Housing assembly, secondary battery and electric device

Abstract

The invention relates to the technical field of energy storage, in particular to a shell assembly, a secondary battery and an electric device. The shell assembly comprises a shell main body, a connecting piece, a first pole and an insulating part, and a first hole is formed in the surface of one side of the shell main body. The connecting piece comprises a protruding part and a connecting part, the connecting part is arranged on the side face, away from the containing cavity, of the shell body, the protruding part extends along the side away from the shell body, the protruding part is provided with a second hole, the central axis of the second hole is parallel to the first direction, the projection of the protruding part is located in the projection of the connecting part, and the projection of the first hole is located in the projection of the second hole. The first pole comprises an extending part and an external part, the extending part penetrates through the first hole and the second hole in the first direction and extends to the containing cavity, and the external part is located outside the containing cavity and is separated from the connecting piece; the end face, facing the shell body, of the external part is provided with an annular groove, the protruding part is located in the annular groove, and a gap is formed between the protruding part and the wall face of the annular groove. The insulating part fills and seals the gap, and the sealing performance of the insulating part is improved.

Description

Technical Field

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

[0002] Battery poles are a key component in batteries and mainly serve as connections. They convert the chemical energy inside the battery into electrical energy, thereby providing power to the external circuit. The positive pole is connected to the positive electrode of the battery, while the negative pole is connected to the negative electrode of the battery. The two cannot touch each other to avoid short circuit. Summary of the invention

[0003] The inventor has found through research that the pole of a hard shell thin cell has an unstable position and is prone to tilt, resulting in poor sealing effect. In view of this, the present application provides a shell assembly, a secondary battery and an electrical device, which can improve the sealing effect of the pole.

[0004] In the first aspect, an embodiment of the present application provides a shell assembly, including a shell body, a connecting piece, a first pole and an insulating member, wherein the shell body has a cavity, and a first hole is provided on one side surface of the shell body, and the central axis of the first hole is parallel to the first direction. The connecting piece includes a protruding portion and a connecting portion connected to each other, the connecting portion is arranged on the side of the shell body away from the cavity, the protruding portion extends along the side away from the shell body, the protruding portion is provided with a second hole, and the central axis of the second hole is parallel to the first direction. Along the first direction, the projection of the protruding portion is located within the projection of the connecting portion, and the projection of the first hole is located within the projection of the second hole. The first pole includes a protruding portion and an external portion connected to each other, along the first direction, the projection of the protruding portion is located within the projection of the external portion, the protruding portion extends to the cavity through the first hole and the second hole along the first direction, and the external portion is located outside the cavity and separated from the connecting piece; an annular groove is provided on the end surface of the external portion facing the shell body, the protruding portion is located in the annular groove, and there is a gap between the protruding portion and the wall surface of the annular groove. The insulating member fills and seals the gap.

[0005] The connecting portion is arranged on the side of the shell body away from the cavity, sealing the gap between the connecting piece and the shell body, and the extending portion extends to the cavity through the first hole and the second hole along the first direction, and is used to connect the electrode assembly in the shell assembly. Compared with the related art, a prefabricated insulating member is arranged between the protrusion and the wall of the annular groove. In order to ensure the assembly tolerance, the prefabricated insulating member and the protrusion and the wall need to retain the assembly tolerance. The insulating member often deforms under pressure to achieve the sealing effect. This technical solution uses an insulating member to fill the gap between the protrusion and the wall of the annular groove, thereby sealing the gap between the protrusion and the wall of the annular groove, without assembly tolerance, thereby improving the sealing performance of the insulating member.

[0006] In the above embodiments, the wall surface includes a first inner annular surface and a second inner annular surface arranged opposite to each other, and along the first direction, the projection of the first inner annular surface is located within the projection of the second inner annular surface, the protrusion is arranged between the first inner annular surface and the second inner annular surface, and there is a gap between the protrusion and the first inner annular surface, and there is a gap between the protrusion and the second inner annular surface.

[0007] By arranging the protrusion between the first inner annular surface and the second inner annular surface, the distance between the protrusion and the wall surface of the annular groove is increased, which is beneficial to improving the sealing performance of the insulating member.

[0008] In one or more of the above embodiments, the wall surface of the annular groove also includes a bottom wall facing the shell body, and the bottom wall is arranged on the side of the first inner annular surface and the second inner annular surface away from the shell body. The bottom wall connects the first inner annular surface and the second inner annular surface, and there is a gap between the protrusion and the bottom wall.

[0009] There is a gap between the protrusion and the bottom wall, so that the insulating member can flow into between the protrusion and the first inner ring surface along the gap between the protrusion and the second inner ring surface, so that the filling of the insulating member is more uniform.

[0010] In one or more of the above embodiments, it is characterized in that a third hole is provided on a surface of the extending portion away from the cavity, and along the first direction, the third hole has a sealing portion facing the cavity.

[0011] A third hole is provided on the surface of the extending portion away from the cavity, so that the welding head can extend from the third hole, so as to facilitate welding the sealing portion and the first adapter, so that the first adapter can be welded inside the shell without folding the first adapter, thereby reducing the space occupied by the first adapter and improving the energy density of the secondary battery.

[0012] In one or more of the above embodiments, the first hole is circular, and along the extension direction of the central axis of the first hole, the minimum overlapping dimension between the projection of the connecting piece and the projection of the shell body is 2W1, 0.2mm≤W1≤2mm.

[0013] By limiting the single-sided minimum overlap size of the projection of the connecting piece and the projection of the shell body to between 0.2mm and 2mm, it is helpful to improve the connection stability between the connecting piece and the shell body. When the single-sided minimum overlap size of the connecting piece and the shell body projected in the extension direction of the central axis of the first hole is less than 0.2mm, the connection distance between the connecting piece and the shell body is insufficient, and there is a risk of the connecting piece and the shell body being separated. When the single-sided minimum overlap size of the connecting piece and the shell body projected in the extension direction of the central axis of the first hole is greater than 2mm, the connection distance between the connecting piece and the shell body is too long, and the problem of extra space is caused.

[0014] In one or more of the above embodiments, along the diameter direction of the protrusion, the length of the overlap between the projection of the first inner annular surface and the projection of the protrusion is L1, the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion is L2, 0.3mm≤L1+L2≤3mm.

[0015] Observing from the cross section formed by the second direction and the first direction, the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion plus the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion is the sealing length of the insulating member. By controlling the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion plus the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion to be between 0.3 mm and 3 mm, it is beneficial to improve the sealing performance of the insulating member. When the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion plus the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion is less than 0.3 mm, the sealing strength between the first pole and the connecting piece is insufficient, and the problem of electrolyte leakage is likely to occur. When the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion plus the length of the overlap between the projection of the second inner annular surface and the projection of the protrusion is greater than 3 mm, the sealing distance between the first pole and the connecting piece is too long, which is likely to cause insufficient filling of the insulating member, and the problem of unsealed between the first pole and the connecting piece.

[0016] In one or more of the above embodiments, 0.5 mm ≤ L1 + L2 ≤ 1.0 mm.

[0017] By controlling the overlap length of the projection of the second inner annular surface and the projection of the protrusion plus the overlap length of the projection of the second inner annular surface and the projection of the protrusion to be between 0.5 mm and 1 mm, the sealing performance of the insulating member is further improved. When the overlap length of the projection of the second inner annular surface and the projection of the protrusion plus the overlap length of the projection of the second inner annular surface and the projection of the protrusion is less than 0.5 mm, for secondary batteries with more serious expansion, the sealing strength between the first pole and the connecting piece is insufficient, and electrolyte leakage is prone to occur. When the overlap length of the projection of the second inner annular surface and the projection of the protrusion plus the overlap length of the projection of the second inner annular surface and the projection of the protrusion is greater than 1 mm, for secondary batteries with smaller volumes, the sealing distance between the first pole and the connecting piece is too long, which can easily lead to insufficient filling of the insulating member and unsealed problems between the first pole and the connecting piece.

[0018] In one or more of the above embodiments, a coating is provided on the surface of the extending portion extending into the cavity, and the thickness of the coating is T1, 0.01 mm≤T1≤0.2 mm.

[0019] The corrosion resistance of the insertion part is improved by providing a coating on the surface of the insertion part that is inserted into the cavity. When the coating is less than 0.01 mm, the protective effect of the coating is insufficient and there is a risk of corrosion of the insertion part. When the coating is greater than 0.01 mm, the processing is difficult and the cost is increased.

[0020] In one or more of the above embodiments, 0.02 mm ≤ T1 ≤ 0.1 mm.

[0021] For some more corrosive electrolytes, when the coating layer of the insertion portion extending into the cavity surface is less than 0.02mm, the coating layer thickness is insufficient, resulting in insufficient corrosion resistance of the insertion portion. When the coating layer of the insertion portion extending into the cavity surface is greater than 0.1mm, the difficulty of the electroplating process will be increased, and the manufacturing cost will increase.

[0022] In one or more of the above embodiments, a through hole is provided on a surface of the external portion away from the shell body, and the through hole is used to connect the gap.

[0023] The molten insulating member can flow into the gap between the protruding portion and the wall surface of the annular groove through the through hole, thereby shortening the flow time of the molten insulating member and improving the convenience of filling the insulating member.

[0024] In one or more of the above embodiments, the insulating member is made of glass.

[0025] The glass has good fluidity after melting, so that it can flow between the protrusion and the wall of the annular groove. The glass after cooling has good strength and sealing performance, which is conducive to sealing the gap between the protrusion and the wall of the annular groove.

[0026] In one or more of the above embodiments, the material of the insulating member is soda-lime glass or resin-based glass.

[0027] Soda-lime glass or resin-based glass has good chemical stability and mechanical strength. By setting the insulating member to soda-lime glass or resin-based glass, the corrosion resistance of the insulating member to the electrolyte is improved, and the connection stability can be guaranteed at the same time.

[0028] In a second aspect, an embodiment of the present application provides a secondary battery, comprising a shell assembly, an electrode assembly, and a first adapter. The shell assembly is the shell assembly in one or more of the above embodiments. The electrode assembly is accommodated in the cavity, and the electrode assembly includes a first pole ear. One end of the first adapter is connected to the first pole ear, and the other end of the first adapter is connected to the extension portion to form a first welding area.

[0029] The secondary battery uses the melted insulating member to fill the gap between the protrusion and the wall surface of the annular groove, thereby utilizing the fluidity of the melted insulating member to improve the sealing performance of the insulating member, thereby improving the safety of the secondary battery.

[0030] In one or more of the above embodiments, the first adapter is connected to the first tab to form a second welding area, and along the second direction, the projection of the second welding area and the projection of the first welding area at least partially overlap, and the second direction is perpendicular to the first direction.

[0031] The first adapter is connected to the first pole ear to form a second welding area, and along the second direction, the projection of the second welding area and the projection of the first welding area at least partially overlap, and the second direction is perpendicular to the first direction. A third hole is provided on the surface of the insertion portion away from the cavity, so that the welding head can be inserted from the third hole, so as to facilitate welding the sealing portion and the first adapter, so that the first adapter can be welded in the shell without folding the first adapter, thereby reducing the space occupied by the first adapter and improving the energy density of the secondary battery.

[0032] In a third aspect, an embodiment of the present application provides an electrical device, comprising a secondary battery in one or more of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of a secondary battery in one embodiment of the present application.

[0034] Figure 2 It is a schematic diagram of the explosion structure of a secondary battery in one embodiment of the present application.

[0035] Figure 3 It is a schematic diagram of the cross-sectional structure of the first pole and the shell body in an embodiment of the present application.

[0036] Figure 4 It is a schematic diagram of the exploded cross-sectional structure of the first pole and the shell body in one embodiment of the present application.

[0037] Figure 5 It is a schematic diagram of the cross-sectional structure of the first pole and the shell body in another embodiment of the present application.

[0038] Figure 6 It is a schematic diagram of the structure of an electrical device in an embodiment of the present application.

[0039] Main component symbols 001, secondary battery; 100, housing assembly; 110, housing body; 111, cavity; 112, bottom shell; 1121, first hole; 113, cover plate; 114, boss; 120, first pole; 121, insertion portion; 1211, third hole; 122, external portion; 1221, annular groove; 1211a, sealing portion; 1221a, first inner annular surface; 1221b, second inner annular surface; 1221c, bottom wall; 1222, through hole; 130, second pole; 140, connecting piece; 141, protruding portion; 1411, second hole; 142, connecting portion; 150, insulating member; 200, electrode assembly; 210, first electrode tab; 220, second electrode tab; 300, first adapter; 310, first welding area; 320, second welding area; 400, second adapter; 002, electrical device; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0041] It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "provided on" another component, it can be directly provided on the other component or there may be an intermediate component at the same time.

[0042] Unless otherwise specified, the term "plurality" as used herein means two or more than two.

[0043] The terms "first", "second", etc. are only used to distinguish different objects and shall not be understood as indicating or implying relative importance or implying the quantity, specific order or primary and secondary relationship of the technical features indicated.

[0044] The term "perpendicular" is used to describe an ideal state between two components. In actual production or use, two components may be in a state that is approximately perpendicular to each other. For example, in combination with numerical descriptions, perpendicularity can refer to the angle between two straight lines being within the range of 90°±10°, perpendicularity can also refer to the dihedral angle between two planes being within the range of 90°±10°, and perpendicularity can also refer to the angle between a straight line and a plane being within the range of 90°±10°.

[0045] The term "parallel" is used to describe an ideal state between two components. In actual production or use, two components may be approximately parallel. For example, in combination with numerical descriptions, parallel can refer to the angle between two straight lines being within the range of 180°±10°, parallel can also refer to the dihedral angle between two planes being within the range of 180°±10°, and parallel can also refer to the angle between a straight line and a plane being within the range of 180°±10°.

[0046] It should be noted that when a parameter is greater than, equal to, or less than a certain endpoint value, it should be understood that the endpoint value is allowed to have a tolerance of ±5%.

[0047] It should be recognized that the dimensions of the structures shown in the drawings are given for better understanding and more convenient description, and the present application is not limited to the dimensions shown in the drawings. In order to make the present invention clear, elements irrelevant to the description are omitted from the details of this specification.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0049] One embodiment of the present application provides a shell assembly, including a shell body, a connecting piece, a first pole and an insulating piece, wherein the shell body has a cavity, and a first hole is provided on one side surface of the shell body, and the central axis of the first hole is parallel to the first direction. The connecting piece includes a connected protruding portion and a connecting portion, the connecting portion is arranged on the side of the shell body away from the cavity, the protruding portion extends along the side away from the shell body, the protruding portion is provided with a second hole, the central axis of the second hole is parallel to the first direction, along the first direction, the projection of the protruding portion is located within the projection of the connecting portion, and the projection of the first hole is located within the projection of the second hole. The first pole includes a connected extending portion and an external portion, along the first direction, the projection of the extending portion is located within the projection of the external portion, the extending portion passes through the first hole and the second hole along the first direction and extends to the cavity, the external portion is located outside the cavity and separated from the connecting piece; an annular groove is provided on the end surface of the external portion facing the shell body, the protruding portion is located in the annular groove, and there is a gap between the protruding portion and the wall of the annular groove. The insulating piece fills and seals the gap.

[0050] In some embodiments, the insulating member fills and seals the gap, and does not need to be completely filled, as long as the insulation and sealing effects are ensured. For example, along the first direction, there may be a gap between the end surface of the protrusion and the inner wall of the annular groove in the first direction.

[0051] The connecting portion is arranged on the side of the shell body away from the cavity, sealing the gap between the connecting piece and the shell body, and the extending portion extends to the cavity through the first hole and the second hole along the first direction, and is used to connect the electrode assembly in the shell assembly. Compared with the related art, a prefabricated insulating member is arranged between the protrusion and the wall of the annular groove. In order to ensure the assembly tolerance, the prefabricated insulating member and the protrusion and the wall need to retain the assembly tolerance. The insulating member often deforms under pressure to achieve the sealing effect. This technical solution uses an insulating member to fill the gap between the protrusion and the wall of the annular groove, thereby sealing the gap between the protrusion and the wall of the annular groove, without assembly tolerance, thereby improving the sealing performance of the insulating member.

[0052] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features in the following embodiments and examples can be combined with each other.

[0053] See also Figure 1 and Figure 2 An embodiment of the present application provides a secondary battery 001 , which includes a shell assembly 100 and an electrode assembly 200 . The shell assembly 100 includes a shell body 110 . The shell body 110 has a cavity 111 . The electrode assembly 200 is accommodated in the cavity 111 .

[0054] In some embodiments, the shell body 110 includes a bottom shell 112 and a cover plate 113 , and the receiving cavity 111 is formed between the bottom shell 112 and the cover plate 113 .

[0055] In some embodiments, the shell body 110 is a hard shell. As an illustrative example, the bottom shell 112 and the cover plate 113 are both plastic shells or metal shells made of at least one of steel alloy, nickel alloy and copper alloy.

[0056] In some embodiments, the bottom shell 112 and the cover plate 113 are made of stainless steel.

[0057] In some embodiments, the bottom case 112 and the cover plate 113 are made of different materials.

[0058] In some embodiments, the secondary battery 001 includes a first adapter 300 , the housing assembly 100 includes a first electrode column 120 , the electrode assembly 200 has a first electrode tab 210 , and the first adapter 300 connects the first electrode tab 210 and the first electrode column 120 .

[0059] In some embodiments, the secondary battery 001 includes a second adapter 400 , the housing assembly 100 includes a second electrode column 130 , the electrode assembly 200 has a second electrode tab 220 , and the second adapter 400 connects the second electrode tab 220 and the second electrode column 130 .

[0060] In some embodiments, the first electrode tab 210 is a positive electrode tab, and the first electrode column 120 is a positive electrode column.

[0061] In some embodiments, the second electrode tab 220 is a negative electrode tab, and the second electrode column 130 is a negative electrode column.

[0062] In some embodiments, the electrode assembly 200 is formed by alternately stacking a plurality of first electrode sheets, a plurality of isolation membranes, and a plurality of second electrode sheets to form a laminated structure.

[0063] In some embodiments, the electrode assembly 200 is formed by winding a first electrode sheet, a separator, and a second electrode sheet that are stacked in layers to form a winding structure.

[0064] The following is a detailed description of the configuration of the first pole 120 .

[0065] See also Figure 2 and 3 In some embodiments, the housing assembly 100 further includes a connecting piece 140 and an insulating member 150. A first hole 1121 is disposed on one side surface of the housing body 110, and a central axis of the first hole 1121 is parallel to the first direction X.

[0066] The connecting piece 140 includes a protruding portion 141 and a connecting portion 142 which are connected to each other. Along the first direction X, the projection of the protruding portion 141 is located within the projection of the connecting portion 142 .

[0067] In some embodiments, the protrusion 141 and the connection portion 142 are both arranged in a circular ring shape. In an ideal condition, the projection of the protrusion 141 and the projection of the connection portion 142 are arranged concentrically.

[0068] In some embodiments, the connecting portion 142 is disposed on a side of the shell body 110 away from the cavity 111 , and the protruding portion 141 extends along a side away from the shell body 110 .

[0069] In some embodiments, the shell body 110 and the connecting portion 142 are connected by welding.

[0070] The protrusion 141 is provided with a second hole 1411, the central axis of the second hole 1411 is parallel to the first direction X, and the projection of the first hole 1121 is located within the projection of the second hole 1411. In an ideal condition, the central axis of the second hole 1411 is colinear with the central axis of the protrusion 141.

[0071] The first pole 120 includes a connected extension portion 121 and an external portion 122. Along the first direction X, the projection of the extension portion 121 is located within the projection of the external portion 122. The extension portion 121 extends to the cavity 111 through the first hole 1121 and the second hole 1411 along the first direction X, and is used to connect the electrode assembly 200 in the shell assembly 100. The external portion 122 is located outside the cavity 111 and separated from the connecting sheet 140.

[0072] An annular groove 1221 is formed on the end surface of the external portion 122 facing the shell body 110 . The protruding portion 141 is located in the annular groove 1221 . There is a gap between the protruding portion 141 and the wall surface of the annular groove 1221 .

[0073] In some embodiments, the insulating member 150 is made of glass.

[0074] Compared with the related art, a prefabricated insulating part is used to be arranged between the protrusion 141 and the wall of the annular groove 1221. In order to ensure the assembly tolerance, the assembly tolerance needs to be retained between the prefabricated insulating part and the protrusion 141 and the wall. The insulating part often achieves a sealing effect by being deformed under pressure.

[0075] In the technical solution, the insulating member 150 has fluidity after melting, the molten insulating member 150 fills the gap, and the cooled insulating member 150 seals the gap. By using the molten insulating member 150 to fill the gap between the protrusion 141 and the wall surface of the annular groove 1221, the fluidity of the molten glass is utilized to improve the sealing performance of the insulating member 150.

[0076] See also Figure 3 and 4 In some embodiments, the wall surface of the annular groove 1221 includes a first inner annular surface 1221a and a second inner annular surface 1221b that are arranged opposite to each other. Along the first direction X, the projection of the first inner annular surface 1221a is located within the projection of the second inner annular surface 1221b.

[0077] In some embodiments, the projection of the first inner annular surface 1221a on the surface of the shell body 110 is circular, the projection of the second inner annular surface 1221b on the surface of the shell body 110 is circular, and the projection of the first inner annular surface 1221a on the shell body 110 is concentric with the projection of the second inner annular surface 1221b on the surface of the shell body 110.

[0078] The protrusion 141 is arranged between the first inner ring surface 1221a and the second inner ring surface 1221b, and there is a gap between the protrusion 141 and the first inner ring surface 1221a, and there is a gap between the protrusion 141 and the second inner ring surface 1221b. By arranging the protrusion 141 between the first inner ring surface 1221a and the second inner ring surface 1221b, the distance between the protrusion 141 and the wall surface of the annular groove 1221 is increased, which is beneficial to improving the sealing performance of the insulating part 150.

[0079] In some embodiments, the wall surface of the annular groove 1221 also includes a bottom wall 1221c facing the shell body 110, and the bottom wall 1221c is arranged on the side of the first inner annular surface 1221a and the second inner annular surface 1221b away from the shell body 110. The bottom wall 1221c connects the first inner annular surface 1221a and the second inner annular surface 1221b, and there is a gap between the protrusion 141 and the bottom wall 1221c, so that the insulating part 150 can flow into between the protrusion 141 and the first inner annular surface 1221a along the gap between the protrusion 141 and the second inner annular surface 1221b, so that the filling of the insulating part 150 is more uniform.

[0080] See also Figure 2 and 5 In some embodiments, a boss 114 is provided on the surface of the shell body 110 away from the cavity 111, the boss 114 and the first hole 1121 are located on the same side surface of the shell body 110, and the first hole 1121 penetrates the boss 114 and the shell body 110 along the first direction X.

[0081] Along the first direction X, the projection of the connecting piece 140 is located within the projection of the boss 114 .

[0082] The connection portion 142 is connected to the surface of the boss 114 away from the shell body 110 . The boss 114 is provided so that the shell body 110 has a thicker connection position, which is beneficial to improving the connection stability between the shell body 110 and the connection portion 142 .

[0083] In some embodiments, the boss 114 and the connecting portion 142 are connected by welding.

[0084] See also Figure 3 and 4 In some embodiments, a third hole 1211 is provided on a surface of the extending portion 121 away from the cavity 111 , and along the first direction X, the third hole 1211 has a sealing portion 1211 a facing the cavity 111 .

[0085] In some embodiments, along the first direction X, the distance between the bottom surface of the third hole 1211 and the surface of the extending portion 121 facing the cavity 111 is S1, the thickness of the connecting portion 142 is S2, and S1=S2.

[0086] See also Figure 2 and 3 In some embodiments, one end of the first adapter 300 is connected to the first electrode tab 210 , and the other end of the first adapter 300 is connected to the extending portion 121 to form a first welding area 310 .

[0087] In some embodiments, the first adapter 300 is connected to the first tab 210 to form a second welding area 320, and along the second direction Y, the projection of the second welding area 320 and the projection of the first welding area 310 at least partially overlap, and the second direction Y is perpendicular to the first direction X. A third hole 1211 is provided on the surface of the insertion portion 121 away from the cavity 111, so that the welding head can be inserted from the third hole 1211, so as to facilitate welding the sealing portion 1211a and the first adapter 300, so that the first adapter 300 can be welded in the shell without folding the first adapter 300, thereby reducing the space occupied by the first adapter 300 and improving the energy density of the secondary battery 001.

[0088] In some embodiments, the insertion portion 121 is integrally formed with the external portion 122. It is worth noting that due to manufacturing tolerance, along the first direction X, the thickness of the connecting portion 142 has a tolerance of ±0.2 mm compared to the distance between the bottom surface of the third hole 1211 and the surface of the insertion portion 121 facing the cavity 111.

[0089] In some embodiments, the first hole 1121 is circular, and along the extension direction of the central axis of the first hole 1121, the minimum overlap size between the projection of the connecting piece 140 and the projection of the shell body 110 is 2W1, 0.2mm≤W1≤2mm. By limiting the single-sided minimum overlap size between the connecting piece 140 and the shell body 110 projected in the extension direction of the central axis of the first hole 1121 to between 0.2mm and 2mm, it is beneficial to improve the connection stability between the connecting piece 140 and the shell body 110. When the single-sided minimum overlap size between the connecting piece 140 and the shell body 110 projected in the extension direction of the central axis of the first hole 1121 is less than 0.2mm, the connection distance between the connecting piece 140 and the shell body 110 is insufficient, and there is a risk of the connecting piece 140 and the shell body 110 being separated. When the single-sided minimum overlap size between the connecting piece 140 and the shell body 110 projected in the extension direction of the central axis of the first hole 1121 is greater than 2mm, the connection distance between the connecting piece 140 and the shell body 110 is too long, and the problem of extra space is occupied.

[0090] In some embodiments, the value of W1 is any one of 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, or 2.

[0091] See also Figure 3 and 4 In some embodiments, along the diameter direction of the protrusion 141, the length of the overlap between the projection of the first inner annular surface 1221a and the projection of the protrusion 141 is L1, the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 is L2, 0.3mm≤L1+L2≤3mm, and the second direction Y is perpendicular to the first direction X. Observing from the cross section formed by the second direction Y and the first direction X, the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 plus the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 is the sealing length of the insulating member 150. By controlling the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 plus the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 to be between 0.3mm and 3mm, it is beneficial to improve the sealing performance of the insulating member 150. When the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 plus the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 is less than 0.3 mm, the sealing strength between the first pole 120 and the connecting piece 140 is insufficient, and the problem of electrolyte leakage is likely to occur. When the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 plus the length of the overlap between the projection of the second inner annular surface 1221b and the projection of the protrusion 141 is greater than 3 mm, the sealing distance between the first pole 120 and the connecting piece 140 is too long, which may easily lead to insufficient filling of the insulating member 150, and the problem of unsealing between the first pole 120 and the connecting piece 140.

[0092] In some embodiments, the value of L1+L2 is 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, Any one of 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, 3.

[0093] In some embodiments, 0.5 mm ≤ L1 + L2 ≤ 1.0 mm.

[0094] In some embodiments, a coating (not shown) is provided on the surface of the extending portion 121 extending into the cavity 111 , thereby improving the corrosion resistance of the extending portion 121 .

[0095] In some embodiments, the thickness of the coating is T1, 0.01 mm ≤ T1 ≤ 0.2 mm. When the coating of the extending portion 121 extending into the surface of the cavity 111 is less than 0.01 mm, the thickness of the coating is insufficient, resulting in insufficient corrosion resistance of the extending portion 121. When the coating of the extending portion 121 extending into the surface of the cavity 111 is greater than 0.2 mm, the difficulty of the electroplating process will be greatly increased, and the manufacturing cost will increase.

[0096] In some embodiments, the value of the coating T1 is any one of 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, and 0.2.

[0097] In some embodiments, 0.02 mm ≤ T1 ≤ 0.1 mm.

[0098] See also Figure 3 and 4 In some embodiments, a through hole 1222 is provided on the surface of the external portion 122 away from the shell body 110, and the through hole 1222 is used to connect the gap so that the molten insulating member 150 can flow into the gap between the protrusion 141 and the wall of the annular groove 1221 through the through hole 1222, thereby shortening the flow time of the molten insulating member 150 and improving the convenience of filling the insulating member 150.

[0099] In some embodiments, the material of the connecting piece 140 is the same as that of the first pole 120 .

[0100] In some embodiments, the material of the insulating member 150 is soda-lime glass or resin-based glass. Soda-lime glass or resin-based glass has good chemical stability and mechanical strength. By setting the insulating member 150 to soda-lime glass or resin-based glass, the corrosion resistance of the insulating member 150 to the electrolyte is improved, and the connection stability can be guaranteed at the same time.

[0101] See also Figure 6 , an embodiment of the present application provides an electric device 002, comprising the secondary battery 001 in the above embodiment.

[0102] In addition, those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of the present application.

Claims

1. A housing assembly, characterized in that: include: The shell body has a cavity, and a first hole is provided on one side surface of the shell body, and the central axis of the first hole is parallel to the first direction; A connecting piece, the connecting piece comprising a connected protrusion and a connecting part, the connecting part is arranged on the side of the shell body away from the cavity, the protrusion extends along the side away from the shell body, the protrusion is provided with a second hole, the central axis of the second hole is parallel to the first direction; along the first direction, the projection of the protrusion is located within the projection of the connecting part, and the projection of the first hole is located within the projection of the second hole; A first pole, the first pole comprises a connected extending portion and an external portion, along the first direction, the projection of the extending portion is located within the projection of the external portion, the extending portion passes through the first hole and the second hole along the first direction and extends to the cavity, the external portion is located outside the cavity and separated from the connecting piece; an annular groove is provided on the end surface of the external portion facing the shell body, the protruding portion is located in the annular groove, and there is a gap between the protruding portion and the wall surface of the annular groove; An insulating member fills and seals the gap.

2. The housing assembly according to claim 1, wherein: The wall surface includes a first inner annular surface and a second inner annular surface arranged opposite to each other. Along the first direction, the projection of the first inner annular surface is located within the projection of the second inner annular surface. The protrusion is arranged between the first inner annular surface and the second inner annular surface. There is the gap between the protrusion and the first inner annular surface, and there is the gap between the protrusion and the second inner annular surface.

3. The housing assembly according to claim 2, wherein: The wall surface of the annular groove also includes a bottom wall facing the shell body, and the bottom wall is arranged on the side of the first inner annular surface and the second inner annular surface away from the shell body. The bottom wall connects the first inner annular surface and the second inner annular surface, and there is the gap between the protrusion and the bottom wall.

4. The housing assembly according to claim 1, wherein: A third hole is disposed on a surface of the extending portion away from the cavity. Along the first direction, the third hole has a sealing portion facing the cavity.

5. The housing assembly according to claim 1, wherein: The first hole is circular, and along the extension direction of the central axis of the first hole, the minimum overlapping dimension between the projection of the connecting piece and the projection of the shell body is 2W1, 0.2mm≤W1≤2mm.

6. The housing assembly according to claim 2, wherein: Along the diameter direction of the protrusion, the overlapping length of the projection of the first inner annular surface and the projection of the protrusion is L1, the overlapping length of the projection of the second inner annular surface and the projection of the protrusion is L2, 0.3mm≤L1+L2≤3mm.

7. The housing assembly according to claim 6, wherein: 0.5mm≤L1+L2≤1.0mm.

8. The housing assembly according to claim 1, wherein: The surface of the extending portion extending into the cavity is provided with a coating, and the thickness of the coating is T1, 0.01 mm≤T1≤0.2 mm.

9. The housing assembly according to claim 8, wherein: 0.02mm≤T1≤0.1mm.

10. The housing assembly according to claim 1, wherein: A through hole is provided on a surface of the external portion away from the shell body, and the through hole is used to connect the gap.

11. The housing assembly according to any one of claims 1 to 10, characterized in that: The insulating member is made of glass.

12. The housing assembly according to claim 11, wherein: The insulating member is made of soda-lime glass or resin-based glass.

13. A secondary battery, characterized in that: include: A housing assembly, wherein the housing assembly is the housing assembly according to any one of claims 1 to 12; An electrode assembly, the electrode assembly is accommodated in the cavity, and the electrode assembly includes a first electrode tab; A first adapter, one end of which is connected to the first electrode tab, and the other end of which is connected to the extending portion to form a first welding area.

14. The secondary battery according to claim 13, characterized in that: The first adapter is connected to the first electrode tab to form a second welding area. Along a second direction, a projection of the second welding area and a projection of the first welding area at least partially overlap. The second direction is perpendicular to the first direction.

15. An electrical device, characterized in that: Comprising the secondary battery as claimed in claim 14.

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