Shell, battery, battery pack and electric device

Abstract

The utility model relates to the technical field of batteries, and provides a shell, a battery, a battery pack and a power utilization device.The shell comprises a top cover and a shell body, the shell body is provided with a containing cavity and a top side opening communicated with the containing cavity, the top end of the shell body is turned over towards the containing cavity to form a turned-over edge, and the top cover covers the top side opening; and the turned-over edge is overlapped on the top side of the top cover and is welded with the top cover. According to the shell provided by the embodiment of the invention, the welding seam between the top cover and the shell is located on the top surface of the top cover, so that the cracking risk of the shell can be reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a housing, a battery, a battery pack and an electrical device. Background Art

[0002] In the related art, the battery includes a shell and a bare cell contained in the shell. The shell includes a top cover and a shell. The top cover is placed on the top of the shell and welded to the shell. When the bare cell expands or produces gas, the shell is deformed by force, and the weld cracks, causing battery leakage and posing safety risks. Utility Model Content

[0003] In view of this, the embodiments of the present application hope to provide a housing, a battery, a battery pack and an electrical device that can reduce the risk of cracking of the housing.

[0004] In a first aspect, an embodiment of the present application provides a housing for a battery, comprising:

[0005] Top cover;

[0006] The shell is formed with a receiving cavity and a top opening connected to the receiving cavity, the top end of the shell is folded toward the receiving cavity to form a flange, the top cover is arranged on the top opening, the flange is overlapped on the top side of the top cover and welded to the top cover.

[0007] The shell provided in the embodiment of the present application is folded toward the receiving cavity to form a flange, the flange is superimposed on the top cover and welded to the top cover, and the weld between the top cover and the shell is located on the top surface of the top cover. By changing the position of the weld, the load-bearing type of the heat-affected zone is converted from shear stress to tensile stress, thereby optimizing the stress form of the shell, reducing the risk of cracking of the shell, and improving the safety of the shell.

[0008] In some embodiments, the periphery of the top surface of the top cover is recessed toward the accommodating cavity to form a welding portion, the welding portion having a supporting surface facing the top side and a first welding surface connected to the supporting surface, the flange having a second welding surface facing the first welding surface, the flange being superimposed on the supporting surface, and the first welding surface and the second welding surface being welded correspondingly.

[0009] In this embodiment, the flange can be quickly positioned at the welding portion. At the same time, since the weld is located at the periphery of the top surface of the top cover, the visual effect is good, which is convenient for operators to weld, thereby improving the welding efficiency and finished product quality of the shell. In addition, since the flange is superimposed on the support surface and is not only fixed by welding, the connection stability between the top cover and the shell can be further enhanced, reducing the risk of cracking of the shell.

[0010] In some embodiments, in the top-bottom direction, the height of the first welding surface is not less than the height of the second welding surface.

[0011] In this embodiment, on the one hand, it is convenient to fold the top end of the shell to form a flange; on the other hand, it prevents the flange from forming a sharp protrusion on the periphery of the top surface, thereby improving the safety of the shell.

[0012] In some embodiments, the width of the support surface along the radial direction is between 2 mm and 6 mm.

[0013] In this embodiment, the width of the supporting surface 111 a is appropriately set to adapt to the size of the heat-affected zone when different materials and different welding processes are used.

[0014] In some embodiments, the radial width of the support surface is not less than the radial width of the flange.

[0015] In this embodiment, the flange is integrally stacked on the support surface. At the same time, the inner wall surface of the shell can also be closely attached to the side surface of the top cover, thereby reducing the gap, improving the connection stability between the top cover and the shell, and enhancing the airtightness of the shell.

[0016] In some embodiments, the shell includes a bottom wall and four side walls, and the four side walls are arranged around the bottom wall to form the receiving cavity and the top opening. Any two adjacent side walls are connected by rounded corners, and the top of each rounded corner has a notch so that the top of the four side walls can be folded toward the receiving cavity to form the flange.

[0017] In this embodiment, the use of rounded corners to connect the side walls is beneficial to the safety of the shell. The rounded corners are relatively smooth and have a certain area, which is convenient for opening a gap.

[0018] In some embodiments, a plane perpendicular to the top and bottom directions is used as a projection plane, and the projection of the shell on the projection plane is a rounded quadrilateral, and the total arc length corresponding to all the notches is not less than the difference between the perimeter of the rounded quadrilateral and the perimeter of the flange.

[0019] In this embodiment, after the top ends of two adjacent side walls are folded, they do not overlap at the rounded corners to produce a gap, that is, the flange does not form a local sharp protrusion, thereby improving the safety and sealing of the housing.

[0020] In some embodiments, in the top and bottom directions, the height of the notch is equal to the width of the flange.

[0021] In this embodiment, no hole is formed at the top of the rounded corner, which can prevent the electrolyte from overflowing and improve the sealing performance of the housing.

[0022] A second aspect of an embodiment of the present application provides a battery, comprising:

[0023] Bare battery cells;

[0024] In the housing described in any one of the above items, the bare battery cell is accommodated in the receiving cavity.

[0025] The battery disclosed in the embodiment of the present application has good safety performance because the welding joint between the top cover and the shell is not easy to crack, thereby improving the safety of the battery and extending the service life of the battery.

[0026] A third aspect of an embodiment of the present application provides a battery pack, comprising the battery as described above.

[0027] A fourth aspect of an embodiment of the present application provides an electrical device, comprising a battery pack for providing electrical energy as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of welding of the top cover and the shell in the related art;

[0029] Figure 2 A schematic diagram of the structure of a housing provided in some embodiments of the present application;

[0030] Figure 3 For this application Figure 2 Enlarged view of point A in the middle;

[0031] Figure 4 A schematic diagram of the structure of a top cover provided in some embodiments of the present application;

[0032] Figure 5 For this application Figure 4 Enlarged view of point B in the middle;

[0033] Figure 6 A schematic diagram of the structure of a housing provided in some embodiments of the present application;

[0034] Figure 7 For this application Figure 6 Schematic diagram of the structure in the first perspective;

[0035] Figure 8 For this application Figure 7 Enlarged view of point D in the middle;

[0036] Fig. 9 A schematic diagram of the structure of a housing provided in some embodiments of the present application from another perspective;

[0037] Fig.10 For this application Fig. 9 Enlarged view of point E in the middle;

[0038] Fig.11 A schematic diagram of the structure of a housing provided in some other embodiments of the present application at another viewing angle;

[0039] Fig.12 For this application Fig.11 Enlarged view of point F in the middle.

[0040] Description of Reference Numerals

[0041] Shell 10; top cover 11; welding portion 111; supporting surface 111a; first welding surface 111b; shell 12; accommodating cavity 12a; top opening 12b; heat-affected zone 12c; flange 121; second welding surface 121a; side wall 122; bottom wall 123; fillet 124; notch 124a. DETAILED DESCRIPTION

[0042] The following is a further detailed description of the implementation of the present application in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

[0043] The various specific technical features and embodiments described in the specific implementation methods can be combined in any suitable manner unless there is any contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments in this application will not be described separately.

[0044] For related technologies, see Figure 1 The weld between the top cover 110 and the shell 120 is located on the side top surface of the shell 120. The weld and the heat-affected zone 120b are affected by the shear stress, which makes the shell 100 prone to cracking. The heat-affected zone 120b refers to an area formed between the molten metal and the unaffected metal when the metal absorbs the heat generated during the cutting or welding process. In this area, the metal is not melted, but the heat causes the microstructure of the metal to change, thereby reducing the strength of the metal.

[0045] Figure 1 In the figure, the dotted lines represent the welds, the top cover welding surface 110a, and the shell welding surface 120a.

[0046] In a first aspect, an embodiment of the present application provides a housing 10 for a battery. Figure 2 and Figure 3 The housing 10 includes a top cover 11 and a shell 12. The shell 12 is formed with a receiving cavity 12a and a top side opening 12b connected to the receiving cavity 12a. The top end of the shell 12 is folded toward the receiving cavity 12a to form a flange 121. The top cover 11 is covered with the top side opening 12b. The flange 121 is overlapped on the top side of the top cover 11 and welded to the top cover 11.

[0047] Figure 3 The dashed line indicates the weld.

[0048] Compared with the weld located on the top surface of the shell side in the related art, the shell 10 provided in the embodiment of the present application has a shell 12 that is folded toward the accommodating cavity 12a to form a flange 121, and the flange 121 is superimposed on the top cover 11 and welded to the top cover 11. The weld between the top cover 11 and the shell 12 is located on the top surface of the top cover 11. By changing the position of the weld, the load-bearing type of the heat-affected zone 12c is converted from shear stress to tensile stress, thereby optimizing the force form of the shell 10, reducing the risk of cracking of the shell 10, and improving the safety of the shell 10.

[0049] The top cover 11 and the housing 12 can both be made of metal. For example, the top cover 11 and the housing 12 can be made of aluminum. The tensile strength of aluminum is greater than the shear strength, which enhances the stability of the housing 10 and reduces the risk of cracking of the housing 10.

[0050] For some examples, see Figures 3 to 5 The periphery of the top surface of the top cover 11 is recessed toward the accommodating cavity 12a to form a welding portion 111, the welding portion 111 has a supporting surface 111a facing the top side and a first welding surface 111b connected to the supporting surface 111a, the flange 121 has a second welding surface 121a facing the first welding surface 111b, the flange 121 is superimposed on the supporting surface 111a, and the first welding surface 111b is correspondingly welded to the second welding surface 121a.

[0051] In this way, the flange 121 can be quickly positioned to the welding portion 111. At the same time, since the weld is located at the periphery of the top surface of the top cover 11, the visual effect is good, which is convenient for operators to weld, and improves the welding efficiency and finished product quality of the shell 10. In addition, since the flange 121 is superimposed on the support surface 111a and is not only fixed by welding connection, the connection stability of the top cover 11 and the shell 12 can be further enhanced, and the risk of cracking of the shell 10 is reduced.

[0052] For some examples, see Figure 2 and Figure 3 In the top-bottom direction, the height of the first welding surface 111b is not less than the height of the second welding surface 121a. That is, the wall thickness of the top of the shell 12 is smaller than the height of the depression of the top surface of the top cover 11, so that the flange 121 does not exceed the top surface of the other part of the top cover 11 that is not depressed. On the one hand, it is convenient to fold the top of the shell 12 to form the flange 121; on the other hand, it prevents the flange 121 from forming a sharp protrusion on the periphery of the top surface, thereby improving the safety of the shell 10.

[0053] For example, see Figure 3 The height of the first welding surface 111b is equal to the height of the second welding surface 121a. In this way, the entire top surface of the top cover 11 is relatively flat, and the shell 10 is overall regular, which is convenient for battery assembly.

[0054] For some examples, see Figure 3 , the radial width of the support surface 111a is between 2 mm (millimeter) and 6 mm. For example, the radial width of the support surface 111a is D1, and the value of D1 can be 2 mm, 3 mm, 4 mm, 5 mm or 6 mm, etc. By setting a suitable width of the support surface 111a, the size of the heat-affected zone 12c when different materials and different welding processes are used can be adapted. For example, please continue to refer to Figure 3 The radial length D2 of the heat affected zone 12c is equal to 4mm, and D1 is 6mm. In this way, at least 2mm wide flange 121 whose structural strength is not affected by the heat affected zone 12c is superimposed on the supporting surface 111a, thereby improving the connection stability between the top cover 11 and the shell 12.

[0055] Figure 3 D1 represents the width of the support surface 111 a along the radial direction, and D2 represents the width of the heat-affected zone 12 c along the radial direction.

[0056] For some examples, see Figure 3 , the width of the support surface 111a in the radial direction is not less than the width of the flange 121 in the radial direction. In this way, the flange 121 is entirely superimposed on the support surface 111a, and at the same time, the inner wall surface of the shell 12 can also be closely attached to the side surface of the top cover 11, reducing the gap, improving the connection stability between the top cover 11 and the shell 12, and enhancing the airtightness of the housing 10.

[0057] Exemplarily, the radial width of the supporting surface 111 a is equal to the radial width of the flange 121 , so that the gap between the first welding surface 111 b and the second welding surface 121 a is small enough to facilitate welding connection.

[0058] For some examples, see Figures 6 to 8 The shell 12 includes a bottom wall 123 and four side walls 122. The four side walls 122 are arranged around the bottom wall 123 to form a receiving cavity 12a and a top opening 12b. Any two adjacent side walls 122 are connected by a rounded corner 124. The top of each rounded corner 124 has a notch 124a, so that the top of the four side walls 122 are folded toward the receiving cavity 12a to form a flange 121. In other words, the shell 12 is in a hexahedral shape, and the use of rounded corners 124 to connect the side walls 122 is beneficial to the safety of the shell 12. At the same time, since the rounded corners 124 are relatively smooth and have a certain area, it is convenient to open the notch 124a.

[0059] In some embodiments, the projection plane is a plane perpendicular to the top and bottom directions, and the projection of the housing 12 on the projection plane is a quadrilateral with rounded corners 124, and the total arc length corresponding to all the notches 124a is not less than the difference between the perimeter of the quadrilateral with rounded corners 124 and the perimeter of the flange 121. Fig. 9 and Fig.10The housing 10 has four fillets 124 and four corresponding notches 124a, the total arc length of the four notches 124a is L, the radius of the fillets 124 is R, the length of the housing 12 is A, the width of the housing 12 is B, the width of the flange 121 in the radial direction is C, and L≥2πR+2×(A+B-4R)-2×(A+B-4C) is satisfied. In this way, after the top ends of the two adjacent side walls 122 are folded, they do not overlap at the position of the fillets 124, resulting in a gap, that is, the flange 121 does not form a local sharp protrusion, thereby improving the safety and sealing of the housing 10.

[0060] Fig. 9 A represents the length of the housing 12, and B represents the width of the housing 12. Fig.10 R represents the radius of the fillet 124 , and C represents the width of the flange 121 along the radial direction.

[0061] It should be noted that the arc lengths of the four notches 124 a are all equal.

[0062] In some other embodiments, please refer to Fig.11 and Fig.12 , the above parameters satisfy L=2πR+2×(A+B-4R)-2×(A+B-4C). Exemplarily, the top ends of two adjacent side walls 122 are folded to form two sub-flanges 121, and the two sub-flanges 121 fit tightly together. In this way, the welding surfaces of the four sub-flanges 121 are welded in sequence, and the notches 124a are closed, so that the flanges 121 form a whole, which is beneficial to the complete transmission of stress and strain along the flanges 121, and no stress concentration occurs at the fillet 124, thereby improving the safety and stability of the housing 10 and further reducing the risk of cracking of the housing 10.

[0063] Fig.11 A represents the length of the housing 12, and B represents the width of the housing 12. Fig.12 R represents the radius of the fillet 124 , and C represents the width of the flange 121 along the radial direction.

[0064] For some examples, see Figure 7 and Figure 8 In the top and bottom directions, the height of the notch 124a is equal to the width of the flange 121. In this way, after the top cover 11 and the housing 12 are welded together, no hole is formed at the top of the fillet 124, which can prevent the electrolyte from overflowing and improve the sealing of the housing 10.

[0065] Figure 8 C represents the height of the shell 12 along the top-bottom direction when the top is not folded, that is, the width of the flange 121 along the radial direction, and H represents the height of the notch 124a along the top-bottom direction.

[0066] The second aspect of the embodiment of the present application provides a battery, comprising a bare cell and a housing 10 in any one of the embodiments of the present application, wherein the bare cell is accommodated in a receiving cavity 12a. The bare cell is an energy storage structure of the battery.

[0067] The battery disclosed in the embodiment of the present application has good safety performance because the welding joint between the top cover 11 and the shell 12 is not easy to crack, thereby improving the safety of the battery and extending the service life of the battery.

[0068] The battery may be a secondary battery, which refers to a battery that can be recharged to activate the active material after the battery is discharged and can be used continuously.

[0069] Exemplarily, the battery may further include an electrolyte, which is located in the receiving chamber 12a. The bare cell includes a positive electrode sheet, a negative electrode sheet, and a separator, and active ions in the electrolyte migrate between the positive electrode sheet and the negative electrode sheet to achieve charging and discharging. The separator is arranged between the positive electrode sheet and the negative electrode sheet, which can prevent short circuits and allow active ions to pass through.

[0070] The bare cell is provided with a tab, which can lead the current from the electrode assembly. The tab includes a positive tab and a negative tab, the positive tab is connected to the positive electrode sheet, and the negative tab is connected to the negative electrode sheet.

[0071] In some embodiments, at least one electrode terminal is provided on the housing 12 or the top cover 11, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or indirectly connected to the tab through a transition component. The electrode terminal can be provided on the top cover 11 or on the housing 12. The electrode terminal is used to be electrically connected to an external circuit.

[0072] The battery may further include an insulating film, which covers the outer surface of the housing 10. The insulating film is used to play an insulating role and can also protect the surface of the housing 10 from being scratched.

[0073] Illustratively, the batteries provided in the embodiments of the present application include but are not limited to lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries or magnesium ion batteries, etc.

[0074] A third aspect of the embodiments of the present application provides a battery pack, comprising the battery in any one of the embodiments of the present application.

[0075] The battery pack includes at least one battery. The battery pack can be formed by placing at least two groups of batteries in a sealed box. This is beneficial to the safety and stability of the battery pack, and has more reliable dust and water resistance, so it can be used in harsher, humid, or even submerged environments.

[0076] For example, at least two batteries in a battery pack may be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that at least two batteries are connected in series and in parallel. At least two batteries may be directly connected in series, in parallel, or in a hybrid connection. Of course, at least two batteries may be first connected in series, in parallel, or in a hybrid connection to form a battery module, and at least two battery modules may then be connected in series, in parallel, or in a hybrid connection to form a whole.

[0077] The battery pack may further include other structures. For example, the battery pack may further include a busbar component for achieving electrical connection between at least two batteries.

[0078] A fourth aspect of the embodiments of the present application provides an electrical device, comprising a battery pack according to any one of the embodiments of the present application for providing electrical energy.

[0079] The electrical devices provided in the embodiments of the present application include, but are not limited to, energy storage systems, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0080] The housing 10 of the present embodiment of the present application is shown in FIG. Figures 2 to 12The housing 10 includes a top cover 11 and a shell 12. The peripheral edge of the top surface of the top cover 11 is recessed to form a welding portion 111. The welding portion 111 has a first welding surface 111b and a supporting surface 111a that are connected to each other. The shell 12 includes a bottom wall 123 and four side walls 122 arranged around the bottom wall 123 to form a receiving cavity 12a and a top opening 12b connected thereto. Two adjacent side walls 122 are connected by a fillet 124. The top ends of the four fillets 124 have notches 124a so that the four side walls 122 are folded toward the receiving cavity 12a to form a flange 121. The flange 121 has a second welding surface 121a. The top cover 11 is covered on the top opening 12b. The first welding surface 111b and the second welding surface 121a are correspondingly welded. The weld is located on the top surface of the top cover 11, which optimizes the stress form of the housing 10 and reduces the risk of cracking of the housing 10. In addition, in the top-bottom direction, the height of the first welding surface 111b is equal to the height of the second welding surface 121a; the height of the notch 124a along the top-bottom direction, the width of the support surface 111a along the radial direction, and the width of the flange 121 along the radial direction are equal; the difference between the total arc length corresponding to all notches 124a and the total arc length of the four fillets 124 is equal to the difference between the circumference of the shell 12 and the circumference of the flange 121. In this way, the top surface of the top cover 11 is flat, and no hole is formed at the top of the fillet 124 after the top of the shell 12 is folded, the flange 121 has no local sharp protrusions and the force form is optimized, the top cover 11 and the shell 12 are firmly connected, the stability of the shell 10 is increased, and the safety of the shell 10 is improved.

[0081] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments" and "exemplarily" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0082] The various embodiments / implementations provided in this application can be combined with each other without causing any contradiction. The above description is only a preferred embodiment of this application and is not intended to limit this application. For those skilled in the art, this application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. A housing for a battery, characterized in that: include: Top cover; The shell is formed with a receiving cavity and a top opening connected to the receiving cavity, the top end of the shell is folded toward the receiving cavity to form a flange, the top cover is arranged on the top opening, the flange is overlapped on the top side of the top cover and welded to the top cover.

2. The housing according to claim 1, characterized in that The periphery of the top surface of the top cover is recessed toward the accommodating cavity to form a welding portion, the welding portion has a supporting surface facing the top side and a first welding surface connected to the supporting surface, the flange has a second welding surface facing the first welding surface, the flange is overlapped on the supporting surface, and the first welding surface is welded correspondingly to the second welding surface.

3. The housing according to claim 2, characterized in that In the top and bottom directions, the height of the first welding surface is not less than the height of the second welding surface.

4. The housing according to claim 2, characterized in that The width of the support surface along the radial direction is between 2 mm and 6 mm.

5. The housing according to claim 2, characterized in that The width of the supporting surface along the radial direction is not less than the width of the flange along the radial direction.

6. The housing according to claim 1, characterized in that The shell includes a bottom wall and four side walls, the four side walls are arranged around the bottom wall to form the receiving cavity and the top opening, any two adjacent side walls are connected by rounded corners, and the top of each rounded corner has a notch so that the top of the four side walls can be folded toward the receiving cavity to form the flange.

7. The housing according to claim 6, characterized in that Taking the plane perpendicular to the top and bottom directions as the projection plane, the projection of the shell on the projection plane is a rounded quadrilateral, and the total arc length corresponding to all the notches is not less than the difference between the perimeter of the rounded quadrilateral and the perimeter of the flange.

8. The housing according to claim 6, characterized in that In the top and bottom directions, the height of the notch is equal to the width of the flange.

9. A battery, characterized in that: include: Bare battery cells; The housing according to any one of claims 1 to 8, wherein the bare battery cell is accommodated in the accommodating cavity.

10. A battery pack, characterized in that: A battery comprising the battery of claim 9.

11. An electrical device, characterized in that: The electrical device comprises the battery pack according to claim 10 for providing electrical energy.

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