Battery and electric device

Abstract

This application provides a battery and an electrical device. The battery includes a casing, which comprises: a housing having a cavity for accommodating a battery cell; at least one end of the housing has an opening communicating with the cavity; a portion of the inner wall at the opening protrudes into the cavity to form a reinforcing protrusion; and a cover plate sealing the opening, which is welded to the housing to form a weld line. The weld line strength is K, the thickness of the housing at the reinforcing protrusion is C, and the thickness of the housing outside the reinforcing protrusion is D, wherein 95 MPa ≤ K × C / D ≤ 2700 MPa. The battery of this application, by providing a reinforcing protrusion at the opening of the housing and designing the thickness ratio C / D between the reinforcing protrusion and the housing, and the strength value K of the weld line formed by the welding between the cover plate and the housing, ensures sufficient storage space within the housing to store electrolyte while balancing welding strength. This improves the installation strength of the cover plate without affecting battery performance, thereby enhancing battery safety.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery and an electrical device. Background Technology

[0002] Advances in battery technology have driven the development of portable electronic devices, electric vehicles, and energy storage systems. However, as battery energy density increases, safety issues have become increasingly important. Internal gas generation, in particular, is a common safety hazard in lithium-ion batteries.

[0003] During charging and discharging, overcharging, over-discharging, short circuits, or other abnormal conditions can lead to electrolyte decomposition and reactions in the positive and negative electrode materials, generating gas. This gas accumulates inside the battery, increasing internal pressure. When the pressure exceeds the capacity of the battery casing or sealing cover, it can damage the battery structure, especially the cover rupture, causing high-temperature gases and liquids to erupt from inside the battery, potentially triggering thermal runaway in adjacent batteries and posing a significant safety risk. Summary of the Invention

[0004] In view of the above problems, this application provides a battery and an electrical device. By providing a reinforcing protrusion at the shell opening of the outer casing, and designing the thickness ratio C / D of the reinforcing protrusion to the casing and the strength value K of the weld line formed by welding the cover plate and the casing, the battery can have sufficient storage space inside the casing to store electrolyte while taking into account the welding strength. This improves the installation strength of the cover plate without affecting the battery performance and enhances the safety of the battery.

[0005] In a first aspect, this application provides a battery, including a casing, the casing comprising: a housing having a receiving cavity for accommodating a battery cell, at least one end of the housing having a casing opening communicating with the receiving cavity, a portion of the inner wall at the casing opening protruding toward the receiving cavity to form a reinforcing protrusion; a cover plate sealing the casing opening, the cover plate being welded to the housing to form a weld line; the weld line strength of the weld line being K, the thickness of the housing at the reinforcing protrusion being C, and the thickness of the housing in the area outside the reinforcing protrusion being D, wherein K, C, and D satisfy: 95 MPa ≤ K × C / D ≤ 2700 MPa.

[0006] The battery of this application has a reinforcing protrusion at the shell opening, which helps to improve the structural strength of the shell. At the same time, when the cover is sealed to the shell opening and welded to the shell, the reinforcing protrusion provides a larger contact area for welding, which helps to improve the connection stability between the cover and the shell, thereby reducing the possibility of the cover flying off due to explosion at the connection between the cover and the shell, and thus improving the safety of the battery.

[0007] However, because the reinforcing protrusion occupies part of the space inside the casing, the electrolyte storage space inside the casing is reduced, which may affect the battery's cycling process and thus its performance. Therefore, by comprehensively designing the thickness ratio C / D of the reinforcing protrusion to the casing and the strength value K of the weld line formed between the cover plate and the casing, sufficient storage space inside the casing is ensured to store electrolyte while taking into account welding strength. This improves the installation strength of the cover plate without affecting battery performance, thereby enhancing battery safety.

[0008] In some embodiments, at least a portion of the cover plate extends into the inside of the shell opening to form an assembly portion, the assembly portion being arranged opposite to the reinforcing protrusion.

[0009] According to some embodiments of this application, the reinforcing protrusion abuts against the sidewall of the assembly portion.

[0010] According to some embodiments of this application, K, C, and D satisfy: 95 MPa ≤ K × C / D ≤ 2000 MPa.

[0011] According to some embodiments of this application, the reinforcing protrusion is spaced apart from the sidewall of the assembly portion.

[0012] According to some embodiments of this application, K, C, and D satisfy: 800 MPa ≤ K × C / D ≤ 2700 MPa.

[0013] According to some embodiments of this application, the distance A between the reinforcing protrusion and the sidewall of the assembly part satisfies: 0 ≤ A ≤ 0.1 mm.

[0014] In some embodiments, the cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening, and the reinforcing protrusion includes a first end facing into the receiving cavity along the opening direction of the shell opening, wherein the first end face does not extend beyond the first end.

[0015] According to some embodiments of this application, the cover plate includes a first end face facing the receiving cavity along the opening direction of the shell opening, and the reinforcing protrusion includes a first end facing the receiving cavity along the opening direction of the shell opening, and the first end face is flush with the first end.

[0016] According to some embodiments of this application, the cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening, and the reinforcing protrusion includes a first end facing into the receiving cavity along the opening direction of the shell opening, and the first end face is higher than the first end.

[0017] According to some embodiments of this application, the height difference B between the first end face and the first end satisfies: 0.5mm≤B≤4mm.

[0018] In some embodiments, the cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening, and the reinforcing protrusion includes a first end facing into the receiving cavity along the opening direction of the shell opening, with the first end face extending beyond the first end.

[0019] According to some embodiments of this application, the distance F of the first end face extending beyond the first end satisfies: 0.5mm ≤ F ≤ 2mm.

[0020] According to some embodiments of this application, the reinforcing protrusion includes a first corner portion facing away from the receiving cavity along the opening direction of the shell opening, the first corner portion being a right angle.

[0021] According to some embodiments of this application, K, C, and D satisfy: 800 MPa ≤ K × C / D ≤ 1800 MPa.

[0022] In some embodiments, the reinforcing protrusion includes a first corner portion facing away from the receiving cavity along the opening direction of the shell opening, the first corner portion being a rounded corner.

[0023] According to some embodiments of this application, K, C, and D satisfy: 1000 MPa ≤ K × C / D ≤ 2000 MPa.

[0024] According to some embodiments of this application, the fillet radius r of the first corner is: 1mm≤r≤3mm.

[0025] In some embodiments, the reinforcing protrusion includes a first end facing the receiving cavity along the opening direction of the shell opening, the first end having a length G along a first direction, and the shell opening end face of the shell having a length H along the first direction, wherein G and H satisfy: G < H, and / or 0.2 mm ≤ HG ≤ 0.8 mm, and the first direction is perpendicular to the opening direction of the shell opening.

[0026] In some embodiments, the weld line includes a weld top and a weld root along the weld depth direction, the width of the weld top is T, and the width of the weld root is t, where t and T satisfy: 0.15≤t / T≤1.2.

[0027] In some embodiments, along the first direction, the length I of the reinforcing protrusion protrudes satisfies: 0.1mm≤I≤0.3mm.

[0028] In some embodiments, along the opening direction of the shell opening, the height J of the reinforcing protrusion satisfies: 1mm≤J≤8mm.

[0029] In some embodiments, the reinforcing protrusion is a continuous structure along the circumferential direction of the shell opening.

[0030] In some embodiments, the reinforcing protrusion is a discontinuous structure along the circumferential direction of the shell opening.

[0031] According to some embodiments of this application, the reinforcing protrusion includes a plurality of protrusions spaced circumferentially along the shell opening, and the distance e between two adjacent protrusions is: 5mm≤e≤80mm.

[0032] According to some embodiments of this application, there is a gap between two adjacent protrusions, and the ratio of the sum of the lengths E of the multiple gaps to the circumference L of the shell opening along the circumference of the shell opening is: 0.15≤E / L≤0.25.

[0033] In some embodiments, the cover plate is provided with an explosion-proof valve; and / or, the cover plate is provided with a liquid injection hole, wherein K, C, and D satisfy: 800 MPa ≤ K × C / D ≤ 2000 MPa.

[0034] According to some embodiments of this application, the cover plate is provided with an explosion-proof valve, and the distance M between the explosion-proof valve and the reinforcing protrusion satisfies: 5mm≤M≤30mm.

[0035] According to some embodiments of this application, the cover plate is provided with an injection hole, and the distance N between the injection hole and the reinforcing protrusion satisfies: 15mm≤N≤35mm.

[0036] In some embodiments, the battery cell includes two large surfaces along a second direction, and the distance O between the large surfaces and the inner wall of the receiving cavity satisfies: 0 ≤ O ≤ 2 mm.

[0037] In some embodiments, the reinforcing protrusion includes a first end facing the receiving cavity along the opening direction of the housing opening, the battery cell includes a tab lead-out surface opposite to the housing opening, the tab lead-out surface is provided with a tab, and the distance P between the root of the tab and the first end satisfies: 0.5mm≤P≤5mm.

[0038] In some embodiments, 1.1 ≤ C / D ≤ 1.3; and / or, 0.3 mm ≤ C ≤ 1 mm; and / or, 0.15 mm ≤ D ≤ 0.18 mm.

[0039] In some embodiments, 82 MPa ≤ K ≤ 1000 MPa.

[0040] In some embodiments, the cover plate includes a base portion and an assembly portion sequentially connected along the opening direction of the shell opening, the projection of the shell opening in a reference plane is located inside the projection of the base portion in the reference plane, the base portion is welded to the end face of the shell opening of the housing to form the weld line, and the assembly portion extends into the shell opening and is arranged opposite to the reinforcing protrusion.

[0041] According to some embodiments of this application, K, C, and D satisfy: 800 MPa ≤ K × C / D ≤ 1800 MPa. In some embodiments, the cover plate is located inside the reinforcing protrusion, and the periphery of the cover plate is welded to the inner wall of the reinforcing protrusion.

[0042] According to some embodiments of this application, K, C, and D satisfy: 1200 MPa ≤ K × C / D ≤ 2000 MPa. According to some embodiments of this application, 1.1 ≤ C / D ≤ 1.3; and / or, 0.3 mm ≤ C ≤ 1 mm; and / or, 0.15 mm ≤ D ≤ 0.8 mm. According to some embodiments of this application, 150 MPa ≤ K ≤ 1000 MPa.

[0043] Secondly, this application also provides an electrical device, including the aforementioned battery.

[0044] The electrical equipment described in this application, due to the use of the aforementioned battery, will not have its battery cover explode during use, which helps to improve the safety of the electrical equipment. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of a battery according to one embodiment of this application;

[0047] Figure 2 This is a schematic diagram showing that the first end face is higher than the first end in one embodiment of this application;

[0048] Figure 3 for Figure 2 Enlarged structural diagram at point a;

[0049] Figure 4 for Figure 2 Enlarged structural diagram at point b in the middle;

[0050] Figure 5This is a schematic diagram showing that the first end face is flush with the first end in another embodiment of this application;

[0051] Figure 6 for Figure 5 A magnified structural diagram at point c in the middle;

[0052] Figure 7 This is a schematic diagram showing that the first end face is lower than the first end face in another embodiment of this application;

[0053] Figure 8 for Figure 7 A magnified structural diagram at point d in the middle;

[0054] Figure 9 This is a cross-sectional view of the bonding wire in an embodiment of this application;

[0055] Figure 10 This is a schematic diagram showing the relationship between the large surface of the battery cell and the receiving cavity in an embodiment of this application;

[0056] Figure 11 This is a schematic diagram of the reinforcing protrusion configuration according to an embodiment of this application;

[0057] Figure 12 This is a schematic diagram of the reinforcing protrusion configuration according to another embodiment of this application;

[0058] Figure 13 This is a schematic diagram of the structure of a battery according to another embodiment of this application.

[0059] Explanation of reference numerals in the attached figures:

[0060] 100. Outer shell;

[0061] 110. Shell; 111. Receiving cavity; 112. Shell opening; 113. Reinforcing protrusion; 1130. Protrusion; 1131. First end; 1132. First corner;

[0062] 120. Cover plate; 120a. Base body; 120b. Assembly part; 122. First end face; 123. Explosion-proof valve; 124. Injection hole;

[0063] 130. Solder wire;

[0064] 200, battery; 210, battery cell. Detailed Implementation

[0065] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0066] Existing batteries produce gas during use. When the gas inside the battery is too large, it can cause the battery cover to burst and fly out. This can not only damage the battery itself, but also impact adjacent batteries. Especially in battery packs or battery modules, this impact can trigger a chain reaction, causing multiple batteries to thermally run away.

[0067] In view of this, this application provides a battery and an electrical device that, by providing a reinforcing protrusion at the opening of the outer casing, and designing the thickness ratio C / D of the reinforcing protrusion to the casing and the strength value K of the weld line formed by welding the cover plate and the casing, ensures sufficient storage space inside the casing to store electrolyte while taking into account the welding strength. This improves the installation strength of the cover plate without affecting the battery performance and enhances the safety of the battery.

[0068] For ease of explanation and understanding, please refer to... Figure 1 The height of the battery can be in the Z direction, the length of the battery can be in the X direction, and the width of the battery can be in the Y direction.

[0069] refer to Figures 1 to 13 In one aspect, this application provides a battery 200, which may include a casing 100 and a cell 210.

[0070] The outer casing 100 may include a housing 110 and a cover plate 120. The housing 110 has a receiving cavity 111 for accommodating a battery cell 210. At least one end of the housing 110 has a shell opening 112 communicating with the receiving cavity 111. For example, the shell opening 112 may be provided at one end of the housing 110, or the shell opening 112 may be provided at both opposite ends of the housing 110 along the height (width / length) direction of the battery 200. The location of the shell opening 112 is related to the arrangement of the battery cell 210 of the battery 200, with the tabs on the battery cell 210 facing the shell opening 112. The shell opening 112 may be located on one side of the housing 110 along the Z direction, or on one side along the Y direction, or on one side along the X direction.

[0071] Understandably, the casing 110 of this application can be used for the battery 200, which can be a prismatic battery. Accordingly, the cross-section of the casing 110 is square, and the casing opening 112 is also square; or, the battery 200 can be a cylindrical battery. Accordingly, the cross-section of the casing 110 is circular, and the casing opening 112 is also circular.

[0072] Optionally, the material of the housing may include at least one of aluminum, aluminum alloy, steel, copper, nickel, magnesium, and titanium, or the housing may also include other alloy materials.

[0073] The battery 200 may contain a battery cell 210, and the receiving cavity 111 contains electrolyte. During normal use, the battery 200 requires the electrolyte to continuously wet the battery cell 210, thus replenishing the electrolyte. The capacity of the electrolyte is related to the performance of the battery 200. If the battery 200 lacks electrolyte, it will affect the electrolyte replenishment process, and consequently affect the charge and discharge performance of the battery 200.

[0074] The battery cell 210 may include a battery cell body, which is formed by winding or stacking a positive electrode plate, a negative electrode plate and a separator disposed between the two.

[0075] The positive electrode sheet may include a positive electrode current collector and a positive electrode active material. The positive electrode current collector may be made of metal materials such as aluminum foil, nickel foil, or stainless steel, or it may be a composite foil formed by combining metals and insulating materials. The positive electrode active material includes the main positive electrode material, conductive agent, and binder. Among them, the main positive electrode material includes one or more lithium-containing positive electrode active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0076] Similarly, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material. The negative electrode current collector may be made of metal materials such as copper foil, aluminum foil, or stainless steel, or it may be a composite foil formed by combining metal and insulating materials. The negative electrode active material may include a negative electrode active material, a conductive agent, and a binder. The negative electrode active material may include one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate. A portion of the inner wall at the opening 112 protrudes into the receiving cavity 111 to form a reinforcing protrusion 113. For example, the reinforcing protrusion 113 may be an annular structure surrounding the inner wall of the receiving cavity 111, or it may be one or more protrusions. When there are multiple reinforcing protrusions 113, they are spaced apart at the periphery of the inner wall of the receiving cavity 111. By providing the reinforcing protrusion 113, the contact area between the cover plate 120 and the housing 110 is increased, resulting in a stronger weld line 130 formed between the cover plate 120 and the housing 110. This improves the connection stability between the cover plate 120 and the housing 110, thereby reducing the possibility of the cover plate 120 bursting out. The reinforcing protrusion 113 also strengthens the structural strength around the housing opening 112, thus improving the structural strength of the housing 110. This, in turn, enhances the structural strength of the battery 200 and reduces the likelihood of damage to the housing 110 during battery use.

[0077] Correspondingly, since the reinforcing protrusion 113 occupies part of the space within the casing 110, when the thickness of the reinforcing protrusion 113 is too large (which can be reflected as an excessively large C / D ratio), the space occupied by the reinforcing protrusion 113 is too large, resulting in a reduction in the electrolyte storage space within the casing 110, which affects the cycle process of the battery 200 and its service life. Furthermore, when the thickness of the reinforcing protrusion 113 is too large, it may also cause the cell 210 to scrape against the reinforcing protrusion 113 when it is sealed into the receiving cavity 111, resulting in damage to the separator of the cell 210 and causing the battery 200 to short-circuit and fail.

[0078] When the thickness of the reinforcing protrusion 113 is too small (i.e., C / D is close to 1), the increased contact area provided by the reinforcing protrusion 113 is too small, and its contribution to improving the welding strength is too small. In this case, the welding quality is poor, which makes the cover plate 120 prone to bursting and flying out when the gas pressure inside the battery 200 increases. Therefore, the thickness of the reinforcing protrusion 113 is closely related to the connection strength between the cover plate 120 and the housing 110, as well as the performance of the battery 200.

[0079] A cover plate 120 is placed over the shell opening 112 and welded to the shell 110 to form a weld line 130. The weld line 130 has a strength of K. Here, K generally refers to the tensile strength of the weld line 130. The thickness of the shell 110 at the reinforcing protrusion 113 is C, and the thickness of the shell 110 in the area outside the reinforcing protrusion 113 is D. K, C, and D satisfy: 95 MPa ≤ K×C / D ≤ 2700 MPa. For example, K×C / D can be 95 MPa, 100 MPa, 500 MPa, 1000 MPa, 1500 MPa, 2000 MPa, 2500 MPa, or 2700 MPa. Of course, K×C / D can also be other values, which are not limited in this application.

[0080] Understandably, when welding the cover plate 120 to the housing 110, the welding area between the cover plate 120 and the housing 110 can be increased by thickening the housing opening 112, thereby improving the connection strength between the two and preventing the cover plate 120 from bursting at the weld joint when gas is generated inside the battery 200, thus preventing the cover plate 120 from flying out. However, this will cause some of the original electrolyte storage space inside the battery 200 to be occupied by the thickened portion of the housing opening 112. When the battery 200 generates gas normally, it may cause an increase in the gas pressure inside the battery 200, which may easily lead to an abnormal burst of the cover plate 120. In addition, the thickening at the housing opening 112 is also not conducive to the encapsulation of the cell 210 into the housing 110. The cell 210 is easily scratched by the housing and the separator is punctured, causing the insulation of the cell 210 to fail and leading to a short circuit in the battery 200. Therefore, the thickness C / D of the housing opening 112 and the welding strength K of the welding wire are comprehensively controlled.

[0081] By comprehensively designing the thickness ratio C / D between the reinforcing protrusion 113 and the housing 110, as well as the strength value K of the weld line 130 formed between the cover plate 120 and the housing 110, K×C / D is made to have a suitable value. While taking into account the welding strength, the housing 110 has sufficient storage space to store electrolyte. This improves the installation strength of the cover plate 120 without affecting the performance of the battery 200, thereby enhancing the safety of the battery 200.

[0082] The battery 200 of this application has a reinforcing protrusion 113 at the shell opening 112 of the shell 110, which helps to improve the structural strength of the shell 110. At the same time, when the cover plate 120 is sealed at the shell opening 112 and welded to the shell 110, the reinforcing protrusion 113 provides a larger contact area for welding, which helps to improve the connection stability between the cover plate 120 and the shell 110. This reduces the possibility of the cover plate 120 exploding at the connection between the cover plate 120 and the shell 110 due to gas generation inside the battery 200, thus improving the safety of the battery 200 in use.

[0083] In some embodiments, at least a portion of the cover plate 120 extends into the inner side of the housing opening 112 to form an assembly portion 120b. Exemplarily, the assembly portion 120b may be formed by a portion of the cover plate 120 facing the housing 110 protruding into the housing 110; alternatively, the entire cover plate 120 may be located within the housing opening 112, with the cover plate 120 integrally formed as the assembly portion 120b. The assembly portion 120b is arranged opposite to the reinforcing protrusion 113, facilitating the positioning and installation between the cover plate 120 and the housing 110, thereby improving the assembly efficiency of the battery 200.

[0084] refer to Figure 11 and Figure 12 Understandably, in this embodiment, the reinforcing protrusion 113 can abut against the side wall of the mounting portion 120b, or the reinforcing protrusion 113 can be spaced apart from the side wall of the mounting portion 120b, or when there are multiple reinforcing protrusions 113, some of the reinforcing protrusions 113 can abut against the side wall of the mounting portion 120b, while other reinforcing protrusions 113 are spaced apart from the side wall of the mounting portion 120b.

[0085] refer to Figure 2 and Figure 4 According to some embodiments of this application, the reinforcing protrusion 113 abuts against the side wall of the mounting portion 120b. Thus, the cooperation between the mounting portion 120b and the reinforcing protrusion 113 increases the contact area between the cover plate 120 and the housing 110, which helps to improve the connection strength between the cover plate 120 and the housing 110, reduces the possibility of the cover plate 120 flying out due to internal air pressure bursting in the battery 200, and improves the safety of the battery 200 in use.

[0086] According to some embodiments of this application, K, C, and D satisfy: 95 MPa ≤ K×C / D ≤ 2000 MPa. Exemplarily, K×C / D can be 95 MPa, 100 MPa, 500 MPa, 1000 MPa, 1500 MPa, or 2000 MPa. Of course, K×C / D can also be other values, and this application does not limit this.

[0087] Understandably, the value of K is related to C / D. When C / D increases, the protrusion thickness of the reinforcing protrusion 113 is larger, providing a larger contact area between the cover plate 120 and the housing 110, resulting in a higher strength K value for the weld line 130. However, the performance of the battery 200 will be affected. When C / D gradually decreases to 1, the protrusion thickness of the reinforcing protrusion 113 is smaller, providing a smaller contact area between the cover plate 120 and the housing 110, resulting in poor welding quality and a decreased strength K value for the weld line 130. In other words, to a certain extent, the value of K is positively correlated with C / D; when C / D increases, the value of K increases, and when C / D decreases, the value of K decreases.

[0088] It is important to note that the strength K of the welding wire 130 is directly related to the welding effect of the cover plate 120. The higher the strength K of the welding wire 130, the better the welding effect of the cover plate 120. However, if we blindly pursue increasing the welding strength K, we need to increase the heat in the welding area and increase the volume of the molten pool during welding. The heat generated during welding can easily affect the battery cells, especially the separator, which may cause the separator to melt and fail due to heat, resulting in a short circuit between the positive and negative electrodes inside the battery.

[0089] By further limiting the upper limit of K×C / D, in other words, under the premise of ensuring that the bonding wire 130 has sufficient strength K, the upper limit of the thickness of the reinforcing protrusion 113 is limited to avoid the thickness of the reinforcing protrusion 113 being too large, so that there is sufficient electrolyte storage space in the housing 110, which is beneficial to maintaining the performance of the battery 200.

[0090] refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 According to some embodiments of this application, the reinforcing protrusion 113 and the sidewall of the mounting portion 120b are spaced apart. In this case, a certain gap can exist between the reinforcing protrusion 113 and the mounting portion 120b, providing storage space for the electrolyte inside the battery 200, which helps to ensure the performance of the battery 200. Furthermore, when an abnormal situation occurs inside the battery 200 and it becomes internally gassy, ​​the gap between the reinforcing protrusion 113 and the mounting portion 120b also provides space to accommodate the gas, thereby improving the safety of the battery 200 in use.

[0091] Furthermore, K, C, and D satisfy: 800 MPa ≤ K×C / D ≤ 2700 MPa. For example, K×C / D can be 800 MPa, 1000 MPa, 1500 MPa, 2000 MPa, 2500 MPa, or 2700 MPa. Of course, K×C / D can also be other values, which are not limited in this application.

[0092] refer to Figure 6 In this embodiment, the spacing between the reinforcing protrusion 113 and the sidewall of the mounting portion 120b reduces the connection strength between the cover plate 120 and the housing 110. By increasing the lower limit of K×C / D, in other words, by increasing the lower limits of K and C / D, the bonding wire 130 can have sufficient strength, thereby ensuring sufficient connection strength between the cover plate 120 and the housing 110.

[0093] refer to Figure 6According to some embodiments of this application, the distance A between the reinforcing protrusion 113 and the sidewall of the mounting portion 120b satisfies: 0 mm ≤ A ≤ 0.1 mm. Exemplarily, the distance A between the reinforcing protrusion 113 and the sidewall of the mounting portion 120b can be 0 mm, 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, or 1 mm. Of course, A can also be other values, and this application does not limit this.

[0094] This ensures that the distance A between the reinforcing protrusion 113 and the side wall of the assembly part 120b has a suitable spacing size, avoiding the situation where the thickness of the reinforcing protrusion 113 is small, resulting in a weak connection strength between the cover plate 120 and the housing 110, which helps to prevent the cover plate 120 from bursting out.

[0095] refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the cover plate 120 includes a first end face 122 facing into the receiving cavity 111 along the opening direction (Z direction) of the shell opening 112, and the reinforcing protrusion 113 includes a first end 1131 facing into the receiving cavity 111 along the opening direction of the shell opening 112. The first end face 122 does not extend beyond the first end 1131. In other words, in the height direction of the battery 200, the mounting portion 120b does not extend into the receiving cavity 111, which helps to reduce the storage space in the receiving cavity 111 occupied by the cover plate 120, thereby increasing the capacity of the electrolyte in the battery 200 and making the battery 200 have good performance.

[0096] Understandably, in this application, the reinforcing protrusion 113 can be a regular horizontal protrusion, or it can be a gradually changing structure, such as the thickness of the reinforcing protrusion 113 gradually increasing or decreasing along the opening direction of the housing 110, forming an inclined surface facing outwards from the housing opening 112 or into the receiving cavity 111. Therefore, the first end 122 can be the bottom end face of the reinforcing protrusion 113 along the Z direction, or it can be one end of the bottom of the reinforcing protrusion 113 along the Z direction.

[0097] refer to Figure 5 and Figure 6The cover plate 120 includes a first end face 122 facing into the receiving cavity 111 along the opening direction (Z direction) of the shell opening 112. The reinforcing protrusion 113 includes a first end 1131 facing into the receiving cavity 111 along the opening direction of the shell opening 112. The first end face 122 and the first end 1131 are flush. This increases the mating surface between the mounting part 120b and the reinforcing protrusion 113, resulting in a better connection strength between the cover plate 120 and the shell 110. This helps to reduce the possibility of the cover plate 120 bursting out and improves the safety of the battery 200.

[0098] refer to Figure 2 and Figure 4 According to some embodiments of this application, the cover plate 120 includes a first end face 122 facing into the receiving cavity 111 along the opening direction (Z direction) of the shell opening 112, and the reinforcing protrusion 113 includes a first end 1131 facing into the receiving cavity 111 along the opening direction of the shell opening 112. The first end face 122 is higher than the first end 1131. In other words, there is a gap between the first end face 122 and the first end 1131 along the Z direction. Thus, the storage space of electrolyte in the battery 200 is increased through the gap, so that the battery 200 has good performance.

[0099] refer to Figure 4 Furthermore, the height difference B between the first end face 122 and the first end 1131 satisfies: 0.5mm ≤ B ≤ 4mm. For example, B can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, or 4mm. Of course, B can also be other values, and this application does not limit this.

[0100] Thus, on the one hand, it avoids the height difference between the first end face 122 and the first end 1131 being too small (e.g., less than 0.5mm), resulting in a small increase in storage space and a small contribution to maintaining the performance of the battery 200. On the other hand, it avoids the height difference between the first end face 122 and the first end 1131 being too large (e.g., exceeding 4mm), which would reduce the corresponding portion between the reinforcing protrusion 113 and the mounting portion 120b, thereby reducing the connection strength between the cover plate 120 and the housing 110, making the cover plate 120 prone to bursting and flying out when the internal air pressure of the battery 200 is too high.

[0101] refer to Figure 7 and Figure 8In some embodiments, the cover plate 120 includes a first end face 122 facing into the receiving cavity 111 along the opening direction of the shell opening 112, and the reinforcing protrusion 113 includes a first end 1131 facing into the receiving cavity 111 along the opening direction of the shell opening 112. The first end face 122 extends beyond the first end 1131. Thus, by making the portion of the cover plate 120 that mates with the reinforcing protrusion 113 extend beyond the first end 1131 at the lower end of the reinforcing protrusion 113, the assembly effect between the cover plate 120 and the shell 110 is good. When the cover plate 120 is subjected to a non-Z-direction force of the gas in the battery 200, the portion of the cover plate 120 that extends beyond the first end 1131 can abut against the side wall at the lower end of the reinforcing protrusion 113, thereby increasing the assembly strength between the cover plate 120 and the shell 110 and improving the structural stability of the battery 200.

[0102] Continue to refer to Figure 8 According to some embodiments of this application, the distance F of the first end face 122 extending beyond the first end 1131 satisfies: 0.5mm ≤ F ≤ 2mm. Exemplarily, F can be 0.5mm, 1mm, 1.5mm, or 2mm. Of course, F can also be other values, and this application does not limit this.

[0103] On the one hand, to avoid the first end face 122 extending too far beyond the first end 1131 (e.g., less than 0.5mm), which would negatively impact the assembly strength between the cover plate 120 and the casing 110, potentially causing it to explode and fly out when the internal pressure of the battery 200 is high. On the other hand, to avoid the first end face 122 extending too far beyond the first end 1131 (e.g., more than 2mm), which would cause the cover plate 120 to occupy too much space within the receiving cavity 111, reducing the electrolyte capacity within the battery 200 and affecting its performance. If the first end face 122 extends too far beyond the first end 1131, it could even cause the cover plate 120 to overlap with the cell 210, resulting in a short circuit in the battery 200. Limiting the distance F of the first end face 122 extending beyond the first end 1131 helps improve the safety of the battery 200.

[0104] refer to Figure 4 and Figure 8 According to some embodiments of this application, the reinforcing protrusion 113 includes a first corner portion 1132 on the side facing away from the receiving cavity 111 along the opening direction of the shell opening 112. The first corner portion 1132 is a right angle. In this way, a corresponding right angle structure can be formed at the mating point of the cover plate 120 with the reinforcing protrusion 113. Through the mating of the first corner portion 1132 with the right angle structure, the matching and positioning effect of the cover plate 120 during installation is good, resulting in a large contact area between the cover plate 120 and the shell 110. This is beneficial to improving the welding strength between the cover plate 120 and the shell 110, thereby improving the safety of the battery 200 in use.

[0105] Furthermore, K, C, and D satisfy: 800 MPa ≤ K×C / D ≤ 1800 MPa. For example, K×C / D can be 800 MPa, 900 MPa, 1000 MPa, 1100 MPa, 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600 MPa, 1700 MPa, or 1800 MPa. Of course, K×C / D can also be other values, and this application does not limit them.

[0106] Thus, with the first corner 1132 being a right angle, the connection between the cover plate 120 and the housing 110 is good, and the welding strength is high. In this case, limiting the upper limit of K×C / D can be understood as: appropriately limiting the upper limit of the thickness of the reinforcing protrusion 113. On the one hand, this helps to increase the electrolyte storage space within the receiving cavity 111, ensuring the performance of the battery 200. On the other hand, by limiting the protruding size of the reinforcing protrusion 113, it also helps to prevent the battery 200 from being damaged due to scratches between the cell 210 and the reinforcing protrusion 113 when the cell 210 is encapsulated in the housing 110, thus improving the production safety of the battery 200.

[0107] In some embodiments, the reinforcing protrusion 113 includes a first corner portion 1132 on the side opposite to the receiving cavity 111 along the opening direction of the shell opening 112, and the first corner portion 1132 is rounded.

[0108] By setting the first corner 1132 as a rounded corner, when the cell 210 is sealed into the housing 110 from the opening 112, the first corner 1132 will not rigidly scrape against the outer surface of the cell 210, which helps to avoid damage to the cell 210 and thus improves the safety of battery 200 production.

[0109] Furthermore, K, C, and D satisfy the condition: 1000 MPa ≤ K×C / D ≤ 2000 MPa. For example, K×C / D can be 1000 MPa, 1100 MPa, 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600, 1700 MPa, 1800 MPa, 1900 MPa, or 2000 MPa. Of course, K×C / D can also be other values, and this application does not limit them.

[0110] When the first corner 1132 is set to a rounded corner, although scratching with the battery cell 210 is avoided and the safety of the production process is improved, the contact area between the cover plate 120 and the reinforcing protrusion 113 is reduced, resulting in a decrease in the welding strength between the cover plate 120 and the housing 110. Accordingly, it is necessary to increase the lower limit of K×C / D, or in other words, increase the lower limit of the thickness of the reinforcing protrusion 113, to ensure that there is sufficient connection strength between the cover plate 120 and the housing 110.

[0111] According to some embodiments of this application, the fillet radius r of the first corner 1132 is: 1mm ≤ r ≤ 2mm. Exemplarily, r can be 1mm, 1.5mm or 2mm, and of course, r can also be other values, which are not limited in this application.

[0112] On the one hand, the radius of the first corner 1132 is not too small (e.g., less than 1mm), so that the cell 210 can be safely encapsulated in the housing 110 and the reinforcing protrusion 113 and the cell 210 are not scratched. On the other hand, the radius of the first corner 1132 is not too large, so that the contact area between the cover plate 120 and the reinforcing protrusion 113 is reduced, which reduces the connection strength between the cover plate 120 and the housing 110.

[0113] refer to Figure 2 and Figure 3In some embodiments, the reinforcing protrusion 113 includes a first end 1131 facing into the receiving cavity 111 along the opening direction of the shell opening 112. The length of the first end 1131 along the first direction (X direction) is G, and the length of the end face of the shell opening 112 of the housing 110 along the first direction is H. G and H satisfy: G < H, and the first direction is perpendicular to the opening direction of the shell opening 112. In other words, the reinforcing protrusion 113 may have a slope that is wider at the top and narrower at the bottom, facing into the receiving cavity 111. This ensures that there is sufficient contact area between the top of the shell opening 112 and the cover plate 120, ensuring sufficient connection strength between the cover plate 120 and the housing 110. The inclined structure on the reinforcing protrusion 113 also increases the storage space of the electrolyte in the battery 200, which is beneficial to the battery 200 having good performance. Specifically, G can satisfy: 0.2mm ≤ G ≤ 0.8mm. For example, G can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm. H can satisfy: 0.4mm ≤ H ≤ 1mm. For example, H can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm. Of course, G and H can also be other values, which designers can choose according to their needs. This application does not limit this. In this way, the reinforcing protrusion 113 forming the inclined platform has a suitable thickness distribution along the height direction (Z direction), avoiding a reduction in the structural strength at the connection between the reinforcing protrusion 113 and the housing 110, which is beneficial to improving the welding stability of the cover plate 120.

[0114] G and H satisfy the condition: 0.2mm ≤ HG ≤ 0.8mm. For example, HG can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm. Of course, HG can also be other values, and this application does not limit this.

[0115] On the one hand, if the HG value is too small, the increased storage space is limited, and its contribution to maintaining the performance of the battery 200 is limited. On the other hand, if the HG is too large, the reinforcing protrusion 113 may protrude too much from the receiving cavity 111, causing the cell 210 to be scratched when it is packaged into the housing 110, affecting product quality.

[0116] refer to Figure 1 , Figure 2 , Figure 5 , Figure 8 , Figure 9 and Figure 11In some embodiments, the weld wire 130 includes a weld top and a weld root in the weld penetration direction. The width of the weld top is T, and the width of the weld root is t. Taking the figure as an example, the weld top can be located on the side of the weld wire 130 facing outward from the housing 110, and the weld root can be located on the side of the weld wire 130 facing inward from the housing 110. t and T satisfy: 0.15 ≤ t / T ≤ 1.2. Exemplarily, t / T can be 0.15, 0.3, 0.45, 0.6, 0.75, 0.9, 1.05, or 1.2, where t can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, or 0.6 mm, and T can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm. Of course, t / T, t, and T can be other values, and this application does not limit them.

[0117] Thus, by limiting the size of the welding wire 130, on the one hand, it avoids the overall size of the welding wire 130 being too small, resulting in poor welding strength between the cover plate 120 and the shell 110. Under high pressure, the cover plate 120 is prone to bursting and flying out, affecting the safety of the battery 200. On the other hand, it also avoids the size of the welding wire 130 being too large, which would cause a large impact on the cover plate 120 and the shell 110 during the welding process, resulting in partial deformation of the cover plate 120 and the shell 110, thereby affecting product quality.

[0118] refer to Figure 4 In some embodiments, along the first direction ( Figure 1 (As shown in the X direction), the length I of the protrusion of the reinforcing convex portion 113 satisfies: 0.1mm ≤ I ≤ 0.3mm. For example, I can be 0.1mm, 0.2mm or 0.3mm, and of course, I can also be other values, which are not limited in this application.

[0119] By designing the protrusion length I of the reinforcing protrusion 113, two considerations are addressed: First, the protrusion length of the reinforcing protrusion 113 is avoided from being too small (e.g., less than 0.1 mm), which would result in a minimal thickening effect on the shell opening 112, a small increase in the contact area with the cover plate 120, and low connection strength between the cover plate 120 and the shell 110. This would make the cover plate 120 prone to bursting and flying out in the event of gas generation inside the battery 200. Second, the protrusion length of the reinforcing protrusion 113 is avoided from being too large (e.g., exceeding 0.3 mm), which would excessively encroach on the space within the receiving cavity 111, leading to a reduction in electrolyte within the battery 200 and affecting its performance. Furthermore, an excessively large protrusion length of the reinforcing protrusion 113 could also cause scratches and damage to the cell 210 during encapsulation within the battery 200, affecting product quality.

[0120] refer to Figure 3In some embodiments, along the opening direction of the shell opening 112 ( Figure 1 (As shown in the Z direction), the height J of the reinforcing protrusion 113 satisfies: 1mm ≤ J ≤ 8mm. For example, J can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm or 7mm. Of course, J can also be other values, which are not limited in this application.

[0121] By designing the height J of the reinforcing protrusion 113, two things are avoided: First, the height of the reinforcing protrusion 113 should not be too small (e.g., less than 1 mm), which would reduce the mating area between the cover plate 120 and the reinforcing protrusion 113, resulting in low connection strength between the cover plate 120 and the housing 110, making the cover plate 120 prone to bursting and flying out when gas is generated inside the battery 200. Second, the height of the reinforcing protrusion 113 should not be too large (e.g., exceeding 8 mm), which would excessively encroach on the space inside the receiving cavity 111, leading to a reduction in electrolyte inside the battery 200 and affecting the performance of the battery 200.

[0122] refer to Figure 11 In some embodiments, the reinforcing protrusion 113 is a continuous structure along the circumference of the opening 112. Thus, the reinforcing protrusion 113 can be an integral ring structure. The contact area between the reinforcing protrusion 113 and the cover plate 120 is large, which helps to improve the connection strength between the cover plate 120 and the housing 110, thereby improving the safety of the battery 200.

[0123] refer to Figure 12 In some embodiments, the reinforcing protrusion 113 is a discontinuous structure along the circumference of the housing opening 112. In other words, the reinforcing protrusion 113 may include a plurality of protrusions 1130, which are arranged at intervals along the circumference of the housing opening 112. Thus, gaps are formed between the protrusions 1130 along the circumference of the housing opening 112, which helps to increase the electrolyte storage space in the battery 200, so that the battery 200 stores enough electrolyte and thus has good performance.

[0124] refer to Figure 12 According to some embodiments of this application, the reinforcing protrusion 113 includes a plurality of protrusions 1130 distributed circumferentially along the shell opening 112, and the distance e between two adjacent protrusions 1130 is: 5mm ≤ e ≤ 80mm. Exemplarily, e can be 5mm, 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm or 80mm. Of course, e can also be other values, which are not limited in this application.

[0125] By designing the spacing e between two adjacent protrusions 1130, on the one hand, it avoids the spacing being too small (e.g., less than 5mm), which would limit the space for the electrolyte to be lifted. On the other hand, it avoids the spacing being too large (e.g., more than 80mm), which would reduce the contact area between the cover plate 120 and the housing 110, thereby reducing the connection strength between the cover plate 120 and the housing 110.

[0126] refer to Figure 12 According to some embodiments of this application, there is a gap between two adjacent protrusions 1130. Along the circumference of the opening 112, the ratio of the sum of the lengths E of the multiple gaps to the circumference L of the opening 112 is: 0.15 ≤ E / L ≤ 0.25. Exemplarily, E / L can be 0.15, 0.5, or 0.25. Of course, E / L can also be other values, which are not limited in this application.

[0127] By limiting the range of E / L, the size of the increased electrolyte storage space defined between the protrusions 1130 is reflected. On the one hand, if the E / L value is too small, the increased storage space is limited, and its contribution to maintaining the performance of the battery 200 is small. On the other hand, if the E / L value is too large, the contact area between the cover plate 120 and the reinforcing protrusion 113 is reduced, resulting in a decrease in the connection strength between the cover plate 120 and the housing 110.

[0128] refer to Figure 1 , Figure 11 and Figure 12 In some embodiments, the cover plate 120 is provided with an explosion-proof valve 123. When high-pressure gas is generated inside the battery 200, the explosion-proof valve 123 can be opened or ruptured to release the internal pressure of the battery 200, so that the cover plate 120 can withstand higher pressure.

[0129] The cover plate 120 is provided with a liquid injection hole 124. During the production process of the battery 200, liquid is injected into the receiving cavity 111 through an external liquid injection device. At this time, the liquid injection end of the liquid injection device needs to abut against the cover plate 120. Therefore, the cover plate 120 is required to have higher connection strength.

[0130] K, C, and D satisfy the condition: 800 MPa ≤ K×C / D ≤ 2000 MPa. For example, K×C / D can be 800 MPa, 900 MPa, 1000 MPa, 1100 MPa, 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600 MPa, 1700 MPa, 1800 MPa, 1900 MPa, or 2000 MPa. Of course, K×C / D can also be other values, and this application does not limit this. By increasing the lower limit of K×C / D, in other words, by increasing the lower limits of K and C / D, the bonding wire 130 can have sufficient strength, thereby ensuring sufficient connection strength between the cover plate 120 and the housing 110.

[0131] refer to Figure 11 and Figure 12 According to some embodiments of this application, an explosion-proof valve 123 is provided on the cover plate 120, and the distance M between the explosion-proof valve 123 and the reinforcing protrusion 113 satisfies: 5mm≤M≤30mm. Exemplarily, M can be 5mm, 10mm, 15mm, 20mm, 25mm or 30mm. Of course, M can also be other values, which are not limited in this application.

[0132] On the one hand, it avoids the distance between the explosion-proof valve 123 and the reinforcing protrusion 113 being too small (e.g., less than 5mm), which would reduce the electrolyte storage space, leading to a decrease in electrolyte and affecting the performance of the battery 200. On the other hand, it avoids the distance between the explosion-proof valve 123 and the reinforcing protrusion 113 being too large (e.g., more than 30mm). In other words, it avoids the thickness of the reinforcing protrusion 113 being too small, which would result in a weak connection strength between the cover plate 120 and the housing 110, thus helping to prevent the cover plate 120 from bursting and flying out.

[0133] refer to Figure 11 and Figure 12 According to some embodiments of this application, the cover plate 120 is provided with an injection hole 124, and the distance N between the injection hole 124 and the reinforcing protrusion 113 satisfies: 15mm≤N≤35mm. Exemplarily, N can be 15mm, 20mm, 25mm, 30mm or 35mm. Of course, N can also be other values, which are not limited in this application.

[0134] On the one hand, it avoids the distance between the injection hole 124 and the reinforcing protrusion 113 being too small (e.g., less than 15mm), which would reduce the electrolyte storage space, leading to a decrease in electrolyte and affecting the performance of the battery 200. On the other hand, it avoids the distance between the injection hole 124 and the reinforcing protrusion 113 being too large (e.g., more than 35mm). In other words, it avoids the reinforcing protrusion 113 being too thin, which would result in a weak connection between the cover plate 120 and the housing 110, thus helping to prevent the cover plate 120 from bursting and flying out.

[0135] refer to Figure 10 In some embodiments, cell 210 includes components along a second direction ( Figure 1 The distance O between the two large surfaces (in the Y direction shown) and the inner wall of the receiving cavity 111 satisfies: 0 ≤ O ≤ 2 mm. For example, O can be 0.1 mm, 0.5 mm, 1 mm, 1.5 mm or 2 mm. Of course, O can also be other values, which are not limited in this application.

[0136] This ensures that the distance O between the large surface and the inner wall of the cavity 111 has a suitable spacing size, avoiding the small thickness of the reinforcing protrusion 113, which would result in a weak connection strength between the cover plate 120 and the housing 110, and helps to prevent the cover plate 120 from bursting out.

[0137] refer to Figure 4 In some embodiments, the reinforcing protrusion 113 includes a portion along the opening direction of the housing opening 112 ( Figure 1 The first end 1131 (in the Z direction shown) faces the cavity 111. The battery cell 210 includes a tab lead-out surface opposite to the shell opening 112. The tab lead-out surface is provided with tabs, which may include a positive tab and a negative tab. The positive and negative tabs are respectively connected to the positive and negative plates of the battery cell body. The tabs are the current inlet and outlet during the battery charging and discharging process, responsible for conducting the electrical energy of the battery cell 210 to an external circuit, or vice versa, inputting electrical energy into the battery cell 210 for storage. The distance P between the root of the tab and the first end 1131 satisfies: 0.5mm ≤ P ≤ 5mm. For example, P can be 0.5mm, 1mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm. Of course, P can also be other values, which are not limited in this application.

[0138] By designing the spacing between the base of the tab and the first end 1131, two things are addressed: First, the spacing between the base of the tab and the first end 1131 is avoided from being too small. In this case, the reinforcing protrusion 113 would be too close to the cell 210, easily scratching the cell 210. At the same time, the reinforcing protrusion 113 being too close to the cell 210 could easily obstruct the gas flow inside the battery 200, affecting the pressure relief effect. Second, the spacing between the reinforcing protrusion 113 and the tab lead-out surface of the cell 210 is avoided from being too large, resulting in a smaller space occupied by the cell 210 inside the casing 110, leading to poor space utilization of the casing 110.

[0139] In some embodiments, 1.1 ≤ C / D ≤ 1.3. For example, C / D can be 1.1, 1.2 or 1.3. Of course, C / D can also be other values, which are not limited in this application.

[0140] C / D represents the thickness at the opening 112. On one hand, a C / D that is too small would result in insufficient thickness at the opening 112, leading to a small contact area between the cover plate 120 and the housing 110, resulting in weak connection strength and making the cover plate 120 prone to bursting and flying out under high internal pressure in the battery 200. On the other hand, a C / D that is too large would result in excessive thickness at the opening 112, causing the reinforcing protrusion 113 to occupy a large space in the receiving cavity 111, reducing the electrolyte capacity within the battery 200 and affecting its performance.

[0141] Wherein, 0.3mm≤C≤1mm, for example, C can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm. Of course, C can also be other values, which are not limited in this application.

[0142] This ensures that the opening 112 has a suitable thickness, providing good connection strength between the cover plate 120 and the housing 110, while preventing the reinforcing protrusion 113 from encroaching on too much of the internal space of the battery 200, thus ensuring that the battery 200 contains enough electrolyte and reducing the impact on the performance of the battery 200.

[0143] 0.15mm ≤ D ≤ 0.18mm, for example, D can be 0.15mm, 0.16mm, 0.17mm or 0.18mm, and of course, D can also be other values, which are not limited in this application. This makes the casing 110 have a suitable thickness, which meets the strength requirements of the battery 200 while saving materials and reducing production costs.

[0144] In some embodiments, 82MPa≤K≤1000MPa. For example, K can be 82 MPa, 200 MPa, 400 MPa, 600 MPa, 800 MPa or 1000 MPa. Of course, K can also be other values, which are not limited in this application.

[0145] By designing the strength K of the welding wire 130, on the one hand, it avoids the situation where the strength of the welding wire 130 is too small, resulting in a low connection strength between the cover plate 120 and the shell 110, which could lead to the cover plate 120 exploding and flying out during the use of the battery 200. On the other hand, the greater the welding strength, the higher the required process requirements. For the sake of production cost considerations, the strength K of the welding wire 130 should not be too large.

[0146] refer to Figure 7 and Figure 8In some embodiments, the cover plate 120 includes a base portion 120a and an assembly portion 120b connected sequentially along the opening direction of the housing opening 112. The projection of the housing opening 112 in the reference plane is inside the projection of the base portion 120a in the reference plane. In other words, above the battery 200, the base portion 120a covers the housing opening 112.

[0147] The base portion 120a is welded to the end face of the shell opening 112 of the housing 110 to form a weld line 130. The assembly portion 120b extends into the shell opening 112 and is arranged opposite to the reinforcing protrusion 113. At this time, the weld line 130 is located on the side of the housing 110. When abnormal gas filling occurs inside the battery 200, the gas pressure mainly acts along the Z direction on the first end face 122 of the assembly portion 120b of the cover plate 120. The gas pressure on the weld line 130 is small, and the fixing effect between the cover plate 120 and the housing 110 is good.

[0148] Furthermore, K, C, and D satisfy the condition: 800 MPa ≤ K×C / D ≤ 1800 MPa. For example, K×C / D can be 800 MPa, 900 MPa, 1000 MPa, 1100 MPa, 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600 MPa, 1700 MPa, or 1800 MPa. Of course, K×C / D can also be other values, and this application does not limit this.

[0149] With the welding wire 130 located on the peripheral wall of the housing 110, the welding wire 130 is subjected to less gas pressure. Under the premise of ensuring that the welding wire 130 has sufficient strength, the upper limit of the thickness of the reinforcing protrusion 113 is limited to avoid the thickness of the reinforcing protrusion 113 being too large, so that there is sufficient electrolyte storage space in the housing 110, which is beneficial to maintaining the performance of the battery 200.

[0150] refer to Figure 13 In some embodiments, the cover plate 120 is located inside the reinforcing protrusion 113, and the periphery of the cover plate 120 is welded to the inner wall of the reinforcing protrusion 113. In this case, the welding line 130 is located at the junction of the top surface of the cover plate 120 along the Z direction and the reinforcing protrusion 113. Under the same material conditions, the storage space inside the battery 200 is larger, which is beneficial to maintaining the performance of the battery 200.

[0151] According to some embodiments of this application, K, C, and D satisfy the following condition: 1200 MPa ≤ K×C / D ≤ 2000 MPa. Exemplarily, K×C / D can be 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600 MPa, 1700 MPa, 1800 MPa, 1900 MPa, or 2000 MPa. Of course, K×C / D can also be other values, and this application does not limit this.

[0152] The welding line 130 is located at the junction of the top surface of the cover plate 120 along the Z direction and the reinforcing protrusion 113. The welding line 130 is greatly affected by the gas pressure inside the housing 110, and the connection strength at the connection between the cover plate 120 and the housing 110 needs to be sufficiently large. Therefore, it is necessary to increase the lower limit value of K×C / D, in other words, increase the lower limit of C / D, so as to ensure that there is sufficient connection strength between the cover plate 120 and the housing 110.

[0153] Furthermore, 1.1≤C / D≤1.3. For example, C / D can be 1.1, 1.2 or 1.3. Of course, C / D can also be other values, which are not limited in this application.

[0154] C / D represents the thickness at the opening 112. On one hand, a C / D that is too small would result in insufficient thickness at the opening 112, leading to a small contact area between the cover plate 120 and the housing 110, resulting in weak connection strength and making the cover plate 120 prone to bursting and flying out under high internal pressure in the battery 200. On the other hand, a C / D that is too large would result in excessive thickness at the opening 112, causing the reinforcing protrusion 113 to occupy a large space in the receiving cavity 111, reducing the electrolyte capacity within the battery 200 and affecting its performance.

[0155] 0.3mm≤C≤1mm, for example, C can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm. Of course, C can also be other values, which are not limited in this application.

[0156] This ensures that the opening 112 has a suitable thickness, providing good connection strength between the cover plate 120 and the housing 110, while preventing the reinforcing protrusion 113 from encroaching on too much of the internal space of the battery 200, thus ensuring that the battery 200 contains enough electrolyte and reducing the impact on the performance of the battery 200.

[0157] 0.15mm ≤ D ≤ 0.18mm, for example, D can be 0.15mm, 0.16mm, 0.17mm or 0.18mm, and of course, D can also be other values, which are not limited in this application. This makes the casing 110 have a suitable thickness, which meets the strength requirements of the battery 200 while saving materials and reducing production costs.

[0158] Furthermore, 150MPa≤K≤1000MPa. For example, K can be 150 MPa, 200 MPa, 400 MPa, 600 MPa, 800 MPa or 1000 MPa. Of course, K can also be other values, which are not limited in this application.

[0159] By designing the strength K of the welding wire 130, on the one hand, it avoids the welding wire 130 being too weak, resulting in a low connection strength between the cover plate 120 and the housing 110, which could lead to the cover plate 120 exploding and flying out during use. On the other hand, the higher the welding strength, the higher the required process requirements; therefore, for production cost considerations, the strength K of the welding wire 130 should not be too high. In this embodiment, since the welding wire 130 is located at the junction of the top surface of the cover plate 120 along the Z direction and the reinforcing protrusion 113, the required strength of the welding wire 130 is higher.

[0160] Secondly, embodiments of this application provide an electrical device including the battery 200 described above.

[0161] The electrical equipment of this application, due to the use of the aforementioned battery 200, will not have its cover 120 explode during use, which is beneficial to improving the safety of the electrical equipment.

[0162] The solution of this application is further illustrated below through several embodiments:

[0163] Example 1: The wire bond strength is 86 MPa, the thickness C of the shell at the reinforcing protrusion is 0.3 mm, the shell thickness is 0.27 mm, C / D is 1.11, and the value of K × C / D is 95.46.

[0164] Example 2: The wire bond strength is 250 MPa, the thickness C of the shell at the reinforcing protrusion is 1 mm, the shell thickness is 0.7 mm, C / D is 1.43, and the value of K × C / D is 357.5.

[0165] Example 3: The wire bonding strength is 500 MPa, the thickness C of the shell at the reinforcing protrusion is 0.45 mm, the shell thickness is 0.15 mm, C / D is 3.0, and the value of K × C / D is 1500.

[0166] Example 4: The wire bonding strength is 750 MPa, the thickness C of the shell at the reinforcing protrusion is 0.92 mm, the shell thickness is 0.8 mm, C / D is 1.15, and the value of K × C / D is 862.5.

[0167] Example 5: The wire bond strength is 82 MPa, the thickness C of the shell at the reinforcing protrusion is 0.8 mm, the shell thickness is 0.32 mm, C / D is 2.50, and the value of K × C / D is 205.

[0168] Example 6: The wire bonding strength is 1000MPa, the thickness C of the shell at the reinforcing protrusion is 0.75mm, the shell thickness is 0.28mm, C / D is 2.68, and the value of K × C / D is 2680.

[0169] Example 7: The wire bond strength is 650 MPa, the thickness C of the shell at the reinforcing protrusion is 0.6 mm, the shell thickness is 0.17 mm, C / D is 3.52, and the value of K × C / D is 2288.

[0170] Example 8: The wire bond strength is 40 MPa, the thickness C of the shell at the reinforcing protrusion is 0.6 mm, the shell thickness is 0.21 mm, C / D is 2.86, and the value of K × C / D is 114.4.

[0171] Comparative Example 1: The wire bond strength is 50 MPa, the thickness C of the shell at the reinforcing protrusion is 0.5 mm, the shell thickness is 0.48 mm, C / D is 1.04, and the value of K × C / D is 52.00.

[0172] Comparative Example 2: The wire bond strength is 800 MPa, the thickness C of the shell at the reinforcing protrusion is 1.12 mm, the shell thickness is 0.28 mm, C / D is 4.0, and the value of K × C / D is 3200.

[0173] The experimental results are shown in the table below:

[0174]

[0175] Based on the table above and referring to Examples 1-8 and Comparative Examples 1 and 2, it can be seen that by controlling the value of K×C / D within a suitable range, the welding stability between the cover plate 120 and the shell opening 112 can be effectively improved, preventing the cover plate 120 from exploding and flying out when the battery 200 experiences thermal runaway, thereby improving the safety of the battery 200.

[0176] Referring to Examples 1-6, Example 7, and Comparative Example 2, it can be seen that by controlling the C / D ratio of the protrusion of the reinforcing protrusion 113 relative to the housing 110, scratches can be avoided when the cell 210 is encapsulated in the housing 110, thereby improving the safety of the battery 200.

[0177] Referring to Examples 1-6, Example 8, and Comparative Example 1, it can be seen that the strength value of the welding wire 130 is directly related to the welding stability of the cover plate 120. If the strength of the welding wire 130 is too low, the welding stability of the cover plate 120 is poor. When abnormal inflation occurs in the battery 200, the cover plate 120 is prone to burst and fly out.

[0178] The parameter testing methods involved in this application are described below:

[0179] The test method for the strength K of wire bonding 130 is as follows:

[0180] 1. Cut a portion of the bonding wire 130 to obtain a sample with a width of 10mm and a length of 100mm;

[0181] 2. The tensile strength of the sample is tested using a tensile testing machine;

[0182] 3. Finally, the fracture location is obtained and the tensile strength value is fed back.

[0183] Cover plate 120 ejection test: A thermal runaway test is performed on the battery 200 to observe whether the cover plate 120 and the casing 110 separate. The thermal runaway test is as follows:

[0184] 1. Charge the battery. The specific charging strategies for nickel-cobalt-manganese ternary cathode materials, lithium iron phosphate cathode materials, lithium manganese iron phosphate cathode materials, lithium-rich manganese-based cathode materials, and lithium nickel manganese oxide cathode materials are as follows: Nickel-cobalt-manganese ternary cathode materials are charged at 1C to 4.25V, and then charged at a constant voltage until the current drops to 0.05C; lithium iron phosphate cathode materials are charged at a constant current of 0.5C to 3.65V, and then charged at a constant voltage until the current drops to 0.05C; lithium manganese iron phosphate cathode materials are charged at 0.5C to 4.25V, and then charged at a constant voltage until the current drops to 0.05C; lithium-rich manganese-based cathode materials are charged at 0.5C to 4.25V, and then charged at a constant voltage until the current drops to 0.05C; lithium nickel manganese oxide cathode materials are charged at 1C to 4.85V, and then charged at a constant voltage until the current drops to 0.05C.

[0185] 2. Place a heating element on the large surface of the battery to heat the triggering object at the maximum power of the heating device.

[0186] 3. When thermal runaway occurs or the temperature at the monitoring point reaches 300 ℃, stop triggering and shut down the heating device.

[0187] Furthermore, the criteria for determining thermal runaway are as follows: if the triggering object generates a voltage drop, and the drop value exceeds 25% of the initial voltage, and the temperature rise rate dT / dt at the monitoring point is ≥ 1 ℃ / s and lasts for more than 3s, then thermal runaway is determined to have occurred.

[0188] Test method for determining whether the 210 battery cell is scratched:

[0189] 1. Observe whether the insulating film wrapped around the outside of the battery cell 210 is damaged when the battery cell 210 is inserted into the casing;

[0190] 2. Observe whether the electrode sheets fall off when the 210 battery cell is inserted into the casing.

[0191] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0192] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0193] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0194] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0195] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery comprising a housing, characterized in that The outer casing includes: A housing having a receiving cavity for accommodating a battery cell, wherein at least one end of the housing has a shell opening communicating with the receiving cavity, and a portion of the inner wall at the shell opening protrudes toward the receiving cavity to form a reinforcing protrusion; A cover plate is provided to seal the opening of the shell. At least a portion of the structure of the cover plate extends into the inner side of the opening to form an assembly portion. The sidewall of the assembly portion and the reinforcing protrusion are arranged opposite to each other in the X direction. The reinforcing protrusion abuts against the sidewall of the assembly portion. The cover plate is welded to the reinforcing protrusion of the shell to form a weld line. Along the opening direction of the shell opening, the height J of the reinforcing protrusion satisfies: 1mm≤J≤8mm; The weld strength of the weld wire is K, the thickness of the housing at the reinforcing protrusion is C, and the thickness of the housing in the area outside the reinforcing protrusion is D, wherein K, C, and D satisfy: 95 MPa ≤ K × C / D ≤ 2700 MPa.

2. The battery of claim 1, wherein, K, C, and D satisfy the condition: 95 MPa ≤ K × C / D ≤ 2000 MPa.

3. The battery according to claim 1, characterized in that, The reinforcing protrusion is spaced apart from the side wall of the assembly part.

4. The battery according to claim 3, characterized in that, K, C, and D satisfy the condition: 800 MPa ≤ K × C / D ≤ 2700 MPa.

5. The battery according to claim 3, characterized in that, The distance A between the reinforcing protrusion and the sidewall of the assembly part satisfies: 0mm≤A≤0.1mm.

6. The battery according to any one of claims 1-5, characterized in that, The cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening. The reinforcing protrusion includes a first end that faces into the receiving cavity along the opening direction of the shell opening. The first end face does not extend beyond the first end, facing the direction of the opening of the shell opening toward the receiving cavity.

7. The battery according to any one of claims 1-5, characterized in that, The cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening. The reinforcing protrusion includes a first end that faces into the receiving cavity along the opening direction of the shell opening. The first end face is flush with the first end along the opening direction of the shell opening toward the receiving cavity.

8. The battery according to any one of claims 1-5, characterized in that, The cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening. The reinforcing protrusion includes a first end that faces into the receiving cavity along the opening direction of the shell opening. The first end face is higher than the first end face in the direction of the opening of the shell opening toward the receiving cavity.

9. The battery according to claim 8, characterized in that, The height difference B between the first end face and the first end satisfies: 0.5mm≤B≤4mm.

10. The battery according to any one of claims 1-5, characterized in that, The cover plate includes a first end face facing into the receiving cavity along the opening direction of the shell opening. The reinforcing protrusion includes a first end that faces into the receiving cavity along the opening direction of the shell opening. The first end face extends beyond the first end, in the direction of the opening of the shell opening toward the receiving cavity.

11. The battery according to claim 10, characterized in that, The distance F that the first end face extends beyond the first end satisfies: 0.5mm ≤ F ≤ 2mm.

12. The battery according to any one of claims 1-5, characterized in that, The reinforcing protrusion includes a first corner portion facing away from the receiving cavity along the opening direction of the shell opening. The first corner is a right angle.

13. The battery according to claim 12, characterized in that, K, C, and D satisfy the condition: 800 MPa ≤ K × C / D ≤ 1800 MPa.

14. The battery according to any one of claims 1-5, characterized in that, The reinforcing protrusion includes a first corner portion facing away from the receiving cavity along the opening direction of the shell opening. The first corner is rounded.

15. The battery according to claim 14, characterized in that, K, C, and D satisfy the condition: 1000 MPa ≤ K × C / D ≤ 2000 MPa.

16. The battery according to claim 14, characterized in that, The radius r of the first corner is: 1mm ≤ r ≤ 3mm.

17. The battery according to any one of claims 1-5, characterized in that, The reinforcing protrusion includes a first end that faces into the receiving cavity along the opening direction of the shell opening. The length of the first end along the first direction is G, and the length of the shell opening end face along the first direction is H. G and H satisfy: G < H, and / or, 0.2 mm ≤ HG ≤ 0.8 mm. The first direction is perpendicular to the opening direction of the shell opening.

18. The battery according to any one of claims 1-5, characterized in that, The weld line extends along the penetration direction and includes a weld top and a weld root. The width of the weld top is T, and the width of the weld root is t. t and T satisfy: 0.15 ≤ t / T ≤ 1.

2.

19. The battery according to any one of claims 1-5, characterized in that, Along the first direction, the length I of the reinforcing protrusion is such that: 0.1mm≤I≤0.3mm.

20. The battery according to any one of claims 1-5, characterized in that, The reinforcing protrusion is a continuous structure along the circumference of the shell opening.

21. The battery according to any one of claims 1-5, characterized in that, Along the circumferential direction of the shell opening, the reinforcing protrusion has a discontinuous structure.

22. The battery according to claim 21, characterized in that, The reinforcing protrusion includes a plurality of protrusions spaced circumferentially along the shell opening, and the distance e between two adjacent protrusions is: 5mm≤e≤80mm.

23. The battery according to claim 22, characterized in that, There is a gap between two adjacent protrusions, and the ratio of the sum of the lengths E of the multiple gaps to the circumference L of the shell opening is: 0.15≤E / L≤0.

25.

24. The battery according to any one of claims 1-5, characterized in that, The cover plate is equipped with an explosion-proof valve; and / or, the cover plate is equipped with a liquid injection hole. K, C, and D satisfy the condition: 800 MPa ≤ K × C / D ≤ 2000 MPa.

25. The battery according to claim 24, characterized in that, The cover plate is equipped with an explosion-proof valve, and the distance M between the explosion-proof valve and the reinforcing protrusion satisfies: 5mm≤M≤30mm.

26. The battery according to claim 24, characterized in that, The cover plate is provided with an injection hole, and the distance N between the injection hole and the reinforcing protrusion satisfies: 15mm≤N≤35mm.

27. The battery according to any one of claims 1-5, characterized in that, The battery cell includes two large surfaces along the second direction, and the distance O between the large surfaces and the inner wall of the receiving cavity satisfies: 0≤O≤2mm.

28. The battery according to any one of claims 1-5, characterized in that, The reinforcing protrusion includes a first end that faces into the receiving cavity along the opening direction of the shell opening. The battery cell includes a tab lead-out surface opposite to the casing opening, and the tab lead-out surface is provided with tabs. The distance P between the root of the electrode and the first end satisfies: 0.5mm ≤ P ≤ 5mm.

29. The battery according to any one of claims 1-5, characterized in that, 1.1≤C / D≤1.3; and / or, 0.3mm≤C≤1mm; and / or, 0.15mm≤D≤0.18mm.

30. The battery according to any one of claims 1-5, characterized in that, 82MPa≤K≤1000MPa.

31. The battery according to any one of claims 1-5, characterized in that, The cover plate includes a base portion and an assembly portion sequentially connected along the opening direction of the shell opening. The projection of the shell opening in the reference plane is located inside the projection of the base portion in the reference plane. The base portion is welded to the end face of the shell opening of the housing to form the weld line. The assembly part extends into the shell opening and is arranged opposite to the reinforcing protrusion.

32. The battery according to claim 31, characterized in that, K, C, and D satisfy the condition: 800 MPa ≤ K × C / D ≤ 1800 MPa.

33. The battery according to any one of claims 1-5, characterized in that, The cover plate is located inside the reinforcing protrusion, and the periphery of the cover plate is welded to the inner wall of the reinforcing protrusion.

34. The battery according to claim 33, characterized in that, K, C, and D satisfy: 1200 MPa ≤ K × C / D ≤ 2000 MPa.

35. The battery according to claim 33, characterized in that, 1.1≤C / D≤1.3; and / or, 0.3mm≤C≤1mm; and / or, 0.15mm≤D≤0.8mm.

36. The battery according to claim 35, characterized in that, 150MPa≤K≤1000MPa.

37. An electrical appliance, characterized in that, The battery includes any one of claims 1-36.

Images