Battery housing assembly, battery, battery pack, and electric device

Abstract

The application relates to the technical field of secondary batteries and discloses a shell assembly of a battery, the battery, a battery pack and a power utilization device. The shell assembly comprises a shell which comprises integrally formed first and second shell walls, the second shell wall extends in a direction perpendicular to the first shell wall, and the second shell wall is connected to the periphery of the first shell wall at one end thereof in the extension direction of the second shell wall; the first and second shell walls jointly enclose a containing space, and the end of the second shell wall away from the first shell wall has an opening which is in communication with the containing space; the composition of the shell comprises titanium elements, the mass content A% of the titanium elements is 99%-99.9%, the hardness of the shell is C HV, the perpendicularity of the second shell wall in the extension direction thereof is m (mm) with the first shell wall as a reference surface, and 16.5<=Cm<=40 is met. The application can improve the strength of the shell and the forming yield of the shell.

Description

Technical Field

[0001] This invention relates to the field of secondary battery technology, specifically to battery casing components, batteries, battery packs, and electrical devices. Background Technology

[0002] The battery casing is an important component of the battery, and its structural strength and weight have a significant impact on the battery's energy density and safety performance.

[0003] Typically, battery casings in related technologies are made of aluminum or steel. Aluminum has a low density but insufficient structural strength, making it prone to deformation under harsh operating conditions. Steel has high structural strength but a high density, resulting in a relatively low overall energy density of the battery. Titanium has higher strength than aluminum and lower density than steel, which is beneficial for improving the structural strength of the casing while reducing its weight. However, titanium casings have a low processing yield. Therefore, how to achieve both structural strength and lightweight design while maintaining a high processing yield has become a pressing technical problem to be solved in related technologies. Summary of the Invention

[0004] This invention provides a battery casing assembly, a battery, a battery pack, and an electrical device to solve the problem of not being able to simultaneously achieve both casing strength and molding yield.

[0005] In a first aspect, the present invention provides a battery casing assembly, comprising a casing, including an integrally formed first casing wall and a second casing wall, one end of the second casing wall being connected to the outer periphery of the first casing wall and extending in a first direction away from the first casing wall, the first casing wall and the second casing wall together forming an accommodating space, and the end of the second casing wall away from the first casing wall having an opening communicating with the accommodating space; wherein, the casing is composed of titanium, the mass content A% of the titanium is 99%~99.9%, the hardness of the second casing wall is C HV, and the perpendicularity of the second casing wall along its extension direction, with the first casing wall as a reference plane, is m, in mm, satisfying 16.5≤C m≤40.

[0006] Beneficial Effects: The casing is made of titanium with a titanium content (A%) of 99%~99.9%. Because titanium has higher strength than aluminum and lower density than steel, the casing maintains high structural strength while keeping its weight low, meeting the requirements for battery lightweighting and increased volumetric energy density. By controlling the casing's hardness (C, H, V) and comprehensively adjusting the perpendicularity (m) of the second shell wall relative to the first shell wall, the casing achieves sufficient structural strength while maintaining a reasonable level of brittleness. During the stretching process that integrally molds the first and second shell walls, the casing material possesses sufficient ductility to withstand tensile deformation. Stress concentration on the surface of the second shell wall and at the connection point between the second and first shell walls is alleviated, thereby reducing the risk of crack formation and improving product molding yield. Simultaneously, the appropriate perpendicularity prevents the second shell wall from encroaching on the cell space, further increasing the battery's volumetric energy density.

[0007] In a second aspect, the present invention also provides a battery comprising: the housing assembly described in the first aspect, the battery further comprising a cover that seals the opening and is connected to the housing, and the battery cell being accommodated within the accommodating space.

[0008] Thirdly, the present invention also provides a battery pack comprising: the battery described in the second aspect.

[0009] Fourthly, the present invention also provides an electrical device, comprising: the battery described in the second aspect or the battery pack described in the third aspect. Attached Figure Description

[0010] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the outer shell of an embodiment of the present invention; Figure 2 for Figure 1 The diagram shown is an exploded view of the shell and cover in the outer casing. Figure 3 for Figure 1 Side view of the battery in the middle; Figure 4 for Figure 3 Schematic diagram of section AA along the middle; Figure 5 for Figure 4 A magnified view of a portion of position B in the diagram; Figure 6This is a schematic diagram of the structure of a battery according to another embodiment of the present invention; Figure 7 for Figure 6 A cross-sectional schematic diagram of the battery; Figure 8 This is a schematic diagram of the battery pack structure according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the vehicle structure according to an embodiment of the present invention.

[0012] Explanation of reference numerals in the attached figures: 10-Outer shell; 11-Shell shell; 111-First shell wall; 112-Second shell wall; 12-Cover body; 20 - Electrode terminal; 30-cell; 100 - Vehicle; 200 - Battery pack; 210 - Housing; 220 - Cover plate; 230 - Battery group; 300 - Controller. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] To meet the high energy density and high safety performance requirements of electric vehicles (such as sports cars) and flying cars, the battery casing needs to be lightweight while ensuring structural strength.

[0015] Titanium has higher strength than aluminum and lower density than steel, which is beneficial for improving the structural strength of the casing while reducing its weight. However, the forming yield of titanium is low in actual processing. Research has found that when applied to harsh conditions such as sports cars or flying cars, the battery charge-discharge rate is high, the gas production inside the cell increases significantly, and the gas pressure on the inner surface of the casing increases, placing higher demands on the structural strength of the casing. While using titanium and adding carbon can improve the structural strength of the casing, the increased hardness and brittleness make it prone to cracking on the surface of the second shell wall and / or at the junction of the second and first shell walls when integrally forming the casing through a stretching process, resulting in a decrease in product yield.

[0016] Furthermore, further research revealed that the perpendicularity of the second shell wall relative to the first shell wall affects the internal storage space of the shell and the residual stress after molding. Therefore, how to improve the structural strength of the titanium shell while taking into account the molding yield, internal space utilization, and stability has become an urgent technical problem to be solved.

[0017] To address the aforementioned technical problems, this application provides a battery casing assembly. The casing includes a housing, comprising an integrally formed first shell wall and a second shell wall. The second shell wall extends in a direction perpendicular to the first shell wall. One end of the second shell wall is connected to the periphery of the first shell wall along its extension direction. The first and second shell walls together form an accommodating space. The end of the second shell wall away from the first shell wall has an opening communicating with the accommodating space. The casing is composed of titanium, with a titanium content (A%) of 99%~99.9%. The casing hardness is C HV. Using the first shell wall as a reference plane, the perpendicularity of the second shell wall along its extension direction is measured in millimeters (m), satisfying 16.5 ≤ C. m≤40.

[0018] In the above scheme, the casing is made of titanium, with a titanium content (A%) of 99%~99.9%. Because titanium has higher strength than aluminum and lower density than steel, the casing maintains high structural strength while keeping its weight low, thus meeting the requirements for battery lightweighting and increased volumetric energy density. By controlling the casing's hardness (CHV) and comprehensively adjusting the perpendicularity (m) of the second shell wall relative to the first shell wall (in mm), the requirement of 16.5 ≤ CHV is satisfied. With m≤40, the casing possesses sufficient structural strength while maintaining a reasonable level of brittleness. During the stretching process that integrally molds the first and second shell walls, the casing material exhibits sufficient ductility to withstand tensile deformation. Stress concentration on the surface of the second shell wall and at the connection between the second and first shell walls is alleviated, thereby reducing the risk of crack formation and improving product molding yield. Simultaneously, the appropriate verticality prevents the second shell wall from encroaching on the cell space, increasing the battery's volumetric energy density.

[0019] The following is combined Figures 1 to 9 The embodiments of the present invention will be described in detail below.

[0020] This application provides a battery casing 11 assembly, including an outer shell 10. The outer shell 10 includes a casing 11, which includes an integrally formed first shell wall 111 and a second shell wall 112. The second shell wall 112 extends in a direction perpendicular to the first shell wall 111. One end of the second shell wall 112 is connected to the periphery of the first shell wall 111 along its extension direction. The first shell wall 111 and the second shell wall 112 together form an accommodating space. The end of the second shell wall 112 away from the first shell wall 111 has an opening communicating with the accommodating space. The casing 11 is composed of titanium, with a titanium content (A%) of 99%~99.9%. The hardness of the casing 11 is C HV. With the first shell wall 111 as a reference plane, the perpendicularity of the second shell wall 112 along its extension direction is m (in mm), satisfying 16.5 ≤ C. m≤40.

[0021] The housing 10 is a component used to provide a receiving space to house the battery cell 30 and other components and isolate them from the outside. The housing 10 can be a cylindrical housing 10 or a rectangular housing 10.

[0022] The outer casing 10 includes a housing 11 with an opening at one end and a receiving space. The opening of the housing 11 can be closed by the cover 12 to seal and isolate the internal environment of the battery cell from the external environment.

[0023] The shell 11 is primarily made of titanium, with a titanium content of 99% to 99.9% by mass, meaning that titanium is the main component of the shell 11. The shell 11 is formed by stretching a titanium alloy sheet, allowing the first shell wall 111 and the second shell wall 112 to be integrally formed from the same blank. During the stretching process, the blank undergoes plastic deformation under the action of the die. The first shell wall 111 essentially maintains its original thickness, while the thickness of the second shell wall 112 decreases under the stretching action.

[0024] The first shell wall 111 is a wall structure at one end of the shell 11, which may be the bottom wall of the shell 11 and is opposite to the opening. The first shell wall 111 is used to close one end of the shell 11 and form the bottom of the receiving space.

[0025] The second shell wall 112 is a wall extending away from the periphery of the first shell wall 111, used to enclose and form an accommodating space together with the first shell wall 111. The second shell wall 112 extends in a direction perpendicular to the first shell wall 111, that is, the extension direction of the second shell wall 112 is consistent with the normal direction of the plane containing the first shell wall 111. The second shell wall 112 can be a cylindrical or frame-like structure.

[0026] The second shell wall 112 has an opening at one end away from the first shell wall 111. The opening is an open structure that communicates with the receiving space for the insertion of the battery cell 30 and the installation of the cover 12.

[0027] The hardness C of shell 11 is Vickers hardness, measured in HV. The method involves using a diamond indenter in the shape of a square pyramid with an included angle of 136° between its faces, applying a test force of 0.5 kgf to the sample surface, holding it for 10 seconds, and then removing it. The hardness is determined by measuring the length of the diagonal of the indentation on the sample surface, using the formula CHV = 0.102. F / d 2 The Vickers hardness value is calculated. The higher the hardness C, the stronger the shell 11's ability to resist external loads and internal air pressure deformation.

[0028] The plane containing the main surface of the first shell wall 111 is used as a geometric reference. The perpendicularity m of the second shell wall 112 along its extension direction is the deviation of the outer or inner surface of the second shell wall 112 relative to the reference perpendicular direction within the height range of the second shell wall 112, in mm.

[0029] The perpendicularity m refers to the vertical deviation of the second shell wall 112 relative to the reference plane along its extension direction, with the plane containing the main surface of the first shell wall 111 as the geometric reference plane. In other words, it represents the degree to which the second shell wall 112 expands or contracts relative to the reference plane of the first shell wall 111 during the stretching process. Specifically, the perpendicularity m can be the distance between the orthographic projection of the end of the second shell wall 112 closest to the first shell wall 111 and the orthographic projection of the end of the second shell wall 112 furthest from the first shell wall, expressed in mm.

[0030] The verticality m can be obtained by measuring the horizontal offset of the top opening of the second shell wall 112 relative to the bottom reference plane.

[0031] The perpendicularity m can be controlled by adjusting the fit between the punch and die in the stretching process, such as the gap between them, the radius of the die inlet fillet, the radius of the punch bottom fillet, and the pressure of the pressure ring.

[0032] If C If m is too small, the hardness C of the casing 11 is relatively low, and the overall structural strength of the casing 11 is insufficient. When applied to harsh conditions such as sports cars or flying cars, the large charge and discharge rate of the battery leads to a significant increase in the amount of gas generated inside the cell 30. The gas pressure on the inner surface of the casing 11 increases, and the casing 11 is prone to deformation due to insufficient structural strength, affecting the safety performance and service life of the battery. At the same time, if the perpendicularity m is relatively small, the outward expansion of the second casing wall 112 relative to the reference plane of the first casing wall 111 along its extension direction is insufficient. After the cell 30 is installed, it is easily squeezed by the inner wall of the second casing wall 112, affecting the safety of the cell 30.

[0033] If C If m is too large, the hardness C of the shell 11 is relatively high, and the brittleness is significantly increased. During the process of integrally forming the first shell wall 111 and the second shell wall 112 through the stretching process, the surface of the second shell wall 112 and the connection between the second shell wall 112 and the first shell wall 111 are prone to stress concentration due to insufficient material ductility, which can lead to cracks and reduce the product molding yield. At the same time, if the perpendicularity m is relatively large, the outward expansion of the second shell wall 112 relative to the reference plane of the first shell wall 111 along its extension direction is too large. In order to meet the assembly and sealing requirements, the surface of the shell 11 needs to excessively pursue flatness and perpendicularity through the shaping process, which introduces a large residual stress. The shell 11 will slowly deform due to the release of residual stress in subsequent welding and liquid injection processes, affecting the sealing performance of the cover 12 and the opening.

[0034] Therefore, by controlling 16.5≤C With m≤40, the shell 11 can maintain reasonable hardness and ductility while possessing sufficient structural strength to resist internal air pressure deformation under harsh working conditions. This facilitates the integral molding of the first shell wall 111 and the second shell wall 112 through a stretching process, reducing the risk of cracks on the surface of the second shell wall 112 and at the connection between the second shell wall 112 and the first shell wall 111, and improving the product molding yield. At the same time, the perpendicularity of the second shell wall 112 is within a reasonable range, ensuring the internal space of the shell 11 and avoiding the compression of the battery cell 30. Furthermore, the perpendicularity requirement can be met without excessive shaping, resulting in low residual stress and improved stability of the shell 11 in subsequent processes.

[0035] For example, C m can be 16.5, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, or a value within the range of any two of the above values.

[0036] In some embodiments, the hardness C HV of the housing 11 ranges from 110HV to 160HV; and / or the verticality m of the second housing wall 112, in mm, ranges from 0.15 mm to 0.25 mm.

[0037] If the hardness C of the shell 11 is too high, the shell 11 becomes brittle, and cracks are likely to occur on the surface of the second shell wall 112 and at the connection between the second shell wall 112 and the first shell wall 111 during the stretch forming process. If the hardness C of the shell 11 is too low, the structural strength of the shell 11 is insufficient, and the shell 11 is prone to deformation when the internal air pressure increases under harsh working conditions. Therefore, by controlling the hardness C of the shell 11 to be between 110HV and 160HV, the shell 11 can maintain reasonable ductility while possessing sufficient structural strength, facilitating stretch forming and reducing the risk of cracking.

[0038] If the perpendicularity m of the second shell wall 112 is too large, the outward expansion of the second shell wall 112 will be too large, and the shell 11 will need to be over-shaped to correct the perpendicularity, introducing large residual stress, which will cause the shell 11 to deform slowly in subsequent processes. If the perpendicularity m of the second shell wall 112 is too small, the outward expansion of the second shell wall 112 will be insufficient or even shrink inward, reducing the space at the opening, and the cell 30 will be easily squeezed. Therefore, by controlling the perpendicularity m of the second shell wall 112, in mm, to be between 0.15 mm and 0.25 mm, the second shell wall 112 can have a reasonable outward expansion, the internal space of the shell 11 can be sufficient, and the perpendicularity requirement can be met without excessive shaping, with low residual stress.

[0039] For example, CHV can be 110HV, 115HV, 120HV, 125HV, 130HV, 135HV, 140HV, 145HV, 150HV, 155HV, 160HV, etc., or a value within the range of any two of the above values.

[0040] For example, m, in mm, can be 0.15mm, 0.17mm, 0.19mm, 0.21mm, 0.23mm, 0.25mm, or a value within the range of any two of the above values.

[0041] In some embodiments, the height of the second shell wall 112 along the extending direction of the second shell wall 112 is hmm, and the range of hmm is 60mm to 180mm.

[0042] The height h of the second shell wall 112 can be the vertical distance along the extension direction of the second shell wall 112 from the end closest to the first shell wall 111 to the end of the second shell wall 112 away from the first shell wall 111.

[0043] If h is too large, the height of the second shell wall 112 will be too high. When the first shell wall 111 and the second shell wall 112 are integrally formed through a stretching process, the required stretching deformation of the second shell wall 112 will increase significantly, leading to stress accumulation. This can cause cracks to easily form on the surface of the second shell wall 112 and at the connection between the second shell wall 112 and the first shell wall 111, reducing product yield. If h is too small, the height of the second shell wall 112 will be too low, resulting in insufficient internal space for the shell 11. This will limit the height of the battery cell 30 and reduce the volumetric energy density of the battery. Therefore, by controlling hmm to be between 60mm and 180mm, it is possible to ensure that the shell 11 has sufficient storage space to improve battery energy density while avoiding the risk of cracks caused by excessive stretching deformation, thus improving product molding yield.

[0044] For example, hmm can be 60mm, 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, etc., or a value within the range of any two of the above values.

[0045] In some embodiments, the height hmm of the second shell wall 112 ranges from 80mm to 180mm, and 18 ≤ C m≤36.

[0046] When h is in the upper range (i.e., the height is relatively large), the tensile deformation of the second shell wall 112 is larger, requiring higher ductility from the shell material 11. Based on this, 18 ≤ C is further constrained. m≤36. If C If the lower limit of m is too low, the hardness of shell 11 is too low and the structural strength is insufficient. When h is large, the deformation resistance of the second shell wall 112 in the height direction is weakened. Under harsh working conditions, when the internal air pressure increases, shell 11 is prone to deformation. By controlling the temperature, it can be ensured that shell 11 has sufficient hardness and structural strength to resist deformation caused by internal air pressure.

[0047] In some embodiments, the height hmm of the second shell wall 112 ranges from 60mm to 160mm, and 20 ≤ C m≤40.

[0048] In schemes where h is in the lower interval (i.e., relatively small height), the tensile deformation of the second shell wall 112 is smaller, and the forming difficulty of shell 11 is relatively lower, but the internal accommodation space is limited. Based on this, 20 ≤ C is further constrained. With m≤40, by increasing the lower limit, it is possible to ensure that the shell 11 has sufficient hardness C to resist the increased internal air pressure under harsh working conditions, and to prevent the shell 11 from deforming, provided that h is in the lower range.

[0049] In some embodiments, the inner wall surface of the first shell wall 111 near the receiving space and the inner wall surface of the second shell wall 112 near the receiving space are connected by an inner arc transition.

[0050] The inner arc transition connection refers to the smooth curved surface transition at the connection point between the first shell wall 111 and the second shell wall 112 inside the accommodating space.

[0051] This design avoids stress concentration at the inner connection between the first shell wall 111 and the second shell wall 112, reducing the risk of breakage. Simultaneously, during the stretch forming process, the material flow at the inner arc transition is smoother, resulting in more uniform deformation, which helps reduce the risk of cracks forming at the connection.

[0052] In some embodiments, the radius of curvature R1mm corresponding to the inner arc ranges from 0.2mm to 1.4mm.

[0053] If R1 is too large, the inner arc transition is too gentle, increasing the space occupied at the connection point, reducing the effective utilization rate of the internal space of the casing 11, limiting the assembly space of the cell 30, and decreasing the volumetric energy density of the battery. If R1 is too small, stress concentration occurs, and cracks or deformations are still likely to occur at the connection point when the internal air pressure increases under harsh operating conditions. Furthermore, the material flow resistance increases during the stretching process, resulting in a low molding yield. Therefore, by controlling R1mm to be between 0.2mm and 1.4mm, the arc transition at the inner connection point can reduce the risk of cracking while controlling the space occupied in the transition area, thereby improving the volumetric energy density of the battery.

[0054] For example, R1mm can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or a value within any two of the above ranges. In some embodiments, the outer wall surface of the first shell wall 111 away from the receiving space and the outer wall surface of the second shell wall 112 away from the receiving space are connected by an outer arc transition, and the radius of curvature R2mm corresponding to the outer arc is greater than or equal to the radius of curvature R1mm corresponding to the inner arc.

[0055] This design prevents the outer side of the casing from being damaged by impacts.

[0056] In some embodiments, the shell 11 also includes iron, and the mass content of iron is 0.01 to 0.8 of the mass content of other elements besides titanium.

[0057] All other elements besides titanium include at least one of iron, oxygen, nitrogen, sulfur, and chlorine.

[0058] If the iron content is too high, the brittleness of the shell 11 increases significantly, and cracks are easily generated on the surface and at the joints of the second shell wall 112 during the stretching process. If the iron content is too low, the strengthening effect of iron on the shell 11 is insufficient, resulting in low structural strength and easy deformation under harsh working conditions when the internal pressure increases. Therefore, by ensuring that the iron content is between 0.01 and 0.8 of the content of other elements besides titanium, the shell 11 can have sufficient structural strength while maintaining a reasonable range of brittleness, facilitating stretching and reducing the risk of cracking.

[0059] For example, the mass content of iron as a percentage of the mass content of other elements besides titanium can be 0.01, 0.02, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.75, 0.8, or a value within any two of the above ranges.

[0060] In some embodiments, the shell 11 further comprises oxygen, and the mass content of oxygen accounts for 0.01 to 0.75 of the mass content of other elements besides titanium.

[0061] If the oxygen content is too high, the material's brittleness increases significantly, while its plasticity decreases, making the second shell wall 112 prone to cracking during stretching. If the oxygen content is too low, the shell 11 has low structural strength, making it prone to deformation under harsh working conditions when internal pressure increases. Therefore, by controlling the oxygen content to be between 0.01 and 0.75 of the content of all elements except titanium, the shell 11 can possess sufficient structural strength while maintaining a reasonable range of brittleness, facilitating stretching and reducing the risk of cracking.

[0062] For example, the mass content of oxygen as a percentage of the mass content of other elements besides titanium can be 0.01, 0.02, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.75, or a value within any two of the above ranges.

[0063] In some embodiments, the thickness of the first shell wall 111 is d1mm, the thickness of the second shell wall 112 is d2mm, d1mm is greater than d2mm, and d1-d2≤0.05 is satisfied.

[0064] The thickness d1 of the first shell wall 111 can be the material thickness of the first shell wall 111 measured along the direction perpendicular to the main surface of the first shell wall 111, and is basically consistent with the thickness of the initial plate.

[0065] The thickness d2 of the second shell wall 112 can be the material thickness of the second shell wall 112 measured along a direction perpendicular to the surface of the second shell wall 112, which is the thickness of the initial sheet after stretching.

[0066] If d1-d2 is too large, the thickness of the second shell wall 112 will be significantly smaller than the thickness of the first shell wall 111, resulting in insufficient strength of the second shell wall 112 and a high risk of deformation. If d1-d2 is too small, the thickness of the second shell wall 112 will be close to the thickness of the first shell wall 111, leading to insufficient space for the cell 30 and low volumetric energy density. Therefore, by controlling d1-d2 to be less than or equal to 0.05, the strength of the second shell wall 112 can be satisfied to avoid deformation, while also improving the volumetric energy density of the battery.

[0067] In some embodiments, d1-d2≤0.05, 20≤C m≤40.

[0068] By raising the lower limit value, the hardness C of the shell 11 can be increased under the premise that d1-d2≤0.05, thereby enhancing the shell 11's ability to resist internal air pressure deformation under harsh working conditions. In some embodiments, along the extending direction of the second shell wall 112, the distance between the orthographic projection of the end of the second shell wall 112 near the first shell wall 111 and the orthographic projection of the end of the second shell wall 112 away from the first shell wall 111 ranges from 0.15mm to 0.25mm.

[0069] If the spacing is too large, the top of the second shell wall 112 will expand too much relative to the bottom, resulting in an opening significantly larger than the bottom. This reduces the utilization rate of the internal space of the shell 11 and requires excessive shaping to correct verticality, increasing residual stress and posing a high risk of deformation. Conversely, if the spacing is too small, the top of the second shell wall 112 will not contract inward or expand enough relative to the bottom, resulting in an opening smaller than the bottom. This reduces the internal space at the opening, making the battery cell 30 susceptible to compression after installation. Therefore, by controlling the spacing to be between 0.15mm and 0.25mm, the internal space of the shell 11 is sufficient, and the verticality requirement can be met without excessive shaping, reducing residual stress and the risk of deformation.

[0070] For example, the interval distance can be 0.15mm, 0.17mm, 0.19mm, 0.21mm, 0.23mm, 0.25mm, etc., or a value within the range of any two of the above values.

[0071] In some embodiments, the area of ​​the opening is greater than or equal to the area of ​​the first shell wall 111.

[0072] The area of ​​the opening is the projected area of ​​the open region of the second shell wall 112 away from the first shell wall 111 on a plane perpendicular to the extension direction of the second shell wall.

[0073] The area of ​​the first shell wall is the projected area of ​​the main surface of the first shell wall on a plane perpendicular to the extension direction of the second shell wall 112, that is, the surface area of ​​the outer or inner surface of the first shell wall.

[0074] If the opening area is smaller than the area of ​​the first shell wall, and the opening size is smaller than the first shell wall, the battery cell is easily squeezed by the second shell wall 112 when it is installed through the opening. Furthermore, the internal space of the shell 11 contracts at the opening, resulting in insufficient clearance between the top of the battery cell and the cover 12, affecting the assembly efficiency and safety of the battery cell. By controlling the opening area to be greater than or equal to the area of ​​the first shell wall, and ensuring the opening size is not smaller than the first shell wall, the battery cell can be smoothly installed through the opening, avoiding squeezing by the second shell wall. Simultaneously, it ensures sufficient assembly clearance between the top of the battery cell and the cover, improving battery assembly efficiency and internal space utilization.

[0075] In some embodiments, the ratio of the opening area to the area of ​​the first shell wall is less than or equal to 1.5.

[0076] By controlling the ratio of the opening area to the first shell wall area to be less than or equal to 1.5, the ease of assembly is improved, while avoiding the increase in the size of the cover 12 and the decrease in structural stability caused by an excessively large opening, thereby improving the molding quality and structural reliability.

[0077] For example, the ratio of the opening area to the area of ​​the first shell wall 111 can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, or a value within the range of any two of the above values.

[0078] In some embodiments, the second shell wall 112 further includes carbon elements, with a carbon content of 0.01% to 0.08% by mass.

[0079] The carbon content is the percentage of the total mass of the second shell wall relative to its mass. Carbon can be used as an interstitial strengthening element in titanium alloys to improve the hardness and strength of the second shell wall.

[0080] If the carbon content in the second shell is too low, the strengthening effect of carbon on the titanium matrix is ​​insufficient, resulting in low hardness and strength. Under internal pressure or external impact, the second shell is prone to plastic deformation, affecting the structural stability of the shell 11. Conversely, if the carbon content is too high, the second shell becomes brittle, increasing the likelihood of cracks on its surface and at the junction with the first shell during stretching, thus reducing product yield. Therefore, controlling the carbon content in the second shell to 0.01%~0.08% improves its hardness and structural strength, keeps its brittleness within a reasonable range, reduces the risk of cracks during stretching, and improves product yield.

[0081] For example, the mass content of carbon in the second shell wall can be 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.045%, 0.05%, 0.055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, or a value within the range of any two of the above values.

[0082] Embodiments of this application also provide a battery. The battery includes a cell 30 and a housing assembly as described in any of the embodiments above. A cover 12 of the housing seals the opening and is connected to the housing to form a closed receiving space for accommodating the cell. The cover 12 can be a sealing component that mates with the opening end of the housing, used to seal the opening and connect to the housing to form a closed receiving space.

[0083] The cover can be fixedly connected to the end of the second shell wall away from the first shell wall by means of welding, riveting, or snap-fitting. Components such as electrode terminals 20 and explosion-proof valves can be installed on the cover. Of course, the electrode terminals and explosion-proof valves can also be installed in other locations on the shell 11.

[0084] The cover can be made of metal or composite material, and its shape can match the shape of the opening. Preferably, the cover can be made of the same material as the shell.

[0085] This design allows the cover and shell to work together to form a closed enclosure, effectively protecting the internal battery cell 30 and electrolyte, and preventing the intrusion of foreign objects such as moisture and dust from the external environment.

[0086] A battery cell is the component in a battery where electrochemical reactions occur; it is the smallest unit in a battery capable of carrying out electrochemical reactions such as charging and discharging.

[0087] A battery cell is the basic unit in a battery, typically consisting of a positive electrode, a negative electrode, and a separator. Lithium-ion battery cells primarily function by the movement of lithium ions between the positive and negative electrodes.

[0088] The battery cell can be a wound cell or a laminated cell.

[0089] A wound battery cell (i.e., a core) is generally made by winding continuous positive electrode sheets, negative electrode sheets, and a separator through a winding process. The separator is located between adjacent positive and negative electrode sheets. The forming process of a wound battery cell includes a winding step and a pressing step. The continuous positive electrode sheets, negative electrode sheets, and separator are continuously wound on a winding needle. After the winding needle is pulled out, the circular battery cell 30 is pressed to form a battery cell that is similar to an ellipse or racetrack shape.

[0090] Laminated cells (laminated cells) are generally multi-layered structures formed by sequentially stacking positive electrode plates, separators, and negative electrode plates. A laminated cell is a cell 30 manufactured using a lamination process, where the positive and negative electrode plates are separated by a separator. Adjacent layers of positive and / or negative electrode plates within the cell are discontinuous. Lamination processes include layering or Z-shaped folding.

[0091] A separator is placed between the positive and negative electrode plates to separate them and prevent them from short-circuiting due to contact.

[0092] In some embodiments, the battery cell 30 includes tabs, and the cover 12 is provided with electrode terminals 20, with the tabs being electrically connected to the electrode terminals.

[0093] The tab can be a positive tab, with the electrode terminal being the positive terminal. The tab can also be a negative tab, with the electrode terminal being the negative terminal.

[0094] The electrode terminals include terminal assemblies, which are used to electrically connect the battery cell located inside the housing 11 to an external device (adjacent battery or other electrical equipment) located outside the housing. The battery can discharge to the external device through the tabs and the output terminal of the external device (terminal assembly). An external power source can charge the battery through the terminal assembly and the tabs. The terminal assembly can be directly electrically connected to the battery cell tabs, or it can be electrically connected to the tabs through a metal adapter.

[0095] The pole assembly includes, but is not limited to, metals such as copper, aluminum, aluminum alloy, and copper-aluminum alloy.

[0096] The tab is located on one side of the positive or negative current collector. It can be separate from or integrally formed with the current collector and is electrically connected to the current collector to conduct the current on the corresponding current collector.

[0097] The tabs are made of a metal material with good electrical conductivity (such as copper, aluminum, copper or nickel).

[0098] In some embodiments, the thickness of the cover 12 is greater than the thickness of the first shell wall 111.

[0099] The cover is usually equipped with components such as electrode terminals and explosion-proof valves, and the cover needs to withstand the expansion force of the battery cell, external impact, and the heat effect of sealing welding during battery use.

[0100] If the cover thickness is too small, the structural strength of the cover will be insufficient, making it prone to deformation under the expansion force of the battery cell or external impact, affecting the positional accuracy and sealing reliability of the electrode terminals. If the cover thickness is equal to or less than the thickness of the first shell wall 111, it will be difficult to meet the higher requirements for structural strength and rigidity of the cover area. By making the cover thickness greater than the thickness of the first shell wall 111, the cover has higher structural strength, which can better support and protect components such as electrode terminals, resist the expansion force of the battery cell and external impact, and improve the top structural stability and sealing reliability of the battery. At the same time, the first shell wall 111 can maintain a relatively thin thickness, which can meet the bottom support requirements while also meeting the requirements for battery lightweighting and high volumetric energy density.

[0101] In some embodiments, the first shell wall is used to support the battery cell, and the d1mm ranges from 0.2mm to 0.6mm.

[0102] If d1 is too small, the structural strength of the first shell wall 111 will be insufficient, affecting the reliability of the connection between the tab and the electrode terminal. Furthermore, deformation of the first shell wall may affect the sealing fit between the cover and the shell 11. If d1 is too large, the overall weight of the shell will increase, the volumetric energy density of the battery will decrease, and the deformation resistance in the area of ​​the first shell wall 111 will increase during stretching, easily leading to uneven thinning of the second shell wall 112 and affecting the molding quality. Therefore, by controlling d1mm to be between 0.2mm and 0.6mm, it is possible to achieve sufficient structural strength in the first shell wall while simultaneously meeting the requirements for lightweighting and high volumetric energy density of the battery, and reducing the difficulty of the stretching process.

[0103] For example, d1mm can be 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, or a value within the range of any two of the above values.

[0104] In some embodiments, the battery is a cylindrical battery.

[0105] In some embodiments, the first casing wall of the cylindrical battery has a radial dimension of 18 mm to 70 mm.

[0106] If the radial dimension of the first shell wall is too small, the diameter of the cylindrical battery will be small, and the radius of curvature of the second shell wall 112 of the shell 11 will be too small. During the stretching process, the deformation of the second shell wall 112 will be large, the stress concentration will be obvious, and cracks will easily occur. If the radial dimension of the first shell wall 111 is too large, the diameter of the cylindrical battery will be large. The large-diameter first shell wall 111 is more likely to bulge and deform under air pressure, and the structural strength requirements of the second shell wall 112 will be higher. Therefore, by controlling the radial dimension of the first shell wall 111 to be 18mm~70mm, the cylindrical battery can be both easy to stretch and form and has good strength.

[0107] For example, the radial dimension of the first shell wall can be 18mm, 21mm, 26mm, 32mm, 38mm, 46mm, 53mm, 60mm, 65mm, 70mm, etc., or a value within the range of any two of the above values.

[0108] In some embodiments, the battery is a prism battery with a carbon content of 0.01% to 0.06% by mass.

[0109] A tetragonal prism battery can be a battery with a tetragonal prism shape. The first shell wall 111 can be the base wall of the tetragonal prism, and the second shell wall 112 can be the four second shell walls of the tetragonal prism. The tetragonal prism can be a cuboid or a cube.

[0110] In some embodiments, the thickness at the junction of the first shell wall 111 and the second shell wall 112 is greater than or equal to 0.15 mm.

[0111] The thickness at the junction of the first shell wall 111 and the second shell wall 112 can be the minimum wall thickness of the area where the first shell wall 111 and the second shell wall 112 intersect, along a direction perpendicular to the surface of the junction. The junction can be the transition area between the first shell wall 111 and the second shell wall 112.

[0112] If the thickness at the junction of the first shell wall 111 and the second shell wall 112 is too small, this area is one of the areas with the greatest deformation during the stretching process. The material is severely thinned, the structural strength is reduced, and the junction is prone to tearing or cracking when subjected to external impact or internal air pressure. Appropriately increasing the thickness at the junction can effectively improve the load-bearing capacity and deformation resistance of the junction and disperse the stress concentration in the corner area.

[0113] For example, the thickness at the connection between the first shell wall 111 and the second shell wall 112 can be 0.15mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, or a value within the range of any two of the above values.

[0114] Embodiments of this application also provide a battery pack 200. The battery pack includes the batteries mentioned above.

[0115] Battery packs can serve as operating power sources or driving power sources for electrical devices, replacing or partially replacing fuel or natural gas to provide driving power for vehicles 100. Electrical devices include: energy storage devices, electric ships, aircraft, laptops, power tools, electric bicycles, electric motorcycles, electric cars, military equipment, aerospace, and many other technological fields.

[0116] The following example uses a vehicle as a specific example of an electrical device.

[0117] The vehicle can be a new energy vehicle, encompassing various types such as pure electric vehicles, hybrid electric vehicles, and range-extended electric vehicles. The battery pack can be located at the bottom, front, or rear of the vehicle to provide electrical support, such as acting as the vehicle's operating power source. In addition, the vehicle typically includes a controller 300, which manages the discharge process of the battery pack to cover various power needs during vehicle start-up, navigation, and driving.

[0118] In some embodiments, one or more battery packs are provided, and the battery packs can be connected in series, parallel, or mixed connection. Mixed connection refers to the simultaneous presence of series and parallel connections in the connection relationship of multiple battery packs 200. In other embodiments, a cluster-level battery architecture is formed by multiple battery packs connected in series, wherein the number of battery packs in each cluster is strictly configured according to voltage and capacity requirements. More specifically, the battery unit of the battery pack includes multiple batteries, some of which are connected in series to form a cluster that meets a preset power supply voltage requirement, and at least one spare battery among the multiple batteries is bypassed.

[0119] The battery pack 200 includes a frame and a base plate, which together form an accommodating space. The battery is placed inside the accommodating space and on the base plate. The first shell wall 111 is fixedly connected to the base plate.

[0120] Battery pack 200 refers to a closed or semi-closed structure made of materials such as metal and plastic. It is the physical carrier of battery pack 230 and is used to meet the safety, reliability and functionality of battery pack in different usage scenarios.

[0121] The battery pack 200 may include a housing 210, which provides installation space for the battery pack, BMS, cooling system, electrical connection components, etc., and fixes these components in the housing to ensure that the battery pack 200 maintains a relatively stable position during operation, and avoids damage to components or loosening of connections due to vibration, impact or other factors.

[0122] The enclosure may include an upper enclosure and a lower enclosure. The lower enclosure includes a bottom plate and side plates connected to and surrounding the bottom plate. The upper enclosure is connected to the side plates and has a cover plate 220 disposed opposite to the bottom plate. The upper and lower enclosures together form a receiving chamber. For example, the lower enclosure generally has four side plates and a bottom plate. The four side plates can be integrally formed with the bottom plate or can be separately formed and fixedly connected.

[0123] The housing may include a bottom and a cover, with the bottom and cover overlapping each other, together defining a space for accommodating the battery module.

[0124] The enclosure can be cast from materials such as steel plates and aluminum alloys, or lightweight materials such as glass fiber reinforced composite materials and carbon fiber reinforced composite materials.

[0125] The shape of the box can be cylinder, cuboid, cube, etc.

[0126] Embodiments of this application also provide an electrical device. This electrical device includes the battery or battery pack mentioned above.

[0127] Batteries or battery packs can serve as the operating power source for electrical devices, or as the driving power source for electrical devices, replacing or partially replacing fuel or natural gas to provide driving power for vehicle 100. Electrical devices include: energy storage devices, electric ships, aircraft, laptops, power tools, electric bicycles, electric motorcycles, electric cars, military equipment, aerospace and many other technical fields.

[0128] There are multiple battery packs, which can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery packs are connected in both series and parallel.

[0129] Multiple battery packs can be connected in series to form a cluster-level battery structure, where the number of battery packs in each cluster is strictly configured according to voltage and capacity requirements.

[0130] A battery pack may include multiple battery packs.

[0131] The battery pack may include battery cells and a switching control unit. The electrical device can be a device or system that consumes or operates using electrical energy. The battery or battery pack can serve as the power system for the electrical device, providing it with the electrical energy required for operation. With this configuration, the electrical device can utilize the high structural strength and reliability of the aforementioned battery or battery pack to maintain a stable power supply under harsh operating conditions, thereby improving the operational safety and range of the electrical device.

[0132] Size measurement methods Use measuring instruments such as micrometers or calipers to measure parameters such as length, width, depth, diameter, radius, distance, and thickness. The area is calculated from the aforementioned parameters.

[0133] Battery manufacturing (1) Preparation of the positive electrode: The positive electrode active material, conductive agent acetylene black, and binder PVDF are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, it is cold-pressed and slit to obtain the positive electrode sheet. Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98):(4~1):(4~1).

[0134] (2) Preparation of negative electrode: The negative electrode active material, conductive agent acetylene black, thickener CMC, and binder SBR are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, air-dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained. The ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96): (4~2): (2~1): (4~1).

[0135] (3) Preparation of electrolyte: Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0136] (4) Preparation of the diaphragm: Polyethylene film is selected as the diaphragm.

[0137] (5) Preparation of the outer shell 10: Titanium alloy blanks containing carbon elements are prepared by powder metallurgy using titanium powder, carbon powder, and other elemental components (such as iron, oxygen, nitrogen, sulfur, etc.), and then stamped into shape using hot stamping process.

[0138] (6) Battery fabrication: The positive electrode, separator, and negative electrode are stacked in sequence and wound to form a bare battery cell 30, which is then placed in the titanium alloy casing of the battery. The battery is dried, injected with electrolyte, sealed with a sealing device, and then subjected to settling, formation, and volume adjustment to obtain the battery.

[0139] The positive electrode active material can be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate; the negative electrode active material can be selected from one or more negative electrode active main materials, such as artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0140] The adhesive includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0141] The solvent can be deionized water, NMP (N-methylpyrrolidone), alcohol, ether, ketone or other types of pyrrolidone, etc.

[0142] The positive electrode current collector foil can be a metal foil or a composite current collector. For example, as a metal foil, it can be made of stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0143] The negative electrode current collector foil can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium, and can be surface-plated with silver. Composite current collectors may include a polymer base layer and a metal layer. Composite current collectors can be formed by forming metal materials (aluminum, aluminum alloys, copper, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer base material (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0144] Methods for controlling the carbon content in the battery casing: The carbon content in the battery casing can be controlled by the amount of carbon powder incorporated during the titanium casing preparation process (the amount of carbon powder incorporated accounts for 0.01%~0.08% of the total mass content of all elements in the titanium casing). The more carbon powder incorporated, the higher the carbon content in the battery casing; the less carbon powder incorporated, the lower the carbon content in the battery casing. Alternatively, it can be controlled by the amount of other elemental powders (such as iron, oxygen, nitrogen, and sulfur) incorporated (the amount of other elemental powders incorporated accounts for 0.02%~0.09% of the total mass content of all elements in the titanium casing). The more other elemental powders incorporated, the lower the carbon content in the battery casing; the less other elemental powders incorporated, the higher the carbon content in the battery casing.

[0145] The testing method is as follows: Test Method 1: Deformation of the second shell wall of the battery under vibration conditions Following the battery fabrication method described above, batteries were prepared for each embodiment and comparative example. The values ​​of C and m for each embodiment and comparative example are shown in Table 2 below, while other structures and test conditions remained consistent. The first shell wall of the battery was bonded to a worktable. The surface of the worktable was taken as the XY plane, the direction perpendicular to the XY plane was taken as the Z direction, the geometric center of the first shell wall was taken as the reference point, and the straight line in the Z direction passing through the reference point was taken as the reference line. Before vibration, the maximum distance between the second shell wall and the reference line in the plane perpendicular to the Z direction was measured and recorded as the distance L1mm.

[0146] According to GB / T2423.43, the battery was mounted on a vibration table, and the testing process was carried out as specified. Random and fixed-frequency vibration loads were applied in each direction, and the loading sequence should preferably be: random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the direction of the line connecting the front and rear of the battery is the x-axis direction, and the other horizontal direction perpendicular to the x-axis direction is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc. are shown in Table 1 below.

[0147] Table 1: Vibration frequency, power spectral density (PSD), and sinusoidal constant-frequency vibration time table

[0148] After vibration, measure again the maximum distance between the second shell wall and the baseline in the plane perpendicular to the Z direction, and record it as distance L2mm. The deformation of the battery's second shell wall is calculated as |L1-L2|. If the deformation of the battery's second shell wall is greater than 0.2mm, the battery's test result is recorded as unqualified; if the deformation of the battery's second shell wall is greater than 0.1mm but less than or equal to 0.2mm, the battery's test result is recorded as qualified; if the deformation of the battery's second shell wall is less than or equal to 0.1mm, the battery's test result is recorded as good.

[0149] Test Method 2: Casing Cracks, i.e., whether there are cracks in the second shell wall and / or the connection between the second shell wall and the first shell wall after the battery casing is formed. According to the battery preparation method described above, for each embodiment and comparative example, the corresponding batteries were prepared. The values ​​of C and m for each embodiment and comparative example are shown in Table 2 below. Other structures and test conditions are kept consistent.

[0150] The size of cracks on the surface of the second shell wall of the battery and / or at the junction of the second shell wall and the first shell wall is observed and recorded using a scanning electron microscope. If the crack size is greater than 50 micrometers, the battery is recorded as unqualified. If the crack size is less than or equal to 50 micrometers but greater than 5 micrometers, the battery is recorded as qualified. If the crack size is less than or equal to 5 micrometers, the battery is recorded as good.

[0151] Table 2: Values ​​of C and m for each embodiment and comparative example. The value of m and performance test results

[0152] As can be seen from Table 2 above, in Examples 1 to 12, C The values ​​of m are all within the range of 16.5 to 40, and the corresponding deformation and crack ratio of the second shell wall are both good. This indicates that by controlling the product of the shell hardness C and the perpendicularity m of the second shell wall to be within the above range, the shell can maintain a low deformation, improve structural stability, and at the same time reduce the risk of cracks on the surface of the second shell wall and at the connection between the second shell wall and the first shell wall during the stretch forming process, thereby improving the product molding yield.

[0153] When C When m is less than 16.5, as in Comparative Example 2, C m is 14.53, indicating that the deformation of the second shell wall is unacceptable. Although the crack ratio is good, the structural strength of the shell is clearly insufficient to resist external loads under vibration conditions, leading to excessive deformation of the second shell wall. This indicates that C If the diameter (m) is too small, the shell hardness is too low, or the verticality is too small, the overall structural strength is weak, making it difficult to meet the usage requirements under working conditions.

[0154] When C When m is higher than 40, such as C in Comparative Example 1 m is 41.33. Although the deformation of the second shell wall is good, the crack ratio is unacceptable. This indicates that C If m is too large, the shell hardness is too high, or the verticality is too large, the brittleness increases significantly. During the stretching process, cracks with dimensions exceeding the acceptable range are easily generated in the second shell wall and at the connection between the second shell wall and the first shell wall, resulting in a decrease in product yield.

[0155] Therefore, by controlling C m satisfies 16.5 ≤ C With m≤40, the shell can maintain reasonable hardness and ductility while having sufficient structural strength to resist deformation under vibration conditions. This facilitates the integral molding of the first and second shell walls through a stretching process, reducing the risk of cracks on the surface of the second shell wall and at the connection between the second and first shell walls, and improving the product molding yield.

[0156] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery casing assembly, characterized in that, include: The shell (11) includes an integrally formed first shell wall (111) and a second shell wall (112). One end of the second shell wall (112) is connected to the outer periphery of the first shell wall (111) and extends toward a first direction away from the first shell wall (111). The first direction is perpendicular to the first shell wall. The first shell wall (111) and the second shell wall (112) together form an accommodating space. The end of the second shell wall (112) away from the first shell wall (111) has an opening that communicates with the accommodating space. The shell (11) is composed of titanium, with a mass content A% of 99%~99.9%. The hardness of the second shell wall (112) of the shell (11) is C, in HV. With the first shell wall (111) as the reference plane, the perpendicularity of the second shell wall (112) along its extension direction is m, in mm, satisfying 16.5≤C. m≤40.

2. The housing assembly according to claim 1, characterized in that, The hardness C of the second shell wall (112) ranges from 110HV to 160HV; and / or the perpendicularity m of the second shell wall (112), in mm, ranges from 0.15mm to 0.25mm.

3. The housing assembly according to claim 1, characterized in that, Along the extension direction of the second shell wall (112), the height of the second shell wall (112) is hmm, and the range of hmm is 60mm~180mm.

4. The housing assembly according to claim 3, characterized in that, The range of hmm is 80mm~180mm, and 18≤C m≤36.

5. The housing assembly according to claim 3, characterized in that, The range of hmm is 60mm~160mm, and 20≤C m≤40.

6. The housing assembly according to claim 1, characterized in that, The inner wall surface of the first shell wall (111) near the accommodating space and the inner wall surface of the second shell wall (112) near the accommodating space are connected by an inner arc transition.

7. The housing assembly according to claim 6, characterized in that, The radius of curvature R1mm corresponding to the inner arc ranges from 0.2mm to 1.4mm.

8. The housing assembly according to claim 6, characterized in that, The outer wall surface of the first shell wall (111) away from the accommodating space and the outer wall surface of the second shell wall (112) away from the accommodating space are connected by an outer circular arc, and the radius of curvature R2mm corresponding to the outer circular arc is greater than or equal to the radius of curvature R1mm corresponding to the inner circular arc.

9. The housing assembly according to any one of claims 1-8, characterized in that, The shell (11) also includes iron, and the mass content of iron is 0.01 to 0.8 of the mass content of other elements besides titanium.

10. The housing assembly according to any one of claims 1-8, characterized in that, The shell (11) also includes oxygen, and the mass content of oxygen is 0.01 to 0.75 of the mass content of other elements besides titanium.

11. The housing assembly according to any one of claims 1-8, characterized in that, The thickness of the first shell wall (111) is d1mm, and the thickness of the second shell wall (112) is d2mm. d1mm is greater than d2mm, satisfying d1-d2≤0.

05.

12. The housing assembly according to claim 11, characterized in that, 20≤C m≤40。 13. The housing assembly according to claim 1, characterized in that, Along the extension direction of the second shell wall (112), the distance between the orthographic projection of the end of the second shell wall (112) near the first shell wall (111) and the orthographic projection of the end of the second shell wall (112) away from the first shell wall (111) is 0.15mm to 0.25mm.

14. The housing assembly according to claim 13, characterized in that, The area of ​​the opening is greater than or equal to the area of ​​the first shell wall (111).

15. The housing assembly according to claim 14, characterized in that, The ratio of the area of ​​the opening to the area of ​​the first shell wall (111) is less than or equal to 1.

5.

16. The housing assembly according to any one of claims 1-8, characterized in that, The second shell wall (112) also includes carbon elements, with a carbon element mass content of 0.01%~0.08%.

17. A battery, characterized in that, include: Battery cell (30); The housing assembly as claimed in any one of claims 1-16, the battery further includes a cover (12) that covers the opening and is connected to the housing (11), and the battery cell (30) is housed within the housing space.

18. The battery according to claim 17, characterized in that, The battery cell (30) includes tabs; The cover (12) is provided with electrode terminals (20), and the electrode tabs are electrically connected to the electrode terminals (20).

19. The battery according to claim 18, characterized in that, The thickness of the cover (12) is greater than the thickness of the first shell wall (111).

20. The battery according to claim 17, characterized in that, The first shell wall (111) is used to support the battery cell (30), and the thickness of the first shell wall (111) ranges from 0.2 mm to 0.6 mm.

21. The battery according to claim 17, characterized in that, The battery is a cylindrical battery.

22. The battery according to claim 21, characterized in that, The first shell wall (111) of the cylindrical battery has a radial dimension of 18mm to 70mm.

23. The battery according to claim 17, characterized in that, The battery is a quadrangular prism battery.

24. The battery according to claim 23, characterized in that, The thickness at the junction of the first shell wall (111) and the second shell wall (112) is greater than or equal to 0.15 mm.

25. A battery pack (200), characterized in that, include: The battery as described in any one of claims 17-24.

26. The battery pack (200) according to claim 25, characterized in that, The battery pack (200) includes a frame and a base plate, which together form an accommodating space. The battery is disposed inside the accommodating space and on the base plate. The first shell wall (111) is fixedly connected to the base plate.

27. An electrical appliance, characterized in that, include: The battery as claimed in any one of claims 17-24; or the battery pack (200) as claimed in claim 25 or 26.

Images