Energy storage dielectric capacitor
By designing explosion-proof components in dielectric capacitors and utilizing metal conductive blocks to disconnect the circuit and release pressure in case of a fault, the problem of thermal runaway and explosion of dielectric capacitors under fault conditions is solved, achieving rapid response and high reliability safety protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-22
- Publication Date
- 2026-03-10
AI Technical Summary
Existing dielectric capacitors may cause thermal runaway, fire, or cascading failures due to continuous charging and discharging under fault conditions, and existing pressure relief structures cannot disconnect the circuit connection in time.
An explosion-proof component was designed, including a pressure relief hole and a cover. The pressure relief hole is sealed by the movable part of the metal conductive block under pre-tightening force, forming a conductive path under normal conditions. In case of failure, the gas pressure pushes the movable part to detach from the conductive post, disconnecting the circuit and venting the gas through the pressure relief channel.
It achieves automatic circuit disconnection and pressure release in fault conditions, preventing thermal runaway and explosion. It has a fast response speed, high reliability, and reduces the number of parts, making it suitable for miniaturized manufacturing.
Smart Images
Figure CN121641683A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of capacitor technology, and particularly relates to energy storage dielectric capacitors. Background Technology
[0002] With the rapid development of new energy, electric vehicles, rail transit, and smart grids, the demand for high-energy-density and high-power-density energy storage components is increasing daily. It is predicted that the electric vehicle stationary energy storage market will grow at an annual rate of 28% by 2029, with the global installed capacity of electric vehicle stationary energy storage systems expected to reach approximately 1900 MW. Besides new energy storage batteries, energy storage dielectric capacitors (such as metallized film capacitors) are frequently mentioned as another technological approach due to their low loss, long lifespan, and high reliability.
[0003] However, in actual operation, dielectric capacitors may generate gas inside due to factors such as overvoltage, local breakdown, manufacturing defects, or environmental stress, leading to a sudden increase in pressure. If the internal pressure cannot be released in time, it can easily cause the casing to bulge, rupture, or even explode. Existing technologies may include pressure relief holes or mechanical explosion-proof valves, but capacitors with these structures remain connected to the external circuit in a fault state, which may exacerbate thermal runaway due to continuous charging and discharging, leading to fire or cascading failures. Summary of the Invention
[0004] To address the problems in the prior art, the present invention proposes the following technical solution: This invention provides an energy storage dielectric capacitor, comprising: A housing and a cover, wherein the cover is sealed and installed at the open end of the housing; The housing contains a core, and the cover has at least one set of terminals. One end of the terminal extends into the housing and is electrically connected to the electrode of the core, while the other end of the terminal extends out of the cover to connect to an external circuit. It also includes an explosion-proof component, which includes a pressure relief hole 1 opened on the cover and a cover body covering the top of the cover body. The cover body is provided with a plurality of pressure relief holes 2, which together with the pressure relief hole 1 form a pressure relief channel connecting the inside of the shell with the outside. The core is electrically connected to a conductive post one, and the end of the conductive post one away from the core extends into a pressure relief hole one. The terminal is fixedly connected to a conductive post two, and the end of the conductive post two away from the terminal is located inside the cover and is provided with a metal conductive block. The metal conductive block includes a fixed part and a movable part, wherein the fixed part is fixedly connected to the second conductive post, the movable part is located on the side close to the first conductive post, and the movable part can move axially relative to the fixed part. In its natural state, the movable part abuts against the first conductive post under the action of pre-tightening force, and at the same time seals the first pressure relief hole. At this time, the movable part is electrically connected to the first conductive post and the second conductive post to form a conductive path. When the internal pressure of the housing rises abnormally, it switches to the pressure relief state. The air pressure pushes the movable part to move towards the fixed part against the pre-tightening force, thereby disengaging from the conductive post and opening the pressure relief hole. At this time, the conductive path is disconnected, and the internal gas is discharged to the outside through the pressure relief hole and the pressure relief hole.
[0005] As a preferred embodiment of the above technical solution, the movable part is provided with a plug-in part at one end near the fixed part, and the fixed part is provided with a matching slot. The plug-in part can be slidably inserted into the slot to guide the movable part to move axially.
[0006] As a preferred embodiment of the above technical solution, the outer periphery of the movable part is provided with a radially extending extension, which, in its natural state, covers and seals the pressure relief hole.
[0007] As a preferred embodiment of the above technical solution, the extension is provided with a flexible sealing gasket on the side facing the cover.
[0008] As a preferred embodiment of the above technical solution, the cover is provided with a fixing frame, and a plurality of guide posts are installed on the inner side of the fixing frame. The guide posts extend along the sliding direction of the extension, and the extension is provided with through holes corresponding to the guide posts. The guide posts pass through the through holes and form a sliding fit with the extension. A spring is fitted around the outer periphery of the guide post. One end of the spring abuts against the fixing frame, and the other end abuts against the extension. In its natural state, the spring pushes the extension toward the pressure relief hole to keep it sealed.
[0009] As a preferred embodiment of the above technical solution, an inner support plate is also included. The inner support plate is disposed on the side of the cover facing the shell. The inner support plate is provided with a plurality of through holes. The conductive post passes through the through holes at corresponding positions, and the through holes limit the radial position of the conductive post.
[0010] The pressure relief hole two is equipped with a movable plug, which closes the pressure relief hole two under normal conditions; A guide post 2 is fixedly installed at one end of the block facing the inside of the cover. A limit plate is provided at the far end of the guide post 2. A support boss is provided inside the pressure relief hole 2. A guide hole is opened on the support boss. The guide post 2 is slidably inserted into the guide hole. A spring 2 is sleeved on the outer periphery of the guide post 2. One end of the spring 2 abuts against the block and the other end abuts against the support boss. Under natural conditions, the block seals the pressure relief hole 2.
[0011] The beneficial effects of this invention are as follows: This invention integrates an explosion-proof component with a linkage function on the cover. Under normal operating conditions, the movable part of the metal conductive block abuts against the first conductive post under the action of pre-tightening force, forming a complete conductive path from the core through the first conductive post, the movable part, the second conductive post to the terminal, ensuring the normal operation of the capacitor. At the same time, it also seals the first pressure relief hole on the cover, maintaining the sealed environment inside the shell. When the internal pressure of the shell rises abnormally due to a fault, the internal air pressure acts directly on the movable part, pushing it to move towards the fixed part against the pre-tightening force, thereby simultaneously achieving two key safety actions: on the one hand, the movable part disengages from the first conductive post, immediately disconnecting the electrical connection between the core and the external circuit, preventing the continuous input of fault current and exacerbating thermal runaway; on the other hand, the first pressure relief hole is opened, allowing high-pressure gas to be discharged to the outside through the pressure relief channel formed by the first pressure relief hole and the second pressure relief hole on the cover, effectively releasing internal pressure and preventing the shell from bulging or exploding. Attached Figure Description
[0012] Figure 1 The diagram shown is a front view of the capacitor in the embodiment. Figure 2 The diagram shown is a schematic representation of the internal structure of the capacitor in the embodiment; Figure 3 What is shown is Figure 2 Enlarged schematic diagram of the structure at point A (explosion-proof components are in normal condition); Figure 4 The diagram shown is a schematic of the explosion-proof component in a depressurized state; Reference numerals: 10, shell; 20, cover; 21, shield; 22, pressure relief hole one; 11, core; 12, terminal; 31, conductive post one; 32, conductive post two; 40, metal conductive block; 41, fixing part; 42, movable part; 43, extension part; 44, fixing frame; 45, guide post one; 46, spring one; 47, plug-in part; 50, pressure relief hole two; 51, plug; 52, guide post two; 53, spring two; 60, inner support plate; 61, perforation. Detailed Implementation
[0013] To clearly illustrate the purpose, technical solution, and advantages of the embodiments of the present invention, the following will provide a detailed description in conjunction with the embodiments.
[0014] Example like Figure 1 The image shown is a schematic front view of the capacitor in the embodiment. This device includes: The housing 10 and the cover 20 are sealed and installed at the open end of the housing 10; The housing 10 has a core 11 inside, and the cover 20 has at least one set of terminals 12. One end of the terminal 12 extends into the housing 10 and is electrically connected to the electrode of the core 11, while the other end extends out of the cover 20 to connect to an external circuit.
[0015] The housing 10 is used to house and protect the internal components. It is usually made of insulating, heat-resistant, and high mechanical strength materials (such as engineering plastics, metal shells with an insulating inner layer, etc.). One end of the housing 10 has an opening to install the cover 20 and the internal core 11. The cover 20 can be made of a material that matches the housing and can be reliably sealed by welding, bonding, threading, or snap-fitting. The core 11 is the core energy storage unit of the capacitor. It is usually made of multiple layers of dielectric material and metal electrodes stacked or wound alternately. Each set of terminals 12 includes two mutually insulated leads for connecting the two electrodes of the core 11.
[0016] like Figure 2 , Figure 3 , Figure 4 As shown, Figure 2 The diagram shown is a schematic representation of the internal structure of the capacitor in the embodiment; Figure 3 What is shown is Figure 2 Enlarged schematic diagram of the structure at point A (explosion-proof components are in normal condition); Figure 4 The diagram shows the explosion-proof components in a depressurized state.
[0017] It also includes explosion-proof components, which include a pressure relief hole 22 opened on the cover 20 and a cover 21 covering the top of the cover 20. The cover 21 is provided with a number of pressure relief holes 50. The pressure relief holes 50 and the pressure relief holes 22 form a pressure relief channel connecting the inside of the housing 10 with the outside. The core 11 is electrically connected to a conductive post 31. The end of the conductive post 31 away from the core 11 extends into the pressure relief hole 22. The terminal 12 is fixedly connected to a conductive post 32. The end of the conductive post 32 away from the terminal 12 is located inside the cover 21 and a metal conductive block 40 is provided at this end. The metal conductive block 40 includes a fixed part 41 and a movable part 42, wherein the fixed part 41 is fixedly connected to the conductive post 32, the movable part 42 is located on the side close to the conductive post 31, and the movable part 42 can move axially relative to the fixed part 41. In its natural state, the movable part 42 abuts against the conductive post 31 under the action of pre-tightening force, and at the same time seals the pressure relief hole 22. At this time, the movable part 42 electrically connects the conductive post 31 and the conductive post 32 to form a conductive path.
[0018] When the internal pressure of the housing 10 rises abnormally, it switches to the pressure relief state. The air pressure pushes the movable part 42 to overcome the pre-tightening force and move towards the fixed part 41, thereby disengaging from the conductive post 31 and opening the pressure relief hole 22. At this time, the conductive path is disconnected, and the internal gas is discharged to the outside through the pressure relief hole 22 and the pressure relief hole 50.
[0019] The explosion-proof components have both pressure relief and circuit disconnection functions.
[0020] The cover 21 is placed on the top of the cover 20 to form a closed chamber. The first pressure relief hole 22 is opened on the cover 20, connecting the inside of the shell 10 with the outside of the cover. The second pressure relief hole 50 is set on the cover 21, and together with the first pressure relief hole 22, they form a pressure relief channel from the inside of the shell → the first pressure relief hole 22 → the chamber of the cover 21 → the second pressure relief hole 50 → the outside. The cover 21 can prevent external foreign objects from blocking the pressure relief hole, and at the same time guide the gas to be discharged in a specific direction.
[0021] In its natural state, the movable part 42, under the action of pre-tightening force, tightly abuts against the conductive post 31, while simultaneously sealing the pressure relief hole 22, maintaining the internal seal of the housing 10. At this time, the current path is: core 11 → conductive post 31 → movable part 42 → fixed part 41 → conductive post 32 → terminal 12 → external circuit, the conductive path is complete, and the capacitor works normally.
[0022] In abnormal conditions (overpressure or fault), gas is generated inside the housing 10 due to breakdown, overheating, etc., and the pressure increases. The internal gas pressure exerts a thrust through the pressure relief hole 22. When the thrust generated by the gas pressure is greater than the preload, the movable part 42 is pushed towards the fixed part 41, causing the movable part 42 to disengage from the conductive post 31, thus breaking the conductive path, cutting off the current, and preventing the fault from spreading. At the same time, the pressure relief hole 22 is opened, and the high-pressure gas is discharged to the outside through the pressure relief hole 22 and the pressure relief hole 50, thereby releasing the internal pressure and preventing the housing 10 from bursting.
[0023] The above structure enables simultaneous electrical cut-off and mechanical pressure relief. When the internal pressure is abnormal, the circuit is automatically disconnected (to prevent continuous charging and discharging from aggravating the fault) and the pressure relief channel is opened (to release gas), effectively preventing the casing 10 from exploding, catching fire or secondary faults. Moreover, it relies on the internal air pressure to directly drive the action, without the need for sensors, controllers or external power supplies, resulting in fast response and high reliability.
[0024] The movable part 42 also serves as a pressure relief hole seal. Under steady state, the movable part 42 of the metal conductive block 40 tightly seals the pressure relief hole 22 to prevent moisture and dust from entering and ensure the long-term stable operation of the capacitor. The metal conductive block 40 serves as both part of the conductive path and the opening and closing element of the pressure relief function, reducing the number of parts, saving space, and facilitating miniaturization and mass production.
[0025] The movable part 42 is provided with a plug-in part 47 at one end near the fixed part 41. The fixed part 41 is provided with a matching slot. The plug-in part 47 can be slidably inserted into the slot to guide the movable part 42 to move axially.
[0026] The insertion part 47 and the slot form a sliding fit pair, which effectively limits the offset or wobbling of the moving part 42 in the non-axial direction and ensures that it moves smoothly only along the axis of the pressure relief hole.
[0027] The outer periphery of the movable part 42 is provided with a radially extending extension 43, which covers and seals the pressure relief hole 22 in the natural state.
[0028] The extension 43 has a flexible sealing gasket on the side facing the cover 20.
[0029] The extension 43 is a ring-shaped or disc-shaped structure that protrudes radially outward from the main body of the movable part 42.
[0030] The flexible sealing gasket is attached to the lower surface of the extension 43 and is typically made of materials such as silicone, fluororubber, nitrile rubber, or elastic polymers. The extension 43 serves as a sealing surface carrier, with an area larger than the diameter of the pressure relief hole 22 to ensure complete coverage. Under pre-tightening force, the flexible sealing gasket undergoes elastic deformation, filling the microscopic unevenness at the edge of the pressure relief hole to achieve a seal. This effectively prevents moisture, salt spray, and dust from entering the interior of the housing 10. Even if there are slight flatness errors around the pressure relief hole 22 on the cover 20, the flexible sealing gasket can adapt and fit, avoiding the risk of leakage caused by rigid metal-to-metal contact.
[0031] The cover 20 is provided with a fixing frame 44, and a number of guide posts 45 are installed on the inner side of the fixing frame 44. The guide posts 45 extend along the sliding direction of the extension 43. The extension 43 is provided with through holes corresponding to the guide posts 45. The guide posts 45 pass through the through holes and form a sliding fit with the extension 43. A spring 46 is fitted around the outer periphery of the guide post 45. One end of the spring 46 abuts against the fixing bracket 44, and the other end abuts against the extension 43. In its natural state, the spring 46 pushes the extension 43 toward the pressure relief hole 22 to keep it sealed.
[0032] Multiple guide posts 45 are symmetrically distributed and form a multi-point sliding pair with the through holes on the extension 43. This effectively prevents the extension 43 from tilting, rotating or getting stuck during movement, ensuring that the moving part 42 always moves perpendicular to the plane of the pressure relief hole 22, ensuring uniform contact of the sealing surface (reliable sealing), and that the contact is aligned with the conductive post 31 (stable conductivity), so that the pressure relief can be opened smoothly (rapid response).
[0033] The preload of spring 46 can be precisely controlled by adjusting the spring stiffness and compression amount, thereby setting the pressure threshold for triggering pressure relief.
[0034] It also includes an inner support plate 60, which is disposed on the side of the cover 20 facing the housing 10. The inner support plate 60 is provided with a plurality of through holes 61, through which the conductive post 31 passes. The through holes 61 limit the radial position of the conductive post 31.
[0035] The inner support plate 60 is usually fixed to the cover 20 by welding, riveting or snap-fitting. The through hole 61 corresponds one-to-one with the conductive post 31. The hole diameter is slightly larger than the outer diameter of the conductive post 31 to form a clearance fit, which restricts the swaying or displacement of the conductive post 31 in the horizontal (radial) direction, but allows it to remain fixed in the axial direction.
[0036] The pressure relief hole 2 50 is equipped with a movable plug 51. Under normal conditions, the plug 51 closes the pressure relief hole 2 50.
[0037] A guide post 52 is fixedly installed at one end of the block 51 facing the inside of the cover 21. A limit plate is provided at the far end of the guide post 52. A support boss is provided in the pressure relief hole 50. A guide hole is provided on the support boss. The guide post 52 is slidably inserted in the guide hole. A spring 53 is sleeved on the outer periphery of the guide post 52. One end of the spring 53 abuts against the block 51 and the other end abuts against the support boss. Under normal conditions, the block 51 seals the pressure relief hole 50.
[0038] Under normal conditions, spring 2 53 presses the plug 51 to the outer outlet of pressure relief hole 2 50, and the plug 51 fits against the hole (a sealing ring or soft pad can be used to prevent rainwater, dust and salt spray from entering the interior of the cover 21 from the outside.
[0039] Under abnormal conditions, the air pressure inside the shell 10 increases → pushing the movable part 42 to move upward → opening the pressure relief hole 22 → gas enters the inner cavity of the cover 21 → the pressure inside the cover 21 increases → overcoming the elastic force of the second spring 53 → pushing the block 51 to move outward → opening the second pressure relief hole 50. The gas passes through pressure relief hole 22 → inner cavity of cover 21 → pressure relief hole 50 → and is discharged to the outside.
[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.
Claims
1. An energy storage dielectric capacitor characterized by, The utility model relates to a battery shell, including: A shell (10) and a cover (20), the cover (20) is sealedly installed to the open end of shell (10); The shell (10) is internally provided with a core (11), and the cover (20) is provided with at least a group of terminals (12), one end of the terminal (12) extends into the shell (10) and is electrically connected with the electrode of the core (11), and the other end of the terminal (12) extends out of the cover (20) to connect external circuit; Further including an explosion-proof assembly, the explosion-proof assembly includes a pressure relief hole one (22) arranged on the cover (20) and a cover (21) arranged on the top end of the cover (20), the cover (21) is provided with a plurality of pressure relief hole two (50), the pressure relief hole two (50) and the pressure relief hole one (22) form the pressure relief channel that communicates the inside of shell (10) with the outside world; The core (11) is electrically connected with a conductive column one (31), one end of the conductive column one (31) away from the core (11) extends into the pressure relief hole one (22), the terminal (12) is fixedly connected with a conductive column two (32), one end of the conductive column two (32) away from the terminal (12) is located on the inside of the cover (21) and is provided with a metal conducting block (40) at the end; The metal conducting block (40) includes a fixed part (41) and a movable part (42), wherein the fixed part (41) is fixedly connected with the conductive column two (32), the movable part (42) is located on the side close to the conductive column one (31), and the movable part (42) can move axially relative to the fixed part (41); Under natural conditions, the movable part (42) abuts against the conductive column one (31) under the action of pre-tightening force, and the pressure relief hole one (22) is closed at the same time, at this time, the movable part (42) is electrically connected with the conductive column one (31) and the conductive column two (32), forming a conductive path; When the pressure in the shell (10) abnormally rises, switch to the pressure relief state, the gas pressure drives the movable part (42) to move to the fixed part (41) direction to overcome the pre-tightening force, thereby separating from the conductive column one (31) and opening the pressure relief hole one (22), at this time, the conductive path is disconnected, and the internal gas is discharged to the outside through the pressure relief hole one (22) and the pressure relief hole two (50).
2. The energy-storing dielectric capacitor of claim 1, wherein, One end of the movable part (42) close to the fixed part (41) is provided with a plug-in part (47), the fixed part (41) is provided with a matching insertion slot, the plug-in part (47) is slidably inserted into the insertion slot to guide the movable part (42) to move axially.
3. The energy-storing dielectric capacitor of claim 1, wherein, The outer periphery of the movable part (42) is provided with an extension (43) extending radially, in the natural state, the extension (43) covers and seals the pressure relief hole one (22).
4. The energy-storing dielectric capacitor of claim 3, wherein, The side of the extension (43) towards the cover (20) is provided with a flexible sealing pad.
5. The energy-storing dielectric capacitor of claim 1, wherein, The cover (20) is provided with a fixing frame (44), the inner side of the fixing frame (44) is provided with a plurality of guide posts (45), the guide posts (45) extend along the sliding direction of the extension part (43), the extension part (43) is provided with a through hole corresponding to the guide posts (45), the guide posts (45) are arranged in the through hole and are in sliding fit with the extension part (43); The outer periphery of the guide post (45) is provided with a spring (46), one end of the spring (46) abuts against the fixing frame (44), the other end abuts against the extension part (43), the spring (46) pushes the extension part (43) to the pressure relief hole (22) in the natural state, so that it is kept sealed.
6. The energy-storing dielectric capacitor of claim 1, wherein, Further comprising an inner support plate (60), the inner support plate (60) is arranged on the side of the cover (20) facing the shell (10), the inner support plate (60) is provided with a plurality of through holes (61), the conductive column (31) passes through the through hole (61) at the corresponding position, the through hole (61) limits the radial position of the conductive column (31).
7. The energy-storing dielectric capacitor of claim 1, wherein, The pressure relief hole (50) is provided with a movable plug (51), the plug (51) closes the pressure relief hole (50) in the natural state; The end of the plug (51) facing the inner side of the cover (21) is fixedly provided with a guide post (52), the distal end of the guide post (52) is provided with a limiting plate, the pressure relief hole (50) is provided with a supporting boss, the supporting boss is provided with a guide hole, the guide post (52) is slidably arranged in the guide hole, the outer periphery of the guide post (52) is provided with a spring (53), one end of the spring (53) abuts against the plug (51), the other end abuts against the supporting boss, the plug (51) seals the pressure relief hole (50) in the natural state.