High-performance supercapacitor and preparation process thereof

Abstract

The invention discloses a high-performance supercapacitor and a preparation process thereof. The super capacitor comprises a shell with a containing cavity formed inside, a battery cell arranged in the containing cavity, a negative current collecting block arranged in the containing cavity and connected with the upper end of the battery cell, a positive current collecting block arranged in the containing cavity and connected with the lower end of the battery cell, and an upper cover assembly arranged at the upper end of the shell and used for sealing the containing cavity. The insulating sheet rubber mat is arranged between the upper cover assembly and the negative current collecting block; the first solder layer is arranged between the negative current collecting block and the battery cell; the second solder layer is arranged between the positive current collecting block and the battery cell; the first solder layer comprises a plurality of solder blocks which are circumferentially distributed between the upper end of the battery cell and the lower end of the negative current collecting block, and a plurality of liquid inlet areas for electrolyte to enter the battery cell are formed between every two adjacent solder blocks; during liquid injection, electrolyte can enter the battery cell from the space between the two solder blocks, so that the battery cell is easier to infiltrate the electrolyte, and gas particles are easier to discharge.

Description

Technical Field

[0001] The present invention belongs to the field of supercapacitor preparation, and in particular relates to a high-performance supercapacitor and a preparation process thereof. Background Art

[0002] As an emerging advanced energy storage device, supercapacitors have both the high power characteristics of traditional capacitors and the high energy characteristics of batteries. Due to its unique high specific power, large current discharge capability, ultra-low temperature characteristics, high reliability and green environmental protection, it has been widely used and developed in many fields such as electricity, transportation, communications, energy, aviation, etc.

[0003] Existing supercapacitors, especially the cell structure with positive and negative electrode aluminum foils leading out at both ends, need to flatten and chamfer the positive and negative electrode aluminum foils during the manufacturing process, laser spot weld them to the end faces of the positive and negative current collectors, and then make the positive current collectors and the shell interference fit, the negative current collectors and the upper cover laser welded, and then the upper cover and the shell laser welded. The preparation process is complicated and has extremely high requirements on equipment. After the cell is flattened, chamfered and laser welded to the current collectors, the inside of the cell is almost in a closed state. During the liquid injection process, the speed at which the electrolyte infiltrates the cell is extremely slow. At the same time, the bubbles inside the cell are difficult to peel off, which can easily have a negative impact on the performance of the capacitor and make it easier for the supercapacitor to accumulate heat energy inside the cell when charging and discharging with a large current. The laser welding between the positive and negative current collectors and the cell aluminum foils is spot welding with a small welding area. The laser welding point is the stress point between the cell and the shell when the capacitor vibrates, which can easily cause the cell to fall off and open.

[0004] At the same time, due to the low rated voltage of existing supercapacitors, they usually need to be connected in series to form modules to make the voltage meet the usage requirements. However, when a cell in the series capacitor is short-circuited, overcurrent or current backflow will occur at the short-circuit node, causing the cell, terminal, and circuit board to burn. While there are safety hazards, flammable and toxic gases are released from the pressure relief valve. There are many reasons for the short circuit inside the capacitor, such as electrode burrs piercing the electrolytic paper, local electrolytic paper burning caused by dust or metal granular impurities, mechanical shock or vibration causing electrode material peeling and causing short circuit, etc. However, these short circuit problems cannot be analyzed through dissection to find the cause of the short circuit after the cell is burned due to overcurrent or current backflow, so the problem point cannot be corrected and prevented. This problem also exists in the failure of capacitors caused by overcharging or overheating due to circuit system failure or other reasons; further improvement is needed. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a high-performance supercapacitor and a preparation process thereof.

[0006] The present invention adopts the following technical solution: A high-performance supercapacitor, comprising a shell with a receiving cavity formed therein, a battery cell arranged in the receiving cavity, a negative current collecting block arranged in the receiving cavity and connected to the upper end of the battery cell, a positive current collecting block arranged in the receiving cavity and connected to the lower end of the battery cell, an upper cover assembly arranged at the upper end of the shell for sealing the receiving cavity, an insulating sheet rubber pad arranged between the upper cover assembly and the negative current collecting block, a first solder layer arranged between the negative current collecting block and the battery cell, and a second solder layer arranged between the positive current collecting block and the battery cell; The first solder layer includes a plurality of solder blocks circumferentially distributed between the upper end of the battery cell and the lower end of the negative current collector, a plurality of liquid inlet areas for electrolyte to enter the battery cell are formed between two adjacent solder blocks, and a plurality of connection parts connected to the plurality of solder blocks are formed at the upper end of the battery cell.

[0007] Furthermore, the battery cell is formed by stacking and winding a negative electrode sheet, an inner separator, a positive electrode sheet and an outer separator. The negative electrode sheet includes a first overlapping portion stacked with the inner separator and a first coating portion located on one side of the inner separator. The first coating portion is provided with a plurality of first coating blocks in sequence along the winding direction. The plurality of first coating blocks form a plurality of connecting portions after the negative electrode sheet is wound.

[0008] Furthermore, the diameter of the solder block increases radially outwards.

[0009] Furthermore, the diameter of the solder block is arranged to be equal in radial direction.

[0010] Furthermore, the structure of the second solder layer is the same as that of the first solder layer, and the positive electrode sheet includes a second overlapping portion stacked with the inner diaphragm or the outer diaphragm and a second plated portion located on one side of the inner diaphragm or the outer diaphragm, and the first plated portion and the second plated portion are relatively arranged on both sides of the inner diaphragm or the outer diaphragm.

[0011] Furthermore, the negative current collector includes a negative current collector body, a negative electrode column extending upward from the top of the negative current collector body, and a sealing assembly sleeved around the outer periphery of the negative electrode column and located between the insulating sheet rubber pad and the upper cover assembly, wherein the sealing assembly includes a first sealing ring sleeved around the outer periphery of the negative electrode column and located between the insulating sheet rubber pad and the upper cover assembly, a metal ring arranged around the first sealing ring, and a second sealing ring arranged on the upper cover assembly to fix the metal ring on the outer periphery of the first sealing ring.

[0012] Furthermore, the first sealing ring includes a first sealing ring body, a first through-hole arranged in the first sealing ring body for the negative electrode column to pass through, an installation groove extending inward from the outer circumference of the first sealing ring body for installing a metal ring, and a plurality of first liquid holes arranged at intervals on the wall of the installation groove and extending inward to communicate with the first through-hole.

[0013] Furthermore, the second sealing ring includes a supporting section supported on the top of the upper cover assembly, an annular positioning section arranged at the lower end of the supporting section and surrounding the mounting groove, and a plurality of second liquid holes arranged at intervals on the annular positioning section. The metal ring is installed in the mounting groove, with one side abutting against the wall of the mounting groove and the other side abutting against the inner wall of the annular positioning section.

[0014] Furthermore, the plurality of first liquid passage holes are opposite to the plurality of second liquid passage holes.

[0015] A preparation process of a high-performance supercapacitor specifically comprises the following steps: Step 1, forming the negative electrode sheet and the positive electrode sheet: A. After the aluminum foil is cleaned and dried, the dry film is laminated and solidified. After the discontinuous area to be plated is reserved at the edge of the aluminum foil, it is immersed in the middle of the electroplating solution, and copper and tin are plated in turn in the area to be plated; B. Clean and dry the copper-tin plated aluminum foil to remove the dry film and its impurities; C. The electrolytic slurry is evenly coated on the middle position of the front and back sides of the aluminum foil, and then dried and roll-formed; D. Cut along the center line of the aluminum foil to obtain a negative electrode sheet and a positive electrode sheet; Step 2, forming the battery cell: stacking and winding the negative electrode sheet, the positive electrode sheet and two separators to form a battery cell; Step 3, injecting tin into the bath, moving the preheated upper end of the battery cell into the bath, absorbing the tin onto the negative electrode sheet to be plated, and forming a first solder layer after cooling; and then soldering the lower end of the battery cell in turn to form the second solder layer; Step 4, facing the upper end of the preheated battery cell downward, fit it to the heated negative current collector, so that the negative current collector is welded to the upper end of the battery cell, and then facing the lower end of the preheated battery cell downward, fit it to the heated positive current collector, so that the positive current collector is welded to the lower end of the battery cell; Step 5, install the insulating sheet rubber pad and the upper cover assembly on the top of the negative current collector from bottom to top, and then seal the upper cover assembly and the upper end of the shell by laser welding; Step 6, after vacuum heating and drying the semi-finished product prepared in step 5, injecting an electrolytic electrolyte into the containing cavity to form the high-performance supercapacitor.

[0016] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following beneficial effects: the present application defines the structural composition of the supercapacitor, and respectively sets a first solder layer and a second solder layer at the upper and lower ends of the negative current collecting block, the positive current collecting block and the battery cell, and further defines the structural composition of the solder layer, so that a plurality of liquid inlet areas for electrolyte to enter the battery cell are formed between two adjacent solder blocks. During liquid injection, the electrolyte can enter the battery cell from between the two solder blocks, so that the battery cell is easier to be infiltrated with the electrolyte and the gas particles are easier to be discharged; in addition, the sealing component is further defined. The structure is composed of: when the capacitor in the series circuit causes overcurrent or current backflow due to a short circuit in a capacitor cell, the heat energy accumulates and is transmitted to the negative electrode column and the sealing component, the metal ring inside the sealing component melts, and the molten conductive metal liquid can flow to the negative electrode column through the first liquid hole and weld to the negative electrode column, or flow to the upper cover component through the second liquid hole and weld to the upper cover component, so that the positive electrode column and the negative electrode column of the abnormal capacitor form a passage on the upper cover plate, and the current no longer passes through the cell, so that the cell can be preserved before being further damaged, so as to facilitate the subsequent anatomical analysis of the capacitor and find the cause of the cell short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a supercapacitor; Figure 2 It is a structural cross-sectional view of a supercapacitor; Figure 3 is a structural cross-sectional view of the shell; Figure 4 It is a partial structural schematic diagram of a supercapacitor; Figure 5 is a structural cross-sectional view of a sealing component; Figure 6 The figure is a flow chart of the preparation of the battery cell; Figure 7 is a schematic structural diagram of a first embodiment of a first solder layer; Figure 8 is a schematic structural diagram of a second embodiment of a second solder layer; In the figure, 1-housing, 2-cell, 3-negative current collector, 4-positive current collector, 5-upper cover assembly, 6-insulating sheet rubber pad, 7-first solder layer, 8-second solder layer, 11-accommodating cavity, 21-negative electrode sheet, 211-first overlapping portion, 212-first plating portion, 213-first plating block, 22-inner diaphragm, 23-positive electrode sheet, 231-second overlapping portion, 232-second plating portion, 233-second plating block, 31-negative current collector body, 32-negative pole, 33-sealing assembly, 34-first Sealing ring, 341-first sealing ring body, 342-installing groove, 343-first liquid hole, 344-first through hole, 35-metal ring, 36-second sealing ring, 361-support section, 362-annular positioning section, 363-second liquid hole, 41-positive current collecting block body, 42-positioning column, 43-liquid injection hole, 44-sealing member, 441-sealing rubber plug, 442-metal plug, 51-upper cover plate, 52-positive pole column, 53-allowance hole, 61-limiting groove, 71-solder block, 72-liquid inlet area. DETAILED DESCRIPTION

[0018] The present invention is further described below through specific implementation modes.

[0019] Reference Figures 1 to 8 As shown, a high-performance supercapacitor includes a shell 1 with a accommodating cavity 11 formed therein, a battery cell 2 arranged in the accommodating cavity 11, a negative current collector 3 arranged in the accommodating cavity 11 and connected to the upper end of the battery cell 2, a positive current collector 4 arranged in the accommodating cavity 11 and connected to the lower end of the battery cell 2, an upper cover assembly 5 arranged on the shell 1 for sealing the accommodating cavity 11, an insulating sheet rubber pad 6 arranged between the upper cover assembly 5 and the negative current collector 3, a first solder layer 7 arranged between the negative current collector 3 and the battery cell 2, and a second solder layer 8 arranged between the positive current collector 4 and the battery cell 2.

[0020] The first solder layer 7 includes a plurality of solder blocks 71 circumferentially distributed between the upper end of the battery cell 2 and the lower end of the negative current collector 3, wherein a plurality of liquid inlet areas 72 for electrolyte to enter the battery cell 2 are formed between two adjacent solder blocks 71, and a plurality of connection portions connected to the plurality of solder blocks 71 are formed at the upper end of the battery cell 2; specifically, refer to Figure 7 or Figure 8 As shown, the diameter of the solder block 71 increases radially outward or is arranged with equal diameter along the radial direction. Furthermore, the structure of the second solder layer 8 is the same as that of the first solder layer 7, and its specific structural composition will not be further described here.

[0021] The battery cell 2 is formed by stacking and winding a negative electrode sheet 21, an inner separator 22, a positive electrode sheet 23 and an outer separator, wherein the widths of the inner separator 22 and the outer separator are respectively smaller than the widths of the negative electrode sheet 21 and the positive electrode sheet 23, and the lengths of the inner separator 22 and the outer separator are respectively larger than the lengths of the negative electrode sheet 21 and the positive electrode sheet 23.

[0022] The negative electrode sheet 21 includes a first overlapping portion 211 stacked with the inner diaphragm 22 and a first plating portion 212 located on one side of the inner diaphragm 22, wherein the first plating portion 212 is sequentially provided with a plurality of first plating blocks 213 along the winding direction, and the plurality of first plating blocks 213 are wound along the negative electrode sheet 21 to form a plurality of the connecting portions; specifically, the intervals and sizes between the plurality of first plating blocks 213 are set according to the number of winding layers of the battery cell 2 and the shape and size of the solder block 71, and how to set them will not be further elaborated here.

[0023] The positive electrode sheet 23 includes a second overlapping portion 231 stacked with the inner diaphragm 22 or the outer diaphragm and a second plating portion 232 located on one side of the inner diaphragm 22 or the outer diaphragm, wherein the second plating portion 232 is provided with a plurality of second plating blocks 233 arranged in sequence along the winding direction, and the plurality of second plating blocks 233 are wound along the positive electrode sheet 23 to form a plurality of connection portions connected to the positive current collecting block 4; specifically, the first plating portion 212 and the second plating portion 232 are relatively arranged on both sides of the inner diaphragm 22 and the outer diaphragm, so that the negative electrode sheet 21 and the positive electrode sheet 23 after winding are respectively connected to the relative negative current collecting block 3 and the positive current collecting block 4; by limiting the structural composition of the battery cell 2, a plurality of connection portions that can be connected to the relative solder blocks 71 are formed at the ends of the negative electrode sheet 21 and the positive electrode sheet 23, and when injecting liquid, the electrolyte can enter the interior of the battery cell 2 from between the two connection portions, so that the battery cell 2 is easier to be infiltrated with the electrolyte and the gas particles are easier to be discharged.

[0024] The negative current collector 3 includes a negative current collector body 31, a negative electrode column 32 extending upward from the top of the negative current collector body 31, and a sealing assembly 33 sleeved on the outer periphery of the negative electrode column 32 and located between the insulating sheet rubber pad 6 and the upper cover assembly 5, wherein the sealing assembly 33 includes a first sealing ring 34 arranged on the outer periphery of the negative electrode column 32 and located between the insulating sheet rubber pad 6 and the upper cover assembly 5, a metal ring 35 arranged around the first sealing ring 34, and a second sealing ring 36 arranged on the upper cover assembly 5 to fix the metal ring 35 on the outer periphery of the first sealing ring 34.

[0025] The first sealing ring 34 includes a first sealing ring body 341, a first through hole 344 arranged in the first sealing ring body 341 for the negative pole 32 to pass through, a mounting groove 342 extending inward from the outer periphery of the first sealing ring body 341 for mounting the metal ring 35, and a plurality of first liquid holes 343 arranged at intervals on the groove wall of the mounting groove 342 and extending inward to communicate with the first through hole 344, wherein the first sealing ring body 341 is arranged in an I-shape, with the upper end supported on the top of the upper cover assembly 5 and the lower end embedded in the insulating sheet rubber pad 6; specifically, the insulating sheet rubber pad 6 is provided with a limiting groove 61 for the lower end of the first sealing ring body 341 to be embedded.

[0026] The second sealing ring 36 includes a supporting section 361 supported on the top of the upper cover assembly 5, an annular positioning section 362 arranged at the lower end of the supporting section 361 and surrounding the mounting groove 342, and a plurality of second liquid holes 363 arranged at intervals on the annular positioning section 362, wherein the metal ring 35 is installed in the mounting groove 342, one side of which is against the groove wall of the mounting groove 342, and the other side of which is against the inner wall of the annular positioning section 362; the upper end of the first sealing ring body 341 is supported on the supporting section 361; specifically, the plurality of first liquid holes 343 and the plurality of second liquid holes 363 are arranged opposite to each other.

[0027] The metal ring 35 is made of a conductive metal, which can be a conductive alloy prepared by combining metals such as indium, bismuth, tin, and lead. The melting point of the conductive alloy is about 110°C-150°C, and it is a hollow metal ring after molding. When the capacitor in the series circuit causes overcurrent or current backflow due to a short circuit in a capacitor cell 2, the heat energy accumulates and is transmitted to the negative pole 32 and the sealing component 33, and the metal ring 35 inside the sealing component 33 melts. The molten conductive metal liquid can flow to the negative pole 32 through the first liquid hole 343 and weld to the negative pole 32, or flow to the upper cover component 5 through the second liquid hole 363 and weld to the upper cover component 5, so that the positive pole 52 and the negative pole 32 of the abnormal capacitor form a path in the upper cover, and the current no longer passes through the cell 2, so that the cell 2 can be preserved before being further damaged, so as to facilitate the subsequent dissection of the capacitor. Analyze and find the cause of the short circuit of the battery cell 2. At the same time, when the capacitor module is designed with a margin in the voltage, the series module can continue to be used after the faulty capacitor forms a path and will not fail due to the melting of a single capacitor; after the external circuit or ambient temperature returns to normal, the capacitor is laid flat with multiple first liquid holes 343 facing downward, and the upper cover is locally heated to melt the welded fusible metal material again and flow into the installation groove 342 through the first liquid hole 343 and the second liquid hole 363, so that the fusible metal material is separated from the negative electrode 32 and the upper cover assembly 5 respectively. After cooling and finalization, the capacitor can be charged and discharged normally again; this function can also be actively turned on by the user to eliminate the interference of the capacitor with poor performance on the voltage equalization of the entire series module during the use of the capacitor module, resulting in accelerated attenuation and failure of the module.

[0028] The preparation method of the sealing component 33 is as follows: Step 1: Weigh high-purity indium (99.99%) and tin (99.99%) in a ratio of 52:48 and place them in a crucible furnace or induction furnace and heat them to 250°C-300°C. After the indium and tin are melted, use a quartz rod or mechanical stirrer to stir the molten alloy to ensure uniform composition, and keep it warm to promote diffusion of the components. Step 2: After the mold is preheated, the molten alloy is injected into the mold, cooled, formed and polished to obtain a hollow metal ring 35 with good electrical conductivity; Step three, install the metal ring 35 into the installation groove 342 of the first sealing ring 34, and install the second sealing ring 36 into the first sealing ring 34, so that the upper end surface of the second sealing ring 36 fits the upper end surface of the first sealing ring 34, the first sealing ring 34 and the second sealing ring 36 cover the metal ring 35, and adjust the relative position of the first sealing ring 34 and the second sealing ring 36 so that the multiple first liquid holes 343 and the multiple second liquid holes 363 are in relative directions, thereby obtaining the sealing assembly 33.

[0029] The positive collector block 4 includes a positive collector block body 41, a positioning column 42 arranged on the top of the positive collector block body 41 and embeddable in the battery cell 2, an injection hole 43 extending outwardly arranged in the positioning column 42, and a seal 44 for sealing the injection hole 43. Specifically, the seal 44 includes a sealing rubber plug 441 arranged in the injection hole 43 and a metal plug 442 for fixing the sealing rubber plug 441, wherein the metal plug 442 is fixed to the injection hole 43 by laser welding, and its end face is flush with the bottom of the shell 1; further, the positive collector block body 41 is integrally formed with the bottom of the accommodating cavity 11, so that the lower end of the battery cell 2 is directly connected to the shell 1, which is easier to dissipate heat, reduce heat accumulation, and make the battery cell 2 and the shell 1 more closely combined, and optimize the vibration stress from laser welding to end plane and internal three-dimensional welding, which can reduce the internal resistance while being able to withstand greater mechanical stress impact.

[0030] The upper cover assembly 5 includes an upper cover plate 51 for sealing the accommodating cavity 11 and a plurality of positive poles 52 circumferentially distributed on the top of the upper cover plate 51 , wherein the upper cover plate 51 is formed with a clearance hole 53 for the negative pole 32 to pass through, and the plurality of positive poles 52 are arranged around the negative pole 32 .

[0031] The preparation process specifically comprises the following steps: Step 1, forming the negative electrode sheet 21 and the positive electrode sheet 23: A. After the aluminum foil is cleaned and dried, the dry film is laminated and solidified. After the discontinuous area to be plated is reserved at the edge of the aluminum foil, it is immersed in the middle of the electroplating solution, and copper and tin are plated in turn in the area to be plated; B. Clean and dry the copper-tin plated aluminum foil to remove the dry film and its impurities; C. The electrolytic slurry is evenly coated on the middle position of the front and back sides of the aluminum foil, and then dried and roll-formed; D. Cutting along the center line of the aluminum foil to obtain a negative electrode sheet 21 and a positive electrode sheet 23; Step 2, forming the battery cell 2: stacking and winding the negative electrode sheet 21, the inner separator 22, the positive electrode sheet 23 and the outer separator to form the battery cell 2; Step 3, inject tin into the bath, move the upper end of the preheated battery cell 2 into the bath, absorb the tin onto multiple connection parts of the negative electrode sheet 21, and form a first solder layer 7 after cooling; and then solder the lower end of the battery cell 2 to form the second solder layer 8; Step 4, the upper end of the preheated battery cell is facing downward, and is attached to the negative current collector 3 heated to about 300° C., so that the negative current collector 3 is welded to the upper end of the battery cell 2, and then the lower end of the preheated battery cell 2 is facing downward, and is attached to the heated positive current collector 4, so that the positive current collector 4 is welded to the lower end of the battery cell 2; Step 5, install the insulating sheet rubber pad 6 on the upper surface of the negative current collector 3, with the limiting groove 61 on the insulating sheet rubber pad 6 facing upward, install the sealing assembly 33 into the clearance hole 53 of the upper cover plate 51, and fit the outer wall of the second sealing ring 36 with the inner wall of the clearance hole 53, and then install the upper cover plate 51 with the sealing assembly 33 installed on the negative current collector 3, so that the inner wall of the first through hole 344 fits with the outer wall of the negative electrode column 32, and the lower end of the first sealing ring 34 is embedded in the limiting groove 61, and then the upper cover plate 51 and the upper end of the housing 1 are sealed by laser welding; In step 6, after vacuum heating and drying the semi-finished product prepared in step 5, the electrolyte is injected into the accommodating cavity 11 from the upwardly placed injection hole 43 in a low dew point environment, and then the sealing rubber plug 441 and the metal plug 442 are installed in sequence, and the metal plug 442 is sealed together with the shell 1 by laser welding to form the high-performance supercapacitor.

[0032] The present application defines the structural composition of the supercapacitor, and respectively sets a first solder layer 7 and a second solder layer 8 at the upper and lower ends of the negative current collecting block 3, the positive current collecting block 4 and the battery cell 2, and further defines the structural composition of the solder layer, so that a plurality of liquid inlet areas 72 for electrolyte to enter the battery cell 2 are formed between two adjacent solder blocks 71. When injecting liquid, the electrolyte can enter the battery cell 2 from between the two solder blocks 71, so that the battery cell 2 is easier to be infiltrated with electrolyte and gas particles are easier to be discharged; in addition, the structural composition of the sealing component 33 is further defined, when the capacitor in the series circuit is shorted due to a capacitor cell 2 When the circuit causes overcurrent or current backflow, the heat energy accumulates and is transmitted to the negative electrode column 32 and the sealing component 33, and the metal ring 35 inside the sealing component 33 melts. The molten conductive metal liquid can flow to the negative electrode column 32 through the first liquid hole 343 and be welded to the negative electrode column 32, or flow to the upper cover component 5 through the second liquid hole 363 and be welded to the upper cover component 5, so that the positive electrode column 52 and the negative electrode column 32 of the abnormal capacitor form a passage on the upper cover plate 51, and the current no longer passes through the battery cell 2, so that the battery cell 2 can be preserved before being further damaged, so as to facilitate the subsequent anatomical analysis of the capacitor and find the cause of the short circuit of the battery cell 2.

[0033] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of implementation of the present invention. That is, equivalent changes and modifications made according to the application 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 performance supercapacitor, characterized in that: It includes a shell with a receiving cavity formed therein, a battery cell arranged in the receiving cavity, a negative current collecting block arranged in the receiving cavity and connected to the upper end of the battery cell, a positive current collecting block arranged in the receiving cavity and connected to the lower end of the battery cell, an upper cover assembly arranged at the upper end of the shell for sealing the receiving cavity, an insulating sheet rubber pad arranged between the upper cover assembly and the negative current collecting block, a first solder layer arranged between the negative current collecting block and the battery cell, and a second solder layer arranged between the positive current collecting block and the battery cell; The first solder layer includes a plurality of solder blocks circumferentially distributed between the upper end of the battery cell and the lower end of the negative current collector, a plurality of liquid inlet areas for electrolyte to enter the battery cell are formed between two adjacent solder blocks, and a plurality of connection parts connected to the plurality of solder blocks are formed at the upper end of the battery cell.

2. A high performance supercapacitor according to claim 1, characterized in that: The battery cell is formed by stacking and winding a negative electrode sheet, an inner diaphragm, a positive electrode sheet and an outer diaphragm. The negative electrode sheet includes a first overlapping portion stacked with the inner diaphragm and a first plating portion located on one side of the inner diaphragm. The first plating portion is sequentially provided with a plurality of first plating blocks along the winding direction. The plurality of first plating blocks form a plurality of the connecting portions after the negative electrode sheet is wound.

3. A high performance supercapacitor according to claim 2, characterized in that: The diameters of the solder blocks increase radially outwards.

4. A high performance supercapacitor according to claim 2, characterized in that: The diameters of the solder blocks are arranged to be equal in radial direction.

5. A high performance supercapacitor according to claim 2, characterized in that: The structure of the second solder layer is the same as that of the first solder layer. The positive electrode sheet includes a second overlapping portion stacked with the inner diaphragm or the outer diaphragm and a second plated portion located on one side of the inner diaphragm or the outer diaphragm. The first plated portion and the second plated portion are relatively arranged on both sides of the inner diaphragm or the outer diaphragm.

6. A high performance supercapacitor according to claim 1, characterized in that: The negative current collector includes a negative current collector body, a negative electrode column extending upward from the top of the negative current collector body, and a sealing assembly sleeved around the outer periphery of the negative electrode column and located between the insulating sheet rubber pad and the upper cover assembly, wherein the sealing assembly includes a first sealing ring sleeved around the outer periphery of the negative electrode column and located between the insulating sheet rubber pad and the upper cover assembly, a metal ring arranged around the first sealing ring, and a second sealing ring arranged on the upper cover assembly to fix the metal ring to the outer periphery of the first sealing ring.

7. A high performance supercapacitor according to claim 6, characterized in that: The first sealing ring includes a first sealing ring body, a first through hole arranged in the first sealing ring body for the negative pole to pass through, a mounting groove extending inward from the outer circumference of the first sealing ring body for mounting a metal ring, and a plurality of first liquid holes spaced apart and extending inward from the wall of the mounting groove and communicating with the first through hole.

8. A high performance supercapacitor according to claim 7, characterized in that: The second sealing ring includes a supporting section supported on the top of the upper cover assembly, an annular positioning section arranged at the lower end of the supporting section and surrounding the mounting groove, and a plurality of second liquid holes arranged at intervals on the annular positioning section. The metal ring is installed in the mounting groove, with one side abutting against the wall of the mounting groove and the other side abutting against the inner wall of the annular positioning section.

9. A high performance supercapacitor according to claim 8, characterized in that: The plurality of first liquid-passing holes are opposite to the plurality of second liquid-passing holes.

10. The process for preparing a high performance supercapacitor according to claim 1, characterized in that: The specific steps include: Step 1, forming the negative electrode sheet and the positive electrode sheet: A. After the aluminum foil is cleaned and dried, the dry film is laminated and solidified. After the discontinuous area to be plated is reserved at the edge of the aluminum foil, it is immersed in the middle of the electroplating solution, and copper and tin are plated in turn in the area to be plated; B. Clean and dry the copper-tin plated aluminum foil to remove the dry film and its impurities; C. The electrolytic slurry is evenly coated on the middle position of the front and back sides of the aluminum foil, and then dried and roll-formed; D. Cut along the center line of the aluminum foil to obtain a negative electrode sheet and a positive electrode sheet; Step 2, forming the battery cell: stacking and winding the negative electrode sheet, the positive electrode sheet and two separators to form a battery cell; Step 3, injecting tin into the bath, moving the preheated upper end of the battery cell into the bath, absorbing the tin onto the negative electrode sheet to be plated, and forming a first solder layer after cooling; and then soldering the lower end of the battery cell in turn to form the second solder layer; Step 4, facing the upper end of the preheated battery cell downward, fit it to the heated negative current collector, so that the negative current collector is welded to the upper end of the battery cell, and then facing the lower end of the preheated battery cell downward, fit it to the heated positive current collector, so that the positive current collector is welded to the lower end of the battery cell; Step 5, install the insulating sheet rubber pad and the upper cover assembly on the top of the negative current collector from bottom to top, and then seal the upper cover assembly and the upper end of the shell by laser welding; Step 6, after vacuum heating and drying the semi-finished product prepared in step 5, injecting an electrolytic electrolyte into the containing cavity to form the high-performance supercapacitor.

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