Electrolytic capacitor, power conversion device, and charging device

Abstract

The utility model provides an electrolytic capacitor, a power conversion device and charging equipment, the electrolytic capacitor comprises a shell, an electrolytic capacitor main body and an insulating explosion-proof layer, and an accommodating cavity of the shell is used for accommodating the electrolytic capacitor main body. The insulating explosion-proof layer wraps at least part of the outer surface of the shell, and the material of the insulating explosion-proof layer comprises a polyolefin copolymer. According to the application, the risk that explosive gas, sparks, electrolyte and the like in the electrolytic capacitor are rapidly diffused outwards due to explosion of the electrolytic capacitor can be reduced, so that the safety performance of the electrolytic capacitor can be improved, and the operation safety of the power conversion device and the charging equipment can be ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of charging equipment, in particular to an electrolytic capacitor, a power conversion device and a charging equipment. BACKGROUND

[0002] The electrolytic capacitor is widely used in the power conversion device of the charging equipment due to the advantages of large capacitance per unit volume and low cost. However, abnormal conditions such as high temperature and high pressure can easily cause the electrolyte inside the electrolytic capacitor to boil and a large amount of explosive gas to be generated inside the electrolytic capacitor, thereby increasing the pressure inside the electrolytic capacitor and causing the electrolytic capacitor to burst. The burst of the electrolytic capacitor can cause the explosive gas, sparks and electrolyte inside the electrolytic capacitor to rapidly spread outside, thereby causing the electronic components around the electrolytic capacitor in the power conversion device to malfunction. SUMMARY

[0003] The present application provides an electrolytic capacitor, a power conversion device and a charging equipment, which can reduce the risk of the explosive gas, sparks and electrolyte inside the electrolytic capacitor rapidly spreading outside due to the burst of the electrolytic capacitor, thereby improving the safety performance of the electrolytic capacitor and ensuring the operation safety of the power conversion device and the charging equipment.

[0004] In a first aspect, the present application provides an electrolytic capacitor, which comprises a shell, an electrolytic capacitor body and an insulating explosion-proof layer. The accommodation cavity of the shell is used to accommodate the electrolytic capacitor body. The insulating explosion-proof layer comprises at least part of the outer surface of the shell, and the material of the insulating explosion-proof layer comprises a polyolefin copolymer.

[0005] In the above technical solution, the insulating explosion-proof layer is made of a polyolefin copolymer material, which can make the insulating explosion-proof layer have excellent toughness and ductility. In actual application, when the pressure inside the shell continuously increases due to abnormal conditions such as high temperature and high pressure, the outer surface of the shell is easy to crack under the action of the high pressure inside, thereby causing the pressure inside the shell to leak outside through the cracking. Therefore, in the present application, the insulating explosion-proof layer wraps at least part of the outer surface of the shell, so that the pressure inside the shell can leak outside through the cracking and reach the insulating explosion-proof layer. Further, under the action of the leaked pressure, the insulating explosion-proof layer with high toughness and ductility can bulge outward to increase the stress area of the insulating explosion-proof layer and relieve the stress concentration phenomenon of the insulating explosion-proof layer caused by the leaked pressure, thereby reducing the risk of the insulating explosion-proof layer being broken under the action of the leaked pressure. In this way, the insulating explosion-proof layer can effectively block the explosive gas, sparks and electrolyte inside the shell from rapidly spreading outside through the cracking of the shell, thereby improving the safety performance of the electrolytic capacitor and preventing the malfunction of the electrolytic capacitor from further spreading to other electronic components around.

[0006] In addition, the structure design of wrapping the outer surface of the shell with the insulating explosion-proof layer made of the polyolefin copolymer material is simple, facilitates the layout of the electrolytic capacitor on the circuit board, and is low in production cost, thereby being beneficial to the cost optimization of the electrolytic capacitor.

[0007] In one embodiment, the thickness of the insulating explosion-proof layer is greater than or equal to 0.15 mm and less than or equal to 0.25 mm.

[0008] In the above technical solution, by setting the thickness of the insulating explosion-proof layer in the range of 0.15 mm to 0.25 mm, the insulating explosion-proof layer can not only ensure the role of blocking the explosive gas, sparks and electrolyte in the shell from rapidly diffusing to the outside of the electrolytic capacitor, but also avoid the problems of increasing the size and cost of the electrolytic capacitor due to the large thickness of the insulating explosion-proof layer.

[0009] In one embodiment, the outer surface includes one or more grooves, and the insulating explosion-proof layer wraps the groove mouth of the one or more grooves.

[0010] In the above technical solution, under the action of the pressure in the shell, the shell in the area where the groove is located is prone to cracking due to the small thickness, so that the pressure in the shell is usually first discharged through the cracking of the groove. Therefore, in the embodiment of the present application, by wrapping the area where the groove is located in the outer surface of the shell with the insulating explosion-proof layer, the explosive gas, sparks and electrolyte in the shell can be better blocked from rapidly diffusing to the outside of the electrolytic capacitor through the cracking of the groove.

[0011] In one embodiment, the shell includes an opening, and the electrolytic capacitor further includes a cover plate located in the opening. The outer surface includes an outer peripheral surface and an outer bottom surface, one end of the outer peripheral surface is connected to the outer bottom surface, and the outer bottom surface and the opening are arranged opposite to each other. The one or more grooves include a first groove, the outer peripheral surface protrudes towards the accommodation cavity to form the first groove, and the first groove is annularly distributed. The first groove is used for fixing the cover plate to face the surface of the electrolytic capacitor body in the direction in which the outer bottom surface and the opening are arranged.

[0012] In the above technical solution, when the cover plate is fixed and positioned by the first groove provided on the outer peripheral surface of the shell, by wrapping the first groove with the insulating explosion-proof layer, the explosive gas, sparks and electrolyte in the shell can be better blocked from rapidly diffusing to the outside of the electrolytic capacitor through the first groove. Further, the safety performance of the electrolytic capacitor can be improved, and the failure of the electrolytic capacitor can be prevented from further spreading to other electronic components around.

[0013] In one embodiment, in the direction in which the outer bottom surface and the opening are arranged, the length of the insulating explosion-proof layer is less than the length of the outer peripheral surface.

[0014] In the technical solution, the insulating explosion-proof layer can only wrap the part of the outer circumferential surface of the shell where the first groove is located. In this way, the insulating explosion-proof layer can prevent the explosive gas, sparks and electrolyte in the shell from rapidly spreading to the outside of the electrolytic capacitor through the first groove, while reducing the use of the material of the insulating explosion-proof layer, thereby facilitating the cost optimization of the electrolytic capacitor.

[0015] In one embodiment, the one or more grooves further include a second groove arranged on the outer circumferential surface. The outer bottom surface, the second groove and the first groove are sequentially and spacedly arranged along the direction in which the outer bottom surface and the opening are arranged.

[0016] In the technical solution, the second groove can be arranged to release the pressure in the shell, thereby reducing the risk of explosion in the shell. Moreover, when the second groove is cracked, the insulating explosion-proof layer can effectively prevent the explosive gas, sparks and electrolyte in the shell from rapidly spreading to the outside of the electrolytic capacitor through the second groove. In this way, the safety performance of the electrolytic capacitor can be improved, and the failure of the electrolytic capacitor can be prevented from further spreading to other electronic components.

[0017] In one embodiment, the insulating explosion-proof layer wraps the outer circumferential surface. That is, the insulating explosion-proof layer can wrap the entire outer circumferential surface of the shell. In this way, in actual application, the insulating explosion-proof layer can wrap the first groove and the second groove on the outer circumferential surface of the shell through one wrapping process, thereby simplifying the processing technology of the electrolytic capacitor.

[0018] In one embodiment, the cover plate includes a through hole, and the electrolytic capacitor further includes a pin, one end of the pin being fixed to the electrolytic capacitor body, and the other end of the pin extending out of the accommodating cavity through the through hole. The insulating explosion-proof layer further wraps at least part of the surface of the cover plate away from the electrolytic capacitor body along the direction in which the outer bottom surface and the opening are arranged.

[0019] In the technical solution, the insulating explosion-proof layer further wraps the outer surface of the cover plate away from the electrolytic capacitor body, and the through hole of the cover plate is exposed to the insulating explosion-proof layer. In this way, when the other end of the pin extending out of the through hole is electrically connected to other electronic components, the outer surface of the cover plate can be ensured to be insulated from other electronic components, thereby improving the safety of the electrical connection between the electrolytic capacitor and other electronic components.

[0020] In a second aspect, the present application provides a power conversion device, which comprises a circuit board and the electrolytic capacitor according to any one of the first aspect.

[0021] In a third aspect, the present application provides a charging device, which comprises a charging gun and the power conversion device according to the second aspect, and the charging gun is used to deliver the electric energy output by the power conversion device to an electric vehicle.

[0022] The beneficial effects of the second and third aspects can refer to the beneficial effects of the first aspect described above, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a scene schematic diagram of a charging device provided by an embodiment of the present application charging an electric vehicle.

[0024] Figure 2 is a structural schematic diagram of an electrolytic capacitor provided by an embodiment of the present application.

[0025] Figure 3 is an example of a structure of an electrolytic capacitor provided by an embodiment of the present application. Figure 2 is a cross-sectional schematic diagram of an electrolytic capacitor.

[0026] Figure 4 is a structural schematic diagram of another electrolytic capacitor provided by an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the embodiments of the present application, the following points are explained before the embodiments of the present application are introduced.

[0028] The terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer" and the like in the embodiments of the present application indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0029] In the embodiments of the present application, the same reference signs represent the same components or the same parts. In the embodiments of the present application, for a plurality of identical parts, only one of the parts may be labeled with a reference sign in the drawings. The reference signs are also applicable to other identical parts or components. In addition, the sizes and dimensions of the parts shown in the drawings are only exemplary.

[0030] The technical solutions in the present application will be described below with reference to the drawings.

[0031] First, in order to facilitate the understanding of the technical solutions provided by the embodiments of the present application, the application scenarios applicable to the embodiments of the present application are introduced.

[0032] Figure 1 is a scene schematic diagram of a charging device 10 provided by an embodiment of the present application charging an electric vehicle 20.

[0033] In combination with Figure 1In (a) and (b) of FIG. 1, the charging device 10 is configured to receive alternating current output by the power grid 30, convert the alternating current into stable direct current, and deliver the direct current to the electric vehicle 20 to charge the electric vehicle 20. Alternatively, in some other embodiments, the electric vehicle 20 can output electric energy to the power grid 30 through the charging device 10.

[0034] In some embodiments, as shown in (a) of FIG. 1, the charging device 10 is a split charging device. Specifically, the charging device 10 includes a charging host 11, one or more charging terminals 12, and one or more charging guns 13. Figure 1 In (a) of FIG. 1, the charging device 10 is a split charging device. Specifically, the charging device 10 includes a charging host 11, one or more charging terminals 12, and one or more charging guns 13.

[0035] The charging host 11 includes a charging host cabinet and a plurality of power conversion devices (not shown in the figure), and the plurality of power conversion devices are located inside the charging host cabinet. Each charging terminal 12 is fixed with at least one charging gun 13 of the one or more charging guns 13. The output ends of the plurality of power conversion devices are connected to the charging guns 13 fixed to each charging terminal 12.

[0036] It should be understood that in the embodiments of the present application, each power conversion device can be an alternating current-direct current (AC-DC) conversion device or a direct current-direct current (DC-DC) conversion device. In addition, the plurality of power conversion devices in the charging host 11 can include one or more alternating current-direct current (AC-DC) conversion devices and one or more direct current-direct current (DC-DC) conversion devices. The output end of each AC-DC conversion device is connected to the input end of each DC-DC conversion device through a direct current bus, and the output end of each DC-DC conversion device is connected to the charging gun 13 through the charging terminal 12.

[0037] In specific implementation, each AC-DC conversion device is configured to convert alternating current from the power grid 30 into direct current and output the direct current to the direct current bus, and each DC-DC conversion device is configured to further convert the direct current obtained from the direct current bus and deliver the direct current to the charging gun 13 fixed to the charging terminal 12. The charging gun 13 is configured to deliver the received direct current to the electric vehicle 20 to charge the electric vehicle 20. Exemplarily, one electric vehicle 20 can simultaneously receive direct current delivered by one charging gun 13 or a plurality of charging guns 13.

[0038] It should also be understood that, in the embodiments of the present application, the charging terminal 12 includes a charging terminal cabinet, a man-machine interface, a charging control unit, a metering and charging unit, etc., for information interaction, energy transmission, metering and charging, etc. with the electric vehicle 20.

[0039] In the embodiments of the present application, the electric vehicle 20 is a kind of vehicle driven by electric energy. The electric vehicle 20 is a pure electric vehicle (pure EV / battery EV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), or a plug-in hybrid electric vehicle (PHEV), etc.

[0040] In other embodiments, as shown in (b) of FIG. (1), the charging device 10 is an integrated charging device. Specifically, the man-machine interface, the charging control unit, the metering and charging unit, and the power distribution device, etc. in the charging terminal 12 can be arranged together with the plurality of power conversion devices in the interior of the charging host cabinet. In this case, the charging device 10 can only include the charging host 11 and one or more charging guns 13 fixed to the charging host 11, and does not include the charging terminal 12.

[0041] As described in the background section above, the current electrolytic capacitor is widely used in power conversion devices, such as AC-DC conversion devices or DC-DC conversion devices. The electrolytic capacitor generally includes a shell for accommodating an electrolytic capacitor body to protect the electrolytic capacitor body. The electrolytic capacitor body is mainly used for power filtering, low-frequency circuit, decoupling and coupling.

[0042] In the working process of the electrolytic capacitor, abnormal conditions such as high temperature and high pressure are easy to make the electrolyte in the shell boil, and a large amount of explosive gas is generated in the shell, thereby continuously increasing the pressure inside the shell, and the shell has a risk of explosion. The explosion of the shell will cause the explosive gas in the shell to rapidly diffuse outward through the cracked shell, and the electrolyte and sparks in the shell will be rapidly ejected outward through the cracked shell, causing the electrical components around the electrolytic capacitor in the power conversion device to malfunction. Further, the running safety of the power conversion device and the charging device 10 is affected.

[0043] Based on the above, the embodiment of the present application provides an electrolytic capacitor, a power conversion device and a charging device comprising the electrolytic capacitor, which can reduce the risk of sharp diffusion of explosive gas, sparks and electrolyte in the electrolytic capacitor to the outside due to the explosion of the electrolytic capacitor, thereby improving the safety performance of the electrolytic capacitor and ensuring the operation safety of the power conversion device and the charging device.

[0044] Firstly, the electrolytic capacitor provided by the embodiment of the present application is introduced below in combination with the drawings.

[0045] Figure 2 is a structural schematic diagram of an electrolytic capacitor 40 provided by the embodiment of the present application. Figure 3 is Figure 2 is a schematic diagram of the electrolytic capacitor along the A-A cross section.

[0046] In combination with Figure 2 and Figure 3 , the electrolytic capacitor 40 comprises a shell 41 and an electrolytic capacitor body 42. The accommodating cavity of the shell 41 is used to accommodate the electrolytic capacitor body 42.

[0047] It should be understood that in the embodiment of the present application, the electrolytic capacitor body 42 is mainly used for power filtering, low-frequency circuit, decoupling and coupling. Exemplarily, the electrolytic capacitor body 42 comprises an electrode pair composed of an anode metal foil and a cathode coating.

[0048] In combination with Figure 2 and Figure 3 , the electrolytic capacitor 40 further comprises an insulating explosion-proof layer 44, the insulating explosion-proof layer 44 wraps at least part of the outer surface 411 of the shell 41, and the material of the insulating explosion-proof layer 44 comprises polyolefin (PO). The polyolefin may, for example, be copolymerized by ethylene, propylene and butylene, etc.

[0049] It should be understood that since the PO material has good ductility after thermal shrinkage, compared with wrapping the outer surface 411 of the shell 41 with the insulating explosion-proof layer 44 made of the commonly used insulating materials such as polyethylene terephthalate (PET) and polyvinyl chloride (PVC), the use of the PO material as the insulating explosion-proof layer 44 can not only maintain the insulating performance, but also make the insulating explosion-proof layer 44 have excellent toughness and ductility.

[0050] It should also be understood that, in actual application, when the pressure inside the shell 41 continuously increases due to boiling of the electrolyte and generation of explosive gas, the outer surface 411 of the shell 41 is prone to cracking under the action of the high pressure inside, thereby causing the pressure inside the shell 41 to leak out through the cracking. Therefore, in the embodiment of the present application, by wrapping the outer surface 411 of the shell 41 with the insulating explosion-proof layer 44, the pressure inside the shell 41 can leak out through the cracking of the outer surface 411 to the insulating explosion-proof layer 44. Further, when the pressure leaking out through the cracking is greater than the wrapping strength of the insulating explosion-proof layer 44, the insulating explosion-proof layer 44 with higher toughness and ductility will bulge outward to increase the stress area of the insulating explosion-proof layer 44 and relieve the stress concentration phenomenon of the pressure leaking out through the cracking on the insulating explosion-proof layer 44, thereby reducing the risk of the insulating explosion-proof layer 44 breaking under the action of the leaking pressure. In this way, the insulating explosion-proof layer 44 can better block the explosive gas, sparks, electrolyte and the like inside the shell 41 from rapidly spreading to the outside of the electrolytic capacitor 40, thereby improving the safety performance of the electrolytic capacitor 40 and preventing the failure of the electrolytic capacitor 40 from further spreading to other electronic components around.

[0051] In addition, the structure of wrapping the outer surface 411 of the shell 41 with the insulating explosion-proof layer 44 made of PO material is simple in design, facilitates the layout of the electrolytic capacitor 40 on the circuit board, and has lower production cost, which is conducive to the cost optimization of the electrolytic capacitor 40.

[0052] In some embodiments, the outer surface 411 of the shell 41 includes one or more recesses 43, which will be described below in combination with Figure 2 and Figure 3 . Specifically, the outer surface 411 of the shell 41 protrudes towards the accommodating cavity of the shell 41 to form one or more recesses 43. In this way, the slot of each recess 43 faces the outside of the shell 41, and the thickness of the area of the shell 41 where each recess 43 is located is smaller than that of other areas. The one or more recesses 43 can be used, for example, to achieve pressure relief inside the shell 41, sealed connection of the shell 41 and the cover plate, etc. In addition, the insulating explosion-proof layer 44 wraps the slot of the one or more recesses 43.

[0053] It should be understood that, in actual application, when the pressure inside the shell 41 continuously increases due to boiling of the electrolyte and generation of explosive gas, since the thickness of the shell 41 in the area where the one or more recesses 43 are located is smaller than that of other areas, the shell 41 in the area where the one or more recesses 43 are located will usually crack first when impacted by the pressure inside the shell 41.

[0054] Therefore, in the embodiments of the present application, the insulation explosion-proof layer 44 wraps the area where the one or more grooves 43 are located on the outer surface 411 of the shell 41, which can effectively prevent the explosive gas, spark and electrolyte in the electrolytic capacitor 40 from rapidly diffusing to the outside of the electrolytic capacitor 40 through the crack of the one or more grooves 43, thereby improving the safety performance of the electrolytic capacitor 40 and preventing the failure of the electrolytic capacitor 40 from further spreading to other electronic components around.

[0055] The one or more grooves 43 on the outer surface 411 of the shell 41 will be described in detail below.

[0056] In some embodiments, in combination with Figure 2 and Figure 3 , the shell 41 further comprises an opening 412 which is in communication with the accommodating cavity of the shell 41. The electrolytic capacitor 40 further comprises a cover plate 45 which is located in the opening 412. In this way, the electrolytic capacitor body 42 can be placed in the accommodating cavity of the shell 41 through the opening 411, and the opening 411 is closed by the cover plate 45 to seal the accommodating cavity of the shell 41.

[0057] In some embodiments, the outer surface 411 of the shell 41 comprises an outer peripheral surface 4111 and an outer bottom surface 4112, one end of the outer peripheral surface 4111 is connected to the outer bottom surface 4112, and the outer bottom surface 4112 and the opening 412 are arranged opposite to each other. That is, the other end of the outer peripheral surface 4111 forms the opening 412. The one or more grooves 43 on the outer surface 411 of the shell 41 comprises a first groove 43a, the outer peripheral surface 4111 of the shell 41 protrudes towards the accommodating cavity of the shell 41 to form the first groove 43a, and the first groove 43a is annularly distributed. The first groove 43a is used to fix the cover plate 45 towards the surface of the electrolytic capacitor body 42 along the direction in which the outer bottom surface 4112 and the opening 412 are arranged.

[0058] For example, as shown in Figure 2 and Figure 3 , the upper end of the shell 41 along the first direction comprises the opening 412, and the outer bottom surface 4112 of the shell 41 is located at the lower end of the shell 41 along the first direction. That is, the outer bottom surface 4112 and the opening 412 are arranged opposite to each other along the first direction. The outer peripheral surface 4111 of the shell 41 protrudes towards the accommodating cavity of the shell 41 at the position close to the opening 412 to form the annular first groove 43a. Correspondingly, the area opposite to the first groove 43a in the inner surface of the shell 41 forms a protruding structure which is annularly distributed. The cover plate 45 is located in the opening 412, and the lower surface of the cover plate 45 along the first direction is fixed to the protruding structure. In this way, the cover plate 45 can be limited in the opening 412 through the first groove 43a to seal the accommodating cavity of the shell 41 through the cover plate 45. In addition, the insulation explosion-proof layer 44 wraps the slot of the first groove 43a along the circumference of the shell 41.

[0059] Based on the above design, when the cover plate 45 is fixed and limited by the first groove 43a arranged on the outer circumferential surface 4111 of the shell 41, by making the insulation explosion-proof layer 44 include the first groove 43a, the explosive gas, sparks, electrolyte and the like inside the shell 41 can be better blocked from rapidly diffusing to the outside of the electrolytic capacitor 40 through the first groove 43a. Furthermore, the safety performance of the electrolytic capacitor 40 can be improved, and the failure of the electrolytic capacitor 40 is prevented from further spreading to other electronic components around.

[0060] It should be understood that the structure of the above-mentioned first groove 43a limiting and fixing the cover plate 45 is only illustrative. For example, in some other embodiments, the cover plate 45 can be arranged above the upper end of the shell 41 along the first direction and cover the opening 411, and the cover plate 45 is also clamped and fixed with the first groove 43a. In this case, in order to better block the explosive gas, sparks, electrolyte and the like inside the shell 41 from diffusing outward through the first groove 43a, the insulation explosion-proof layer 44 can wrap the slot of the first groove 43a and the cover plate 45 together along the circumference of the shell 41.

[0061] It should be noted that in the embodiments of the present application, the specific structure of the cover plate 45 closing the opening 412 is not limited, as long as the first groove 43a can fix and limit the cover plate 45.

[0062] In some embodiments, continuing to combine Figure 2 and Figure 3 , along the direction in which the outer bottom surface 4112 of the shell 41 and the opening 412 are arranged, the length of the insulation explosion-proof layer 44 is less than the length of the outer circumferential surface 4111. That is, the insulation explosion-proof layer 44 wraps part of the outer circumferential surface 4111.

[0063] For example, along the first direction shown in Figure 2 and Figure 3 , the insulation explosion-proof layer 44 can only wrap the upper half of the outer circumferential surface 4111 of the shell 41 in which the first groove 43a is formed, and not wrap the lower half of the outer circumferential surface 4111. In this way, while blocking the explosive gas, sparks, electrolyte and the like inside the shell 41 from rapidly diffusing to the outside of the electrolytic capacitor 40 through the first groove 43a, the use of material of the insulation explosion-proof layer 44 is also reduced, thereby facilitating the cost optimization of the electrolytic capacitor 40.

[0064] Figure 4 is another structure diagram of an electrolytic capacitor 40 provided by the embodiments of the present application.

[0065] In some embodiments, referring to Figure 4In addition to the first groove 43a, the one or more grooves 43 on the outer surface of the shell 41 includes a second groove 43b located on the outer circumferential surface 4111 of the shell 41. Specifically, the outer circumferential surface 4111 of the shell 41 can be protruded towards the accommodating cavity of the shell 41 to form the second groove 43b. And along the direction in which the outer bottom surface 4112 and the opening 412 are arranged, the outer bottom surface 4112, the second groove 43b and the first groove 43a are sequentially and spacedly arranged.

[0066] For example, as shown in Figure 4 , the outer bottom surface 4112 and the opening 412 are oppositely arranged along the first direction, and the outer bottom surface 4112, the second groove 43b and the first groove 43a are sequentially and spacedly arranged along the first direction from bottom to top. The second groove 43b may, for example, extend along the first direction. In addition, the insulation explosion-proof layer 44 circumferentially wraps around the first groove 43a and the second groove 43b.

[0067] Based on the above design, when the pressure inside the shell 41 continues to increase due to the boiling of the electrolyte and the generation of explosive gas, since the thickness of the second groove 43b is small, the second groove 43b will preferentially crack when subjected to pressure impact, so that the pressure inside the shell 41 is released through the second groove 43b, thereby reducing the risk of explosion inside the shell 41. And by wrapping the second groove 43b with the insulation explosion-proof layer 44, the explosive gas, sparks and electrolyte inside the shell 41 can be better blocked from rapidly diffusing outside the electrolytic capacitor 40 through the second groove 43b. Furthermore, the safety performance of the electrolytic capacitor 40 can be improved, and the failure of the electrolytic capacitor 40 can be prevented from further spreading to other electronic components in the surrounding.

[0068] In some embodiments, continuing to refer to Figure 4 , the insulation explosion-proof layer 44 wraps around the outer circumferential surface 4111 of the shell 41. That is, the insulation explosion-proof layer 44 wraps around the entire portion of the outer circumferential surface 4111. In this way, in actual application, the insulation explosion-proof layer 44 can be wrapped around the first groove 43a and the second groove 43b located on the outer circumferential surface 4111 of the shell 41 through one wrapping process, thereby simplifying the processing technology of the electrolytic capacitor 40.

[0069] It should be understood that the above-mentioned second groove 43b is arranged on the outer circumferential surface 4111 of the shell 41 only for illustration and is not a limitation of the present application. For example, in other embodiments, as shown in Figure 4 , the second groove 43b can also be located on the outer bottom surface 4112 of the shell 41. In this case, the insulation explosion-proof layer 44 can wrap around the outer circumferential surface 4111 of the shell 41 and the outer bottom surface 4112 of the shell 41 to wrap around the first groove 43a and the second groove 43b.

[0070] The above describes the one or more grooves 43 arranged on the outer surface 411 of the shell 41. The following describes other structures in the electrolytic capacitor 40.

[0071] In some embodiments, the thickness of the insulation explosion-proof layer 44 is greater than or equal to 0.15 mm and less than or equal to 0.25 mm. Figures 2 to 4

[0072] It should be understood that, in the embodiments of the present application, the thickness of the insulation explosion-proof layer 44 refers to the length of the insulation explosion-proof layer 44 along the outer surface 411 of the shell 41 and the arrangement direction of the insulation explosion-proof layer 44.

[0073] For example, as shown in FIG. 4, taking the cylindrical structure of the shell 41 as an example, in the case where the insulation explosion-proof layer 44 is wrapped around the outer circumferential surface 4111 of the shell 41, the thickness of the insulation explosion-proof layer 44 refers to the length L1 of the insulation explosion-proof layer 44 along the radial direction of the shell 41. Alternatively, in the case where the insulation explosion-proof layer 44 is wrapped around the outer bottom surface 4112 of the shell 41, the thickness of the insulation explosion-proof layer 44 refers to the length of the insulation explosion-proof layer 44 along the axial direction of the shell 41. The axial direction may, for example, be the first direction. Figure 4 Exemplarily, the thickness of the insulation explosion-proof layer 44 may, for example, be any one of 0.15 mm, 0.17 mm, 0.19 mm, 0.21 mm, 0.23 mm or 0.25 mm.

[0074] It should also be understood that, when the thickness of the insulation explosion-proof layer 44 is less than 0.15 mm, the insulation explosion-proof layer 44 cannot well resist the pressure impact inside the shell 41 due to the thinness, resulting in that the insulation explosion-proof layer 44 is prone to be broken under the pressure of the leakage from the cracking of the outer surface 411 of the shell 41, and thus cannot play the role of blocking the explosive gas, sparks and electrolyte etc. inside the shell 41 from rapidly diffusing to the outside of the electrolytic capacitor 40. When the thickness of the insulation explosion-proof layer 44 is greater than 0.25 mm, the thickness of the insulation explosion-proof layer 44 is large, which is prone to result in the increase of the size and the cost of the electrolytic capacitor 40.

[0075] Therefore, in the embodiments of the present application, by setting the thickness of the insulation explosion-proof layer 44 in the range of 0.15 mm to 0.25 mm, the insulation explosion-proof layer 44 can play the role of blocking the explosive gas, sparks and electrolyte etc. inside the shell 41 from rapidly diffusing to the outside of the electrolytic capacitor 40, and the problems of the increase of the size and the cost of the electrolytic capacitor 40 due to the large thickness of the insulation explosion-proof layer 44 can be avoided.

[0076] In some embodiments, the thickness of the insulation explosion-proof layer 44 is greater than or equal to 0.15 mm and less than or equal to 0.25 mm.

[0077] Figures 2 to 4 ​​The cover plate 45 includes a through hole 451 arranged along the outer bottom surface 4112 and the opening 412 of the shell. In addition, the electrolytic capacitor 40 further includes a pin 46. One end of the pin 46 is located in the accommodating cavity of the shell 41 and fixedly connected with the electrolytic capacitor body 42, and the other end of the pin 46 extends out of the accommodating cavity of the shell 41 through the through hole 451. That is, the other end of the pin 46 is exposed to the accommodating cavity for electrical connection with other electronic components.

[0078] As shown in the example, Figures 2 to 4 the number of the pin 46 of the electrolytic capacitor 40 is two, and the number of the through hole 451 is also two. Among them, one end of the two pins 46 is connected with the cathode and the anode in the electrolytic capacitor body 42, and the other end of the two pins 46 is respectively exposed to the accommodating cavity of the shell 41 through the two through holes 451, for corresponding connection with the positive electrode and the negative electrode of other electronic components.

[0079] In some embodiments, the insulating explosion-proof layer 44 also wraps the surface of the cover plate 45 away from the electrolytic capacitor body 42 along the direction in which the outer bottom surface 4112 and the opening 412 are arranged. For example, as shown in the example, Figures 2 to 4 the outer bottom surface 4112 and the opening 412 are arranged in a first direction. The through hole 451 penetrates the cover plate 45 along the first direction, and the insulating explosion-proof layer 44 also wraps part of the upper surface of the cover plate 45 along the first direction.

[0080] Based on the above design, the insulating explosion-proof layer 44 also wraps the outer surface of the cover plate 45 away from the electrolytic capacitor body 42, and the through hole 451 of the cover plate 45 is exposed to the insulating explosion-proof layer 44. In this way, when the other end of the pin 46 extending from the through hole 451 is electrically connected with other electronic components, the outer surface of the cover plate 45 can be ensured to be insulated from other electronic components, so that the safety of the electrical connection between the electrolytic capacitor 40 and other electronic components can be improved.

[0081] The embodiment of the present application also provides a power conversion device, which includes a circuit board and the electrolytic capacitor 40 shown in the example, Figures 2 to 4 The circuit board is connected with the electrolytic capacitor 40. As an example, the circuit board can be fixedly and electrically connected with the other end of the pin 46 extending from the through hole 451 of the electrolytic capacitor 40 by welding.

[0082] It should be understood that, in the embodiment of the present application, the power conversion device can be the AC-DC conversion device or the DC-DC conversion device mentioned in the example, Figure 1 For specific description, reference can be made to the related description of the example, Figure 1 The power conversion device can also be an inverter conversion device. The inverter conversion device is used to convert the received direct current into alternating current and then output.

[0083] The embodiment of the present application also provides a charging device, which comprises a charging gun and the power conversion device described above. The power conversion device comprises the AC-DC conversion device and the DC-DC conversion device described above. Figures 2 to 4 The charging gun is used for delivering the electric energy output by the power conversion device to the electric vehicle.

[0084] It should be understood that in the embodiment of the present application, the number of the power conversion devices in the charging device can be multiple, and the multiple power conversion devices comprise one or more AC-DC conversion devices and one or more DC-DC conversion devices. The specific description can be referred to the related description of the embodiment shown in Figure 1 Fig. 3, which will not be repeated here.

[0085] The above description is merely specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electrolytic capacitor characterized by comprising: The electrolytic capacitor comprises a shell, an electrolytic capacitor body and an insulating explosion-proof layer, a containing cavity of the shell is used for containing the electrolytic capacitor body, and the insulating explosion-proof layer wraps at least part of an outer surface of the shell, and a material of the insulating explosion-proof layer comprises a polyolefin copolymer.

2. The electrolytic capacitor according to claim 1, wherein The thickness of the insulating explosion-proof layer is greater than or equal to 0.15 mm and less than or equal to 0.25 mm.

3. The electrolytic capacitor according to claim 1 or 2, characterized in that, The outer surface comprises one or more grooves, and the insulating explosion-proof layer wraps a groove mouth of the one or more grooves.

4. The electrolytic capacitor according to claim 3, wherein The shell comprises an opening, and the electrolytic capacitor further comprises a cover plate located in the opening. The outer surface comprises an outer peripheral surface and an outer bottom surface, one end of the outer peripheral surface is connected to the outer bottom surface, and the outer bottom surface and the opening are arranged opposite to each other. The one or more grooves comprise a first groove, the outer peripheral surface protrudes towards the containing cavity to form the first groove, and the first groove is annularly distributed, and the first groove is used for fixing the cover plate to face a surface of the electrolytic capacitor body in a direction in which the outer bottom surface and the opening are arranged.

5. The electrolytic capacitor according to claim 4, wherein In the direction in which the outer bottom surface and the opening are arranged, the length of the insulating explosion-proof layer is less than the length of the outer peripheral surface.

6. The electrolytic capacitor according to claim 4, wherein The one or more grooves further comprise a second groove, and the second groove is arranged on the outer peripheral surface. In the direction in which the outer bottom surface and the opening are arranged, the outer bottom surface, the second groove and the first groove are sequentially and spacedly arranged.

7. The electrolytic capacitor according to claim 6, wherein The insulating explosion-proof layer wraps the outer peripheral surface.

8. The electrolytic capacitor according to any one of claims 4 to 7, wherein The cover plate comprises a through hole, the electrolytic capacitor further comprises a pin, one end of the pin is fixed to the electrolytic capacitor body, the other end of the pin extends out of the containing cavity through the through hole, and the insulating explosion-proof layer further wraps at least part of a surface of the cover plate away from the electrolytic capacitor body in the direction in which the outer bottom surface and the opening are arranged.

9. A power conversion device, characterized by, The power conversion device comprises a circuit board and the electrolytic capacitor according to any one of claims 1 to 8, and the circuit board is connected to the electrolytic capacitor.

10. A charging device, characterized by The charging device comprises a charging gun and the power conversion device according to claim 9, and the charging gun is used for delivering electric energy output by the power conversion device to an electric vehicle.

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