Secondary battery and electric device

Abstract

The invention discloses a secondary battery and electric equipment, the secondary battery comprises a shell, an electrode assembly, a sealing piece and a first bonding piece, the electrode assembly is arranged in the shell, the shell comprises a first shell with a first wall and a first side wall and a second shell with a second wall and a second side wall, the first side wall is provided with a first surface, and the second side wall is provided with a second surface; the first side wall is provided with a first face, the first face faces the second side wall in the extending direction of the first side wall, the second side wall is provided with a second face, the second face faces the first side wall in the extending direction of the second side wall, the first face and the second face are oppositely arranged and have a gap, and the sealing piece seals the gap and comprises a filling part arranged in the gap. The first bonding piece is arranged on the first side wall and comprises a first bonding part arranged on the first face and a second bonding part arranged on the inner wall of the first side wall, and the first bonding part and the second bonding part are integrally arranged and fixedly arranged with the filling part. The packaging strength of the sealing element and the shell can be improved, and the possibility of relative torsion of the first shell and the second shell can be reduced.

Description

Technical Field

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

[0002] Current secondary batteries include steel-cased batteries and soft-pack batteries. Generally speaking, both steel-cased batteries and soft-pack batteries include an outer shell and an electrode assembly disposed within the outer shell. The outer shell of a steel-cased battery includes a first shell and a second shell, which are sealed together by welding or a sealant. Summary of the Invention

[0003] Regarding the secondary batteries in the prior art, the inventors have found that if the first shell and the second shell are sealed and connected by a seal, when the secondary battery falls, relative twisting is likely to occur between the first shell and the second shell, causing the outer shell to deform, thereby resulting in a higher risk of failure of the outer shell and the seal package.

[0004] In view of the above situation, it is necessary to provide a secondary battery that is conducive to reducing the possibility of relative twisting between the first shell and the second shell.

[0005] In a first aspect, the present application provides a secondary battery comprising a housing, an electrode assembly, a sealing member, and a first adhesive member. The housing comprises a first shell and a second shell. The first shell and the second shell together form a receiving cavity filled with electrolyte, and the electrode assembly is disposed within the receiving cavity. The first shell comprises a first wall and a first sidewall connected to the periphery of the first wall. The second shell comprises a second wall and a second sidewall connected to the periphery of the second wall. The first sidewall has a first surface, the first surface facing the second sidewall along the extension direction of the first sidewall. The second sidewall has a second surface, the second surface facing the first sidewall along the extension direction of the second sidewall. The first surface and the second surface are disposed opposite each other and have a gap therebetween. A sealing member is disposed around the periphery of the first and second sidewalls and seals the gap. The sealing member includes a filling portion disposed in the gap. A first adhesive member is disposed on the first sidewall and comprises a first adhesive portion and a second adhesive portion. The first adhesive portion is disposed on the first surface of the first sidewall, and the second adhesive portion is disposed on the inner wall of the first sidewall. The first adhesive portion and the second adhesive portion are integrally disposed. The first adhesive portion and the filling portion are fixedly disposed.

[0006] The first adhesive portion is provided on the first surface of the first sidewall, and the second adhesive portion is provided on the inner wall of the first sidewall. The first and second adhesive portions are integrally provided, enabling the adhesive member to be more stably fixed to the first sidewall. Furthermore, the first adhesive portion is fixedly provided with the filling portion. The cooperation between the first adhesive portion and the sealing member improves the sealing strength between the sealing member and the housing, thereby reducing the possibility of relative twisting between the first and second housings.

[0007] In one or more of the above embodiments, the secondary battery further includes a second adhesive member, which is disposed on the second side wall. The second adhesive member includes a third adhesive portion and a fourth adhesive portion. The third adhesive portion is disposed on the second surface of the second side wall, and the fourth adhesive portion is disposed on the inner wall of the second side wall. The third adhesive portion and the fourth adhesive portion are integrally disposed, thereby enabling the second adhesive member to be more stably fixed to the second side wall. Furthermore, the third adhesive portion is fixedly disposed with the filling portion. The cooperation between the second adhesive member and the sealing member further improves the sealing strength between the sealing member and the outer shell, thereby further reducing the possibility of relative twisting between the first shell and the second shell.

[0008] In one or more of the above embodiments, the spacing between the first surface and the second surface is D, and 20μm≤D≤5000μm. By setting 20μm≤D, the spacing between the first surface and the second surface is not too small, which helps reduce the possibility of short circuits caused by burr contact between the first shell and the second shell. By setting D≤5000μm, the spacing between the first surface and the second surface is not too large, which helps increase the energy density of the secondary battery.

[0009] In one or more of the above embodiments, 40 μm ≤ D ≤ 3000 μm. Setting 40 μm ≤ D further reduces the possibility of a short circuit between the first shell and the second shell due to burr contact. Setting D ≤ 3000 μm further increases the energy density of the secondary battery.

[0010] In one or more of the above embodiments, the thickness of the first adhesive portion is H1, the thickness of the second adhesive portion is H2, 3μm≤H1≤500μm, and 90%H1≤H2≤110%H1. By setting 3μm≤H1, it is beneficial to reduce the risk of burrs piercing the first adhesive portion after the filling portion is melted, causing a short circuit. By setting H1≤500μm, it is beneficial to improve the energy density of the secondary battery. Taking into account the accuracy of the processing technology, by setting 90%H1≤H2≤110%H1, it is possible to facilitate the integrated arrangement of the first adhesive portion and the second adhesive portion. The thickness of the third adhesive portion is H3, and the thickness of the fourth adhesive portion is H4, 3μm≤H3≤500μm, and 90%H3≤H4≤110%H3. By setting 3μm≤H3, it is beneficial to reduce the risk of burrs piercing the third adhesive portion after the filling portion is melted, causing a short circuit. By setting H3≤500μm, it is beneficial to improve the energy density of the secondary battery. Taking into account the accuracy of the processing technology, by setting 90% H3≤H4≤110% H3, the third bonding portion and the fourth bonding portion can be easily set as one piece.

[0011] In one or more of the above embodiments, 6μm≤H1≤200μm. By setting 6μm≤H1, it is beneficial to further reduce the risk of burrs piercing the first adhesive portion after the filling portion is melted, causing a short circuit. By setting H1≤200μm, it is beneficial to further improve the energy density of the secondary battery. 6μm≤H3≤200μm. By setting 6μm≤H3, it is beneficial to further reduce the risk of burrs piercing the third adhesive portion after the filling portion is melted, causing a short circuit. By setting H1≤200μm, it is beneficial to further improve the energy density of the secondary battery.

[0012] In one or more of the above embodiments, the first adhesive portion is integrally provided with the filling portion, which is beneficial for improving the stability of the connection between the first adhesive portion and the filling portion. The third adhesive portion is integrally provided with the filling portion, which is beneficial for improving the stability of the connection between the third adhesive portion and the filling portion.

[0013] In one or more of the above embodiments, the width of the second bonding portion is W2, 30μm≤W2≤3000μm. By setting 30μm≤W2, the bonding area between the second bonding portion and the inner wall of the side wall can be made not too small, which is beneficial to improving the stability of the second bonding portion provided on the inner wall of the first side wall. Moreover, when the first bonding portion and the filling portion are provided as a whole, setting 30μm≤W2 is also beneficial to reducing the possibility of electrolyte erosion of the interface between the second bonding portion and the first side wall. By setting W2≤3000μm, the bonding area between the second bonding portion and the inner wall of the first side wall can be made not too large, and when the polarity of the electrode assembly is led out through the first side wall, the first side wall can have a larger area for connection, which is beneficial to improving the convenience of connecting the electrode assembly to the first side wall. The width of the fourth bonding portion is W4, 30μm≤W4≤3000μm. By setting 30μm≤W4, the bonding area between the fourth bonding part and the inner wall of the second side wall can be made not too small, which is beneficial to improving the stability of the fourth bonding part provided on the inner wall of the second side wall. Moreover, when the third bonding part and the filling part are provided as one piece, setting 30μm≤W4 is also beneficial to reducing the possibility of electrolyte corroding the interface between the fourth bonding part and the second side wall. By setting W4≤3000μm, the bonding area between the fourth bonding part and the inner wall of the second side wall can be made not too large. When the polarity of the electrode assembly is led out through the second side wall, the second side wall can have a larger area for connection, which is beneficial to improving the convenience of connecting the electrode assembly to the second side wall.

[0014] In one or more of the above embodiments, 100μm≤W2≤1500μm. By setting 100μm≤W2, it is beneficial to further improve the stability of the second bonding portion provided on the inner wall of the first side wall. Moreover, when the first bonding portion and the filling portion are provided as one piece, setting 100μm≤W2 is also beneficial to further reduce the possibility of the electrolyte corroding the interface between the second bonding portion and the first side wall. By setting W2≤1500μm, it is beneficial to further improve the convenience of connecting the electrode assembly to the first side wall. 100μm≤W4≤1500μm. By setting 100μm≤W4, it is beneficial to further improve the stability of the fourth bonding portion provided on the inner wall of the second side wall. Moreover, when the third bonding portion and the filling portion are provided as one piece, setting 100μm≤W4 is also beneficial to further reduce the possibility of the electrolyte corroding the interface between the fourth bonding portion and the second side wall. By setting W4≤1500μm, it is beneficial to further improve the convenience of connecting the electrode assembly to the second side wall.

[0015] In one or more of the above embodiments, the seal comprises a first adhesive layer, a metal layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are respectively disposed on either side of the metal layer along the thickness direction of the metal layer. The first adhesive layer is adhered to the periphery of the first and second side walls, and the filling portion is integrally provided with the first adhesive layer. The seal comprises a first adhesive layer, which is adhered to the first and second side walls. The first adhesive layer facilitates improving the stability of the adhesion between the seal and the outer shell. The seal comprises a metal layer, which is disposed on the side of the first adhesive layer facing away from the outer shell. The water barrier properties of the metal layer are superior to those of the first adhesive layer, which facilitates improving the sealing performance of the seal between the first and second shells. The seal comprises a second adhesive layer, which is disposed on the side of the metal layer facing away from the first adhesive layer. The second adhesive layer can protect the metal layer, which facilitates reducing the risk of damage and failure of the metal layer. Thus, the seal between the first and second shells is facilitated to be maintained during the long-term use of the secondary battery.

[0016] In one or more of the above embodiments, along the thickness direction of the seal, the thickness of the first adhesive layer is d1, the thickness of the metal layer is d2, and the thickness of the second adhesive layer is d3, and the following conditions are met: 7μm≤d1≤500μm, 7μm≤d2≤250μm, and 6μm≤d3≤500μm. By setting 7μm≤d1, 7μm≤d2, and 6μm≤d3, the first adhesive layer, the metal layer, and the second adhesive layer are not too thin, which helps reduce the risk of the first adhesive layer being corroded and failing by the electrolyte, and the risk of the second adhesive layer being damaged after the secondary battery is dropped, leading to damage and failure of the metal layer, or failure of the metal layer due to corrosion. By setting d1≤500μm, d2≤250μm, and d3≤500μm, the first adhesive layer, the metal layer, and the second adhesive layer are not too thick, which helps increase the energy density of the secondary battery.

[0017] In one or more of the above embodiments, 10μm≤d1≤200μm, 10μm≤d2≤150μm, and 8μm≤d3≤200μm. By setting 10μm≤d1, 10μm≤d2, and 8μm≤d3, the first adhesive layer, the metal layer, and the second adhesive layer can be made thicker, which is beneficial to further reduce the risk of the first adhesive layer being corroded and failing by the electrolyte, and is beneficial to further reduce the risk of the second adhesive layer being damaged after the secondary battery falls, resulting in the metal layer being damaged and failing, or the metal layer being corroded and failing. By setting d1≤200μm, d2≤150μm, and d3≤200μm, the energy density of the secondary battery can be further improved while the thickness of the first adhesive layer basically meets the requirement of not being corroded and failing by the electrolyte, the thickness of the second adhesive layer meets the requirement of most falling situations, and the thickness of the metal layer basically meets the requirement of not being damaged and failing, or not being corroded and failing.

[0018] The second aspect of the present application provides an electrical device comprising the secondary battery of the first aspect of the present application. The secondary battery has good sealing performance, and the electrolyte is not easily leaked, which is conducive to extending the service life of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A top view of a secondary battery provided in accordance with an embodiment of the present application.

[0020] Figure 2 This is a front view of a secondary battery provided in one embodiment of the present application.

[0021] Figure 3 An exploded view of a secondary battery provided in one embodiment of the present application.

[0022] Figure 4 For the first embodiment of this application Figure 1 Cross-section along the median line AA.

[0023] Figure 5 The second embodiment of this application is Figure 1 Cross-section along the median line AA.

[0024] Figure 6 A schematic cross-sectional view of a first adhesive member provided in one embodiment of the present application.

[0025] Figure 7 This is an overall schematic diagram of an electrical device provided in one embodiment of the present application.

[0026] Description of main component symbols 1000. Electrical equipment; 100. Secondary battery; 10. Casing; 101. Accommodation cavity; 11. First shell; 111. First wall; 112. First side wall; 1121. First surface; 12. Second shell; 121. Second wall; 122. Second side wall; 1221. Second surface; 20. Electrode assembly; 201. First tab bundle; 202. Second tab bundle; 21. First pole piece; 22. Second pole piece; 23. Diaphragm; 30. Sealing member; 301. Filling portion; 31. First adhesive layer; 32. Metal layer; 33. Second adhesive layer; 40. Adhesive member; 41. First adhesive portion; 42. Second adhesive portion; 50. Second adhesive member; 51. Third adhesive portion; 52. Fourth adhesive portion; 60. Fixing member. DETAILED DESCRIPTION

[0027] 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 the embodiments.

[0028] It should be noted that when an element is considered to be “connected” to another element, it may be directly connected to the other element or there may be a centrally disposed element. When an element is considered to be “disposed on” another element, it may be directly disposed on the other element or there may be a centrally disposed element.

[0029] Unless otherwise specified, the term "plurality" as used herein means two or more than two.

[0030] The terms "first", "second", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implying the quantity, specific order or primary and secondary relationship of the technical features indicated.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] It should be understood that, taking into account the actual processing tolerance factors, in the technical solution of the present application, when two elements are arranged parallel / perpendicularly, the angle between the two elements and the angle corresponding to the parallel / perpendicular arrangement are allowed to have a tolerance within a range of 10%.

[0033] An embodiment of the present application provides a secondary battery comprising a housing, an electrode assembly, a sealing member, and a first adhesive member. The housing comprises a first shell and a second shell. The first shell and the second shell together form a receiving chamber filled with electrolyte, and the electrode assembly is disposed within the receiving chamber. The first shell comprises a first wall and a first sidewall connected to the periphery of the first wall. The second shell comprises a second wall and a second sidewall connected to the periphery of the second wall. The first sidewall has a first surface, the first surface facing the second sidewall along the extension direction of the first sidewall. The second sidewall has a second surface, the second surface facing the first sidewall along the extension direction of the second sidewall. The first surface and the second surface are disposed opposite each other and have a gap therebetween. A sealing member is disposed around the periphery of the first and second sidewalls and seals the gap. The sealing member includes a filling portion disposed in the gap. A first adhesive member is disposed on the first sidewall and comprises a first adhesive portion and a second adhesive portion. The first adhesive portion is disposed on the first surface of the first sidewall, and the second adhesive portion is disposed on the inner wall of the first sidewall. The first adhesive portion and the second adhesive portion are integrally disposed. The first adhesive portion and the filling portion are fixedly disposed.

[0034] In the secondary battery of the present application, the first adhesive portion is disposed on the first surface of the first sidewall, and the second adhesive portion is disposed on the inner wall of the first sidewall. The first and second adhesive portions are integrally disposed, enabling the first adhesive member to be relatively stably fixed to the first sidewall. Furthermore, the first adhesive portion is fixedly disposed to the filling portion. The cooperation between the first adhesive portion and the sealing member improves the sealing strength between the sealing member and the outer shell, thereby reducing the possibility of relative twisting between the first and second shells.

[0035] The following will describe some embodiments of the present application in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0036] See also Figures 1 to 6 The embodiment of the present application provides a secondary battery 100, including a housing 10, an electrode assembly 20, a sealing member 30, and a first adhesive member 40. The electrode assembly 20 is accommodated in the housing 10. The sealing member 30 is provided on the outer wall of the housing 10 and is used to seal the housing 10. The first adhesive member 40 is provided on the side wall of the housing 10 and is connected to the sealing member 30.

[0037] In some embodiments, see Figure 2 and Figure 3 The housing 10 includes a first shell 11 and a second shell 12. In some embodiments, the first shell 11 and the second shell 12 are arranged to face each other. In some embodiments, the first shell 11 and the second shell 12 are arranged to be insulated.

[0038] In some embodiments, the housing 10 is a metal housing, and the material of the housing 10 includes at least one of steel alloy, aluminum alloy, and copper alloy. The material of the first housing 11 and the material of the second housing 12 can be the same or different.

[0039] In some embodiments, see Figure 3 The first shell 11 includes a first wall 111 and a first side wall 112, and the second shell 12 includes a second wall 121 and a second side wall 122. The first side wall 112 connects the periphery of the first wall 111, and the second side wall 122 connects the periphery of the second wall 121. In a direction perpendicular to the second side wall 122, the projection of the second side wall 122 is separated from the projection of the first side wall 112. The first side wall 112 can be inclined or perpendicular to the first wall 111, and the second side wall 122 can be inclined or perpendicular to the second wall 121, and this application does not impose any restrictions on this. The first side wall 112 is provided with a first surface 1121, and the first surface 1121 faces the second side wall 122 along the extension direction of the first side wall 112. The second side wall 122 is provided with a second surface 1221, and the second surface 1221 faces the first side wall 112 along the extension direction of the second side wall 122. The first surface 1121 and the second surface 1221 are arranged to face each other and have a gap. The extension direction of the first side wall 112 refers to the direction of extension away from the side of the first side wall 112 connected to the periphery of the first wall 111, and the extension direction of the second side wall 122 refers to the direction of extension away from the side of the second side wall 122 connected to the periphery of the second wall 121. It should be understood that the so-called first surface 1121 and second surface 1221 can be either flat or curved, and this application does not impose any restrictions on this.

[0040] See also Figure 4 and Figure 5 The first shell 11 and the second shell 12 together form a receiving cavity 101, which is filled with electrolyte and the electrode assembly 20 is disposed in the receiving cavity 101. Figure 3 The electrode assembly 20 includes a first electrode piece 21 , a second electrode piece 22 and a diaphragm 23 . The second electrode piece 22 has a polarity opposite to that of the first electrode piece 21 . The diaphragm 23 separates the first electrode piece 21 from the second electrode piece 22 .

[0041] In some embodiments, see Figure 4 and Figure 5 The electrode assembly 20 has a laminated structure, wherein the first electrode sheets 21 and the second electrode sheets 22 are alternately stacked, wherein the separator 23 is disposed between adjacent first electrode sheets 21 and second electrode sheets 22. In some embodiments, the electrode assembly 20 has a wound structure, wherein the first electrode sheets 21 and the second electrode sheets 22 are alternately wound, wherein the separator 23 is disposed between adjacent first electrode sheets 21 and second electrode sheets 22.

[0042] In some embodiments, the first electrode sheet 21 is a negative electrode sheet, and the second electrode sheet 22 is a positive electrode sheet. In some embodiments, the first electrode sheet 21 is a positive electrode sheet, and the second electrode sheet 22 is a negative electrode sheet. Along the thickness direction of the electrode assembly 20, the projection of the negative electrode sheet overlaps the projection of the positive electrode sheet.

[0043] In some embodiments, the first pole piece 21 includes a first current collector and a first active material layer, with the first active material layer disposed on two opposing surfaces of the first current collector along the thickness direction. The second pole piece 22 includes a second current collector and a second active material layer, with the second active material layer disposed on two opposing surfaces of the second current collector along the thickness direction. In some embodiments, when the first pole piece 21 or the second pole piece 22 is the outermost pole piece of the electrode assembly 20, the active material layer may not be disposed on the side of the current collector facing away from the interior of the electrode assembly 20.

[0044] In some embodiments, the material of the first current collector includes at least one of copper, nickel, tantalum, and titanium, and the material of the second current collector includes at least one of aluminum, nickel, tantalum, and titanium.

[0045] In some embodiments, the first active material layer is made of at least one of graphite, hard carbon, soft carbon, silicon, silicon-oxygen material, and silicon-carbon material. The second active material layer is made of at least one of lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, or lithium manganese oxide.

[0046] In some embodiments, the diaphragm 23 is made of insulating film materials such as polyethylene film, polypropylene film, polyester film, or polyimide film.

[0047] In some embodiments, the first current collector and the second current collector each have a hollow foil region. One of the hollow foil region of the first current collector and the hollow foil region of the second current collector is directly connected to the first housing 11, and the other of the hollow foil region of the first current collector and the second current collector is directly connected to the second housing 12. The first housing 11 and the second housing 12 are insulated from each other. In some embodiments, the hollow foil region is indirectly connected to the first housing 11 and / or the second housing 12 via a conductive member (not shown). The conductive member includes, but is not limited to, a conductive protrusion, a metal spring, and a conductive adhesive. The conductive protrusion can be formed by laser roughening the housing 10.

[0048] In some embodiments, see Figure 3The secondary battery 100 further includes a plurality of first tabs connected to the first electrode sheet 21, which are gathered together to form a first tab bundle 201. The secondary battery 100 further includes a plurality of second tabs connected to the second electrode sheet 22, which are gathered together to form a second tab bundle 202. One of the first tab bundle 201 and the second tab bundle 202 is electrically connected to the first housing 11, and the other of the first tab bundle 201 and the second tab bundle 202 is electrically connected to the second housing 12. The first housing 11 and the second housing 12 are insulated from each other. In some embodiments, one of the first tab bundle 201 and the second tab bundle 202 is connected to the first sidewall 112, and the other of the first tab bundle 201 and the second tab bundle 202 is connected to the second sidewall 122.

[0049] In some embodiments, the seal 30 is used to separate and seal the first housing 11 and the second housing 12. Figure 1 and Figure 2 The seal 30 surrounds the outer periphery of the first side wall 112 and the second side wall 122. Along the thickness direction of the seal 30, the projection of the seal 30 at least partially overlaps with the projections of the first shell 11 and the second shell 12. The seal 30 includes a filling portion 301 disposed in the gap between the first surface 1121 and the second surface 1221. The filling portion 301 separates the first shell 11 and the second shell 12, facilitating the insulation between the first and second shells 11 and 12.

[0050] See also Figure 4 and Figure 5 The first adhesive member 40 is provided on the first side wall 112 and connected to the sealing member 30. The first adhesive member 40 includes a first adhesive portion 41 and a second adhesive portion 42 (see Figure 6 ), the first adhesive portion 41 is disposed on the first surface 1121 of the first sidewall 112, and the second adhesive portion 42 is disposed on the inner wall of the first sidewall 112. The first adhesive portion 41 and the second adhesive portion 42 are integrally provided. This allows the adhesive member 40 to be relatively stably fixed to the first sidewall 112. In some embodiments, the first adhesive portion 41 is fixed to the filling portion 301. The cooperation between the first adhesive member 40 and the sealing member 30 improves the sealing strength between the sealing member 30 and the housing 10, thereby reducing the possibility of relative twisting between the first shell 11 and the second shell 12.

[0051] In some embodiments, the first adhesive portion 41 is adhesively fixed to the filling portion 301. In some embodiments, the first adhesive portion 41 is welded to the filling portion 301.

[0052] In some embodiments, the first adhesive portion 41 is integrally formed with the filling portion 301. This helps improve the stability of the connection between the first adhesive portion 41 and the filling portion 301. In some embodiments, before assembling the first and second housings 11 and 12, a first adhesive member 40 is pre-attached to the first sidewall 112 to form the first adhesive portion 41 and the second adhesive portion 42. The filling portion 301 is molten and welded to the first adhesive portion 41. After cooling, the filling portion 301 and the first adhesive portion 41 are integrally formed.

[0053] In some embodiments, see Figure 6 , the thickness of the first adhesive portion 41 is H1, 3μm≤H1≤500μm. For example, H1 is 3μm, 6μm, 10μm, 20μm, 50μm, 100μm, 200μm, 300μm, 500μm or a range between the listed endpoint values or any value between the listed endpoint values. By setting 3μm≤H1, it is beneficial to reduce the risk of burrs piercing the first adhesive portion 41 and causing a short circuit after the filling portion 301 melts. By setting H1≤500μm, it is beneficial to improve the energy density of the secondary battery 100. Among them, the thickness of the first adhesive portion 41 is the dimension of the first adhesive portion 41 along the direction perpendicular to the first surface 1121.

[0054] In some embodiments, 6 μm ≤ H1 ≤ 200 μm. Setting 6 μm ≤ H1 further reduces the risk of burrs from melting the filling portion 301 and piercing the first bonding portion 41, causing a short circuit. Setting H1 ≤ 200 μm further increases the energy density of the secondary battery 100.

[0055] In some embodiments, see Figure 6 The thickness of the second adhesive portion 42 is H2, and 90% H1 ≤ H2 ≤ 110% H1. Considering the accuracy of the processing technology, by setting 90% H1 ≤ H2 ≤ 110% H1, it is possible to facilitate the integrated arrangement of the first adhesive portion 41 and the second adhesive portion 42. The thickness of the second adhesive portion 42 is the dimension of the second adhesive portion 42 along the direction perpendicular to the first side wall 112.

[0056] In some embodiments, see Figure 6 The first adhesive portion 41 has a width W1, which is less than or equal to the thickness of the first sidewall 112. Considering the accuracy of the manufacturing process, when W1 is greater than the thickness of the first sidewall 112 within a 10% error range, W1 can also be considered equal to the thickness of the first sidewall 112. The width of the first adhesive portion 41 is the dimension of the first adhesive portion 41 along a direction parallel to the first surface 1121.

[0057] In some embodiments, see Figure 6, the width of the second adhesive portion 42 is W2, 30μm≤W2≤3000μm. For example, W2 is 30μm, 50μm, 100μm, 200μm, 500μm, 1000μm, 1500μm, 3000μm, or a range between the listed endpoint values or any value between the listed endpoint values. By setting 30μm≤W2, the bonding area between the second adhesive portion 42 and the inner wall of the first side wall 112 can be made not too small, which is beneficial to improving the stability of the second adhesive portion 42 provided on the inner wall of the first side wall 112. Moreover, when the first adhesive portion 41 and the filling portion 301 are provided as a whole, setting 30μm≤W2 is also beneficial to reducing the possibility of electrolyte erosion of the interface between the second adhesive portion 42 and the first side wall 112. By setting W2 ≤ 3000 μm, the bonding area between the second bonding portion 42 and the inner wall of the first side wall 112 can be kept small. When the polarity of the electrode assembly 20 is led out through the first side wall 112, the first side wall 112 has a larger area for connection, which helps to improve the convenience of connecting the electrode assembly 20 to the first side wall 112. The width of the second bonding portion 42 is the dimension along the extension direction of the first side wall 112.

[0058] In some embodiments, 100 μm ≤ W2 ≤ 1500 μm. Setting 100 μm ≤ W2 helps further improve the stability of the second bonding portion 42 provided on the inner wall of the first sidewall 112. Furthermore, when the first bonding portion 41 and the filling portion 301 are integrally provided, setting 100 μm ≤ W2 also helps further reduce the possibility of electrolyte erosion at the interface between the second bonding portion 42 and the first sidewall 112. Setting W2 ≤ 1500 μm helps further improve the convenience of connecting the electrode assembly 20 to the first sidewall 112.

[0059] In some embodiments, the melting point of the first adhesive 40 is between 95°C and 130°C. For example, the melting point of the first adhesive 40 is 95°C, 100°C, 110°C, 130°C, or a range between the listed endpoints, or any value between the listed endpoints. In some embodiments, the melting point of the first adhesive 40 is between 150°C and 500°C. For example, the melting point of the first adhesive 40 is 150°C, 200°C, 250°C, 300°C, 500°C, or a range between the listed endpoints, or any value between the listed endpoints.

[0060] In some embodiments, the secondary battery 100 further includes a second adhesive member 50, which is disposed on the second sidewall 122. The second adhesive member 50 includes a third adhesive portion 51 and a fourth adhesive portion 52. The third adhesive portion 51 is disposed on the second surface 1221 of the second sidewall 122, and the fourth adhesive portion 52 is disposed on the inner wall of the second sidewall 122. The third adhesive portion 51 and the fourth adhesive portion 52 are integrally disposed, enabling the second adhesive member 50 to be more stably fixed to the second sidewall 122. In some embodiments, the third adhesive portion 51 is fixed to the filling portion 301. The cooperation between the second adhesive member 50 and the sealing member 30 can further improve the sealing strength between the sealing member 30 and the outer shell 10, thereby further reducing the possibility of relative twisting between the first shell 11 and the second shell 12.

[0061] In some embodiments, the third adhesive portion 51 is adhesively fixed to the filling portion 301. In some embodiments, the third adhesive portion 51 is welded and fixed to the filling portion 301.

[0062] In some embodiments, the third adhesive portion 51 is integrally formed with the filling portion 301. This helps improve the stability of the connection between the third adhesive portion 51 and the filling portion 301. In some embodiments, before assembling the first housing 11 and the second housing 12, a second adhesive member 50 is pre-attached to the second sidewall 122 to form the third adhesive portion 51 and the fourth adhesive portion 52. The filling portion 301 is molten and welded to the third adhesive portion 51. After cooling, the filling portion 301 and the third adhesive portion 51 are integrally formed.

[0063] In some embodiments, the thickness of the third adhesive portion 51 is H3, 3μm≤H3≤500μm. For example, H3 is 3μm, 6μm, 10μm, 20μm, 50μm, 100μm, 200μm, 300μm, 500μm, or a range between the listed endpoint values or any value between the listed endpoint values. By setting 3μm≤H3, it is helpful to reduce the risk of burrs piercing the third adhesive portion 51 after the filling portion 301 melts and causing a short circuit. By setting H3≤500μm, it is helpful to improve the energy density of the secondary battery 100. The thickness of the third adhesive portion 51 is the dimension of the third adhesive portion 51 in a direction perpendicular to the second surface 1221.

[0064] In some embodiments, 6 μm ≤ H3 ≤ 200 μm. Setting 6 μm ≤ H3 further reduces the risk of burrs from melting the filling portion 301 and piercing the third bonding portion 51, causing a short circuit. Setting H3 ≤ 200 μm further improves the energy density of the secondary battery 100.

[0065] In some embodiments, the thickness of the fourth adhesive portion 52 is H4, where 90% H3 ≤ H4 ≤ 110% H3. Considering the accuracy of the processing, setting 90% H3 ≤ H4 ≤ 110% H3 facilitates the integrated arrangement of the third adhesive portion 51 and the fourth adhesive portion 52. The thickness of the fourth adhesive portion 52 is the dimension perpendicular to the second sidewall 122.

[0066] In some embodiments, the width of the third adhesive portion 51 is W3, which is less than or equal to the thickness of the second sidewall 122. Considering the accuracy of the processing, when W3 is greater than the thickness of the second sidewall 122 within a 10% error range, W3 can also be considered equal to the thickness of the second sidewall 122. The width of the third adhesive portion 51 is the dimension of the third adhesive portion 51 along a direction parallel to the second surface 1221.

[0067] In some embodiments, the width of the fourth adhesive portion 52 is W4, and 30μm≤W4≤3000μm. For example, W4 is 30μm, 50μm, 100μm, 200μm, 500μm, 1000μm, 1500μm, 3000μm, or a range between the listed endpoint values, or any value between the listed endpoint values. By setting 30μm≤W4, the bonding area between the fourth adhesive portion 52 and the inner wall of the second side wall 122 is not too small, which helps to improve the stability of the fourth adhesive portion 52 provided on the inner wall of the second side wall 122. In addition, when the third adhesive portion 51 and the filling portion 301 are provided integrally, setting 30μm≤W4 also helps to reduce the possibility of electrolyte erosion of the interface between the fourth adhesive portion 52 and the second side wall 122. By setting W4 ≤ 3000 μm, the bonding area between the fourth bonding portion 52 and the inner wall of the second side wall 122 can be kept small. When the polarity of the electrode assembly 20 is led out through the second side wall 122, the second side wall 122 has a larger area for connection, which helps to improve the convenience of connecting the electrode assembly 20 to the second side wall 122. The width of the fourth bonding portion 52 is the dimension of the fourth bonding portion 52 along the extension direction of the second side wall 122.

[0068] In some embodiments, 100 μm ≤ W4 ≤ 1500 μm. Setting 100 μm ≤ W4 helps further improve the stability of the fourth bonding portion 52 provided on the inner wall of the second sidewall 122. Furthermore, when the third bonding portion 51 and the filling portion 301 are integrally provided, setting 100 μm ≤ W4 also helps further reduce the possibility of electrolyte erosion at the interface between the fourth bonding portion 52 and the second sidewall 122. Setting W4 ≤ 1500 μm helps further improve the convenience of connecting the electrode assembly 20 to the second sidewall 122.

[0069] In some embodiments, the melting point of the second adhesive 50 is between 95°C and 130°C. For example, the melting point of the second adhesive 50 is 95°C, 100°C, 110°C, 130°C, or a range or any value between the listed endpoints. In some embodiments, the melting point of the second adhesive 50 is between 150°C and 500°C. For example, the melting point of the second adhesive 50 is 150°C, 200°C, 250°C, 300°C, 500°C, or a range or any value between the listed endpoints.

[0070] In some embodiments, the spacing between the first surface 1121 and the second surface 1221 is D, and 20 μm ≤ D ≤ 5000 μm. For example, D is 20 μm, 40 μm, 100 μm, 200 μm, 500 μm, 1000 μm, 2000 μm, 3000 μm, 5000 μm, or a range between the listed endpoint values, or any value between the listed endpoint values. By setting 20 μm ≤ D, the spacing between the first surface 1121 and the second surface 1221 is not too small, which helps reduce the possibility of a short circuit between the first shell 11 and the second shell 12 due to burr contact. By setting D ≤ 5000 μm, the spacing between the first surface 1121 and the second surface 1221 is not too large, which helps improve the energy density of the secondary battery 100.

[0071] In some embodiments, 40 μm ≤ D ≤ 3000 μm. Setting 40 μm ≤ D further reduces the possibility of a short circuit between the first shell 11 and the second shell 12 due to burr contact. Setting D ≤ 3000 μm further increases the energy density of the secondary battery 100.

[0072] In some embodiments, see Figure 4 and Figure 5 The sealing member 30 includes a first adhesive layer 31, which is adhered to the outer periphery of the first side wall 112 and the second side wall 122. The filling portion 301 is connected to the first adhesive layer 31. The adhesion of the first adhesive layer 31 to the first side wall 112 and the second side wall 122 helps to improve the stability of the adhesion between the sealing member 30 and the housing 10.

[0073] In some embodiments, the filling portion 301 is integrally formed with the first adhesive layer 31. The filling portion 301 can be formed directly by melting a portion of the first adhesive layer 31, which then enters the gap between the first surface 1121 and the second surface 1221 and cools. This can simplify the assembly process of the secondary battery 100 and facilitate the process flow for manufacturing the secondary battery 100. Furthermore, the filling portion 301 is integrally formed with the first adhesive layer 31, fully fitting the gap between the first surface 1121 and the second surface 1221, thereby improving the sealing performance of the sealing member 30 between the first and second shells 11 and 12. In other embodiments, the filling portion 301 is provided separately from the first adhesive layer 31.

[0074] In some embodiments, the first adhesive layer 31 can melt or lose adhesion when heated, and forms part of a pressure relief channel connected to the receiving cavity 101. When the secondary battery 100 experiences thermal runaway, the melting or loss of adhesion of the first adhesive layer 31 can promptly relieve pressure in the receiving cavity 101, thereby improving the safety of the secondary battery 100.

[0075] In some embodiments, the melting point of the first adhesive layer 31 is between 95°C and 130°C. For example, the melting point of the first adhesive layer 31 is 95°C, 100°C, 110°C, 130°C, or a range between the listed endpoint values, or any value between the listed endpoint values. By setting the melting point of the first adhesive layer 31 to 95°C to 130°C, the possibility of premature melting or loss of adhesion of the first adhesive layer 31 before thermal runaway of the secondary battery 100 can be reduced, which is beneficial for maintaining the sealing effect of the seal 30 on the outer shell 10. Furthermore, it can ensure that the first adhesive layer 31 melts or loses adhesion in time to relieve pressure in the receiving cavity 101 when thermal runaway of the secondary battery 100 occurs, which is beneficial for improving the safety of the secondary battery 100. It should be understood that when the filling portion 301 is integrally provided with the first adhesive layer 31, and the filling portion 301 is directly formed by a portion of the first adhesive layer 31 melting and entering the gap between the first surface 1121 and the second surface 1221 and then cooling, the melting point of the filling portion 301 is substantially the same as the melting point of the first adhesive layer 31.

[0076] In some embodiments, the first shell 11 and the second shell 12 have the same polarity, the melting point of at least one of the first adhesive 40 and the filling portion 301 is between 95°C and 130°C, and the melting point of the first adhesive layer 31 is between 95°C and 130°C. This reduces the likelihood of premature melting or loss of adhesion of at least one of the first adhesive 40 and the filling portion 301 before thermal runaway of the secondary battery 100 occurs, thereby maintaining the sealing effect of the seal 30 on the outer shell 10. Furthermore, if thermal runaway of the secondary battery 100 occurs, the first adhesive 40, at least one of the filling portion 301, and the first adhesive layer 31 can melt or lose adhesion in a timely manner to relieve pressure in the receiving cavity 101, thereby improving the safety of the secondary battery 100.

[0077] In some embodiments, the first shell 11 and the second shell 12 have the same polarity, the melting point of at least one of the second adhesive 50 and the filling portion 301 is between 95°C and 130°C, and the melting point of the first adhesive layer 31 is between 95°C and 130°C. This reduces the likelihood of premature melting or loss of adhesion of at least one of the second adhesive 50 and the filling portion 301 before thermal runaway of the secondary battery 100 occurs, thereby maintaining the sealing effect of the seal 30 on the outer shell 10. Furthermore, if thermal runaway of the secondary battery 100 occurs, the second adhesive 50, at least one of the filling portion 301, and the first adhesive layer 31 can melt or lose adhesion in a timely manner to relieve pressure in the receiving cavity 101, thereby improving the safety of the secondary battery 100.

[0078] In some embodiments, the polarity of the first shell 11 and the second shell 12 is different, the melting point of the first glue layer 31 is 95°C to 130°C, the melting point of the filling part 301 is 95°C to 130°C, and the melting point of the first adhesive 40 is 150°C to 500°C. When the secondary battery 100 has thermal runaway, it is convenient for the first glue layer 31 and the filling part 301 to melt or lose adhesion in time to relieve the pressure of the receiving cavity 101 while reducing the possibility of the first adhesive 40 melting or losing adhesion, which is beneficial to reducing the risk of contact short circuit between the first shell 11 and the second shell 12. Alternatively, the melting point of the first glue layer 31 is 95°C to 130°C, the melting point of the filling part 301 is 150°C to 500°C, and the melting point of the first adhesive 40 is 95°C to 130°C. When the secondary battery 100 experiences thermal runaway, the first glue layer 31 and the first adhesive 40 can be melted or debonded in time to relieve the pressure of the receiving cavity 101 while reducing the possibility of melting of the filling part 301, which is beneficial to reducing the risk of contact short circuit between the first shell 11 and the second shell 12.

[0079] In some embodiments, the polarity of the first shell 11 and the second shell 12 is different, the melting point of the first adhesive layer 31 is 95°C to 130°C, the melting point of the filling part 301 is 95°C to 130°C, and the melting point of the second adhesive 50 is 150°C to 500°C. When the secondary battery 100 has thermal runaway, it is convenient for the first adhesive layer 31 and the filling part 301 to melt or lose adhesion in time to relieve the pressure of the receiving cavity 101 while reducing the possibility of the second adhesive 50 melting or losing adhesion, which is beneficial to reducing the risk of contact short circuit between the first shell 11 and the second shell 12. Alternatively, the melting point of the first adhesive layer 31 is 95°C to 130°C, the melting point of the filling part 301 is 150°C to 500°C, and the melting point of the second adhesive 50 is 95°C to 130°C. When the secondary battery 100 experiences thermal runaway, the first adhesive layer 31 and the second adhesive 50 can be melted or debonded in time to relieve the pressure of the receiving cavity 101 while reducing the possibility of melting of the filling part 301, which is beneficial to reducing the risk of contact short circuit between the first shell 11 and the second shell 12.

[0080] In some embodiments, the material of the first adhesive layer 31 comprises an electrolyte-resistant polymer. The polymer of the first adhesive layer 31 comprises at least one of polyolefin, fluororubber, and polyurethane. Polyolefins may include polypropylene and polyethylene, among others. This allows the first adhesive layer 31 to have high resistance to electrolyte corrosion. In some embodiments, the first adhesive layer 31 comprises a single layer or multiple layers of the polymer.

[0081] In some embodiments, see Figure 4 and Figure 5 The seal 30 includes a metal layer 32, which is arranged on the side of the first adhesive layer 31 away from the outer shell 10. The water resistance of the metal layer 32 is better than that of the first adhesive layer 31, which is beneficial to improving the sealing performance of the seal 30 to the first shell 11 and the second shell 12.

[0082] In some embodiments, the material of metal layer 32 includes at least one of steel, aluminum, nickel, silver, copper, and alloys thereof. In some embodiments, metal layer 32 is a single layer or a multilayer structure. For example, the multilayer structure includes a steel layer plus an aluminum layer, or a nickel layer plus a copper layer.

[0083] In some embodiments, see Figure 4 and Figure 5 The sealing member 30 includes a second adhesive layer 33, which is disposed on a side of the metal layer 32 facing away from the first adhesive layer 31. The second adhesive layer 33 can protect the metal layer 32, thereby reducing the risk of damage and failure of the metal layer 32.

[0084] In some embodiments, the melting point of the second adhesive layer 33 is greater than the melting point of the first adhesive layer 31. In some embodiments, the difference in melting point between the second adhesive layer 33 and the first adhesive layer 31 is greater than 10°C.

[0085] In some embodiments, the melting point of the second adhesive layer 33 is 140° C. to 500° C. For example, the melting point of the second adhesive layer 33 is 140° C., 160° C., 200° C., 250° C., 300° C., 500° C., or any value therebetween.

[0086] In some embodiments, the material of the second adhesive layer 33 comprises an electrolyte-resistant polymer. The polymer of the second adhesive layer 33 includes at least one of polyolefin, fluoropolymer, polyetheretherketone, fluororubber, and polyurethane. Polyolefins may include polypropylene and polyethylene, and fluoropolymers may include polytetrafluoroethylene. This allows the second adhesive layer 33 to have high resistance to electrolyte corrosion. In some embodiments, the second adhesive layer 33 comprises a single layer or multiple layers of the polymer.

[0087] It should be understood that when the seal 30 includes a first adhesive layer 31, a metal layer 32, and a second adhesive layer 33, the first adhesive layer 31 and the second adhesive layer 33 are respectively disposed on either side of the metal layer 32 along the thickness direction of the metal layer 32. In some embodiments, the first adhesive layer 31 and the metal layer 32, as well as the second adhesive layer 33 and the metal layer 32, are fixed by gluing, so that the first adhesive layer 31, the metal layer 32, and the second adhesive layer 33 are fixed by hot pressing, so that the first adhesive layer 31, the metal layer 32, and the second adhesive layer 33 are fixed by hot pressing, so that the first adhesive layer 31, the metal layer 32, and the second adhesive layer 33 are fixed by hot pressing. This helps maintain the sealing performance of the seal 30 against the first shell 11 and the second shell 12 during long-term use of the secondary battery 100.

[0088] In some embodiments, along the thickness direction of the sealant 30, the first adhesive layer 31 has a thickness d1, the metal layer 32 has a thickness d2, and the second adhesive layer 33 has a thickness d3. The following conditions are met: 7 μm ≤ d1 ≤ 500 μm, 7 μm ≤ d2 ≤ 250 μm, and 6 μm ≤ d3 ≤ 500 μm. For example, d1 is 7 μm, 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, 500 μm, or any value therebetween; d2 is 7 μm, 10 μm, 20 μm, 50 μm, 100 μm, 150 μm, 250 μm, or any value therebetween; and d3 is 6 μm, 8 μm, 20 μm, 50 μm, 100 μm, 200 μm, 500 μm, or any value therebetween. By setting d1 to 7μm ≤ d1, d2 to 7μm ≤ d2, and d3 to 6μm ≤ d3, the first adhesive layer 31, metal layer 32, and second adhesive layer 33 are kept from being too thin, thereby reducing the risk of first adhesive layer 31 being corroded and failing by the electrolyte. This also reduces the risk of second adhesive layer 33 breaking after the secondary battery 100 is dropped, leading to damage and failure of the metal layer 32, or corrosion and failure of the metal layer 32. By setting d1 to 500μm ≤ 250μm, and d3 to 500μm, the first adhesive layer 31, metal layer 32, and second adhesive layer 33 are kept from being too thick, thereby increasing the energy density of the secondary battery 100.

[0089] In some embodiments, 10μm ≤ d1 ≤ 200μm, 10μm ≤ d2 ≤ 150μm, and 8μm ≤ d3 ≤ 200μm. By setting 10μm ≤ d1, 10μm ≤ d2, and 8μm ≤ d3, the first adhesive layer 31, metal layer 32, and second adhesive layer 33 can be made thicker, further reducing the risk of first adhesive layer 31 being corroded and failing by the electrolyte. This also helps reduce the risk of second adhesive layer 33 being damaged after the secondary battery 100 is dropped, leading to damage and failure of the metal layer 32, or failure of the metal layer 32 due to corrosion. By setting d1 ≤ 200μm, d2 ≤ 150μm, and d3 ≤ 200μm, the energy density of the secondary battery 100 can be further improved while ensuring that the thickness of the first adhesive layer 31 is substantially sufficient to prevent failure due to electrolyte corrosion, the thickness of the second adhesive layer 33 is sufficient to withstand most drops, and the thickness of the metal layer 32 is substantially sufficient to prevent failure due to damage or corrosion.

[0090] In some embodiments, the thickness of the first adhesive layer 31 can be uniform or non-uniform. In some embodiments, the thickness of the metal layer 32 can be uniform or non-uniform. In some embodiments, the thickness of the second adhesive layer 33 can be uniform or non-uniform. In some embodiments, the thickness of the seal 30 can be uniform or non-uniform, and the thickness of the seal 30 is equal to the sum of the thicknesses of the first adhesive layer 31, the metal layer 32, and the second adhesive layer 33.

[0091] In some embodiments, see Figure 4 and Figure 5 The secondary battery 100 further includes a fixing member 60 that bonds the outer shell 10 to the electrode assembly 20, thereby reducing the risk of the electrode assembly 20 moving within the receiving cavity 101 and causing separation between the first shell 11 and / or the second shell 12 and the seal 30. In some embodiments, the fixing member 60 is disposed between the outer shell 10 and the electrode assembly 20 along the thickness direction of the electrode assembly 20. In some embodiments, the fixing member 60 is a hot melt adhesive.

[0092] See also Figure 7 One embodiment of the present application provides an electrical device 1000, comprising the aforementioned secondary battery 100. The secondary battery 100 has good sealing properties, preventing electrolyte leakage, thereby extending the service life of the electrical device 1000. The electrical device 1000 includes, but is not limited to, electronic devices such as e-book players, mobile phones, fax machines, copiers, printers, headphones, video recorders, LCD televisions, tape recorders, radios, cameras, tablet computers, and laptop computers.

[0093] In addition, those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the substantive scope of the present application, appropriate changes and modifications to the above embodiments are within the scope disclosed in the present application.

Claims

1. A secondary battery, characterized in that: include: The housing comprises a first shell and a second shell, the first shell and the second shell together forming a receiving cavity filled with an electrolyte; the first shell comprises a first wall and a first side wall connected to a periphery of the first wall; the second shell comprises a second wall and a second side wall connected to a periphery of the second wall; the first side wall is provided with a first surface, the first surface facing the second side wall along an extension direction of the first side wall; the second side wall is provided with a second surface, the second surface facing the first side wall along an extension direction of the second side wall; the first surface and the second surface are arranged opposite to each other with a gap therebetween; an electrode assembly, disposed in the receiving cavity; a sealing member disposed around the outer periphery of the first side wall and the second side wall and sealing the gap; the sealing member includes a filling portion disposed in the gap; as well as A first adhesive member is provided on the first side wall, and the first adhesive member includes a first adhesive portion and a second adhesive portion. The first adhesive portion is provided on the first surface of the first side wall, and the second adhesive portion is provided on the inner wall of the first side wall. The first adhesive portion and the second adhesive portion are provided integrally; the first adhesive portion and the filling portion are fixedly provided.

2. The secondary battery according to claim 1, wherein The secondary battery also includes a second adhesive member, which is arranged on the second side wall. The second adhesive member includes a third adhesive portion and a fourth adhesive portion. The third adhesive portion is arranged on the second surface of the second side wall, and the fourth adhesive portion is arranged on the inner wall of the second side wall. The third adhesive portion and the fourth adhesive portion are arranged integrally; the third adhesive portion is fixed to the filling portion.

3. The secondary battery according to claim 1, wherein A distance D between the first surface and the second surface is 20 μm≤D≤5000 μm.

4. The secondary battery according to claim 3, wherein 40μm≤D≤3000μm.

5. The secondary battery according to claim 2, wherein The thickness of the first adhesive portion is H1, the thickness of the second adhesive portion is H2, 3μm≤H1≤500μm, 90%H1≤H2≤110%H1; the thickness of the third adhesive portion is H3, the thickness of the fourth adhesive portion is H4, 3μm≤H3≤500μm, 90%H3≤H4≤110%H3.

6. The secondary battery according to claim 5, characterized in that 6μm≤H1≤200μm; 6μm≤H3≤200μm.

7. The secondary battery according to claim 2, characterized in that The first adhesive portion is integrally provided with the filling portion, and the third adhesive portion is integrally provided with the filling portion.

8. The secondary battery according to claim 2 or 7, characterized in that The width of the second adhesive portion is W2, 30 μm≤W2≤3000 μm, and the width of the fourth adhesive portion is W4, 30 μm≤W4≤3000 μm.

9. The secondary battery according to claim 8, characterized in that 100μm≤W2≤1500μm, 100μm≤W4≤1500μm.

10. The secondary battery according to claim 1, wherein The sealing component includes a first adhesive layer, a metal layer and a second adhesive layer. Along the thickness direction of the metal layer, the first adhesive layer and the second adhesive layer are respectively arranged on both sides of the metal layer. The first adhesive layer is adhered to the outer periphery of the first side wall and the second side wall, and the filling part is integrally arranged with the first adhesive layer.

11. The secondary battery according to claim 10, wherein Along the thickness direction of the seal, the thickness of the first adhesive layer is d1, the thickness of the metal layer is d2, and the thickness of the second adhesive layer is d3, 7μm≤d1≤500μm, 7μm≤d2≤250μm, and 6μm≤d3≤500μm.

12. The secondary battery according to claim 11, wherein 10μm≤d1≤200μm, 10μm≤d2≤150μm, 8μm≤d3≤200μm.

13. An electrical device, characterized in that: The secondary battery according to any one of claims 1 to 12 is included.

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