove provided on the inner wall of the shell cylinder wall (6), or the top end of the spiral outward reinforcing strip (10) is directly connected to the top cavity.

5. A reinforced casing structure for a cylindrical battery according to claim 2, characterized in that, The internal air guide groove is a straight groove or a spiral groove.

6. A reinforced casing structure for a cylindrical battery according to claim 2, characterized in that, The convex reinforcing strip includes at least one annular convex reinforcing strip (2) and at least one spiral convex reinforcing strip (10). The annular convex reinforcing strip (2) forms an annular composite air guiding groove on the inner side of the shell cylinder wall (6). The spiral convex reinforcing strip (10) forms a spiral composite air guiding groove on the inner side of the shell cylinder wall (6). The annular composite air guiding groove and the spiral composite air guiding groove are interconnected. The top end of the spiral air guiding groove is connected to the top cavity.

7. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, Multiple annular convex reinforcing strips (2) are provided, and the multiple annular convex reinforcing strips (2) are distributed at intervals along the axial direction of the cylindrical battery housing (1); the axial distance between two adjacent annular convex reinforcing strips (2) is 1 / 5 to 1 / 3 of the height of the cylindrical battery housing (1).

8. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, The annular convex reinforcing strip (2) is arranged in a continuous annular shape along the circumference of the cylindrical battery housing (1), or in an arc shape along the circumference of the cylindrical battery housing (1).

9. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, The spiral convex reinforcing band (10) extends continuously along the outer periphery of the cylindrical battery casing (1), and the spiral angle of the spiral convex reinforcing band (10) is 10° to 60°.

10. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, The depth of the composite air guide groove is 0.5 to 3.0 times the thickness of the shell wall (6), and the ratio of the depth of the composite air guide groove to the width of the groove is (0.5 to 3):

1.

11. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, The inner surface of the composite air-guiding groove is provided with at least one of a metal coating, a ceramic coating, or a polymer coating.

12. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, The cylindrical battery casing (1) is made of stainless steel, aluminum alloy or low alloy high-strength structural steel.

13. A reinforced casing structure for a cylindrical battery according to claim 1, characterized in that, The outer diameter of the cylindrical battery casing (1) is greater than or equal to 50 mm.

14. A cylindrical battery, characterized in that, The invention includes a reinforced casing structure for a cylindrical battery according to any one of claims 1 to 13, and a battery cell disposed within the reinforced casing structure; the rated capacity of the cylindrical battery is greater than or equal to 50 Ah.

15. A battery module, characterized in that, It includes multiple cylindrical batteries as described in claim 14 arranged side by side; the convex reinforcing strips of adjacent cylindrical batteries are staggered to avoid each other.

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