High voltage resistant electrolytic capacitor

Abstract

This utility model discloses a high-voltage resistant electrolytic capacitor, comprising a core, a shell, and a sleeve. The shell is fitted over the core to form a bare product, and the sleeve is fitted over the bare product. The core is formed by winding an anode foil, a cathode foil, and a guide pin. The guide pin is riveted to both the anode foil and the cathode foil. A riveted cathode foil is provided at the riveting point between the guide pin and the riveted cathode foil, with the guide pin located between the cathode foil and the riveted cathode foil. The 400V 33μF capacitor prepared by this utility model can stably withstand the high voltage, high temperature, and high ripple current conditions of high-power fast charging equipment. It can be applied to 100W-600W fast chargers, adapters, and charging piles, solving the problems of short lifespan and low reliability of conventional products in fast charging scenarios. Under the same capacity and voltage withstand conditions, the capacitor of this utility model is 15%-20% smaller in volume than conventional capacitors of the same type, which is more in line with the design trend of miniaturization and lightweighting of fast charging equipment and helps to improve the market competitiveness of the equipment.

Description

Technical Field

[0001] This utility model belongs to the field of capacitor manufacturing technology, and in particular relates to a high-voltage resistant electrolytic capacitor. Background Technology

[0002] As a core energy storage and filtering component in fast charging circuits, the performance of aluminum electrolytic capacitors directly determines the stability, safety, and lifespan of fast charging equipment. Currently, aluminum electrolytic capacitors commonly exhibit the following problems under the harsh operating conditions of fast charging equipment, including high voltage (above 300V), high temperature (internal temperature can reach 85℃ and above), and high ripple current (instantaneous ripple current can reach several amperes): 1) Short lifespan: The electrolyte is easily decomposed and volatilized under high temperature and high pressure, which leads to rapid decay of capacitor capacity. The lifespan is usually less than 2,000 hours, which is far below the design lifespan requirement of more than 5,000 hours for fast charging equipment.

[0003] 2) Low reliability: Under high ripple current impact, the capacitor heats up severely inside, which can easily lead to problems such as local overheating of the core and poor contact between the lead pin and the aluminum foil, causing equipment downtime or even safety accidents.

[0004] 3) Difficulty in balancing performance: Aluminum electrolytic capacitors manufactured by conventional processes often suffer from insufficient capacity if they are made to be small in size to fit the miniaturized design of fast charging devices; if the capacity is increased, the size will increase, and it is difficult to meet the requirements of low equivalent series resistance (ESR) and high withstand voltage at the same time, making them unsuitable for high-power fast charging.

[0005] To address the aforementioned issues, the industry urgently needs a new aluminum electrolytic capacitor manufacturing process that can achieve comprehensive performance characteristics such as high capacity, low ESR, high withstand voltage, high temperature resistance, and long lifespan while ensuring product miniaturization, in order to meet the technological upgrade requirements of fast charging equipment. Summary of the Invention

[0006] To solve the above-mentioned technical problems, this utility model provides a high-voltage resistant electrolytic capacitor.

[0007] This utility model is achieved through the following technical solution.

[0008] This utility model provides a high-voltage resistant electrolytic capacitor, including a core, a shell, and a sleeve. The shell is fitted over the core to form a bare product, and the sleeve is fitted over the bare product. The core is formed by winding an anode foil, a cathode foil, and a guide pin. The guide pin is riveted to both the anode foil and the cathode foil. A riveted cathode foil is provided at the riveting point between the guide pin and the cathode foil, and the guide pin is located between the cathode foil and the riveted cathode foil.

[0009] Preferably, the guide needle includes a tongue, a stem, and an outlet. One end of the stem is connected to the tongue, and the other end of the stem is connected to the outlet. The guide needle is riveted to the anode foil or cathode foil through the tongue.

[0010] Preferably, the tongue is flat and has a groove at one end, while the stem is cylindrical and has one end placed in the groove to connect with the tongue.

[0011] Preferably, the core further includes electrolytic paper, which is stacked in the order of electrolytic paper, anode foil, electrolytic paper, and cathode foil from the inside out before the core is wound.

[0012] Preferably, an electrolytic paper tape is provided at the riveting point between the guide pin and the anode foil, and the guide pin is located between the anode foil and the electrolytic paper tape.

[0013] Preferably, after the outer shell and the core are fitted together, a sealing plug is provided at the open end of the outer shell, and the guide needle passes through the sealing plug.

[0014] Preferably, an insulating layer is provided between the inner wall of the outer shell and the bottom of the core.

[0015] Preferably, the outer casing is provided with an explosion-proof groove.

[0016] Preferably, the cathode foil and the cathode foil are riveted together.

[0017] The beneficial effects of this utility model are as follows: 1. This application prepares a 400V 33μF 10×18mm capacitor, which can stably withstand the high voltage, high temperature and high ripple current conditions of high power fast charging equipment. It can be applied to 100W-600W fast chargers, adapters and charging piles, etc., and solves the problems of short life and low reliability of conventional products in fast charging scenarios.

[0018] 2. Under the same capacity and voltage resistance conditions, the volume of the capacitor of this utility model is reduced by 15%-20% compared with conventional capacitors of the same type, which is more in line with the design trend of miniaturization and lightweighting of fast charging equipment and helps to enhance the market competitiveness of the equipment. Attached Figure Description

[0019] Figure 1 This is an exploded view of this utility model; Figure 2 This is a schematic diagram of the structure of this utility model; Figure 3 This is a schematic diagram of the core winding of this utility model; Figure 4 This is a schematic diagram of the anode foil riveting of this utility model; Figure 5 This is a schematic diagram of the cathode foil riveting of this utility model; Figure 6 This is a schematic diagram of the bare product sleeve shell of this utility model; Figure 7 This is a schematic diagram of the present invention; In the diagram: 1-Core, 2-Outer shell, 3-Sleeve, 4-Bare product, 5-Anode foil, 6-Cathode foil, 7-Guide pin, 71-Tongue, 72-Stem, 73-Lead-out section, 74-Slot, 8-Riveted cathode foil, 9-Electrolytic paper, 10-Electrolytic paper tape, 11-Sealing plug, 12-Insulation layer, 13-Explosion-proof groove. Detailed Implementation

[0020] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0021] Example 1: like Figures 1 to 7 As shown, a high-voltage electrolytic capacitor includes a core 1, a shell 2, and a sleeve 3. The shell 2 is fitted over the core 1 to form a bare product 4. The shell 2 is an aluminum shell. The sleeve 3 is fitted over the bare product 4. The core 1 is formed by winding an anode foil 5, a cathode foil 6, and a guide pin 7. The guide pin 7 is riveted to both the anode foil 5 and the cathode foil 6. A riveted cathode foil 8 is provided at the riveting point between the guide pin 7 and the cathode foil 6. The guide pin 7 is located between the cathode foil 6 and the riveted cathode foil 8.

[0022] The anode foil 5 uses a 510VF high specific capacitance anode foil, with a stable specific capacitance of 1.12μF / cm² and uniform oxide film thickness, ensuring sufficient capacity in a small size; the withstand voltage of this type of anode foil can reach more than 450V, and can withstand the high voltage impact of fast charging circuits.

[0023] The cathode foil 6 is a 20C type cathode foil with a specific capacitance of 100μF / cm². At the same time, a 30C type riveted cathode foil 8 is used as reinforcement at the cathode foil riveting joint, with a specific capacitance of 120μF / cm², to improve the current carrying capacity of the riveting joint and prevent local overheating under high ripple current.

[0024] The guide needle 7 includes a tongue 71, a stem 72, and an outlet 73. One end of the stem 72 is connected to the tongue 71, and the other end of the stem 72 is connected to the outlet 73. The guide needle 7 is riveted to the anode foil 5 or the cathode foil 6 through the tongue 71. The contact resistance at the riveting point is ≤1.2mΩ to ensure stable current conduction.

[0025] The tongue 71 is flat and has a groove 74 at one end. The stem 72 is cylindrical and has one end placed in the groove 74 to connect with the tongue 71.

[0026] The core 1 also includes electrolytic paper 9, which is stacked in the order of anode foil 5, W100-15 electrolytic paper 9, cathode foil 6, and W100-20 electrolytic paper 9 from the inside to the outside before the core 1 is wound.

[0027] W100-15 is used in combination with W100-20. W100-15 paper is 15μm thick and has high air permeability, which is conducive to electrolyte penetration; W100-20 paper is 20μm thick and has high strength and low resistance. The combination of the two can reduce ESR by 15%-20% and improve breakdown voltage.

[0028] Electrolytic paper tape 10 is provided at the rivet joint between the guide pin 7 and the anode foil 5. The guide pin 7 is located between the anode foil 5 and the electrolytic paper tape 10. The two ends of the electrolytic paper tape 10 extend 3mm beyond the width on both sides of the rivet joint to prevent the anode foil 5 and the cathode foil 6 from directly contacting each other and causing a short circuit during winding.

[0029] After the outer shell 2 is fitted onto the core 1, a sealing plug 11 is provided at the open end of the outer shell 2, and the guide pin 7 passes through the sealing plug 11. The sealing plug 11 is a rubber plug, and the compression of the sealing plug 11 is controlled at 10%. The seal is completed by mechanical pressing. The rolled edge width of the aluminum outer shell 1 is preferably 0.8-1.0 mm.

[0030] An insulating layer 12 is provided between the inner wall of the outer shell 2 and the bottom of the core 1. The insulating layer 12 is insulating paper, which is used to improve the safety of the core 1.

[0031] The outer casing 2 is provided with an explosion-proof groove 13, which is arranged in a cross shape. When the internal temperature of the capacitor is too high and high pressure is generated, the explosion-proof groove 13 guides the internal pressure gas to be discharged in one direction, reducing the damage caused by gas ejection.

[0032] The riveted cathode foil 8 and the cathode foil 6 are riveted together, which improves the connection stability and avoids displacement of the riveted cathode foil 8 caused by the high ripple current heating effect.

[0033] The capacitors prepared in Example 1 were tested. Twenty capacitors prepared in Example 1 were placed in an 85°C oven and charged with rippled DC current. A 400V DC current was superimposed with a 30V 50HZ AC current. (Test equipment: ripple power supply.) A life test was conducted. The capacitors were taken out every 500 hours to check whether they were qualified. The test qualification criteria were: ESR (100KHZ) ≤ 0.5Ω, capacitance 29.7-36.3μF, tanδ < 10%, leakage current < 62.8uA; test time: ≥ 5000 hours. Capacitors that meet the test criteria are considered to have a long lifespan.

[0034] The capacitor prepared in Example 1 was compared with an existing 400V 33μF capacitor, and the results are shown in the table below.

[0035] As can be seen from the table above, the capacitor prepared in this application has a smaller volume, a longer lifespan, and electrical performance parameters that are superior to those of capacitors of the same specifications in the prior art.

Claims

1. A high-voltage resistant electrolytic capacitor, characterized in that: The product includes a core (1), a shell (2) and a sleeve (3). The shell (2) is fitted over the core (1) to form a bare product (4). The sleeve (3) is fitted over the bare product (4). The core (1) is formed by winding an anode foil (5), a cathode foil (6) and a guide pin (7). The guide pin (7) is riveted to the anode foil (5) and the cathode foil (6) respectively. A riveted cathode foil (8) is provided at the riveting point between the guide pin (7) and the cathode foil (6). The guide pin (7) is located between the cathode foil (6) and the riveted cathode foil (8).

2. The high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: The guide needle (7) includes a tongue (71), a stem (72) and an outlet (73). One end of the stem (72) is connected to the tongue (71), and the other end of the stem (72) is connected to the outlet (73). The guide needle (7) is riveted to the anode foil (5) or the cathode foil (6) through the tongue (71).

3. A high-voltage resistant electrolytic capacitor as described in claim 2, characterized in that: The tongue (71) is flat and has a slot (74) at one end. The stem (72) is cylindrical and has one end placed in the slot (74) to connect with the tongue (71).

4. A high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: The core (1) also includes electrolytic paper (9), which is stacked in the order of electrolytic paper (9), anode foil (5), electrolytic paper (9), and cathode foil (6) from the inside to the outside before the core (1) is wound.

5. A high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: Electrolytic paper tape (10) is provided at the riveting point between the guide pin (7) and the anode foil (5), and the guide pin (7) is located between the anode foil (5) and the electrolytic paper tape (10).

6. A high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: After the outer shell (2) is fitted with the core (1), a sealing plug (11) is provided at the open end of the outer shell (2), and the guide needle (7) passes through the sealing plug (11).

7. A high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: An insulating layer (12) is provided between the inner wall of the outer shell (2) and the bottom of the core (1).

8. A high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: An explosion-proof groove (13) is provided on the outer shell (2).

9. A high-voltage resistant electrolytic capacitor as described in claim 1, characterized in that: The cathode foil (8) and the cathode foil (6) are riveted together.

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