Cylinder housing, cylinder battery and battery module

Abstract

A cylinder housing characterized in that the cylinder housing is an aluminum metal housing or an aluminum alloy housing comprising an end plate and a side plate, wherein the end plate is a circular end plate, wherein the side plate is provided in a circumferential direction of the end plate and extends in an axial direction of the cylinder housing; wherein a transition section is provided between the end plate and the side plate, the transition section comprising an arc-shaped segment; wherein a ratio of a dimension of the transition section in the axial direction of the cylinder housing to a dimension of the transition section in a radial direction of the end plate is L; wherein a radius of the arc-shaped segment is R, and wherein a Brinell hardness of the cylinder housing is H;where the value of R is in a range of 1 mm to 4 mm, where the value of H is in a range of 20 HB to 70 HB, where the value of L is in a range of 0.6 to 1.4.;

Description

Technical field The present application relates to the technical field of batteries, in particular a cylindrical housing, a cylindrical battery and a battery module. Technical background The battery casing is typically a metal casing, and the end plates, such as the base plate and side plates, are usually one-piece machined and formed structures. The prior art manufacturing process is a stretching process, and due to the limitations of this process, the transition between the side plate and the base plate of the casing typically has pronounced edges, as shown in Fig. 1. Since the outer surface of the battery must be provided with an insulating layer, these edges can easily lead to the failure of the insulating layer, reducing the insulating performance of the casing and thus impairing the battery's performance and lifespan. Technical background The present application discloses a cylinder housing, a cylinder battery and a battery module to solve the problem of uneven insulating coating thickness on the side plate and end plate. To achieve the above purpose, the present application provides the following technical solutions: According to a first aspect, the present application provides a cylinder housing, wherein the cylinder housing is an aluminum metal housing or an aluminum alloy housing comprising an end plate and a side plate, wherein the end plate is a circular end plate, wherein the side plate is provided in a circumferential direction of the end plate and extends in an axial direction of the cylinder housing; A transition section is provided between the end plate and the side plate, wherein the transition section comprises an arc-shaped segment; wherein a ratio of a dimension of the transition section in the axial direction of the cylinder housing to a dimension of the transition section in a radial direction of the end plate is L; The radius of the arc-shaped segment is R and the Brinell hardness of the cylinder housing is H. The value of R is in the range of 1 mm to 4 mm, the value of H is in the range of 20 HB to 70 HB and the value of L is in the range of 0.6 to 1.4. According to a second aspect, the present application provides a cylindrical battery comprising an electrical core and a cylindrical housing of the present application, wherein the electrical core is arranged inside the cylindrical housing. According to a third aspect, the present application provides a battery module, wherein the battery module comprises several cylindrical batteries according to the second aspect of the present application. The technical solutions of the present application can achieve the following advantageous effects: The cylinder housing of the present application includes a transition section with an arcuate segment between a side plate and an end plate, wherein the radius R of the arcuate segment is in a range of 1 mm to 4 mm, the Brinell hardness H of the cylinder housing is in a range of 20 HB to 70 HB, and the ratio L between a dimension of the transition section in an axial direction of the cylinder housing and a dimension of the transition section in a radial direction of the end plate is in a range of 0.6 to 1.4. The value of R is controlled in a range of 1 mm to 4 mm to prevent sagging during spraying, thereby ensuring a uniform coating thickness and reducing the risk of battery insulation failure.Simultaneously, interference between the cylinder housing and the electrical core can be avoided, thus reducing the problem of uneven force on the electrical core within the cylinder housing. The H value is controlled within a range of 20 HB to 70 HB. This not only prevents the formation of a transition section with an uneven transition and the increased risk of snagging during spraying due to excessive cylinder housing hardness, but also prevents the cylindrical shell's ability to withstand the expansion of the electrical core due to excessively low cylinder housing hardness.The value of L is controlled in the range of 0.6 to 1.4, which increases the flowability of the spray fluid during the spraying process, as well as the resistance of the spray fluid in the flow of the arc-shaped transition section, and reduces the problem of uneven spray thickness during the spraying process. The cylinder housing with this structure, due to the more rounded transition section featuring the arc-shaped segment, reduces the occurrence of insulation layer failure during the insulation layer arrangement, thus improving battery safety. By integrally controlling the range of values ​​of the ratio L, the radius R of the arc-shaped segment and the hardness H of the housing, the shaping of the housing is improved to facilitate the formation of an arc-shaped segment with a smooth transition between the side plate and the end plate, which promotes the formation of the insulating layer and at the same time prevents the occurrence of interference between the electrical core and the housing when the electrical core is inserted into the housing. If the cylinder battery of the present application is characterized by the above parameters, an insulating layer with fewer defects can be obtained in the cylinder battery of the present application due to the cylinder housing of the present application, thereby improving the insulation of the cylinder battery and thus improving the safety of the cylinder battery. If the cylindrical battery of the present application is characterized by the above parameters, an insulating layer with fewer defects can be obtained in the battery module of the present application due to the cylindrical battery of the present application, thereby improving the insulation between the multiple cylindrical batteries in the battery module and thus improving the safety of the battery module. Brief description of the drawings Fig. 1 shows a schematic representation of a local structure of a radial cross-sectional surface of a housing in the prior art; Fig. 2 shows a schematic representation of a local structure under a radial cross-sectional surface of a cylindrical battery of an embodiment of the present application; Fig. 3 shows a schematic representation of a local structure under a radial cross-sectional surface of a housing of an embodiment of the present application; and Fig. 4 shows a schematic representation of a local structure of a bottom surface of the cylindrical battery of an embodiment of the present application. Reference symbol list: 10-Cylinder housing; 11-Side plate; 12-Bottom plate; 120-Liquid injection port; 121-Protrusion section; 13-Transition section; 130-Arc-shaped segment; 14-Insulating plate; 20-Electrical core. Description of the embodiments The technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application, and it is clear that the described embodiments represent only a part of the embodiments of the present application and not all embodiments. Based on the embodiments of the present application, all other embodiments that could be obtained by a person skilled in the art without inventive step fall within the scope of protection of the present application. The casings in prior art batteries are typically formed by a drawing process. Cylindrical batteries, in particular, typically have casings formed by a drawing process to create a hollow cylindrical casing with a cartridge structure. The electrical core is located inside the casing and encapsulated within it. In a cylindrical battery, the casing is a cylindrical housing made of a metal, such as aluminum or an aluminum alloy (aluminum-magnesium alloy or aluminum-manganese alloy, etc.). To ensure the insulation of the cylindrical battery, an insulating layer is usually applied to the outer surface of the cylindrical housing, such as by spraying an insulating coating or wrapping it with an insulating film.The insulating coating can be, for example, a polyethylene (PE) coating, a polyurethane (PU) coating, an epoxy (EP) coating, a potassium silicate coating, a siloxane coating, and the like. The insulating coating can be applied to the outer surface of the cylinder housing by spraying, coating, or electrophoresis. The insulating film can be, for example, a polypropylene (PP) insulating film, a PE insulating film, and similar materials. Fig. 1 shows a schematic representation of the local structure of a radial cross-sectional surface of a prior art cylinder housing. As shown in Fig. 1, the prior art cylinder housing 10 is bounded by a machining process, and there is a flat area in the transition section 13 between the side wall 11 and the bottom wall 12, creating an edge between the side wall 11 and the bottom wall 12. The presence of this edge affects the arrangement of the insulating layer, which in turn affects the insulating performance of the battery. The insulating layer is, for example, an insulating coating, and if the insulating coating is formed in the form of spraying, the presence of such an edge can lead to an uneven thickness of the insulating coating formed by spraying, a lack of insulating coating on the surface of part of the transition section, and the like, thereby impairing the insulating performance of the battery. For this reason, the present application provides a cylindrical battery. Fig. 2 shows a schematic representation of the structure under a radial cross-section of a cylindrical battery of an embodiment of the present application. As shown in Fig. 2, the cylindrical battery comprises a cylindrical housing 10 and an electrical core 20 arranged inside the cylindrical housing 10, the cylindrical housing 10 serving to encapsulate the electrical core 20. The cylindrical housing 10 comprises an end plate and a side plate 11, as well as a transition section 13 provided between the end plate and the side plate 11. The end plate may comprise a top plate and a bottom plate. The top plate and the bottom plate are arranged along the axial direction of the cylindrical housing at opposite ends of the side plates.In the axial direction of the cylinder housing, the end plate on the upper side is the top plate and the end plate on the lower side is the bottom plate. The following end plates are shown as examples of the bottom plate. It is understood that it is equally possible to replace the bottom plate with a top plate in the structures shown below. That is to say, in the following embodiment of the present application, there is a transition section 13 between the bottom plate 12 and the side plate 11. As shown in Fig. 2, the transition section 13 between the base plate 12 and the side plate 11 comprises an arc-shaped segment 130 in a radial cross-sectional area of ​​the cylinder housing. The transition section 13 has a dimension h1 in the axial direction of the side plate 11 and a dimension h2 in the radial direction of the base plate 12. As shown in Fig. 2, h1 is the distance from the intersection of the transition section 13 with the side plate 11 to the outer extension line of the base plate 12. h2 is the distance from the intersection of the transition section 13 and the base plate 12 to the outer extension line of the side plate 11 in Fig. 2. During the measurement, the base plate of the cylinder housing can be laid flat on the test table, and the vertical distance from the point where the side plate meets the transition section to the base plate is h1, and the vertical distance from the point where the base plate meets the transition section extending along the radial direction of the base plate to the side plate is h2. The ratio L of h1 to h2 is between 0.6 and 1.4. The cylinder housing in the embodiment of the present application can be manufactured by a cold pressing process. The base plate and the side plate are formed in one piece by the cold pressing process, which can improve the shape of the transition section between the side plate and the base plate. By providing the transition section with an arc-shaped segment, the fit of the insulating layer on the cylinder housing can be improved and the occurrence of insulation failure reduced. In an embodiment relating to Fig. 2, the arc-shaped segment 130 of the transition section 13 can be a circular arc within a radial cross-sectional surface of the cylinder housing 10. The circular arc shape promotes the flow of the sprayed fluid and reduces flow resistance. As an example, consider the insulating coating produced by spraying. By arranging the transition section with the arc-shaped segment, the flow direction of the sprayed liquid can be improved during the spraying process, ensuring that the liquid flows evenly from the side plate to the base plate in one direction. If the ratio L of the dimensions of the transition section, h1 to h2, is too small, an unevenly thick insulating coating is easily sprayed on. If the ratio L of h1 to h2 is too large, interference between the electrical core and the cylinder housing can easily occur, making assembly of the electrical core more difficult and reducing the available space for its placement, thus negatively impacting the capacity increase of the cylindrical battery.The ratio of h1 to h2 is controlled in the range of 0.6 to 1.4, which can increase the flowability of the spray liquid during the spraying process as well as the resistance of the spray liquid in the flow of the arc-shaped transition section and reduce the problem of uneven spray thickness during the spraying process. For example, during the coating process, the insulating film and the transition section can have a higher degree of fit, and the gap between the insulating film and the transition section can be reduced. In addition to an arc-shaped segment, the transition section can, in some other embodiments, include a small flat segment, and the transition section and the side plate or the transition section and the bottom plate can be joined by welding the small flat segment. In one embodiment, the transition section comprises only the arc-shaped segment. In embodiments of the present application, the dimensions of h1 and h2 can be adjusted by modifying the dimensions of the squish die of the cylinder housing. The ratio L of h1 to h2 can be 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, or 1.4, etc., or any value in a range between any two of these values. The cylinder housing of an embodiment of the present application, wherein the relationship between R, H, and L satisfies 0 ≤ H*|L-1 | / R ≤ 28, 0 < H*|L-1 | / R ≤ 28, and 0.5 ≤ H*|L-1 | / R ≤ 28. The unit of R is mm and the unit of H is HB. By integrally controlling the relationship between the hardness of the cylinder housing, the ratio of h1 to h2, and the radius R of the arc-shaped segment, the shaping of the cylinder housing is improved to facilitate the formation of a transition section with a smooth transition between the side plate and the bottom plate. This promotes the uniform application of the insulating coating and the coating of the insulating film, while simultaneously preventing the occurrence of interference between the electrical core and the housing when the electrical core is inserted into the housing.In a preferred embodiment, the relationship H*|L-1| / R between R, H and L satisfies the following conditions: 0 ≤ H*|L-1| / R ≤ 20, further 0.5 ≤ H*|L-1| / R ≤ 20, further 0.5 ≤ H*|L-1| / R ≤ 15. By optimizing the relationship between R, L and H, the arrangement effect of the insulating layer, such as the spray effect of the insulating coating, can be further improved. The value of H*|L-1| / R can be, for example, 0, 1, 2, 4, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28 or any value in a range between any two of these values. As shown in Fig. 2, in one embodiment, after the electrical core 20 has been inserted into the cylinder housing 10, the edges of the electrical core 20 may be in contact with the transition section 13. If the area of ​​the transition section 13 is too small to support the electrical core 20, it is very likely that the electrical core 20 will crush the electrode foil on the underside when shaken or tilted. In one embodiment, the value of h1 can be in a range of 0.5 mm to 4 mm, preferably 1 mm to 3 mm. By controlling the range of h1, it is possible to prevent h1 from being too small, resulting in poor insulating performance, and also to prevent h1 from being too large, which would cause the electrical core to interfere with the cylinder housing when inserted into the housing. For example, the value of h1 can be 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4.0 mm or any value in a range between any two of these values. In one embodiment, the value of h2 can be in a range of 0.5 mm to 4 mm, preferably 1 mm to 3 mm. If the dimension of h2 is too small, it is insufficient to ensure adequate support for the electrical core, which can easily lead to uneven stress on the core. If the dimension of h2 is too large, the spray fluid does not flow as easily to the transition between the arc-shaped transition section and the base plate during spraying, which impairs the quality of the sprayed insulating coating. For example, the value of h2 can be 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4.0 mm or any value in a range between any two of these values. In one embodiment, h1 can be smaller than h2 to reduce the risk of insertion into the housing during battery assembly. In one embodiment, the radius R of the arc-shaped segment lies in a range of 1 mm to 4 mm. With the insulating coating formed by spraying, the radius R of the arc-shaped segment is too small, allowing it to flow easily during spraying, resulting in uneven thickness of the insulating coating. This increases the risk of battery insulation failure. Conversely, the radius R of the arc-shaped segment must not be too large, as this can lead to interference between the cylinder housing and the electrical core, and the electrical core, located inside the cylinder housing, becomes susceptible to uneven stress. For example, the value of R can be 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4.0 mm or any value in a range between any two of these values. In the embodiment of the present application, the radius of the arc-shaped segment in the transition section can be measured using the three-point method, wherein the radius of the corresponding circle is determined as the radius of the arc-shaped segment by taking three points evenly spaced on the arc-shaped segment. The value of H is in the range of 20 HB to 80 HB, preferably 30 HB to 70 HB. If the hardness of the cylinder housing is too high, it becomes more difficult to form a smooth transition section during forming, which in turn increases the risk of flow stalling during spraying. Conversely, the hardness of the cylinder housing must not be too low. If the hardness is too low, the cylinder housing will be weak and susceptible to expansion of the electrical core. For example, the value of H can be 20HB, 25HB, 30HB, 35HB, 40HB, 45HB, 50HB, 55HB, 60HB, 65HB, 70HB, 75HB, 80HB or any value in a range between any two of these values. The Brinell hardness of the cylinder housing can be measured using the HBW 2.5 / 62.5 standard specified in national standard GB / T 231.1-2018. The Brinell hardness of the cylinder housing can be adjusted by modifying the manganese and magnesium content in the material composition and the parameters of the heat treatment process. The ratio between the minimum thickness and the maximum thickness of the transition section is less than or equal to 0.8, preferably 0.3 to 0.8. For example, the ratio between the two can be 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8, or any value in a range between any two of these values. The thickness of the battery's side plates is generally less than the thickness of the base plate, and there may be a variation in the thickness of the transition section between the side and base plates. The thickness of the portion of the transition section near the side plate may be less than the thickness of the portion near the base plate. If the ratio between the minimum and maximum thickness of the transition section is too small, the cylindrical casing is prone to side plate breakage during molding. In one embodiment, as shown in Fig. 2, the ratio between the height h1 of the transition section and the height H1 of the cylinder housing in the axial direction of the cylinder housing is 0.005 to 0.04. For example, the ratio can be 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, or any value in a range between two of these values. The ratio between the height h1 of the transition section and the height of the cylinder housing must not be too large. If the ratio is too large, the transition section is relatively long, and there is a high risk of it interfering with the cylinder housing when the electrical core is inserted. If the ratio is too small, the cylinder housing is difficult to form, and there is a greater risk of formed edges. Furthermore, with a ratio that is too small, the arrangement of the insulating layer is more difficult, and insulation failure can easily occur. In one embodiment, the ratio between the dimension h2 of the transition section in the radial direction of the base plate and the diameter H2 of the cylinder housing is 0.01 to 0.12. The ratio must not be too small, otherwise the dimension of the transition section will be too small, which will adversely affect the arrangement of the insulating layer and increase the risk of insulation failure. The ratio must also not be too large, otherwise the base plate will be poorly supported. For example, the ratio between the dimension of the transition section in the radial direction of the base plate and the diameter of the base plate can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, or any value in the range between two of these values. Fig. 3 shows a schematic representation of the local structure of a radial cross-sectional surface of a cylinder housing of an embodiment of the present application. As shown in Fig. 3, in one embodiment, within a radial cross-sectional surface of the cylinder housing 10, at an intersection of the side plate 11 with the transition section 13, there is an angle α1 between a tangent of the transition section 13 and an extension line of the side plate 11 greater than 0° and less than or equal to 50°. The angle α1 can be measured with a microscope. If the angle a1 is less than 50°, the problem of the spray liquid hanging is reduced and the flow of the spray liquid along the surface of the arc-shaped transition section in the direction towards the base plate is facilitated. In one embodiment, the thickness of the side plate is 0.2 mm to 0.6 mm. The thickness of the base plate is 0.5 mm to 1.2 mm. The cylinder housing is made of an aluminum alloy, and the composition of the aluminum alloy housing includes manganese and / or magnesium elements; the mass fraction of the manganese element in the total composition of the aluminum alloy housing is 0.5% to 2%; the mass fraction of the magnesium element in the total composition of the aluminum alloy housing is greater than 0 and less than or equal to 0.5%. The above manganese and magnesium content can contribute to improving the dimensional properties of the housing. The elemental composition and content of the cylinder casing can be measured using the spectral analysis method specified in GB / T 7999-2007. In Fig. 2, the electrical core 20 of an embodiment of the present application is arranged inside the cylinder housing 10 and encapsulated by means of the cylinder housing 10. In one embodiment, a liquid injection port 120 may be provided in a central part of the base plate 12. In other embodiments, the liquid injection port 120 may not be provided in the central part. The electrical core 20 in the present application can be a wound core. A wound core hole can be provided corresponding to the liquid filling opening 120. The electrical core 20 comprises a cathode foil, a separator, and an anode foil, and the cathode foil, the separator, and the anode foil are wound. The cathode foil comprises a cathode collector and an active cathode substance layer, and the anode foil comprises an anode collector and an active anode substance layer. The present application does not impose any specific restrictions on the cathode collector, provided it is electrically conductive without causing harmful chemical changes in the battery and can be made of, for example, stainless steel, aluminum, nickel, titanium, calcined carbon; or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, and the like. The anode collector can be made of copper, stainless steel, nickel, titanium, and the like. In specific embodiments, the cathode can be made of aluminum and the anode of copper.The active cathode substance layer comprises an active cathode material, and the active cathode material comprises a ternary nickel-cobalt-manganese material, a lithium iron phosphate material, a lithium manganese iron phosphate material, and the like; and the active anode substance layer comprises an active anode material, and the active anode material comprises synthetic graphite, natural graphite, a silicon-based material, and the like. The separator is positioned between the cathode foil and the anode foil to keep them apart and prevent them from short-circuiting. The separator can be made of various materials suitable for use as insulating films in electrochemical energy storage devices, according to the prior art. In particular, the separator comprises at least one of the following materials: polyethylene, polypropylene, polyvinylidene fluoride, aramid, polyethylene terephthalate, polytetrafluoroethylene, polyacrylonitrile, polyimide, polyamide, polyester, and natural fibers. The electrical core comprises a core body, a cathode tab, and an anode tab extending from the core body, the cathode tab being connected to a cathode foil of the core body, and the anode tab being connected to an anode foil of the core body. The cylindrical housing comprises an electrode column assembly, one of which is electrically connected to the electrode column assembly via the cathode tab and the other via the anode tab, and the other of which is electrically connected to the cylindrical housing. Electrode tabs (cathode tab or anode tab) can be formed by cutting out the collector of an electrode foil (cathode foil or anode foil), or they can consist of separate conductive parts. The electrode tabs are used to facilitate current transfer within the electrical core. The electrode tab material can be the same as that of the collector and can be, for example, aluminum, copper, etc. For instance, the cathode tab and cathode collector can be made of aluminum, and the anode tab and anode collector can be made of copper. The cylindrical battery comprises an electrode column assembly. The electrode column assembly serves to connect to an external circuit, for example, via a busbar or similar device, to the electrode column assembly to connect multiple batteries electrically in series and parallel. The electrode tabs are electrically connected to the electrode column assembly. The electrical core is a cylindrical core, and the electrode tabs can extend axially from both ends of the core or from one end. The electrical connection between the cathode and anode tabs and the electrode column assembly can be direct or indirect.In the case of an indirect electrical connection, the electrode tabs can first be electrically connected to the current collector disk, and the current collector disk is then electrically connected to the electrode column assembly. The other connection, between the cathode and anode tabs, can be electrically connected to the cylinder housing directly or indirectly. In some other embodiments, the electrical core can also have other shapes; it is not limited to these. After the electrical core is inserted into the housing, in the axial direction of the cylinder housing, a bottom surface of the electrical core lies above a plane (e.g. the horizontal plane at the AB line shown in Fig. 2) in which a section line of the side plate and the transition section is located, or a bottom surface of the electrical core lies below the plane in which the section line of the side plate and the transition section is located. If the base surface of the electrical core is located above the plane where the side plates and the transition section intersect, the electrical core is less risky when inserted into the housing. If the base surface of the electrical core is located below the plane where the side plates and the transition section intersect, the electrical core can be made taller to increase the energy density. In one embodiment, the edge of the positive projection of the electrical core onto the base plate lies within the intersection line of the base plate and the transition section. In this mounting structure, the electrical core exhibits a higher degree of stability. In another embodiment, the edge of the positive projection of the electrical core onto the base plate lies outside the intersection line of the base plate and the transition section. In this mounting structure, the dimensions of the electrical core can be increased, which in turn increases the energy density of the electrical core. In one embodiment, the cylinder housing is provided with an insulating coating on an outer surface, wherein the thickness d1 of the insulating coating on the side wall is less than or equal to 0.2 mm, the value of R is in a range of 1 mm to 4 mm, and the value of L is in a range of 0.8 to 1.1 mm. Optimizing the thickness of the insulating coating on the side plate, as well as the radius of the arc-shaped segment and the value of L, can further optimize the spray effect of the insulating coating, resulting in greater uniformity of the insulating coating thickness. If the outer surface of the cylinder housing is coated with the insulating film, the thickness of the film applied to the outer surface of the cylinder housing can range from 0.05 mm to 2 mm. An insulating film of this thickness can achieve a better coating effect and prevent problems such as warping or bulging of the insulating film due to a thickness that is too thin or too thick. In one embodiment, the separator between the electrical core and the base plate is larger than the cathode foil and the anode foil. In another embodiment, in the axial direction of the cylindrical housing, a lower edge of the anode foil and the cathode foil lies above the plane in which the intersection of the side plate and the transition section is located, and a lower edge of the separator lies below the plane in which the intersection of the side plate and the transition section is located. In another embodiment, the separator projects from the underside of the electrical core by a dimension of 0.5 mm to 3 mm beyond the anode foil. The portion of the separator that extends beyond the cathode foil and the anode foil is filled between the electrical core and the base plate to improve the insulation between the electrical core and the housing. Fig. 4 shows a schematic representation of a local structure of the underside of a cylinder battery of an embodiment of the present application. As shown in Fig. 4, in one embodiment the base plate 12 of the cylinder housing 10 is provided on the side facing the electrical core 20 with a projecting section 121, which projects in a direction towards the electrical core 20. The liquid injection port 120 is provided in the projecting section 121, and part of the bottom surface of the electrical core 20 is in contact with the projecting section 121. The projecting section 121 can be used to support the electrical core 20. Corresponding to the position of the projecting section 121, the outer surface of the base plate 12 is recessed in the direction towards the electrical core 20, the recess serving to accommodate a locking element for the liquid injection port. In one embodiment, the diameter of the liquid injection port is greater than or equal to 2 mm, and the value of L is between 0.8 and 1.4. The larger the diameter of the liquid injection port, the larger the area occupied by the base plate, while the value of L remains limited to the range of 0.8 to 1.4. This prevents the base plate from causing problems during assembly of the battery with other structural components, such as the bonded area between the battery and the housing, due to insufficient support surface area. Furthermore, it prevents the electrical core from tipping over due to collisions. In one embodiment, the wound core is provided with a wound core hole, the diameter of which is greater than or equal to 4 mm, with R being between 1 mm and 3 mm. The wound core hole provides space for the expansion of the electrical core. The larger the diameter of the wound core hole, the smaller the outward expansion of the electrical core, and by further controlling the radius R of the arc-shaped segment in the range of 1 mm to 3 mm, the arrangement effect of the insulating layer can be improved and the insulating performance increased. In one embodiment, see Fig. 4, an insulating plate 14 is provided between the electrical core 20 and the base plate 12, the thickness of which is 0.1 mm to 1.2 mm. A transition section is provided between the base plate and the side plate, and the edge of the electrical core can come into contact with the contact of this transition section. At this point, a certain gap will exist between the base plate and the electrical core. The insulating plate 14 closes this gap, preventing vibration of the electrical core. Furthermore, the insulating plate 14 provides insulation between the electrical core 20 and the base plate 12, and adequately supports the electrical core 20. The insulating plate 14 can be made of an organic polymer material, such as polyethylene or polypropylene. In one embodiment, the distance between the electrical core and the side plate in the radial direction of the end plate is less than or equal to 0.8 mm, with a radius R of the arcuate segment of 0.5 mm to 3 mm. When the distance between the electrical core and the side plate is less than or equal to 0.8 mm, the radius of the arcuate segment in the transition section must be controlled to be relatively small, thus providing more space for the expansion of the electrical core. The insulation performance of the cylinder battery with the cylinder housing of the embodiments of the present application is tested and illustrated below in combination with specific embodiments and comparative examples. Exemplary embodiments 1 to 8 and comparative examples 1 to 2 each consist of a cylinder housing. The specific parameters of the cylinder housing for each exemplary embodiment and comparative example are listed in Table 1. Example 1221,0005020 Exemplary embodiment 21,820,900402,81,43 Exemplary embodiment 31,21,70,706451,58,82 Exemplary embodiment 42,52,11,190451,55,71 Exemplary embodiment 51,52,50,600521,414,86 Exemplary embodiment 642,91,379303,53,25 Exemplary embodiment 723,10,645781,223,07 Exemplary embodiment 832,41,25070117,5 Comparative example 10,50,80,62580130 Comparative example 20,330,100120427 An insulating coating was sprayed onto the outer surface of the cylinder housing of each embodiment and comparison example. The thickness of the insulating coating at the transition section was tested for compliance with the requirements on 200 samples of each embodiment and comparison example. Compliance with the thickness requirement requires that the ratio between the thickness of the insulating coating at the transition section and the thickness of the insulating coating on the side plate is greater than 0.5 and that it is observed whether the electrode foil falls off when the electrical core is inserted into the housing. The test and observation results are listed in Table 2. Example implementation 199.50% No Example implementation 298.00% No Example 398.50% No Example implementation 498.50% No Example implementation 596.00% No Example 695.50% Light waste Example implementation 792.00% No Example implementation 893.50% No Comparative example 160.50% No Comparative example: 250.50% Heavy waste As can be seen from the data in Tables 1 and 2, the compliance with the thickness of the insulating coating of the transition section in the corresponding samples is over 90% when the value of H*||L-1| / R is within the range limited by this application. In contrast, the compliance of the samples corresponding to Comparative Example 1 and Comparative Example 2 is all below 70%. Furthermore, if the hardness of the cylinder housing is high, resulting in a value of H*||L-1| / R outside the range limited by this application, the electrode foil of the electrical core is easily damaged when inserted into the housing, leading to the electrode foil material falling out. Based on the same purpose, embodiments of the present application also provide a battery module that can comprise several cylindrical batteries of the embodiments of the present application. The multiple cylindrical batteries can be connected in series and in parallel to each other as required. Naturally, a person skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. Therefore, if these modifications and variations of the present application fall within the scope of the claims of the present application and their technical equivalents, the present application shall also encompass these modifications and variations. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited non-patent literature GB / T 231.1-2018

[0039] GB / T 7999-2007

[0049]

Claims

Cylinder housing, characterized in that the cylinder housing is an aluminum metal housing or an aluminum alloy housing comprising an end plate and a side plate, wherein the end plate is a circular end plate, wherein the side plate is provided in a circumferential direction of the end plate and extends in an axial direction of the cylinder housing; wherein a transition section is provided between the end plate and the side plate, the transition section comprising an arc-shaped segment; wherein a ratio of a dimension of the transition section in the axial direction of the cylinder housing to a dimension of the transition section in a radial direction of the end plate is L; wherein a radius of the arc-shaped segment is R, and wherein a Brinell hardness of the cylinder housing is H;where the value of R is in a range of 1 mm to 4 mm, where the value of H is in a range of 20 HB to 70 HB, where the value of L is in a range of 0.6 to 1.4.; Cylinder housing according to claim 1, characterized in that the ratio of a minimum thickness to a maximum thickness of the transition section is less than or equal to 0.8, and that the value of H is in a range of 30 HB to 70 HB. Cylinder housing according to claim 1, characterized in that the ratio of the height of the transition section to the height of the cylinder housing in the axial direction of the cylinder housing is 0.005 to 0.

04. Cylinder housing according to claim 1, characterized in that the ratio of a dimension of the transition section in the radial direction of the end plate to a diameter of the cylinder housing is 0.01 to 0.

12. Cylinder housing according to claim 1, characterized in that within a radial cross-sectional surface of the cylinder housing at an intersection of the side plate with the transition section, an angle between a tangent of the transition section and an extension line of the side plate is greater than 0° and less than or equal to 50°. Cylinder housing according to claim 1, characterized in that the thickness of the side plates is 0.2 mm to 0.6 mm, wherein the thickness of the end plates is 0.5 mm to 1.2 mm. Cylinder housing according to claim 1, characterized in that the cylinder housing is an aluminum alloy housing, wherein a composition of the aluminum alloy housing comprises a manganese element and / or a magnesium element; wherein a mass fraction of the manganese element in the total composition of the aluminum alloy housing is 0.5% to 2%; wherein a mass fraction of the magnesium element in the total composition of the aluminum alloy housing is greater than 0 and less than or equal to 0.5%. Cylinder housing according to claim 1, characterized in that the cylinder housing is provided on an outer surface with an insulating coating, wherein a thickness d1 of the insulating coating of the side wall is less than or equal to 0.2 mm, wherein the value of L is in a range of 0.8 to 1.

1. Cylinder housing according to claim 1, characterized in that the outer surface of the cylinder housing is coated with an insulating film, wherein the thickness of the insulating film is 0.05 mm to 2 mm. Cylinder housing according to claim 1, characterized in that the end plate is provided with a liquid injection opening, wherein the diameter of the liquid injection opening is greater than or equal to 2 mm, wherein the value of L is in a range of 0.8 to 1.

4. Cylindrical battery, characterized in that it comprises an electrical core and a cylindrical housing according to one of claims 1 to 10, wherein the electrical core is arranged inside the cylindrical housing. Cylindrical battery according to claim 11, characterized in that in the axial direction of the cylinder housing a bottom surface of the electrical core lies above a plane in which a line of intersection of the side plate and the transition section is located, or that a bottom surface of the electrical core lies below the plane in which the line of intersection of the side plate and the transition section is located. Cylindrical battery according to claim 11 or 12, characterized in that an edge of a positive projection of the electrical core in the end plate lies within a region of the intersection line between the end plate and the transition section, or that the edge of the positive projection of the electrical core in the end plate lies outside the region of the intersection line between the end plate and the transition section. Cylindrical battery according to claim 13, characterized in that the end plate is provided with a projecting section facing the electrical core, wherein a part of the bottom surface of the electrical core is in contact with the projecting section; wherein the electrical core is a wound core, the wound core comprising a cathode foil, a separator and an anode foil, which are wound; wherein on an underside of the electrical core the separator projects beyond the anode foil by a dimension of 0.5 mm to 3 mm. Cylindrical battery according to claim 14, characterized in that in the axial direction of the cylinder housing a lower edge of the anode foil and the cathode foil lies above the plane in which the intersection line of the side plate and the transition section is located, and wherein a lower edge of the separator lies below the plane in which the intersection line of the side plate and the transition section is located. Cylindrical battery according to claim 11 or 12, characterized in that the electrical core is a wound core, wherein the wound core is provided with a wound core hole, wherein the diameter of the wound core hole is greater than or equal to 4 mm, wherein R is 1 mm to 3 mm. Cylindrical battery according to claim 11 or 12, characterized in that in the radial direction of the end plate the distance between the electrical core and the side plate is less than or equal to 0.8 mm, wherein a radius R of the arc-shaped segment is 0.5 mm to 3 mm. Cylindrical battery according to claim 11 or 12, characterized in that an insulating plate is provided between the electrical core and the end plate, wherein the thickness of the insulating plate is 0.1 mm to 1.2 mm. Cylindrical battery according to claim 11 or 12, characterized in that the electrical core comprises a core body, a cathode tab and an anode tab which extend from the core body, wherein the cathode tab is connected to a cathode foil of the core body, wherein the anode tab is connected to an anode foil of the core body; Cylindrical housing, characterized in that the cylindrical housing comprises an electrode column arrangement, wherein one of the cathode tabs and the anode tab is electrically connected to the electrode column arrangement, and the other is electrically connected to the cylindrical housing. Battery module, characterized in that it comprises several cylindrical batteries according to one of claims 11 to 20.

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