Battery case and manufacturing method thereof and battery pack

Abstract

The present invention discloses the field of vehicle parts, and relates to a battery shell, a manufacturing method thereof, and a battery pack. It includes at least one shell body, each shell body has at least one battery accommodating cavity matched with a battery cell, and at least one heat exchange liquid channel is opened in at least one side wall of the shell body corresponding to each battery accommodating cavity. The chemical composition of the shell body includes: 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements and 94.9-98.18% Al. The manufacturing method of the battery shell includes: manufacturing the shell body by extrusion molding. The battery pack includes at least one battery cell and the above-mentioned battery shell. The battery shell provided in the present application has good safety, high heat exchange efficiency, and simple production process.

Description

Technical Field

[0001] The present invention relates to the field of vehicle parts, and in particular to a battery case and a manufacturing method thereof, and a battery pack. Background Art

[0002] Power batteries and similar energy storage batteries that are used in new energy vehicles are becoming increasingly widespread. With the increasing requirements for charging speed and charging voltage, as well as the changing operating environment of electric vehicles, battery cooling and heating have become major key issues that hinder the improvement of battery performance.

[0003] Traditional battery cooling is divided into air cooling, liquid cooling and phase change cooling. Air cooling has been eliminated in mid-to-high-end application scenarios due to its low efficiency, large environmental impact and poor heating effect. Liquid cooling and phase change cooling both use a water cooling plate structure for heat dissipation. For square and soft-pack batteries, since the water cooling plate is often laid at the bottom of the battery module, the heat dissipation and heating area is small, and the efficiency and speed are very low. If the charging speed is increased, the heating of the battery is inevitable. If used in winter, the heating of the battery consumes more energy, which limits the improvement of the battery's charging and discharging performance.

[0004] There are also designs that attempt to place the water cooling plate on a large surface area of ​​the battery, sandwiched between each battery. However, due to the increase in the number of parts of the water cooling plate, the thickness of the water cooling plate also squeezes the battery layout space, which is not conducive to improving the battery's energy density.

[0005] Conventional battery shell designs (taking square shells as an example) are all thin-walled aluminum alloy structures, with front and rear end welding and sealing. The battery shell wall thickness is about 0.7-1mm, and the material of the battery shell is conventional 3003 material. Its characteristics are that the tensile strength in the O state is only greater than 95Mpa, which is equivalent to the strength of pure aluminum. Only after cold working strengthening (including cold working processes such as drawing and fine drawing), the H state can increase the yield strength to more than 100Mpa, but the elongation is only 3-5%. Therefore, in the production process of conventional battery shells, hot extrusion is first used to produce thick-walled battery shell blanks, and then a cold working process must be performed to reduce the wall thickness of the blank to the required thickness, otherwise the strength cannot meet the requirements. At the same time, due to the elongation of only 3-5%, it is easy to crack and cause battery leakage in the process of collision deformation, causing battery thermal runaway, thereby expanding losses.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] An object of the present invention is to provide a battery case and a method for manufacturing the same, and a battery pack, so as to improve at least one of the problems mentioned in the background art.

[0008] The present invention is achieved in that:

[0009] In a first aspect, an embodiment of the present invention provides a battery shell, comprising at least one shell body, each shell body having at least one battery accommodating cavity matching a battery cell, at least one side wall of the shell body corresponding to each battery accommodating cavity is provided with at least one heat exchange liquid channel, each heat exchange liquid channel is used to pass a heat exchange liquid to perform heat exchange with the battery cell;

[0010] The chemical components of the shell body include, by mass percentage:

[0011] 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements and 94.9-98.18% Al.

[0012] In an optional embodiment, the battery shell further includes a heat exchange liquid distribution member and a heat exchange liquid collection member, and the extension direction of each heat exchange liquid channel is the same as the length direction of the battery accommodating cavity and passes through opposite ends of the shell body;

[0013] The number of shell bodies is 1, and each shell body has at least two battery accommodating cavities arranged in parallel. The heat exchange liquid distribution component is arranged at one end of the shell body and communicates with one end of each heat exchange liquid channel. The heat exchange liquid collection component is arranged at the other end of the shell body and communicates with the other end of each heat exchange liquid channel.

[0014] In an optional embodiment, the battery shell further includes a heat exchange liquid distribution member and a heat exchange liquid collection member, and the extension direction of each heat exchange liquid channel is the same as the length direction of the battery accommodating cavity and passes through opposite ends of the shell body;

[0015] There are multiple shell bodies, each of which is in the shape of a rectangular parallelepiped. Each shell body has a battery accommodating cavity. Multiple shell bodies are arranged in parallel to form an integrated body. The heat exchange liquid distribution component is arranged at one end of the integrated body and communicates with one end of each heat exchange liquid channel. The heat exchange liquid collection component is arranged at the other end of the integrated body and communicates with the other end of each heat exchange liquid channel.

[0016] In an optional embodiment, the battery shell further includes a heat exchange liquid distribution member and a heat exchange liquid collection member, and the extension direction of each heat exchange liquid channel is the same as the length direction of the battery accommodating cavity and passes through opposite ends of the shell body;

[0017] There are multiple shell bodies, each of which is in the shape of a rectangular parallelepiped. Each shell body has multiple battery accommodating cavities arranged in parallel. The multiple shell bodies are arranged in parallel to form an integrated body. The heat exchange liquid distribution component is arranged at one end of the integrated body and communicates with one end of each heat exchange liquid channel. The heat exchange liquid collection component is arranged at the other end of the integrated body and communicates with the other end of each heat exchange liquid channel.

[0018] In an optional embodiment, the chemical composition of the shell body further includes 0.1-0.3% Zr by mass.

[0019] In an optional embodiment, the rare earth element is selected from at least one of Er and Sc.

[0020] In an optional embodiment, the chemical composition of the shell body contains 0.02-0.2% Sc and 0.02-0.3% Er by mass percentage;

[0021] In an optional embodiment, the chemical composition of the shell body contains 0.02-0.3% Li by mass.

[0022] In an optional embodiment, each heat exchange fluid channel is in the shape of a cuboid with a thickness of 0.4 to 0.6 mm.

[0023] In an optional embodiment, each battery accommodating cavity has two relatively narrow side walls corresponding to the size of the battery cell and two relatively wide side walls corresponding to the width of the battery cell; at least one of the two wide side walls is provided with a heat exchange liquid channel, and the thickness of the side wall provided with the heat exchange liquid channel is 1.2 to 1.4 mm.

[0024] In an optional embodiment, one of the two wide side walls is provided with a heat exchange fluid channel, and the other is not provided with a heat exchange fluid channel, and the thickness of the wide side wall not provided with a heat exchange fluid channel is 0.3-0.4 mm.

[0025] In an optional embodiment, the thickness of each narrow side wall is 1-1.2 mm.

[0026] In a second aspect, an embodiment of the present application provides a method for manufacturing a battery shell, comprising: manufacturing the shell body by extrusion molding.

[0027] In an optional embodiment, the method for manufacturing the shell body includes: extruding an aluminum ingot at a temperature of 510-580°C.

[0028] In an optional embodiment, the aluminum ingot is heated to 510-580° C. before extrusion molding, and then the oxide film of the car body is removed.

[0029] In a third aspect, an embodiment of the present application provides a battery pack, comprising at least one battery cell and any one of the above-mentioned battery shells or a battery shell made by the above-mentioned manufacturing method, wherein at least one battery cell is arranged in a one-to-one correspondence in at least one battery accommodating cavity.

[0030] The present invention has the following beneficial effects:

[0031] The chemical composition of the shell body of the present application is to remove the copper contained therein on the basis of the conventional 3003 aluminum alloy to improve the corrosion resistance of the aluminum alloy and give the aluminum alloy welding performance, and to add a suitable amount of magnesium to the alloy to improve the corrosion resistance of the aluminum alloy to the coolant, and to add a suitable amount of rare earth elements to the alloy to improve the strength and rigidity of the aluminum alloy. The present application designs the composition of the aluminum alloy so that the elongation of the aluminum alloy can be increased from the original 3-5% to 18-22% on the basis of the 3003 aluminum alloy, so that the battery shell is not easy to crack in the collision, and the safety of the battery is improved. In addition, due to the redesign of the composition, the aluminum alloy can be formed into the structure of the shell body designed by the present application at one time through the hot extrusion process, and reach or even exceed the material strength that can be achieved by the original cold working strengthening, thereby simplifying the production process, improving production efficiency, and reducing the fixed asset investment and energy consumption pollution at the production end.

[0032] This structural design of the shell body of the present application eliminates the water-cooling plate and integrates the cooling circuit into the shell body, which not only increases the cooling or heating efficiency, but also reduces the water-cooling plate parts and the number of heat transfer layers between the coolant and the battery, thereby improving the cooling and heating performance and reducing the weight of the battery structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 and 2 All of them are structural schematic diagrams of a shell body of a battery shell provided in an embodiment of the present application;

[0035] Figure 3 for Figure 2 A magnified image of area A;

[0036] Figure 4 A schematic diagram of the structure of a battery shell provided in an embodiment of the present application;

[0037] Figure 5A schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0038] Figure 6-8 Schematic diagrams of three different structures of the shell body of the battery shell provided in the embodiments of the present application;

[0039] Figure 9-12 Schematic diagrams of four different structures of the shell body of the battery shell provided in the embodiments of the present application;

[0040] Figure 13-15 They are schematic diagrams of various heat exchange liquid distribution methods for the "multi-shell, one cavity per shell" type battery shells provided in the embodiments of the present application;

[0041] Figure 16-19 Schematic diagrams of various heat exchange liquid distribution methods for the "multi-shell, multi-cavity per shell" type battery shells provided in the embodiments of the present application.

[0042] Icons: 10-battery pack; 11-upper module shell; 12-lower module shell; 100-battery shell; 101-integrated body; 110-shell body; 111-battery accommodating chamber; 112-heat exchange liquid channel; 113-wide side wall; 114-narrow side wall; 120-heat exchange liquid distribution component; 130-heat exchange liquid collection component. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0044] The embodiments of the present application provide a battery case 100 and a method for preparing the same, as well as a battery pack 10 .

[0045] like Figure 1-3 As shown, the battery shell 100 provided in the embodiment of the present application includes at least one shell body 110, each shell body 110 has at least one battery accommodating cavity 111 matching a battery cell, and at least one heat exchange liquid channel 112 is opened in at least one side wall of the shell body 110 corresponding to each battery accommodating cavity 111, and each heat exchange liquid channel 112 is used to pass a heat exchange liquid to perform heat exchange with a battery cell;

[0046] The chemical components of the housing body 110 include, by mass percentage:

[0047] 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements and 94.9-98.18% Al.

[0048] The chemical composition of the shell body 110 of the present application is to improve the corrosion resistance of the aluminum alloy by removing the copper contained therein on the basis of the conventional 3003 aluminum alloy, and to give the aluminum alloy welding performance, and to add a suitable amount of magnesium to the alloy to improve the corrosion resistance of the aluminum alloy to the coolant, and to add a suitable amount of rare earth elements to the alloy to improve the strength and rigidity of the aluminum alloy. The present application designs the composition of the aluminum alloy so that the elongation of the aluminum alloy can be increased from the original 3-5% to 18-22% on the basis of the 3003 aluminum alloy, so that the battery shell is not easy to crack in a collision, and the safety of the battery is improved. In addition, due to the redesign of the composition, the aluminum alloy can be formed into the structure of the shell body 110 designed by the present application at one time through a hot extrusion process, and reach or even exceed the material strength that can be achieved by the original cold working strengthening, thereby simplifying the production process, improving production efficiency, and reducing fixed asset investment and energy consumption pollution at the production end.

[0049] This structural design of the shell body 110 of the present application eliminates the water cooling plate and integrates the cooling circuit into the shell body 110, which not only increases the cooling or heating efficiency, but also reduces the water cooling plate parts and the number of heat transfer layers between the coolant and the battery, thereby improving the cooling and heating performance and reducing the weight of the battery structure.

[0050] Therefore, due to the chemical composition and structural design of the shell body 110, the heat transfer efficiency of the battery shell 100 of the present application is effectively improved, and on this premise, the strength and rigidity of the battery shell 100 are improved, the structural strength and collision resistance of the battery are improved, and the weight of the battery shell 100 is reduced.

[0051] Regarding the chemical composition of the housing body 110:

[0052] Preferably, the chemical composition of the housing body 110 further includes 0.1-0.3% Zr by mass.

[0053] Adding zirconium to the chemical composition can further improve the strength of the shell body 110 . In particular, zirconium can synergize with rare earth elements to significantly improve the strength of the shell body 110 .

[0054] Preferably, in order to ensure that the strength and other mechanical properties of the shell body 110 can be further improved, the rare earth element is selected from at least one of Er and Sc.

[0055] Preferably, under the premise of acceptable manufacturing cost, in order to ensure that the shell body 110 has better performance, the chemical composition of the shell body 110 contains 0.02-0.2% Sc and 0.02-0.3Er by mass percentage;

[0056] Furthermore, the chemical composition of the shell body 110 contains 0.02-0.3% Li by mass.

[0057] The addition of lithium element can further improve the mechanical properties of the shell body 110 such as ductility and wear resistance.

[0058] Regarding the structure of the housing body 110:

[0059] In order to facilitate matching with an electrical appliance (such as an electric vehicle), the housing body 110 of the present application is in the shape of a rectangular parallelepiped, and in order to facilitate matching with a battery cell, the battery receiving cavity 111 is also in the shape of a rectangular parallelepiped.

[0060] Preferably, in order to ensure the strength and heat exchange capacity of the shell body 110, a plurality of heat exchange fluid channels 112 are generally opened, and the specific number of heat exchange fluid channels 112 opened can be adjusted according to usage requirements.

[0061] Preferably, each heat exchange fluid channel 112 is in a rectangular shape, and a thickness c thereof is 0.4-0.6 mm.

[0062] The heat exchange fluid channel 112 of this thickness can ensure better heat transfer efficiency and avoid causing the shell volume to be too large.

[0063] Specifically, each battery receiving cavity 111 has two opposite narrow side walls 114 corresponding to the size of the battery cell and two opposite wide side walls 113 corresponding to the width of the battery cell.

[0064] If there is a wide side wall 113 without a heat exchange liquid channel 112, since the chemical composition of the shell body 110 of the present application has been specially designed, the side wall thickness of 0.3 to 0.4 mm can meet the strength requirements. This thickness is thinner than the side wall of the battery shell structure currently equipped with a water cooling plate system.

[0065] For example, the thickness c of the heat exchange liquid channel 112 is 0.5 mm, and the thickness d on both sides of the heat exchange liquid channel 112 is set to 0.4 mm to meet the strength requirement. Then, the thickness e of the wide side wall 113 provided with the heat exchange liquid channel 112 is 0.4+0.5+0.4 mm, which is equal to 1.3 mm. Even if the thickness e of the wide side wall 113 provided with the heat exchange liquid channel 112 is 1.3 mm, this thickness still has a volume advantage over the method of sandwiching a water cooling plate in the middle of the shell, so that the volume utilization rate of the battery pack 10 is higher, the water cooling plate and related components are reduced, and the overall energy density of the battery pack 10 is improved.

[0066] Preferably, the thickness h of each narrow side wall 114 may be 1-1.2 mm.

[0067] The shell body 110 provided in the present application can be formed by hot extrusion due to its chemical composition design, so the thickness h of the narrow side wall 114 can be made to 1-1.2 mm, which is slightly thicker than the thickness of the existing battery shell, and can improve the rigidity of the overall module arrangement and the structural strength of the battery pack 10 and the battery cell. Of course, it should be noted that even if the thickness of the narrow side wall is less than 1 mm, for example, the same as the thickness of the wide side wall, its mechanical properties are sufficient to achieve the technical effects claimed in the present application.

[0068] At least one heat exchange liquid channel 112 is opened in at least one of the side walls of the shell body 110 corresponding to each battery accommodating cavity 111. For example, the heat exchange liquid channel 112 may be opened in 1, 2, 3 or 4 side walls.

[0069] Preferably, if Figure 4 As shown, the battery case 100 further includes a heat exchange liquid distributor 120 and a heat exchange liquid collector 130. The extension direction of each heat exchange liquid channel 112 is the same as the length direction of the battery accommodating cavity 111, and runs through the opposite ends of the shell body 110. Since the material of the shell body 110 has been redesigned to have welding properties, the heat exchange liquid distributor 120 and the heat exchange liquid collector 130 are connected to the shell body by laser welding.

[0070] Heat exchange liquid (coolant or heating liquid, the coolant is used to cool the battery when the battery is at a high temperature; or the heating liquid is used to heat the battery in extremely cold weather. The heat exchange liquid here mainly refers to the coolant) is passed into the heat exchange liquid distribution component 120, and the heat exchange liquid is distributed to each heat exchange liquid channel 112 and flows through the side walls of each battery accommodating cavity 111 to exchange heat with the battery cells. The liquid after heat exchange is finally collected in the heat exchange liquid collection component 130 and uniformly transported out of the battery pack.

[0071] There are three types of specific structures involved in the embodiments of the present application.

[0072] The first type, multiple shells, each shell has one cavity:

[0073] The battery shell 100 has multiple shell bodies 110, each of which is in the shape of a rectangular parallelepiped. Each shell body 110 has a battery accommodating cavity 111. All the shell bodies 110 are arranged in parallel to form an integrated body 101. The heat exchange liquid distribution component 120 is arranged at one end of the integrated body 101 and is connected to one end of each heat exchange liquid channel. The heat exchange liquid collection component 130 is arranged at the other end of the integrated body 101 and is connected to the other end of each heat exchange liquid channel.

[0074] For a structure with multiple shells and one cavity in each shell, the wide side walls 113 of two adjacent battery accommodating cavities 111 are fitted together. In this structure, it is preferred to provide multiple heat exchange liquid channels 112 on one of the two wide side walls 113 of the two adjacent battery accommodating cavities 111, and the thickness of the other side wall is thinner than the side wall with the heat exchange liquid channels 112, so that two adjacent battery accommodating cavities 111 share the same heat exchange liquid channel 112, thereby achieving efficient heat exchange and avoiding excessive thickness of the shell wall.

[0075] There are four ways to set the heat exchange fluid channel 112 on the side wall of this type of shell body 110, such as Figure 1 , 6 -8, Figure 1 A plurality of heat exchange fluid channels 112 are provided on a wide side wall 113 and a narrow side wall 114; Figure 6 In order to open a plurality of heat exchange fluid channels 112 in each of the four side walls, Figure 7 In order to open a plurality of heat exchange fluid channels 112 on a wide side wall 113, Figure 8 A plurality of heat exchange fluid channels 112 are provided on the narrow side wall 114 .

[0076] like Fig.13 As shown, Fig.13 and Figure 6 correspond, Fig.13 For multiple Figure 6 The schematic diagram of the structure of the battery case 100 is shown in which the shell bodies 110 are arranged with heat exchange liquid channels on four side walls and are assembled in parallel. The arrow in the figure shows the flow direction of the coolant.

[0077] like Fig.14 As shown, Fig.14 and Figure 7 correspond, Fig.13 For multiple Figure 7 The schematic diagram of the structure of the battery case 100 is shown in which the shell body 110 with a heat exchange liquid channel arranged in a wide side wall 113 is assembled in parallel, and the arrow in the figure indicates the flow direction of the coolant.

[0078] like Fig.15 As shown, Fig.15 and Figure 8correspond, Fig.15 For multiple Figure 8 The schematic diagram of the structure of the battery case 100 is shown in which the shell body 110 with heat exchange liquid channels arranged on the narrow side wall 114 is assembled in parallel, and the arrow in the figure indicates the flow direction of the coolant. This method of liquid inlet on a single narrow side wall is equivalent to integrating the lower water cooling plate into the battery single body shell.

[0079] The above-mentioned various configurations of the heat exchange fluid channel 112 are only examples. The specific configurations can be combined according to the heat exchange requirements. If the cooling requirements are not high and only one side needs to be cooled, the specific configuration of the heat exchange fluid channel is simpler, for example Fig.14 , 15 If the cooling requirement is high and multi-side cooling is required, the specific setting of the heat exchange fluid channel is slightly more complicated, for example Fig.13 shown.

[0080] The second type, one shell, multiple cavities per shell:

[0081] The battery shell 100 has a shell body 110, which has at least two battery accommodating cavities 111 arranged in parallel. The heat exchange liquid distribution component 120 is arranged at one end of the shell body 110 and communicates with one end of each heat exchange liquid channel. The heat exchange liquid collection component 130 is arranged at the other end of the shell body 110 and communicates with the other end of each heat exchange liquid channel.

[0082] For the multi-shell multi-cavity structure, two adjacent battery accommodating cavities 111 share a wide side wall 113. In this structure, it is preferred to open multiple heat exchange liquid channels 112 on the wide side wall 113 to enable two adjacent battery accommodating cavities 111 to share the heat exchange liquid channel 112. In this way, efficient heat exchange can be achieved and the shell wall can be avoided from being too thick.

[0083] The third type, multiple shells, multiple cavities per shell:

[0084] The battery shell 100 has a plurality of shell bodies 110, each of which is in the shape of a rectangular parallelepiped, and each of which has a plurality of battery accommodating cavities 111 arranged in parallel. The plurality of shell bodies 110 are arranged in parallel to form an integrated body 101, and a heat exchange liquid distribution component 120 is arranged at one end of the integrated body 101 and communicates with one end of each heat exchange liquid channel, and a heat exchange liquid collection component 130 is arranged at the other end of the integrated body 101 and communicates with the other end of each heat exchange liquid channel.

[0085] For a structure with multiple shells and multiple chambers per shell, in a shell body 110, two adjacent battery accommodating chambers 111 share a wide side wall 113. In this structure, it is preferred to open multiple heat exchange liquid channels 112 on the wide side wall 113 to enable two adjacent battery accommodating chambers 111 to share the heat exchange liquid channel 112; for two adjacent battery accommodating chambers 111 belonging to two adjacent shell bodies 110, their wide side walls 113 are fitted together, and it is preferred to set multiple heat exchange liquid channels 112 on one of the two wide side walls 113 that are attached to the two adjacent battery accommodating chambers 111, and the thickness of the other side wall is thinner than the side wall with the heat exchange liquid channel 112, so that two adjacent battery accommodating chambers 111 share the same heat exchange liquid channel 112, so that efficient heat exchange can be achieved and the shell wall can be avoided from being too thick.

[0086] There are four ways to set the heat exchange fluid channel 112 on the side wall of this type of housing body 110. For example, the four side walls corresponding to each battery receiving cavity 111 are as follows: Figure 9-12 As shown, Fig. 9 A plurality of heat exchange fluid channels 112 are provided on a wide side wall 113 and a narrow side wall 114; Fig.10 In order to open a plurality of heat exchange fluid channels 112 in each of the four side walls, Fig.11 In order to open a plurality of heat exchange fluid channels 112 on a wide side wall 113, Fig.12 A plurality of heat exchange fluid channels 112 are provided on the narrow side wall 114 .

[0087] like Fig.16 As shown, Fig.16 and Fig.10 correspond, Fig.16 For multiple Fig.10 The schematic diagram of the structure of the battery case 100 is shown in which the shell bodies 110 with heat exchange liquid channels arranged in four side walls are assembled in parallel, and the arrow in the figure indicates the flow direction of the coolant.

[0088] like Fig.17 As shown, Fig.17 and Fig.12 correspond, Fig.17 For multiple Fig.12 The schematic diagram of the structure of the battery case 100 is shown in which the shell body 110 with a heat exchange liquid channel arranged in a narrow side wall is assembled in parallel, and the arrow in the figure shows the flow direction of the coolant.

[0089] like Fig.18 As shown, Fig.18 and Fig.11 correspond, Fig.18 For multiple Fig.11The schematic diagram of the structure of the battery case 100 is shown in which the shell body 110 with a heat exchange liquid channel arranged in a wide side wall is assembled in parallel, and the arrow in the figure shows the flow direction of the coolant.

[0090] like Fig.19 , Fig.19 and Fig. 9 correspond, Fig.18 For multiple Fig. 9 1 is a schematic diagram of a structure in which a shell body 110 with a heat exchange liquid channel arranged in a wide side wall and in a narrow side wall is assembled in parallel to form a battery shell 100, and the arrow in the figure indicates the flow direction of the coolant.

[0091] The above-mentioned various configurations of the heat exchange fluid channel 112 are only examples. The specific configurations can be combined according to the heat exchange requirements. If the cooling requirements are not high and only one side needs to be cooled, the specific configuration of the heat exchange fluid channel is simpler, for example Fig.17 , 18 If the cooling requirement is high and multi-side cooling is required, the specific setting of the heat exchange fluid channel is slightly more complicated, for example Fig.16 Or as shown in 19.

[0092] The above three types of battery shells all have good use effects in practical applications. As for which one to choose when using it, it depends on the needs of use. Figure 16-19 The figure shows that 5 shell bodies are assembled in parallel to form a battery shell. Each shell body is produced by merging 4 monomers into a module and extruding it at one time. In practical applications, it can be selected according to customer requirements and the cross-sectional size of the battery monomer. In extreme application scenarios, multiple modules of the entire battery pack can be combined into a one-time extrusion molding, that is, the above-mentioned "one shell, multiple cavities per shell". This type of battery shell minimizes the fixed parts and weight between modules.

[0093] The embodiment of the present application also provides a method for manufacturing the battery shell 100, including: manufacturing the shell body 110 by extrusion molding.

[0094] Preferably, the method for manufacturing the housing body 110 includes: extruding an aluminum ingot at a temperature of 510-580° C.

[0095] Furthermore, in order to ensure the quality of the shell body 110, the aluminum ingot is heated to 510-580°C before extrusion molding, and then the oxide film is removed from the car body.

[0096] The manufacturing method is specifically as follows:

[0097] The aluminum ingot with the same chemical composition as the present application is heated to 510-580°C, after the oxide film of the car skin is removed, it is put into an extruder, pressurized to form the aluminum through a mold, cooled and straightened, and then cut into the required length.

[0098] like Figure 5 As shown, the embodiment of the present application also provides a battery pack 10, including at least one battery cell and a battery shell 100 provided in the embodiment of the present application or a battery shell 100 manufactured by the manufacturing method provided in the embodiment of the present application, at least one battery cell is arranged in a one-to-one correspondence in at least one battery accommodating cavity 111, that is, each battery accommodating cavity 111 is provided with a battery cell whose size exactly matches that of the battery accommodating cavity.

[0099] Furthermore, the battery pack 10 also includes an upper mold shell 11 and a lower mold shell 12 , which are buckled together, and the battery shell 100 and the battery cells are arranged inside the cavity formed by the upper mold shell 11 and the lower mold shell 12 .

[0100] The features and performances of the present invention are further described in detail below in conjunction with specific experimental examples.

[0101] Experimental Example 1

[0102] The mechanical properties of the samples prepared in the following experimental groups were tested. Each test sample was uniformly extruded into a thin plate with a thickness of 1 mm for testing.

[0103] Experimental Group 1:

[0104] The chemical composition of the samples is:

[0105] 0.2% Si, 0.8% Fe, 1.5% Mn, 0.2% Mg, 0.3% Cr, 0.1% Ti, 0.02% Sc, 0.2% Zr, 0.02% Li and the balance Al.

[0106] Manufacturing method:

[0107] The aluminum ingot is heated to 510°C and extruded.

[0108] Experimental Group 2:

[0109] The chemical composition is:

[0110] 0.8% Si, 0.2% Fe, 0.7% Mn, 1.2% Mg, 0.1% Cr, 0.2% Ti, 0.05% Sc, 0.05% Er, 0.3% Zr and the balance Al.

[0111] The manufacturing method is:

[0112] The aluminum ingot is heated to 580°C and extruded.

[0113] Experimental Group 3:

[0114] The chemical composition is:

[0115] 0.5% Si, 0.5% Fe, 1.2% Mn, 0.5% Mg, 0.2% Cr, 0.15% Ti, 0.1% Sc, 0.1% Er, 0.1% Zr, 0.1% Li and the balance Al.

[0116] The aluminum ingot is heated to 540°C and extruded.

[0117] The following experimental groups were all formed by extrusion of aluminum ingots heated to 540°C.

[0118] Experimental Group 4:

[0119] The chemical composition is:

[0120] 0.5% Si, 0.5% Fe, 1.2% Mn, 0.5% Mg, 0.2% Cr, 0.15% Ti, 0.3% Sc, 0.2% Zr, 0.2% Li and the balance Al.

[0121] Experimental Group 5:

[0122] The chemical composition is:

[0123] 0.5% Si, 0.5% Fe, 1.2% Mn, 0.5% Mg, 0.2% Cr, 0.15% Ti, 0.3% Er, and the balance Al.

[0124] Experimental Group 6

[0125] This experimental group is basically the same as experimental group 3, except that Zr is replaced by an equal amount of Al in this experimental group.

[0126] Experimental Group 7

[0127] This experimental group is basically the same as experimental group 3, except that Li is replaced by an equal amount of Al in this experimental group.

[0128] Experimental Group 8

[0129] This experimental group is basically the same as experimental group 3, except that Mg is replaced by an equal amount of Al in this experimental group.

[0130] Experimental Group 9

[0131] 3003 Aluminum Alloy.

[0132] Experimental Group 10

[0133] This experimental group is basically the same as experimental group 9, except that the samples were made by cold working process.

[0134] The mechanical properties of the thin plate samples of experimental groups 1-8 were tested, and the test method was based on the national standard GB / T228.1-2021. The results are shown in Table 1.

[0135] Table 1 Test data of each experimental group in Experimental Example 1

[0136]

[0137]

[0138] It can be seen from the above table that the tensile strength, yield strength and elongation of the samples of Experimental Examples 1-7 are all high. The performance of Example 1-5 is better, which shows that when zirconium and lithium are added to the alloy, its yield strength can reach more than 140Mpa. Comparing Experimental Group 8 with Experimental Group 3, the performance of Experimental Group 8 is significantly worse, indicating that it is necessary to add Mg to the composition, and the addition of Mg can significantly increase its mechanical properties. Comparing Experimental Group 9 with Experimental Group 3, the performance of Experimental Group 9 is significantly worse, indicating that the mechanical properties of the samples made by hot extrusion process using 3003 aluminum alloy as raw material are very poor and cannot meet the use requirements. Comparing Experimental Groups 1-7 with Experimental Group 10, Experimental Group 10 is made by cold working process of 3003 aluminum alloy. It can be seen that although its tensile strength and flexural strength are not much different, its elongation is significantly lower, which means that the battery shell manufactured by cold working of 3003 is prone to collision and cracking, and its safety is poor.

[0139] Experimental Example 2

[0140] The mechanical properties of samples with the following chemical compositions at different thicknesses were tested, as shown in Examples 1-7:

[0141] Si 0.18%, Fe 0.35%, Mn 1.4%, Mg 0.8%, Zr 0.15%, Cr 0.17%, Sc 0.08%, Er 0.05%, Ti 0.15% balance Al.

[0142] The test method is GB / T 228.1-2021. Record the test results in the table below.

[0143] Table 2 Mechanical properties of each embodiment

[0144]

[0145] It can be seen from the table above that within the wall thickness range of 0.44 to 1.2 mm, the elongation, tensile strength and yield strength of the thin plate are all high. When the extruded wall thickness decreases, the material shows an upward trend in yield strength due to the increase in deformation and extrusion pressure.

[0146] Experimental Example 3

[0147] Experimental Group 9:

[0148] The chemical composition is Si 0.18%, Fe 0.35%, Mn 1.4%, Mg 0.8%, Zr 0.15%, Cr 0.17%, Sc 0.08%, Er 0.05%, Ti 0.15%, and the balance is Al.

[0149] The sample thickness is 2 mm.

[0150] Experimental Group 10:

[0151] 3003 Aluminum Alloy.

[0152] The sample thickness is 0.5 mm.

[0153] The mechanical properties of the samples obtained from Experimental Group 9 and Experimental Group 10 were tested, and the test results were recorded in Table 3.

[0154] Table 3 Mechanical properties of each experimental group

[0155]

[0156] From the experimental results of Experimental Example 2, it can be seen that the thinner the thickness, the greater the extrusion force during the extrusion process, so its yield strength will be better. From the experimental results of Table 3, it can be seen that even if a thicker sample is made of the aluminum alloy of the composition of the present application, its yield strength is better than that of the thinner 3003 aluminum alloy, which can further illustrate that the aluminum alloy composition of the present application has an effect that is significantly better than that of the 3003 aluminum alloy.

[0157] In summary, the battery case provided by this application has the following advantages:

[0158] This application uses a unique design and process of integrating micro-water channels into the battery cell housing, and adopts a new aluminum alloy material that meets the process requirements, eliminating the water cooling plate system, cooling and heating the battery separately, reducing the heat exchange distance and wall thickness, and improving the heat transfer efficiency. At the same time, due to the structure of the microchannel, the strength and rigidity of the battery shell are improved, the impact and collision resistance are improved, and the safety of the battery is improved.

[0159] Due to the improvement and optimization of material properties, the originally necessary cold processing processes (cold drawing, precision drawing, and stretching processes) have been eliminated, and the hot extrusion process is directly used for one-time forming, and the material strength that can only be achieved by the original cold processing strengthening is achieved or exceeded, thereby simplifying the production process, improving production efficiency, and reducing fixed asset investment and energy consumption pollution on the production side.

[0160] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery shell, characterized in that: The invention comprises at least one shell body, each of which has at least one battery receiving cavity matched with a battery cell, at least one heat exchange liquid channel is opened in at least one side wall of the shell body corresponding to each battery receiving cavity, and each heat exchange liquid channel is used to pass a heat exchange liquid to perform heat exchange with the battery cell; The chemical composition of the shell body is calculated by mass percentage: 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements and 94.9-98.18% Al; Alternatively, 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements, 0.1-0.3% Zr and 94.9-98.18% Al; Alternatively, 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements, 0.02-0.3% Li and 94.9-98.18% Al; Alternatively, 0.2-0.8% Si, 0.2-0.8% Fe, 0.7-1.5% Mn, 0.2-1.2% Mg, 0.1-0.3% Cr, 0.1-0.2% Ti, 0.02-0.3% rare earth elements, 0.1-0.3% Zr, 0.02-0.3% Li and 94.9-98.18% Al; The shell body is made by hot extrusion.

2. The battery case according to claim 1, characterized in that: The battery shell further includes a heat exchange liquid distribution member and a heat exchange liquid collection member, wherein the extension direction of each heat exchange liquid channel is the same as the length direction of the battery accommodating cavity and passes through opposite ends of the shell body; The number of the shell bodies is one, and each shell body has at least two battery accommodating cavities arranged in parallel. The heat exchange liquid distribution component is arranged at one end of the shell body and communicates with one end of each of the heat exchange liquid channels. The heat exchange liquid collection component is arranged at the other end of the shell body and communicates with the other end of each of the heat exchange liquid channels.

3. The battery case according to claim 1, characterized in that: The battery shell further includes a heat exchange liquid distribution member and a heat exchange liquid collection member, wherein the extension direction of each heat exchange liquid channel is the same as the length direction of the battery accommodating cavity and passes through opposite ends of the shell body; There are multiple shell bodies, each of which is in the shape of a rectangular parallelepiped and has a battery accommodating cavity. Multiple shell bodies are arranged in parallel to form an integrated body. The heat exchange liquid distribution component is arranged at one end of the integrated body and communicates with one end of each of the heat exchange liquid channels. The heat exchange liquid collection component is arranged at the other end of the integrated body and communicates with the other end of each of the heat exchange liquid channels.

4. The battery case according to claim 1, characterized in that: The battery shell further includes a heat exchange liquid distribution member and a heat exchange liquid collection member, wherein the extension direction of each heat exchange liquid channel is the same as the length direction of the battery accommodating cavity and passes through opposite ends of the shell body; There are multiple shell bodies, each of which is in the shape of a rectangular parallelepiped. Each of the shell bodies has multiple battery accommodating cavities arranged in parallel. The multiple shell bodies are arranged in parallel to form an integrated body. The heat exchange liquid distribution component is arranged at one end of the integrated body and communicates with one end of each of the heat exchange liquid channels. The heat exchange liquid collection component is arranged at the other end of the integrated body and communicates with the other end of each of the heat exchange liquid channels.

5. The battery case according to claim 1, characterized in that: The rare earth element is selected from at least one of Er and Sc.

6. The battery case according to claim 5, characterized in that: The chemical composition of the shell body contains 0.02-0.2% Sc and 0.02-0.3% Er by mass percentage.

7. The battery case according to claim 1, characterized in that: Each of the heat exchange fluid channels is in the shape of a rectangular parallelepiped, and has a thickness of 0.4-0.6 mm.

8. The battery case according to claim 7, characterized in that: Each of the battery accommodating cavities has two relatively narrow side walls corresponding to the size of the battery cell and two relatively wide side walls corresponding to the width of the battery cell; at least one of the two wide side walls is provided with the heat exchange liquid channel, and the thickness of the side wall provided with the heat exchange liquid channel is 1.2~1.4mm.

9. The battery case according to claim 8, characterized in that: One of the two wide side walls is provided with the heat exchange fluid channel, and the other is not provided with the heat exchange fluid channel. The thickness of the wide side wall not provided with the heat exchange fluid channel is 0.3-0.4 mm.

10. The battery case according to claim 8, characterized in that: The thickness of each narrow side wall is 1-1.2 mm.

11. The method for manufacturing a battery case according to any one of claims 1 to 10, characterized in that: include: The shell body is manufactured by extrusion molding.

12. The manufacturing method according to claim 11, characterized in that: The method for manufacturing the shell body comprises: extruding an aluminum ingot at a temperature of 510-580°C.

13. The battery case according to claim 11, characterized in that: Before extrusion molding, the aluminum ingot is heated to 510~580℃, and then the oxide film is removed from the car body.

14. A battery pack, characterized in that: The invention comprises at least one battery cell and a battery shell as claimed in any one of claims 1 to 10 or a battery shell made by the manufacturing method as claimed in any one of claims 11 to 13, wherein the at least one battery cell is arranged in at least one of the battery accommodating cavities in a one-to-one correspondence.

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