A double-layer capacitor and a method for manufacturing the same

Abstract

This invention discloses a double-layer capacitor and its preparation method, belonging to the field of capacitor technology. A sealing plate is installed inside the casing, located on the top surface of the capacitor element and in press-fit contact with it. The sealing plate is press-fitted with a cap mounted on the open end via a disc spring. A raised circular stopper is coaxially located in the center of the cap, with threads on its circumference to connect with the threads on the inner wall of the open end, thus securing the cap. An electrolyte injection channel is also provided on the sealing plate, with a detachable sealing component that vertically penetrates the sealing plate and cap to seal the channel. During assembly, the capacitor element is directly placed in the center of the casing using a positioning cover, then the sealing plate and cap are closed, and electrolyte is injected. This invention allows for rapid and reliable assembly of double-layer capacitors, is safe and reliable, and is easy to disassemble for convenient testing and maintenance.

Description

Technical Field

[0001] This invention relates to the field of capacitor technology, and in particular to a double-layer capacitor and its fabrication method. Background Technology

[0002] Double-layer capacitors, as a type of supercapacitor, have attracted widespread attention due to their high power density, long cycle life, and fast charge / discharge capabilities. Existing double-layer capacitors almost all adopt a structure similar to that of ordinary capacitors. The bonded capacitor elements are directly placed and fixed inside a casing for overall encapsulation. During overall encapsulation, the method is usually the same as fixing the individual electronic components inside the capacitor element, using adhesive bonding. For example, the most common structure uses insulating elastic resin for bonding and sealing. This bonding and sealing is relatively convenient, simply filling the corresponding adhesive. However, it requires considerable operational experience because the adhesive often cannot be fully filled between the corresponding components of the casing. For example, it is difficult to inject sufficient adhesive into the seam between the casing cap and the main body because the seam is very small, and the adhesive flow itself is somewhat inconsistent. If the gap is too large, too much adhesive will be applied, making cracking more likely.

[0003] In addition, double-layer capacitors have a higher power density and larger internal structure. Therefore, the bonding path required by the adhesive is longer, which increases the possibility of insufficient adhesive flow or incomplete injection. Moreover, this type of adhesive assembly structure is difficult to disassemble. When disassembly and maintenance are required, the original adhesive must be scraped off, otherwise it will directly affect the reliability of subsequent re-bonding and assembly, which is undoubtedly very difficult. Summary of the Invention

[0004] In view of the above-mentioned technical status, the purpose of this invention is to provide a double-layer capacitor and its preparation method. This double-layer capacitor and its preparation method can quickly and comprehensively encapsulate the double-layer capacitor, which is robust and reliable, and has good quick disassembly and reassembly performance.

[0005] To achieve the above objectives, the present invention employs a double-layer capacitor, comprising a shell and a capacitor element located inside the shell, with an electrolyte filling the space between the capacitor element and the shell. The inner wall of the shell has an annular step. A sealing plate is vertically and slidably mounted on the open end of the shell, the sealing plate being located on the top surface of the capacitor element and in pressure contact with it. The sealing plate is axially pressure-contacted with a cover plate mounted on the open end via a disc spring, the disc spring being located between the sealing plate and the cover plate. A raised circular stopper is coaxially located at the center of the cover plate, the circular stopper plate having threads on its circumference to connect with the threads on the inner sidewall of the open end to fix the cover plate. An electrolyte injection channel is also provided on the sealing plate, and a sealing component is detachably provided on the electrolyte injection channel, vertically penetrating the sealing plate and the cover plate, the sealing component sealing the electrolyte injection channel.

[0006] Furthermore, the cap has an annular protrusion near its edge, and the circular plug is coaxially and spaced apart inside the annular protrusion; an annular slot is provided on the fixed end face of the opening end, and the annular protrusion is inserted into the annular slot and presses an annular sealing gasket inside the slot.

[0007] Furthermore, the sealing component includes a bolt and a nut that mates with the bolt. The sealing plate has a countersunk hole on the side facing the capacitor element. The nut of the bolt is located in the countersunk hole and presses against the sealing ring on the countersunk hole step. The stud of the bolt passes vertically through the sealing cover and is tightened by the nut installed on the upper surface of the sealing cover to maintain the compressive force of the nut on the sealing ring.

[0008] A coaxial injection hole is provided inside the bolt. The top end of the injection hole has a screw plug, and the bottom end does not penetrate the nut. Several diversion channels are connected to the bottom end in all directions, extending out of the upper end face of the nut. The injection hole and diversion channels together form the electrolyte injection channel.

[0009] Furthermore, the upper surface of the cap has a circular groove in which the nut is coaxially installed. The sidewall of the nut has a sliding post that elastically expands and contracts radially. One end of the sliding post extends out of the sidewall of the nut and presses against the sidewall of the circular groove. A blind hole is provided radially on the sidewall of the circular groove. A threaded hole is provided vertically downward in the upper part of the blind hole and communicates with it. The top of the threaded hole penetrates the upper surface of the cap. A screw is threaded into the threaded hole. The size and installation position of the screw must meet the following conditions: When the screw is screwed vertically into the blind hole, rotating the nut allows the end of the sliding post to contact the threaded section and slide out of the blind hole. When the screw is screwed into the blind hole, the end of the sliding post springs into the blind hole to its limit depth position during the rotation of the nut. Below the limit depth position, the sliding post can no longer slide out of the blind hole.

[0010] The capacitor element, from top to bottom, includes: a first current collector, a first polarized electrode layer, an insulator, a second polarized electrode layer, and a second current collector within the housing.

[0011] The first current collector is in contact with the sealing plate by compression, and the second current collector is in contact with the inner bottom surface of the outer casing by compression.

[0012] Furthermore, the insulator is a circular groove structure with the groove opening facing downwards, and the second polarizable electrode layer is located inside the groove structure and is centrally positioned.

[0013] Meanwhile, this invention also proposes a method for preparing a double-layer capacitor, comprising installing the capacitor element inside a casing, injecting an electrolyte, and finally encapsulating the casing, following the steps below.

[0014] Lay the outer casing flat with its open end facing upwards; temporarily place the capacitor element into the outer casing through the open end; coaxially install a positioning cover on the annular step inside the outer casing. The positioning cover has a conical hole with one end facing downwards. Specifically, after placing the capacitor element, move the positioning cover vertically downwards along the inner wall of the outer casing and gradually slip it onto the capacitor element. When the positioning cover moves down until its hole wall contacts the largest size of the capacitor element, the bottom end of the positioning cover is located on the annular step, and at this time, the positioning cover automatically adjusts the capacitor element to the centered position inside the outer casing; press down the top surface of the capacitor element and gradually remove the positioning cover. Then, slide the sealing plate vertically into the outer casing through the open end and place it flat on the top surface of the capacitor element. Then tighten the cap and use the sealing plate to press and fix the capacitor element; after injecting electrolyte through the electrolyte injection channel, seal the opening of the electrolyte injection channel.

[0015] Furthermore, when filling the electrolyte, if the electrolyte injection channel adopts the structure of filling hole and diversion channel, it is necessary to first loosen the bolts that penetrate the cover and the cover plate, so that the nut is removed from the lower surface of the cover plate, and then unscrew the plug, inject the electrolyte through the filling hole, and let it flow into the space between the shell and the capacitor element through the diversion channel.

[0016] The present invention discloses a double-layer capacitor and its preparation method, which can quickly realize the overall encapsulation of the double-layer capacitor, effectively prevent electrolyte leakage, and has the function of buffering and shock absorption. It protects the capacitor element as the core component, has a stable and reliable structure, and can be quickly disassembled at any time, providing the possibility of replenishing electrolyte or replacing some components when necessary. Attached Figure Description

[0017] The following are auxiliary illustrations used to explain some specific embodiments of the present invention. The accompanying drawings mainly describe the principles of specific operation execution structures or methods of some embodiments of the present invention, but this does not mean that the physical structure or operation steps of the present invention can only be as shown in the figures.

[0018] Figure 1 This is a simplified structural diagram of the double-layer capacitor of the present invention;

[0019] Figure 2 yes Figure 1 Enlarged view of point A in the image.

[0020] In the figure, the components are: 1. Outer shell; 101. Annular step; 2. Capacitor element; 201. First current collector; 202. First polarizable electrode layer; 203. Insulator; 204. Second polarizable electrode layer; 205. Second current collector; 3. Sealing plate; 4. Sealing component; 4. Bolt; 401. Filling hole; 40101. Diverter channel; 40102. Nut; 403. Sliding column; 404. Screw; 405. Plug; 406. Disc spring; 5. Annular sealing gasket; 6. Positioning cover; 7. Cover; 8. Circular disc plug; 801. Annular boss; 802. Blind hole; 803. Sealing ring; 9. Detailed Implementation

[0021] The embodiments of the present invention will be fully described below. Some core features of the embodiments will be specifically illustrated in the accompanying drawings, wherein the same or similar reference numerals in the drawings represent the same or similar technical features, or structures, steps, or processes with similar functions. Other embodiments derived by those skilled in the art based on these embodiments without requiring creative effort are also within the protection scope of the present invention.

[0022] Please refer to the simplified structural diagram of a double-layer capacitor shown in Figure 1. Like existing double-layer capacitors, it includes a housing 1 and a capacitor element 2 located inside the housing 1, with an electrolyte filling the space between the capacitor element 2 and the housing 1. The difference is that in this embodiment, the inner wall of the housing 1 has an annular step 101, and a sealing plate 3 is vertically and slidably mounted on the open end of the housing 1. The sealing plate 3 has a smooth surface and is located on the top surface of the capacitor element 2, pressing against it to seal the area inside the housing 1 and pressing the capacitor element 2. During fixed installation, the sealing plate 3 is axially pressed against a cover 8 mounted on the open end via a disc spring 5. The disc spring 5 is located between the sealing plate 3 and the cover 8, providing elastic compression and cushioning for shock absorption. Specifically, as... Figure 1The cover 8 has a raised circular stopper plate coaxially located in the center. The circular stopper plate has threads on its circumference to connect with the threads on the inner wall of the opening end, thereby compressing the disc spring 5, pressing the cover 8, and then fixing the cover 8 to stabilize the capacitor element 2. Due to the presence of the cover plate 3, an electrolyte injection channel is also provided on the cover plate 3. A sealing component 4 is detachably provided on the electrolyte injection channel, which vertically penetrates the cover plate 3 and the cover 8. The sealing component 4 seals the electrolyte injection channel so that electrolyte can be injected into the outer casing 1 through the sealing component 4 when needed.

[0023] In addition, such as Figure 1 The cover 8 has an annular protrusion 802 near its edge. The annular protrusion 802 has a circular plug plate arranged coaxially and at intervals. An annular slot is provided on the fixed end face of the opening end. The annular protrusion 802 is inserted into the annular slot and squeezes an annular sealing gasket 6 in the slot. This allows the cover 8 to be reliably fixed to the opening end of the outer shell 1 while effectively sealing the entire capacitor.

[0024] As one of the specific implementation structures, such as Figure 2 The sealing component 4 includes a bolt 401 and a nut 403 that mates with the bolt 401. Specifically, the sealing plate 3 has a countersunk hole on the side facing the capacitor element 2. The nut 402 of the bolt 401 is located in the countersunk hole and presses against the sealing ring 9 on the countersunk hole step to achieve a seal. In addition, after the stud of the bolt 401 passes vertically through the cover 8, it is tightened by the nut 403 installed on the upper surface of the cover 8 to maintain the compressive force of the nut 402 on the sealing ring 9, while also fixing the sealing plate 3 and the cover 8 together.

[0025] In the specific production process, such as Figure 2 A coaxial injection hole 40101 can be provided inside the bolt 401. The top end of this injection hole 40101 has a screw plug 406, which can seal the injection hole 40101. The screw plug 406 can be a general screw plug 406 mechanical seal, because due to the special design of the electrolyte injection channel mentioned later, no special sealing is required here. The bottom end of the injection hole 40101 does not penetrate the nut 402, and the bottom end of the injection hole 40101 is connected to several diversion channels 40102 that extend out of the upper end face of the nut 402. The injection hole 40101 and the diversion channels 40102 combine to form the electrolyte injection channel. After the electrolyte is injected through the injection hole 40101 with the screw plug 406 removed, it flows into the outer shell 1 through the diversion channels 40102.

[0026] As one of the preferred design structures, such as Figure 1-2As shown, the upper surface of the cover 8 has a circular groove for the nut 403 to be coaxially installed. The side wall of the nut 403 has a sliding post 404 that elastically expands and contracts radially, which can be achieved by using a cylindrical spring. One end of the sliding post 404 extends out of the side of the nut 403, thereby pressing against the side wall of the circular groove. That is, during rotation, the end of the sliding post 404 will press and slide against the side wall of the circular groove. At the same time, a blind hole 803 is provided radially on the side wall of the circular groove. For example, this blind hole 803 is horizontally arranged, and a threaded hole communicating with it is provided vertically downward in the upper part of the blind hole 803. The top of the threaded hole penetrates the upper surface of the cover 8 to allow operation of the screw 405, and the screw 405 is threaded into the threaded hole. It should be noted that the dimensions and installation position of screw 405 must meet the following conditions: when screw 405 is vertically screwed into the blind hole 803, rotating nut 403 allows the end of sliding post 404 to contact the threaded section, thus allowing it to slide out of the blind hole 803. However, when screw 405 is screwed in vertically into the blind hole 803, the screw 405 must be able to slide out of the blind hole 803. Figure 2 As shown, when the threaded section of the nut 404 is not located in the blind hole 803, during the rotation of the nut 403, the end of the sliding column 404 springs into the limit depth position in the blind hole 803. That is, the sliding column 404 can freely spring into the blind hole 803. At this limit depth position, due to the obstruction of the blind hole 803, the sliding column 404 cannot continue to slide out of the opening of the blind hole 803. At this moment, the nut 403 is locked and fixed in the cover 8 and cannot be rotated arbitrarily. It is necessary to further screw in the screw 405 to squeeze part of the sliding column 404 into the nut 403 before the sliding column 404 can slide away from the blind hole 803 by rotating the nut 403.

[0027] As a specific design structure, such as Figure 1 The capacitor element 2, within the housing 1, comprises, from top to bottom, a first current collector 201, a first polarizable electrode layer 202, an isolator 203, a second polarizable electrode layer 204, and a second current collector 205. The first current collector 201 is in contact with the sealing plate 3, and the second current collector 205 is in contact with the inner bottom surface of the housing 1, thereby fixing the entire capacitor element 2 within the housing 1. For ease of isolation and subsequent installation and positioning, the isolator 203 is a circular groove structure with the groove opening facing downwards, and the second polarizable electrode layer 204 is centrally located within the groove structure.

[0028] Based on the aforementioned structural design of a double-layer capacitor, another embodiment also proposes a method for fabricating a double-layer capacitor. The main steps involve mounting the capacitor element 2 inside the casing 1, injecting an electrolyte, and finally encapsulating the casing 1. Specifically, the casing 1 can be laid flat with its open end facing upwards, and then the capacitor element 2 can be temporarily placed inside the casing 1 through the open end. Subsequently, a capacitor element 2 is coaxially mounted on the annular step 101 inside the casing 1. Figure 1 The positioning cover 7 shown has a conical hole with a large end facing downwards to guide the adjustment of the position. In practice, after the capacitor element 2 is placed, the positioning cover 7 is moved vertically downwards against the inner wall of the outer casing 1 and gradually fitted onto the capacitor element 2. When the positioning cover 7 moves down to the point where its hole wall contacts the largest size of the capacitor element 2, for example, when it contacts the outer wall of the aforementioned isolator 203, the bottom end of the positioning cover 7 is located on the annular step 101. At this point, the positioning cover 7 cannot move further down and has reached its limit position, which also means that the positioning cover 7 has automatically adjusted the capacitor element 2 to the central position inside the outer casing 1. Then, the top surface of the capacitor element 2 is pressed down, and the positioning cover 7 is gradually removed. Then, the sealing plate 3 is vertically slid into the outer casing 1 through the opening end and placed flat on the top surface of the capacitor element 2. Then, the sealing cap 8 is tightened. The squeezing force of the sealing cap 8 is then pressed onto the capacitor element 2 through the sealing plate 3, thereby fixing the capacitor element 2. Finally, after injecting electrolyte through the electrolyte injection channel, the channel opening is sealed, and the initial assembly of the entire double-layer capacitor is completed.

[0029] As a specific detail in this embodiment, when performing electrolyte filling, if the electrolyte injection channel adopts the structure of the filling hole 40101 and the diversion channel 40102 mentioned above, it is necessary to first loosen the bolt 401 that passes through the cover 8 and the cover plate 3. Figure 1 The diagram shown is a simplified sketch and does not fully illustrate that after loosening, the nut 402 can be positioned entirely below the sealing plate 3. In this embodiment, the nut 402 should be detached from the lower surface of the sealing plate 3. Then, the plug 406 is unscrewed, and electrolyte is injected through the filling hole 40101. The electrolyte flows through the distribution channel 40102 into the space between the outer shell 1 and the capacitor element 2. After the electrolyte injection is complete, the nut 403 is tightened, and finally, the plug 406 is screwed back on. When the aforementioned sliding post 404 and blind hole 803 are used, it is important to note that the screw 405 needs to be screwed upwards a short distance at the end so that the sliding post 404 can naturally slide into the maximum depth of the blind hole 803, thereby preventing the nut 403 from loosening and ensuring that the electrolyte is fully encapsulated within the outer shell 1.

[0030] The above series of specific implementation details are merely some preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the claims of the present invention. Those skilled in the art, based on their understanding of the above embodiments and referring to the basic principles recorded in the claims of the present invention, can easily modify the design ideas, but these modifications still fall within the scope of protection of the invention.

Claims

1. A double-layer capacitor, comprising a casing (1) and a capacitor element (2) located inside the casing (1), wherein an electrolyte is filled between the capacitor element (2) and the casing (1), characterized in that, The inner wall of the outer shell (1) has an annular step (101). A sealing plate (3) is vertically and slidably installed at the opening end of the outer shell (1). The sealing plate (3) is located on the top surface of the capacitor element (2) and is in contact with it. The sealing plate (3) is in axial contact with a cover (8) installed on the opening end through a disc spring (5). The disc spring (5) is located between the sealing plate (3) and the cover (8). The cap (8) has a raised circular stopper plate coaxially in the center. The circular stopper plate is threaded on its circumferential surface to connect with the thread on the inner sidewall of the opening end to fix the cap (8). An electrolyte injection channel is also provided on the sealing plate (3), and a sealing component (4) that vertically penetrates the sealing plate (3) and the cover (8) is detachably provided on the electrolyte injection channel. The sealing component (4) seals the electrolyte injection channel.

2. A double-layer capacitor according to claim 1, characterized in that, The cover (8) has an annular boss (802) near its edge, and the circular plug is provided coaxially and at intervals inside the annular boss (802); an annular slot is provided on the top surface of the opening end, and the annular boss (802) is inserted into the annular slot and presses an annular sealing gasket (6) inside the slot.

3. A double-layer capacitor according to claim 1, characterized in that, The sealing component (4) includes a bolt (401) and a nut (403) that mates with the bolt (401). The sealing plate (3) has a countersunk hole on the side facing the capacitor element (2). The nut (402) of the bolt (401) is located in the countersunk hole and presses against the sealing ring (9) on the countersunk hole step. The stud of the bolt (401) passes vertically through the cover (8) and is tightened by the nut (403) installed on the upper surface of the cover (8) to maintain the compressive force of the nut (402) on the sealing ring (9). A coaxial injection hole (40101) is provided in the bolt (401). The top end of the injection hole (40101) has a screw plug (406), and the bottom end does not penetrate the nut (402). The bottom end is connected to several diversion channels (40102) that extend out of the upper end face of the nut (402). The injection hole (40101) and the diversion channels (40102) together form the electrolyte injection channel.

4. A double-layer capacitor according to claim 3, characterized in that, The upper surface of the cover (8) has a circular groove for the nut (403) to be coaxially installed therein. The side wall of the nut (403) has a sliding post (404) that elastically expands and contracts along its radial direction. One end of the sliding post (404) extends out of the side of the nut (403) and presses against the side wall of the circular groove. A blind hole (803) is provided radially on the side wall of the circular groove. A threaded hole communicating with the blind hole (803) is provided vertically downward in the upper part of the blind hole (803). The top of the threaded hole penetrates the upper surface of the cover (8). A screw (405) is threaded into the threaded hole. The size and installation position of the screw (405) must meet the following conditions: When the screw (405) is screwed vertically into the blind hole (803), rotating the nut (403) allows the end of the slide column (404) to contact the threaded section and slide out of the blind hole (803). However, when the screw (405) is screwed into a position where its threaded section is not in the blind hole (803), during the rotation of the nut (403), the end of the slide column (404) springs into the blind hole (803) to its limit depth position. At the limit depth position, the slide column (404) can no longer slide out of the blind hole (803).

5. A double-layer capacitor according to claim 3, characterized in that, The capacitor element (2) includes, from top to bottom, the following components within the housing (1): a first current collector (201), a first polarizable electrode layer (202), an isolator (203), a second polarizable electrode layer (204), and a second current collector (205).

6. A double-layer capacitor according to claim 5, characterized in that, The first current collector (201) is in contact with the sealing plate (3) by compression, and the second current collector (205) is in contact with the inner bottom surface of the outer shell (1) by compression.

7. A double-layer capacitor according to claim 5, characterized in that, The isolator (203) is a circular groove structure with the groove opening facing downwards, and the second polarizable electrode layer (204) is located inside the groove structure and is centrally positioned.

8. A method for preparing a double-layer capacitor, comprising installing a capacitor element (2) inside a housing (1) and then injecting an electrolyte, and finally encapsulating the housing (1), characterized in that, Follow these steps: S1. Lay the outer shell (1) flat with the open end of the outer shell (1) facing upward; S2. Temporarily place the capacitor element (2) into the outer casing (1) through the opening end; S3. A positioning cover (7) is coaxially installed on the annular step (101) inside the outer shell (1). The positioning cover (7) has a conical hole with the large end facing down. The specific operation is as follows: After the capacitor element (2) is placed, the positioning cover (7) is moved vertically downward along the inner side wall of the outer shell (1) and gradually fitted onto the capacitor element (2). When the positioning cover (7) moves down to the point where its hole wall contacts the maximum size of the capacitor element (2), the bottom end of the positioning cover (7) is located on the annular step (101), and at this time the positioning cover (7) automatically adjusts the capacitor element (2) to the central position inside the outer shell (1). S 4. Press down the top surface of the capacitor element (2), gradually remove the positioning cover (7), and then slide the sealing plate (3) vertically through the opening end of the outer shell (1) into the outer shell (1), and place it flat on the top surface of the capacitor element (2). Then tighten the cover (8) and press and fix the capacitor element (2) by the sealing plate (3). S5. After injecting electrolyte through the electrolyte injection channel, seal the opening of the electrolyte injection channel.

9. The method for preparing a double-layer capacitor according to claim 8, characterized in that: When performing step S4, if the electrolyte injection channel adopts the structure of a filling hole (40101) and a diversion channel (40102), it is necessary to first loosen the bolt (401) that runs through the cover (8) and the cover plate (3), so that the nut (402) is removed from the lower surface of the cover plate (3), and then unscrew the plug (406) to inject the electrolyte through the filling hole (40101) and flow into the space between the outer shell (1) and the capacitor element (2) through the diversion channel (40102).

10. A method for preparing a double-layer capacitor according to claim 9, characterized in that: When tightening the nut (403) on the bolt (401), the screw (405) needs to be screwed up a bit, and then the bolt (401) is screwed in until the slide (404) can freely spring into the blind hole (803) of the cover (8).

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