Explosion-proof battery

Abstract

The application provides an explosion-proof battery, which comprises a shell, an electric core and an insulating rubber ring. The inner metal shell of the shell is in a cylindrical structure with a first opening at one end, and the outer metal shell is in a cylindrical structure with a second opening at one end. The first opening and the second opening are in butt joint. The electric core is arranged in the inner metal shell. The insulating rubber ring is arranged in sealing between the outer metal shell and the inner metal shell. One end of the outer metal shell is locked and connected to the outer periphery of the insulating rubber ring to form a seal, and one side of the insulating rubber ring close to the outer metal shell is provided with a rubber ring air vent. When the battery generates heat to produce high-pressure gas inside, the high-pressure gas will separate the outer metal shell and the insulating rubber ring. When the outer metal shell and the insulating rubber ring are separated to a certain extent, the rubber ring air vent can connect the inner space of the outer metal shell and the outer space, so that the high-pressure gas can be released through the rubber ring air vent, preventing the battery from catching fire or exploding.

Description

[0001] This application is a divisional application. The original application has the application number "202010399039.0" and the application date "May 12, 2020". The invention title is "Battery with Explosion-proof Structure". Technical Field

[0002] This invention relates to the field of batteries, and in particular to an explosion-proof battery. Background Technology

[0003] A battery is a device containing an electrolyte solution and metal electrodes, converting chemical energy into electrical energy. Because of their thinness and small size, batteries are commonly used in various electronic products to power them. However, batteries are prone to overheating under extreme conditions such as exposure to fire or severe impacts. This increases the internal gas volume and pressure, potentially causing the outer metal casing to rupture and release energy, leading to a fire or explosion. Therefore, batteries often incorporate explosion-proof structures. However, in current technology, these structures require stamping on the battery casing, which often occupies internal space and affects the battery's capacity.

[0004] Therefore, it is necessary to provide an explosion-proof battery to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides an explosion-proof battery to solve the problem that the explosion-proof structure on batteries in the prior art is not optimized enough, often occupying part of the internal space of the battery and affecting the battery capacity.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: an explosion-proof battery, comprising:

[0007] The shell includes an inner metal shell and an outer metal shell. The inner metal shell is a cylindrical structure with a first opening at one end, and the outer metal shell is a cylindrical structure with a second opening at one end. The first opening and the second opening are connected.

[0008] The battery cell is disposed within the inner metal casing; and

[0009] An insulating rubber ring is sealed between the outer metal shell and the inner metal shell. One end of the outer metal shell is locked to the outer periphery of the insulating rubber ring, so that a seal is formed between the edge of the outer metal shell and the insulating rubber ring. A vent is provided on the side of the insulating rubber ring near the outer metal shell. The insulating rubber ring covers the inner and outer surfaces of the axial side plate of the inner metal shell.

[0010] In this invention, the inner metal shell has a folded edge near the first opening, the folded edge protrudes outward, and the folded edge is secured to the insulating rubber ring.

[0011] In this invention, a constriction section is provided at the end of the outer metal shell away from the second opening, and the inner diameter of the end of the constriction section near the second opening is larger than the inner diameter of the end of the constriction section away from the second opening.

[0012] The ratio of the height of the constricted section to the height of the outer metal shell is between 0.15 and 0.7.

[0013] In addition, the angle between the inner wall surface of the compressed section L and the inner wall surface of the outer metal shell is between 170° and 179°.

[0014] In this invention, an annular protrusion is provided on the inner wall of the outer metal shell, and the annular protrusion is interference-fitted with the insulating rubber ring. The annular protrusion is formed by stamping the outer side of the outer metal shell.

[0015] In this invention, an inner shell snap-fit ​​portion is provided at one end of the outer side surface of the inner metal shell. The inner shell snap-fit ​​portion includes a first protrusion on the inner side and a first concave portion on the outer side. The insulating rubber ring on the inner side covers the non-setting area of ​​the first protrusion on the inner surface of the inner metal shell.

[0016] The insulating rubber ring is provided with a rubber ring snapping part, which includes an inner second protrusion and an outer second concave part. The second protrusion snaps into the first concave part, and the edge of the outer metal shell snaps into the second concave part.

[0017] In this invention, the inner edge of the insulating rubber ring near the first opening is provided with a chamfer, and the outer edge is provided with a rounded chamfer.

[0018] In this invention, the housing is provided with an explosion-proof through hole, which connects the inner cavity of the housing with the external space. An explosion-proof plate is provided to seal the explosion-proof through hole. The area opposite the explosion-proof plate to the through hole is the explosion-proof area. A crack line is provided on the explosion-proof plate. The crack line is a ring structure, which includes a closed end and a non-closed end. The closed end is located within the explosion-proof area, and the non-closed end is offset from the explosion-proof area.

[0019] Compared to existing technologies, the advantages of this invention are as follows: When the explosion-proof battery of this invention heats up, high-pressure gas is generated inside the battery. This high-pressure gas causes the outer metal shell and the insulating ring to separate. When the outer metal shell and the insulating ring separate to a certain extent, the insulating ring is no longer sealed to the outer metal shell, allowing the vent of the ring to connect the internal and external spaces of the outer metal shell. This allows the high-pressure gas to be released through the vent, preventing the battery from catching fire or exploding. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments are briefly introduced below. The drawings described below are only the corresponding drawings of some embodiments of the present invention.

[0021] Figure 1 This is a cross-sectional view of the battery of the present invention with the explosion-proof through hole provided on the inner metal shell.

[0022] Figure 2 for Figure 1 Enlarged view of the local structure at point X.

[0023] Figure 3 for Figure 1 Enlarged view of the local structure at point Y.

[0024] Figure 4 This is a schematic diagram of an explosion-proof disc with two crack lines.

[0025] Figure 5 This is a schematic diagram of an explosion-proof disc with a crack line featuring a ring structure.

[0026] Figure 6 This is a schematic diagram of an explosion-proof disc with a crack line featuring a ring structure.

[0027] Figure 7 This is a schematic diagram of the upper insulating sheet.

[0028] Figure 8 This is a schematic diagram of the structure of the battery of the present invention when an annular protrusion is provided on the outer metal shell.

[0029] Figure 9 This is a schematic diagram of the structure of the battery of the present invention when the inner metal shell is provided with an inner shell snap-fit ​​part.

[0030] Figure 10 This is a cross-sectional view of the battery of the present invention with the explosion-proof through hole provided on the outer metal shell.

[0031] Outer metal shell 11; Annular protrusion 111; Explosion-proof through hole in outer shell 112; Inner metal shell 12; Explosion-proof through hole in inner shell 121; Folded edge 122; Inner shell snap-fit ​​part 123; Insulating rubber ring 13; Rubber ring vent 131; Rubber ring snap-fit ​​part 132; Battery cell 14; Negative electrode tab 15; Positive electrode tab 16; Upper insulating sheet 17; Vent hole 171; Lower insulating sheet 18; Explosion-proof sheet 19; Crack line 191; Compacted section L. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The directional terms mentioned in this invention, such as "up", "down", "front", "back", "left", "right", "inner", "outer", "side", "top" and "bottom", are only for reference to the orientation of the accompanying drawings. The directional terms used are for the purpose of explaining and understanding this invention, and are not intended to limit this invention.

[0034] The terms "first" and "second" used in the terminology of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor as limiting the order of events.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, a connection can be a detachable connection or a connection of an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components or an interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] In the existing technology, the explosion-proof structure on the battery needs to be stamped on the battery casing. This stamped structure often occupies part of the internal space of the battery, thus affecting the battery capacity.

[0037] The following is a first embodiment of a battery provided by the present invention that can solve the above-mentioned technical problems.

[0038] Please refer to Figure 1 and Figure 2 ,in Figure 1 This is a cross-sectional view of the battery of the present invention with the explosion-proof through hole provided on the inner metal shell. Figure 2 for Figure 1 Enlarged view of the local structure at point X.

[0039] In the diagram, units with similar structures are represented by the same labels.

[0040] The present invention provides a battery comprising a casing, an explosion-proof sheet 19, a battery cell 14, and an insulating rubber ring 13.

[0041] The shell includes an inner metal shell 12 and an outer metal shell 11. The inner metal shell 12 is a cylindrical structure with a first opening at one end, and the outer metal shell 11 is a cylindrical structure with a second opening at one end. The first opening and the second opening are connected. The shell is provided with a groove and an explosion-proof through hole. The explosion-proof through hole connects the inner cavity of the shell and the external space. The groove is formed by cutting the outer surface of the shell, such as milling the outer surface of the shell to form the groove. The explosion-proof through hole is located in the groove.

[0042] The explosion-proof plate 19 is connected in the settling tank. The explosion-proof plate 19 seals the explosion-proof through hole. The area of ​​the explosion-proof plate 19 opposite to the through hole is the explosion-proof area. Crack lines 191 are provided on the explosion-proof plate 19. At least part of the crack lines 191 are located in the explosion-proof area.

[0043] The battery cell 14 is disposed inside the inner metal shell 12. The battery cell 14 is connected to the outer metal shell 11 through the positive electrode tab 16 and the battery cell 14 is connected to the inner metal shell 12 through the negative electrode tab 15.

[0044] An insulating rubber ring 13 is sealed between the outer metal shell 11 and the inner metal shell 12, so that the outer metal shell 11 and the inner metal shell 12 form a seal and insulation. One end of the outer metal shell 11 is locked to the outer periphery of the insulating rubber ring 13, so that the edge of the outer metal shell 11 and the insulating rubber ring 13 form a seal.

[0045] When the battery heats up, high-pressure gas is generated inside. When the gas pressure reaches a certain level, the high-pressure gas will rupture the explosion-proof plate 19 along the crack line 191. A release hole is formed on the explosion-proof plate 19, and the high-pressure gas can be released through the explosion-proof hole and the release hole to prevent the battery from catching fire or exploding.

[0046] The height-to-diameter ratio of the battery in this invention is between 0.4 and 1.

[0047] Please refer to Figure 1 In this embodiment, the recessed groove can be an inner shell recessed groove provided on the outer end face of the inner metal shell 12, and the explosion-proof through hole is an inner shell explosion-proof through hole 121 provided on the end face of the inner metal shell 12. The inner shell explosion-proof through hole 121 is located in the inner shell recessed groove, and the inner shell recessed groove is close to the edge of the end face of the inner metal shell 12, thereby avoiding interference between the inner shell explosion-proof through hole 121 and the negative electrode tab 15.

[0048] Or please refer to Figure 10 In this embodiment, the recessed groove can also be a recessed groove on the outer end face of the outer metal shell 11, and the explosion-proof through hole is an explosion-proof through hole 112 on the end face of the outer metal shell 11. The explosion-proof through hole 112 is located inside the recessed groove, and the recessed groove is close to the edge of the end face of the inner metal shell 12, so as to avoid interference between the explosion-proof through hole 121 of the inner shell and the positive electrode tab 16.

[0049] Please refer to Figure 4 Preferably, two crack lines 191 are provided on the inner surface of the explosion-proof sheet 19, the two crack lines 191 are staggered, and the intersection of the two crack lines 191 is located within the explosion-proof area.

[0050] Please refer to Figure 5 and Figure 6 Furthermore, a crack line can be provided on the explosion-proof sheet 19. The crack line has a ring-shaped structure, including a closed end and a non-closed end, with the closed end located within the explosion-proof area. By providing the non-closed end, when the high-pressure gas inside the battery ruptures the explosion-proof sheet 19 along the crack line, fragments of the explosion-proof sheet 19 can be prevented from flying off.

[0051] like Figure 5 The lower end of the crack line is the closed end, and the upper end is the open end, such as... Figure 6 The lower end of the crack line is the closed end, and the upper end of the crack line is the unclosed end.

[0052] Please refer to Figure 7 In this invention, the battery also includes an upper insulating sheet 17 and a lower insulating sheet 18. The upper insulating sheet 17 is disposed between the inner top surface of the battery cell 14 and the inner metal shell 12, and the lower insulating sheet 18 is disposed between the inner bottom surface of the battery cell 14 and the outer metal shell 11. The upper insulating sheet 17 and the lower insulating sheet 18 can isolate the battery cell 14 and the inner metal shell 12. A vent hole 171 is provided on the upper insulating sheet 17 or the lower insulating sheet 18 so that when the battery cell 14 heats up, the gas inside the battery can flow to the explosion-proof through hole through the vent hole 171.

[0053] like Figure 1 Especially when the battery cell 14 is a wound battery cell, the battery cell 14 heats up, and the gas generated in the gaps between the various battery cell films of the battery cell 14 can flow well through the vent hole 171 to the explosion-proof through hole.

[0054] In this embodiment, the explosion-proof sheet 19 is a copper foil sheet. The copper foil sheet is connected in the sink by thermoforming. The depth of the sink is equal to the thickness of the copper foil sheet. The depth of the sink is processed based on the thickness of the copper foil sheet.

[0055] In this invention, an insulating rubber ring 13 covers the inner and outer surfaces of the axial side plate of the inner metal shell 12. The insulating rubber ring 13 on the inner surface of the inner metal shell 12 can isolate the inner metal shell 12 and the battery cell 14, thereby forming insulation between the inner metal shell 12 and the battery cell 14.

[0056] Please refer to Figure 3 The inner metal shell 12 has a folded edge 122 near the first opening. The folded edge 122 protrudes outward and is secured to the insulating rubber ring 13, so that the inner metal shell 12 and the insulating rubber ring 13 are tightly connected.

[0057] A vent 131 is provided on the insulating rubber ring 13. When the battery heats up, high-pressure gas is generated inside, which causes the outer metal shell 11 and the insulating rubber ring 13 to separate. When the outer metal shell 11 and the insulating rubber ring 13 separate to a certain extent, the insulating rubber ring 13 is no longer sealed to the outer metal shell 11, allowing the vent 131 to connect the internal space and the external space of the outer metal shell 11. This allows the high-pressure gas to be released through the vent 131, preventing the battery from catching fire or exploding.

[0058] When the battery heats up rapidly and the high-pressure gas cannot be released through the explosion-proof through hole and the release through hole in time, the high-pressure gas will cause the outer metal shell 11 and the insulating rubber ring 13 to separate. The explosion-proof structure of the rubber ring vent 131 can then play its role. The explosion-proof structure of the rubber ring vent 131 combined with the explosion-proof structure of the explosion-proof plate 19 forms a double explosion-proof structure, which has better explosion-proof performance.

[0059] In this embodiment, the inner edge of the insulating ring 13 near the first opening is provided with a chamfer, and the outer edge is provided with a rounded chamfer. The chamfer on the inner side of the insulating ring 13 can avoid excessive interference between the insulating ring 13 and the battery cell 14 during assembly, and the rounded chamfer on the outer side of the insulating ring 13 is conducive to the assembly of the insulating ring 13 and the outer metal shell 11.

[0060] In this invention, a constriction section L is provided at the end of the outer metal shell 11 away from the second opening. The inner diameter of the constriction section L gradually decreases along the direction from the second opening to the bottom surface of the outer metal shell 11. That is, the inner diameter of the end of the constriction section L near the second opening is greater than the inner diameter of the end of the constriction section L away from the second opening.

[0061] In the early stage of fitting the insulating rubber ring 13 onto the outer metal shell 11, there is a gap between the insulating rubber ring 13 and the inner wall of the outer metal shell 11, making installation relatively convenient and easy.

[0062] As the insulating rubber ring 13 gradually connects with the compression section L, the insulating rubber ring 13 gradually forms an interference fit with the outer metal shell 11. Then, pressure is applied to the edge of the outer metal shell 11 to deform it. After deformation, the edge of the outer metal shell 11 is locked to the outer periphery of the insulating rubber ring 13, so that a seal is formed between the edge of the outer metal shell 11 and the insulating rubber ring 13. The outer metal shell 11 and the insulating rubber ring 13 are firmly fitted together, and the sealing performance between the insulating rubber ring and the outer metal shell 11 is better.

[0063] In this embodiment, the ratio of the height of the constricted section L to the height of the outer metal shell 11 is between 0.15 and 0.7, and the angle between the inner wall surface of the constricted section L and the inner wall surface of the outer metal shell 11 is between 170° and 179°.

[0064] Please refer to Figure 8In this invention, an annular protrusion 111 is provided on the inner wall of the outer metal shell 11. The annular protrusion 111 is interference-fitted with the insulating rubber ring 13. The annular protrusion 111 is formed by stamping the outer side of the outer metal shell 11.

[0065] The annular protrusion 111 can enhance the connection between the outer metal shell 11 and the inner metal shell 12. Furthermore, the annular protrusion 111 is formed by stamping after the outer metal shell 11 and the inner metal shell 12 are assembled, so it will not affect the assembly operation of the outer metal shell 11 and the inner metal shell 12.

[0066] Please refer to Figure 9 In this invention, an inner shell snap-fit ​​portion 123 is provided at one end of the outer side surface of the inner metal shell 12. The inner shell snap-fit ​​portion 123 includes a first protrusion on the inner side and a first recess on the outer side. The insulating rubber ring 13 on the inner side covers the non-deposited area of ​​the first protrusion region on the inner surface of the inner metal shell 12, i.e., as shown in the figure. Figure 9 In the middle, the insulating rubber ring 13 on the inner side of the inner metal shell 12 extends from bottom to top until it contacts the first protrusion and then stops extending, which saves more space.

[0067] The insulating rubber ring 13 is provided with a rubber ring snap-fit ​​part 132, which includes an inner second protrusion and an outer second concave part. The second protrusion snaps into the first concave part, and the edge of the outer metal shell 11 snaps into the second concave part. By providing the inner shell snap-fit ​​part 123 and the rubber ring snap-fit ​​part 132, the outer metal shell 11 and the insulating rubber ring 13 can be connected more firmly.

[0068] This invention forms a groove by cutting the outer surface of the casing, and the explosion-proof sheet is connected in the groove. When the battery heats up, high-pressure gas is generated inside. The high-pressure gas can break the explosion-proof sheet and release the high-pressure gas, so that the battery has an explosion-proof function. At the same time, it increases the internal space of the battery, thereby making the battery capacity larger.

[0069] In summary, although the present invention has been disclosed above with two embodiments, the above embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. An explosion-proof battery, characterized by comprising: The application relates to a battery shell. The battery shell comprises an inner metal shell and an outer metal shell, the inner metal shell is in a cylindrical structure with a first opening at one end, the outer metal shell is in a cylindrical structure with a second opening at one end, the first opening and the second opening are connected, an electric core is arranged in the inner metal shell, and an insulating rubber ring is arranged between the outer metal shell and the inner metal shell. The outer metal shell is locked and connected at one end of the insulating rubber ring, so that a seal is formed between the edge of the outer metal shell and the insulating rubber ring, a rubber ring air vent is arranged on one side of the insulating rubber ring close to the outer metal shell, and the insulating rubber ring is wrapped on the inner and outer surfaces of the axial side plate of the inner metal shell. The battery shell is provided with a sinking groove and an explosion-proof through hole, the explosion-proof through hole is connected with the inner cavity of the battery shell and the external space, the explosion-proof through hole is located in the sinking groove, an explosion-proof sheet is arranged on the explosion-proof through hole in a sealed mode, the explosion-proof sheet is connected in the sinking groove, the explosion-proof sheet seals the explosion-proof through hole, the area of the explosion-proof sheet opposite to the through hole is an explosion-proof area, a crack line is arranged on the explosion-proof sheet, at least part of the crack line is located in the explosion-proof area, the sinking groove is formed by cutting the outer surface of the battery shell, the explosion-proof sheet is a copper foil sheet, the depth of the sinking groove is equal to the thickness of the copper foil sheet, one crack line is arranged on the explosion-proof sheet, the crack line is in a ring structure, the ring structure comprises a closed end and an unclosed end, the closed end is located in the explosion-proof area, and the unclosed end is dislocated from the explosion-proof area. The edge of the inner metal shell close to the first opening is provided with a folded edge, the folded edge protrudes outward, the folded edge is clamped with the insulating rubber ring, so that the inner metal shell and the insulating rubber ring are connected and fastened. The outer metal shell is provided with a necking section at one end away from the second opening, the inner diameter of the one end of the necking section close to the second opening is greater than the inner diameter of the one end of the necking section away from the second opening. The ratio of the height of the necking section to the height of the outer metal shell is between 0.15 and 0.

7.

2. The explosion-proof battery of claim 1, wherein, The included angle between the inner wall surface of the necking section L and the inner wall surface of the outer metal shell is between 170 degrees and 179 degrees.

3. The explosion-proof battery of claim 2, wherein, The inner wall of the outer metal shell is provided with an annular convex strip, the annular convex strip is connected with the insulating rubber ring in an interference mode, and the annular convex strip is formed by stamping the outer side of the outer metal shell.

4. The explosion-proof battery of claim 2, wherein, One end of the outer side surface of the inner metal shell is provided with an inner shell clamping part, the inner shell clamping part comprises a first convex part on the inner side and a first concave part on the outer side, and the insulating rubber ring on the inner side is wrapped on the non-arranged area of the first convex part of the inner surface of the inner metal shell.

5. The explosion-proof battery of claim 1, wherein The insulating rubber ring is provided with a rubber ring clamping part, the rubber ring clamping part comprises a second convex part on the inner side and a second concave part on the outer side, the second convex part is clamped in the first concave part, and the edge of the outer metal shell is clamped in the second concave part.

6. The explosion-proof battery of claim 1, wherein, The inner side edge of the insulating rubber ring close to the first opening is provided with an inclined chamfer, and the outer side edge is provided with a round chamfer. ​ 7. The explosion-proof battery of claim 1, wherein ​

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