A high-safety non-solid tantalum capacitor and its preparation method

Abstract

A high-safety non-solid tantalum capacitor and its manufacturing method are disclosed. The non-solid tantalum capacitor includes a shell with an internal mounting cavity, a tantalum core disposed in the mounting cavity, a cathode assembly disposed in the mounting cavity, a sealing cap for sealing the mounting cavity, and an electrolyte filled in the mounting cavity. The sealing cap includes a sealing cap body, a glass insulator disposed in the sealing cap body, a tantalum wire fixed on the glass insulator, a nickel tube sleeved on the upper section of the tantalum wire, and a cathode lead disposed on the sealing cap body. The upper end face of the glass insulator is flush with the upper end face of the sealing cap body. The nickel tube is vertically opposite to the glass insulator, and a separation gap is formed between the lower end face of the nickel tube and the upper end face of the glass insulator. A hydrophobic insulating coating is disposed on the outer periphery of the tantalum wire, and the hydrophobic insulating coating is located in the separation gap. The hydrophobic insulating layer effectively prevents the electrochemical corrosion of the nickel tube by acid, thereby improving the safety of the non-solid tantalum capacitor.

Description

Technical Field

[0001] This invention belongs to the field of tantalum capacitor manufacturing technology, specifically relating to a high-safety non-solid tantalum capacitor and its manufacturing method. Background Technology

[0002] Liquid tantalum capacitors, due to their superior performance, are widely used in various electronic devices such as electronic circuits, aerospace, and precision instruments, and are one of the indispensable basic components in electronic systems. The interior of a liquid tantalum capacitor is typically filled with a sulfuric acid electrolyte, and its sealing reliability mainly depends on the sintering effect of the glass insulator. However, during the manufacturing process of liquid tantalum capacitors, the sintering process of the glass insulator is easily affected by various factors such as temperature control precision, sintering time, and raw material purity, which can easily produce sintering defects that are difficult to detect (such as micro-cracks and pores). These micro-defects can lead to micro-leakage of the internal sulfuric acid electrolyte. Because the leakage is small and highly concealed, it is difficult to detect in time during production testing and use, posing a serious safety hazard to the stable operation of electronic equipment.

[0003] Because the anode leads of liquid tantalum capacitors are typically covered with nickel tubing to improve solderability, when a micro-leak occurs in the electrolyte, the leaking sulfuric acid solution connects the capacitor cathode and the external anode nickel tubing. Under energized conditions, the external nickel tubing loses electrons and dissolves, corroding. Electrons are transferred from the external circuit to the ruthenium oxide cathode, where they combine with hydrogen ions to produce hydrogen gas. As hydrogen gas continues to be generated, the internal pressure of the liquid tantalum capacitor gradually increases. This pressure further pushes the internal sulfuric acid electrolyte out through sintering defects in the glass insulator, creating a vicious cycle of "micro-leakage—electrochemical corrosion—hydrogen generation—increased pressure—exacerbated leakage," ultimately leading to severe capacitor failure. The leaked sulfuric acid electrolyte also causes irreversible corrosion damage to the circuit board and other surrounding components, inducing even greater losses.

[0004] Currently, existing technologies lack effective measures to prevent acid leakage corrosion in liquid tantalum capacitors. They mainly focus on optimizing the sintering process of glass insulators to reduce sintering defects. However, these measures cannot effectively remedy or prevent existing micro-defects, and therefore cannot meet the high reliability and high safety requirements of electronic equipment for liquid tantalum capacitors. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-safety non-solid tantalum capacitor and its preparation method.

[0006] The present invention adopts the following technical solution: A high-safety non-solid tantalum capacitor includes a shell with an internal mounting cavity, a tantalum core disposed within the mounting cavity, a cathode assembly disposed within the mounting cavity, a sealing cap for sealing the mounting cavity, and an electrolyte filling the mounting cavity. The sealing cap includes a sealing cap body, a glass insulator disposed within the sealing cap body, a tantalum wire fixed to the glass insulator, a nickel tube sleeved on the upper section of the tantalum wire, and a cathode lead disposed on the sealing cap body. The lower section of the tantalum wire extends into the mounting cavity and is connected to the tantalum core via the tantalum wire lead. The cathode assembly is connected to the cathode lead via the sealing cap body. The upper end face of the glass insulator is flush with the upper end face of the sealing cap body. The nickel tube is vertically opposite to the glass insulator, and a separation gap is formed between the lower end face of the nickel tube and the upper end face of the glass insulator. A hydrophobic insulating coating is disposed on the outer periphery of the tantalum wire, and the hydrophobic insulating coating is located in the separation gap.

[0007] Furthermore, it also includes multiple diaphragms disposed in the mounting cavity. The tantalum core includes at least one tantalum block stacked sequentially along the height of the mounting cavity. The bottom and top surfaces of the tantalum block are provided with the diaphragm. The upper end of the tantalum wire lead is connected to the tantalum wire, and the lower end is connected to the sides of the multiple tantalum blocks respectively.

[0008] Furthermore, the cathode assembly includes a first cathode sheet and at least one second cathode sheet. The lower section of the first cathode sheet is supported on the bottom of the mounting cavity, and the upper section extends upward from the lower section and bends to connect with the sealing cover body. The second cathode sheet is disposed above the lower section of the first cathode sheet, and one end extends to connect with the upper section of the first cathode sheet. When both the tantalum block and the second cathode sheet are single, the tantalum block and its two diaphragms on the top and bottom surfaces are located between the lower section of the first cathode sheet and the second cathode sheet. When both the tantalum block and the second cathode sheet are multiple, the tantalum block and its two diaphragms on the top and bottom surfaces are located between the lower section of the first cathode sheet and the second cathode sheet or between two adjacent second cathode sheets.

[0009] Furthermore, the hydrophobic insulating coating is formed by brushing or spraying a hydrophobic insulating liquid onto the area where the tantalum wire is located in the gap, followed by heating and drying before curing.

[0010] Furthermore, the hydrophobic insulating coating liquid comprises a solvent and a fluoropolymer, wherein the fluoropolymer has a mass fraction of 2-10%.

[0011] Furthermore, the solvent is a fluorinated hydrocarbon; the fluorinated polymer includes one or more of perfluoroalkyl ether polymers, fluorinated acrylate polymers, fluorinated organosilicon copolymers, and fluorinated epoxy polymers.

[0012] Furthermore, the thickness of the hydrophobic insulating coating is 2-15 μm.

[0013] Furthermore, the height of the separation interval is 0.5-3mm, the length of the hydrophobic insulating coating is 1-4mm, and the hydrophobic insulating coating can extend to the bottom surface of the nickel tube.

[0014] Furthermore, the electrolyte comprises the following raw materials in parts by weight: 75-99 parts sulfuric acid solution, 0.5-5 parts depolarizer, and 0.5-20 parts electron-rich additive, wherein the sulfuric acid solution has a mass fraction of 35-45%; the depolarizer is one or more of copper sulfate, ferric sulfate, silver sulfate, and oxysulfate; and the electron-rich additive may be one or more of ethylene glycol methyl ether, diethylene glycol methyl ether, diethylene glycol dimethyl ether, oxalic acid, citric acid, triethanolamine, aminotriacetic acid, maleic acid, aminotrimethylenephosphonic acid, salicylic acid, and benzoic acid.

[0015] A method for preparing a high-safety non-solid tantalum capacitor includes the following steps: Step 1: Coat the outer circumferential surface of the tantalum wire located in the separation gap with a hydrophobic insulating coating, and then transfer the sealing cap to an oven and dry it at a temperature of 60-120℃ for 15-30 minutes to obtain a sealing cap with a hydrophobic insulating coating. Step 2: Assemble the tantalum core and cathode assembly into the housing according to the installation requirements, and then weld the sealing cap onto the housing to obtain a capacitor semi-finished product without electrolyte filling. Step 3: Inject electrolyte into the capacitor semi-finished product. After injection, age the capacitor at room temperature for 20-30 hours and at 80-130℃ for 1-5 hours. After replenishing the lost electrolyte, seal to obtain the initial finished capacitor product. Step 4: After further aging the obtained capacitor pre-finished product at 25°C for 24 hours and at 85°C for 48 hours, test the electrical performance parameters, remove unqualified products, and obtain the high-safety non-solid tantalum capacitor.

[0016] As can be seen from the above description of the present invention, compared with the prior art, the beneficial effects of the present invention are as follows: By defining the structure of the non-solid tantalum capacitor, the present application sets a separation gap between the nickel tube and the glass insulator, and sets a hydrophobic insulating layer on the outer surface of the tantalum wire located in the separation gap, effectively preventing the electrochemical corrosion of the nickel tube by acid, avoiding the rapid and severe failure mode of "micro-acid leakage - electrochemical corrosion - hydrogen generation - pressure increase - aggravated acid leakage - severe deformation of the shell", and improving the safety of the non-solid tantalum capacitor in use. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a non-solid tantalum capacitor. In the diagram, 1 is the outer casing; 2 is the tantalum core; 3 is the cathode assembly; 4 is the sealing cover; 5 is the polytetrafluoroethylene sheet; 6 is the tantalum wire lead; 7 is the diaphragm; 11 is the mounting cavity; 21 is the tantalum block; 31 is the first cathode sheet; 32 is the second cathode sheet; 41 is the sealing cover body; 42 is the glass insulator; 43 is the tantalum wire; 44 is the nickel tube; 45 is the cathode lead; 46 is the separation gap; and 47 is the hydrophobic insulating coating. Detailed Implementation

[0018] The present invention will be further described below through specific embodiments.

[0019] Reference Figure 1 As shown, a high-safety non-solid tantalum capacitor includes a housing 1 with an internal mounting cavity 11, a tantalum core 2 disposed in the mounting cavity 11, a cathode assembly 3 disposed in the mounting cavity 11, a sealing cap 4 for sealing the mounting cavity 11, a polytetrafluoroethylene sheet 5 disposed on the tantalum core 2, a plurality of diaphragms 7 disposed in the mounting cavity 11, and an electrolyte filling the mounting cavity 11. The diaphragms 7 are polymer diaphragms.

[0020] In this embodiment, the tantalum core 2 includes at least one tantalum block 21 stacked sequentially along the height of the mounting cavity 11, wherein a diaphragm 7 is disposed on the top and bottom surfaces of the tantalum block 21, and the length of the diaphragm 7 is longer than the length of the tantalum block 21.

[0021] In this embodiment, the sealing cover 4 includes a sealing cover body 41, a glass insulator 42 disposed in the sealing cover body 41, a tantalum wire 43 fixed on the glass insulator 42, a nickel tube 44 sleeved on the upper section of the tantalum wire 43, and a cathode lead 45 disposed on the sealing cover body 41. The lower section of the tantalum wire 43 extends into the mounting cavity 11 and is connected to the tantalum core 2 via the tantalum wire lead 6. The upper end face of the glass insulator 42 is flush with the upper end face of the sealing cover body 41. The nickel tube 44 is vertically opposite to the glass insulator 42, and a gap 46 is formed between the lower end face of the nickel tube 44 and the upper end face of the glass insulator 42. Specifically, the upper end of the tantalum wire lead 6 is connected to the tantalum wire 43, and the lower end is connected to the sides of multiple tantalum blocks 21. The cathode lead 45 is integrally formed with the sealing cover body 41. The main components of the sealing cover body 41 are tantalum and niobium metals.

[0022] In this embodiment, the cathode sheet assembly 3 includes a first cathode sheet 31 and at least one second cathode sheet 32. Specifically, the lower section of the first cathode sheet 31 is supported on the bottom of the mounting cavity 11, and the upper section is bent upward and extends to connect with the sealing cover body 41. A plurality of second cathode sheets 32 are arranged at intervals along the direction of the mounting cavity 11, and one end of the second cathode sheet 32 ​​extends to connect with the upper section of the first cathode sheet 31.

[0023] When both the tantalum block 21 and the second cathode plate 32 are single, two diaphragms 7 are provided, with the two diaphragms 7 located on the top and bottom surfaces of the tantalum block 21, respectively. During assembly, the tantalum block 21 and the two diaphragms 7 on its top and bottom surfaces are located between the lower section of the first cathode plate 31 and the second cathode plate 32, such that the tantalum block 21, the lower section of the first cathode plate 31, the second cathode plate 32, and the two diaphragms 7 are stacked vertically in the mounting cavity 11 in the stacking order of the lower section of the first cathode plate 31, the diaphragms 7, the tantalum block 21, the diaphragms 7, and the second cathode plate 32.

[0024] When there are multiple tantalum blocks 21 and multiple second cathode plates 32, during assembly, the tantalum blocks 21 and the two diaphragms 7 on their top and bottom surfaces are located between the lower section of the first cathode plate 31 and the second cathode plate 32 or between two adjacent second cathode plates 32, so that the tantalum blocks 21, the first cathode plate 31, multiple second cathode plates 32 and multiple diaphragms 7 are stacked vertically in the mounting cavity 11 in the basic order of the lower section of the first cathode plate 31, diaphragm 7, tantalum blocks 21, diaphragm 7 and second cathode plates 32, in conjunction with the stacking order of diaphragm 7, tantalum blocks 21, diaphragm 7 and second cathode plates 32.

[0025] In this embodiment, the first cathode sheet 31 includes a tantalum foil substrate and ruthenium oxide coatings disposed on the top and bottom surfaces of the tantalum foil substrate; wherein, the upper section of the aluminum foil substrate of the first cathode sheet 31 is not coated with ruthenium oxide, and extends upward from the tantalum foil substrate and bends to connect with the sealing cap body 41. Specifically, the structure of the second cathode sheet is the same as that of the lower section of the first cathode sheet 31, and will not be described further.

[0026] In this embodiment, the polytetrafluoroethylene sheet 5 is supported on the second cathode sheet 32 ​​located at the top by a separator membrane. Specifically, the separator membrane is a polymer separator membrane.

[0027] In this embodiment, a hydrophobic insulating coating 47 is provided on the outer periphery of the tantalum wire 43, and the hydrophobic insulating coating 47 is located in the separation gap 46. Specifically, the hydrophobic insulating coating 47 is formed by brushing or spraying a hydrophobic insulating liquid onto the area of ​​the tantalum wire 43 located in the separation gap 46, followed by heating and drying and curing; wherein, the hydrophobic insulating liquid includes a solvent and a fluorinated organic compound, and the mass fraction of the fluorinated organic compound is 2-10%.

[0028] In this embodiment, the solvent is a fluorinated hydrocarbon; the fluorinated polymer includes one or more of perfluoroalkyl ether polymers, fluorinated acrylate polymers, fluorinated organosilicon copolymers, and fluorinated epoxy polymers.

[0029] In this embodiment, the height of the separation interval 46 is 0.5-3mm; the length of the hydrophobic insulating coating 47 is 1-4mm, the thickness is 2-15μm, and the hydrophobic insulating coating 47 can extend to the bottom surface of the nickel tube 44.

[0030] In this embodiment, the electrolyte comprises the following raw materials in parts by weight: 75-99 parts sulfuric acid solution, 0.5-5 parts depolarizer, and 0.5-20 parts electron-rich additive, wherein the mass fraction of the sulfuric acid solution is 35-45%; the depolarizer is one or more of copper sulfate, ferric sulfate, silver sulfate, and oxysulfate; the electron-rich additive may be one or more of ethylene glycol methyl ether, diethylene glycol methyl ether, diethylene glycol dimethyl ether, oxalic acid, citric acid, triethanolamine, aminotriacetic acid, maleic acid, aminotrimethylenephosphonic acid, salicylic acid, and benzoic acid.

[0031] A method for preparing a high-safety non-solid tantalum capacitor includes the following steps: Step 1: Mix tantalum powder and tantalum wire at a ratio of 5-7 g / cm 3 The tantalum block blank is pressed into a tantalum density, and the tantalum block blank is vacuum sintered. The sintered tantalum block blank is then electrochemically sintered in an aqueous solution of phosphoric acid or nitric acid to form a dielectric oxide layer, thus obtaining tantalum block 21. Step 2: Dilute 95-98 wt% concentrated sulfuric acid with water to a sulfuric acid concentration of 35-45 wt%. Add 0.5-5 parts of depolarizer and 0.5-20 parts of electron-rich additive to 77-99 parts of sulfuric acid solution, mix well to obtain electrolyte. Step 3: Coat the outer peripheral surface of the tantalum wire 43 located in the separation gap 46 with a hydrophobic insulating coating, and then transfer the sealing cover 4 to an oven and dry it at a temperature of 60-120℃ for 15-30 minutes to obtain the sealing cover 4 with a hydrophobic insulating coating 47. Step 4: Assemble the tantalum core 2, cathode plate assembly 3, and diaphragm 7 into the housing 1 according to the installation requirements, and then assemble and weld the sealing cover 4 onto the housing 1 to obtain a capacitor semi-finished product without electrolyte filling. Step 5: Inject electrolyte into the capacitor semi-finished product. After injection, age the capacitor at room temperature for 20-30 hours and at 80-130℃ for 1-5 hours. After replenishing the lost electrolyte, seal to obtain the initial finished capacitor product. Step 6: After further aging the obtained capacitor pre-finished product at 25°C for 24 hours and at 85°C for 48 hours, test the electrical performance parameters, remove unqualified products, and obtain the high-safety non-solid tantalum capacitor. Example 11

[0032] A method for preparing a high-safety non-solid tantalum capacitor includes the following steps: Step 1: Mix tantalum powder with a specific volume of 10000 uF•V / g and tantalum wire at a ratio of 6 g / cm. 3The tantalum block blanks were pressed into 20mm diameter and 3mm thick tantalum blocks according to the pressing density. The tantalum block blanks were vacuum sintered. The sintered tantalum block blanks were placed in an aqueous solution of 0.1wt% phosphoric acid and 50wt% ethylene glycol to carry out electrochemical formation so that the thickness of the dielectric oxide layer formed on the tantalum block blanks reached the design requirements. After cleaning off the excess acid, the tantalum block 21 was obtained by drying. Step 2: Dilute 98% concentrated sulfuric acid with water to 38 wt%, add 10 parts of diethylene glycol methyl ether and 2 parts of CuSO4 to 88 parts of sulfuric acid solution, mix well, transfer to a fluorinated bottle, seal and store at low temperature. Step 3: Coat the outer peripheral surface of the tantalum wire 43 located in the separation gap 46 with a hydrophobic insulating coating, and then transfer the sealing cap 4 to an oven and dry it at 100°C for 20 minutes to obtain a sealing cap 4 with a hydrophobic insulating coating 47. The hydrophobic insulating coating is 5% by mass of poly-2-(perfluorohexyl)ethyl methacrylate and the solvent is HFE-7100 (methoxynonfluorobutane). Step 4: Assemble the tantalum core 2, cathode plate assembly 3, and diaphragm 7 into the housing 1 according to the installation requirements, and then assemble and weld the sealing cover 4 onto the housing 1 to obtain a capacitor semi-finished product without electrolyte filling. Step 5: Inject electrolyte into the capacitor semi-finished product. After injection, the capacitor is aged at room temperature for 24 hours and at 85°C for 2 hours. After replenishing the lost electrolyte, it is sealed to obtain the initial finished capacitor product. Step 6: After further aging the obtained capacitor pre-finished product at 25°C for 24 hours and at 85°C for 48 hours, test the electrical performance parameters, remove unqualified products, and obtain the high-safety non-solid tantalum capacitor.

[0033] The non-solid tantalum capacitor prepared above was tested and evaluated using the following method: 125℃ High Temperature Life Test: Place the capacitor in a 125℃ constant temperature chamber and let it stand for 1 hour to allow the capacitor to heat up to 125℃. Increase the voltage of the capacitor to 60% of the rated voltage at a rate of 5V / min. After reaching the specified voltage, switch to constant voltage test. Record the leakage current in the first hour after constant voltage, denoted as I. Thereafter, test the leakage current and observe the appearance of the capacitor every 10 hours. If the leakage current increases by a multiple of I (1 hour) or the appearance bulges, the capacitor is considered to have failed. The test duration is 2000 hours. After the test, calculate the product pass rate and the proportion of severely bulging products among the unqualified products. Example 2

[0034] The preparation method is basically the same as that in Example 1, except that: in step 3, a hydrophobic insulating coating is applied to the outer peripheral surface of the tantalum wire 43 located in the separation gap 46, and then the sealing cap 4 is transferred to an oven and dried at 100°C for 20 minutes to obtain a sealing cap 4 with a hydrophobic insulating coating 47. The hydrophobic insulating coating is trifluoropropylmethyl polysiloxane with a mass fraction of 4% and the solvent is HFE-7100 (methoxynonfluorobutane).

[0035] Comparative Example 1 The preparation method is basically the same as that in Example 1. The difference is that there is no gap between the nickel tube 44 and the glass insulator 42, and no hydrophobic insulating coating 47 is provided on the tantalum wire 43.

[0036] The results of the tests in Examples 1-2 and Comparative Example 1 are shown in Table 1.

[0037] Table 1 Test Results

[0038] As can be seen from the table above, the non-solid tantalum capacitors prepared in Examples 1 and 2 have high safety in use.

[0039] This application defines the structure of a non-solid tantalum capacitor by setting a separation gap 46 between the nickel tube 44 and the glass insulator 42, and setting a hydrophobic insulating layer 47 on the outer surface of the tantalum wire 43 located in the separation gap 46. This effectively prevents the electrochemical corrosion of the nickel tube 44 by acid, avoids the rapid and severe failure mode of "micro-acid leakage - electrochemical corrosion - hydrogen generation - pressure increase - aggravated acid leakage - severe deformation of the shell", and improves the safety of non-solid tantalum capacitors.

[0040] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A high-safety non-solid tantalum capacitor, characterized in that: The device includes an outer shell with an internal mounting cavity, a tantalum core disposed within the mounting cavity, a cathode assembly disposed within the mounting cavity, a sealing cover for sealing the mounting cavity, and an electrolyte filling the mounting cavity. The sealing cover includes a sealing cover body, a glass insulator disposed within the sealing cover body, a tantalum wire fixed to the glass insulator, a nickel tube sleeved on the upper section of the tantalum wire, and a cathode lead disposed on the sealing cover body. The lower section of the tantalum wire extends into the mounting cavity and is connected to the tantalum core via the tantalum wire lead. The cathode assembly is connected to the cathode lead via the sealing cover body. The upper end face of the glass insulator is flush with the upper end face of the sealing cover body. The nickel tube is vertically opposite to the glass insulator, and a separation gap is formed between the lower end face of the nickel tube and the upper end face of the glass insulator. A hydrophobic insulating coating is disposed on the outer periphery of the tantalum wire, and the hydrophobic insulating coating is located in the separation gap.

2. The high-safety non-solid tantalum capacitor according to claim 1, characterized in that: It also includes multiple diaphragms disposed in the mounting cavity. The tantalum core includes at least one tantalum block stacked sequentially along the height of the mounting cavity. The bottom and top surfaces of the tantalum block are provided with the diaphragm. The upper end of the tantalum wire lead is connected to the tantalum wire, and the lower end is connected to the side of the multiple tantalum blocks respectively.

3. A high-safety non-solid tantalum capacitor according to claim 2, characterized in that: The cathode assembly includes a first cathode sheet and at least one second cathode sheet. The lower section of the first cathode sheet is supported on the bottom of the mounting cavity, and the upper section extends upward from the lower section and bends to connect with the sealing cover body. The second cathode sheet is disposed above the lower section of the first cathode sheet, and one end extends to connect with the upper section of the first cathode sheet. When both the tantalum block and the second cathode sheet are single, the tantalum block and its two diaphragms on the top and bottom surfaces are located between the lower section of the first cathode sheet and the second cathode sheet. When both the tantalum block and the second cathode sheet are multiple, the tantalum block and its two diaphragms on the top and bottom surfaces are located between the lower section of the first cathode sheet and the second cathode sheet or between two adjacent second cathode sheets.

4. A high-safety non-solid tantalum capacitor according to claim 1, characterized in that: The hydrophobic insulating coating is formed by brushing or spraying a hydrophobic insulating liquid onto the area where the tantalum wire is located in the gap, followed by heating and drying to cure.

5. A high-safety non-solid tantalum capacitor according to claim 4, characterized in that: The hydrophobic insulating coating liquid comprises a solvent and a fluoropolymer, wherein the fluoropolymer has a mass fraction of 2-10%.

6. A high-safety non-solid tantalum capacitor according to claim 5, characterized in that: The solvent is a fluorinated hydrocarbon; the fluorinated polymer includes one or more of perfluoroalkyl ether polymers, fluorinated acrylate polymers, fluorinated organosilicon copolymers, and fluorinated epoxy polymers.

7. A high-safety non-solid tantalum capacitor according to claim 1, characterized in that: The thickness of the hydrophobic insulating coating is 2-15 μm.

8. A high-safety non-solid tantalum capacitor according to claim 1, characterized in that: The height of the separation interval is 0.5-3mm, the length of the hydrophobic insulating coating is 1-4mm, and the hydrophobic insulating coating can extend to the bottom surface of the nickel tube.

9. A high-safety non-solid tantalum capacitor according to claim 1, characterized in that: The electrolyte comprises the following raw materials in parts by weight: 75-99 parts sulfuric acid solution, 0.5-5 parts depolarizer, and 0.5-20 parts electron-rich additive, wherein the sulfuric acid solution has a mass fraction of 35-45%; the depolarizer is one or more of copper sulfate, ferric sulfate, silver sulfate, and oxysulfate; the electron-rich additive may be one or more of ethylene glycol methyl ether, diethylene glycol methyl ether, diethylene glycol dimethyl ether, oxalic acid, citric acid, triethanolamine, aminotriacetic acid, maleic acid, aminotrimethylenephosphonic acid, salicylic acid, and benzoic acid.

10. The method for preparing a high-safety non-solid tantalum capacitor according to claim 1, characterized in that: Includes the following steps: Step 1: Coat the outer circumferential surface of the tantalum wire located in the separation gap with a hydrophobic insulating coating, and then transfer the sealing cap to an oven and dry it at a temperature of 60-120℃ for 15-30 minutes to obtain a sealing cap with a hydrophobic insulating coating. Step 2: Assemble the tantalum core and cathode assembly into the housing according to the installation requirements, and then weld the sealing cap onto the housing to obtain a capacitor semi-finished product without electrolyte filling. Step 3: Inject electrolyte into the capacitor semi-finished product. After injection, age the capacitor at room temperature for 20-30 hours and at 80-130℃ for 1-5 hours. After replenishing the lost electrolyte, seal to obtain the initial finished capacitor product. Step 4: After further aging the obtained capacitor pre-finished product at 25°C for 24 hours and at 85°C for 48 hours, test the electrical performance parameters, remove unqualified products, and obtain the high-safety non-solid tantalum capacitor.

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