A safety device for supercapacitors

Abstract

The application discloses a safety protection device of a super capacitor, and relates to the technical field of electrochemical energy storage devices, which comprises a temperature memory element arranged in an electrochemical monomer and electrically connected with one electrode of the electrochemical monomer; the temperature memory element is disconnected from and contacted with another electrode in a low-temperature memory mode and a high-temperature memory mode, respectively; when the temperature memory element in the electrochemical monomer is contacted with another electrode and is short-circuited, a voltage detection module detects that the voltage of the electrochemical monomer is suddenly reduced below a preset threshold value, and sends a signal to a control module; the control module controls an isolation actuator connected in series with the electrochemical monomer to be started, and the isolation actuator cuts off the electrical connection between the electrochemical monomer and other electrochemical monomers in a super capacitor module. Therefore, the problems existing in the pressure relief safety of the super capacitor are solved, active intervention and prevention of thermal runaway escalation are realized, and active protection is achieved.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage device technology, and in particular to a safety protection device for a supercapacitor. Background Technology

[0002] Supercapacitors, as energy storage devices with high power density and long cycle life, are widely used in electric vehicles, rail transportation, smart grids, backup power supplies, and industrial equipment. In practical applications, especially under high-current charging and discharging or extreme conditions, individual supercapacitor cells may experience abnormal temperature rises due to internal faults (such as overcharging) or environmental overheating. If heat continues to accumulate, it will lead to electrolyte vaporization, a sudden increase in internal pressure, and pose risks of casing rupture, fire, or even explosion.

[0003] Currently, the main pressure relief safety mechanism of supercapacitors relies on the explosion-proof valve at the top. When the internal pressure exceeds a threshold, the explosion-proof valve ruptures or opens, releasing the pressure. However, the activation of the explosion-proof valve is a "post-event" and "irreversible" physical destruction: firstly, once opened, the supercapacitor is permanently disabled and cannot be used; secondly, pressure release may be accompanied by electrolyte ejection, posing a safety hazard; thirdly, in the early stages of thermal runaway, the temperature rise may reach the dangerous value before the pressure does, at which point the explosion-proof valve has not yet activated, but the heat may have already caused irreversible damage.

[0004] It is worth noting that the internal short-circuit behavior of supercapacitors differs fundamentally from that of chemical power sources such as lithium-ion batteries. An internal short circuit in a lithium-ion battery triggers a violent chain of exothermic chemical reactions (thermal runaway), leading to a rapid and uncontrollable rise in temperature and pressure; therefore, the core of its safety design is "preventing short circuits." In contrast, the energy storage mechanism of supercapacitors is primarily physical-level double-layer adsorption. The internal short circuit releases stored electrostatic energy, a process that does not involve violent self-sustaining chemical reactions. Once the energy is rapidly dissipated as heat through the short-circuit point, the heat generation process ceases. This "one-time, terminateable" energy release characteristic makes "controllable internal short circuits" a theoretically feasible, proactive, and rapid energy release safety measure in supercapacitors.

[0005] Therefore, the industry urgently needs an internal safety protection technology that can proactively intervene in the early stages of abuse to prevent the escalation of thermal runaway without damaging the capacitor's structure. Based on the aforementioned characteristics of supercapacitors, developing an active protection device capable of "controlled triggering and rapid energy dissipation" within them has significant theoretical basis and engineering value. Summary of the Invention

[0006] To address the aforementioned problems, achieve proactive intervention and prevent the escalation of thermal runaway, and thus provide proactive protection, this application provides a safety protection device for supercapacitors.

[0007] The safety protection device for a supercapacitor provided in this application adopts the following technical solution.

[0008] A safety protection device for a supercapacitor includes an electrochemical cell and a supercapacitor module. The supercapacitor module is equipped with an electrochemical cell, a control module, a voltage detection module, and an isolation actuator. The electrochemical monomer is provided with a temperature memory element electrically connected to one electrode of the electrochemical monomer. The temperature memory element is disconnected from and in contact with the other electrode in low temperature memory mode and high temperature memory mode, respectively. The temperature memory element can be transformed from low temperature memory mode to high temperature memory mode when the internal temperature of the electrochemical monomer is higher than a preset temperature control threshold. The voltage detection module is used to detect whether the temperature memory element of the electrochemical cell is in contact with another electrode and short-circuited, and sends this signal to the control module. The control module controls the start of the isolation actuator to cut off the electrical connection between the electrochemical cell and other electrochemical cells in the supercapacitor module.

[0009] By adopting the above technical solution and setting a temperature memory element, when the electrochemical monomer is in an abnormal working condition and the temperature rises, causing the bimetallic strip to reach the temperature threshold, the bimetallic strip deforms and overlaps with the end cap substrate with opposite polarity, short-circuiting the positive and negative electrodes, releasing the stored electrical energy, and preventing thermal runaway from escalating. The bimetallic strip is designed to be reusable, that is, it can automatically reset after the temperature drops, i.e., the bimetallic strip resets, which has the ability to provide repeated protection, improving the product's economy and applicability.

[0010] Optionally, the electrochemical monomer further includes a housing, an electrode assembly, a tab connector, and an end cap assembly; The electrode assembly is housed inside the housing and outputs electrical energy through the positive and negative electrodes. The end opening of the housing is closed by an end cap base. The electrode connector is located inside the housing and is connected to the positive electrode and the negative electrode respectively, for realizing the electrical connection between the electrode assembly and the electrode terminal; The end cap assembly includes an end cap base and an adapter. The electrode terminals are disposed on the end cap base and are insulated from the end cap base. The adapter is located on the side of the end cap base closer to the electrode assembly and is spaced apart from the end cap base. The adapter is connected to the electrode terminals and the tab connector. The electrode terminals on the end cap base are connected to the positive electrode tab, and the end cap base is connected to the negative electrode tab of the electrode assembly through the housing and the electrode tab connector. The temperature memory element is mounted on the adapter, and under high temperature memory conditions, the temperature memory element deforms and comes into contact with the end cap substrate.

[0011] Optionally, the end cap assembly further includes an insulating component and a sealing ring; The end cap base is provided with a first mounting groove, and a first through hole is coaxially opened in the first mounting groove. The electrode terminal is disposed in the first mounting groove. An insulating component is provided between the electrode terminal and the first mounting groove, and the bottom end of the electrode terminal passes through the first through hole. A sealing ring is provided between the electrode terminal and the first through hole. The bottom end of the electrode terminal is inserted into the adapter. The electrode terminal has a first connecting part, a second connecting part, and a third connecting part. The first connecting part is a first welding surface for electrical connection with the outside. The second connecting part is smaller than the first through hole and is used for installation with the adapter and serves as a second welding surface. The third connecting part is larger than the size of the first through hole.

[0012] By adopting the above technical solution, the insulation and sealing between various components are ensured through the setting of insulating parts and sealing rings, thus ensuring circuit connection.

[0013] Optionally, the insulating member wraps around the lower part and outer periphery of the third connection portion of the electrode terminal, is spaced apart from the end cap base by a circuit, and is housed in the first mounting groove of the end cap base; After the electrode terminal passes through the first through hole, an L-shaped sealing ring is provided in the gap between the circumferential part and the first through hole, and the foot of the L-shaped sealing ring is placed on the lower surface of the end cap base, so as to achieve sealing and insulation between the end cap base and the electrode terminal.

[0014] Optionally, the adapter has a second through hole, and the bottom end of the electrode terminal passes through the first through hole and is inserted into the second through hole for a tight fit; the outer ring of the adapter is slightly smaller than the inner diameter of the opening at the end of the housing, and the outer ring of the adapter contacts the tab connector to form a third welding surface.

[0015] By adopting the above technical solution, the adapter and the electrode connector are welded through the third welding surface, thereby achieving a fixed connection between the two components and a stable electrical connection.

[0016] Optionally, the through hole on the adapter has an annular inner boss in the inner circle of the through hole. The temperature memory element includes a bimetallic strip with a tongue that is bent toward the end cap base. The bimetallic strip is mounted on the inner boss and is pressed by a pressure ring. The pressure ring and the adapter form a fourth welding surface for welding and fixation.

[0017] By adopting the above technical solution and setting the tongue piece, the overlap strength is increased on the one hand, and the deformation connection stroke is increased on the other hand.

[0018] Optionally, the adapter has a cutting groove, and cuts are made on both sides of the cutting groove, so that the adapter at the cutting groove becomes an active metal layer; a passive metal layer with a smaller temperature volume change rate is set in the cutting groove, the inner end of the passive metal layer is fixed to the inner end of the active metal layer, and the outer end of the passive metal layer is fixed by the outer end of the passive metal layer; when the high temperature threshold is reached, the outer ends of the two metal layers bend upward and contact the end cap substrate.

[0019] By adopting the above technical solution, and by setting up an active metal layer and a passive metal layer, and by using the different volume change rates of the heat source, the two metal layers can be bent to achieve contact with the end cap substrate, thereby achieving short-circuiting of the positive and negative terminals of the circuit.

[0020] Optionally, the lower surface of the end cap substrate is provided with an annular weakening part. When the internal pressure of the electrochemical monomer continues to increase, the middle part of the end cap substrate deforms and bends upward, while the edge bends downward, and the adapter comes into contact with the end cap substrate.

[0021] By adopting the above technical solution, the opening of the annular weakening part will reduce the overall strength of the cover plate substrate, making it softer and more prone to deformation due to increased internal pressure.

[0022] Optionally, an explosion-proof valve is provided on the end cap base.

[0023] By adopting the above technical solution, the presence of the explosion-proof valve can ensure timely pressure relief when the internal pressure of the electrochemical cell is too high, providing a safety redundancy and improving safety.

[0024] Optionally, the supercapacitor module includes a cabinet and a cover plate. The electrochemical cell, control module, voltage detection module and isolation actuator are all installed in the cabinet, and the cover plate is installed on the cabinet to form a closed space inside the cabinet.

[0025] In summary, this application includes at least the following beneficial effects: 1. In this application, by setting a temperature memory element, when the electrochemical monomer is in an abnormal working condition and the temperature rises, causing the bimetallic strip to reach the temperature threshold, the bimetallic strip deforms and overlaps with the end cap substrate with opposite polarity, short-circuiting the positive and negative electrodes, releasing the stored electrical energy, and preventing thermal runaway from escalating; the bimetallic strip is set to be reusable, that is, it can automatically reset after the temperature drops, that is, the bimetallic strip returns to the first working position, which has the ability to provide repeated protection, improving the economy and applicability of the product.

[0026] 2. In this application, when the bimetallic strip inside an electrochemical cell activates due to overheating, causing a short circuit between the positive and negative electrodes of the cell, the voltage detection module detects the abnormal voltage drop and sends this signal to the control module. The control module then sends a disconnect command to the isolator connected in series with the faulty electrochemical cell. The isolator responds to the command, quickly cutting off the series path between the faulty electrochemical cell and other electrochemical cells in the supercapacitor module, thereby achieving electrical isolation, active intervention, prevention of thermal runaway escalation, and active protection. Furthermore, the current in the electrochemical cell will bypass the faulty cell through other paths, maintaining the continued operation and power supply of the electrochemical cell.

[0027] 3. The annular weakening part of the end cap substrate in this application can be used simultaneously with the design of the bimetallic strip. When the bimetallic strip is set at the same time, the threshold for deformation of the end cap substrate is higher than the threshold of the bimetallic strip, which is beneficial to the lifespan and reusability of the electrochemical monomer. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a simplified schematic diagram of the control logic of the supercapacitor module in Embodiment 1.

[0030] Figure 2 This is a schematic diagram of the supercapacitor module structure in Example 1.

[0031] Figure 3 This is a schematic diagram of the electrochemical monomer structure in Example 1.

[0032] Figure 4 This is a schematic diagram of the disassembled structure of the electrochemical monomer in Example 1.

[0033] Figure 5 This is a schematic diagram of the half-section structure of the electrochemical monomer in Example 1.

[0034] Figure 6 This is a schematic diagram of the end cap assembly structure in Embodiment 1.

[0035] Figure 7 This is a schematic diagram of the end cap assembly from another perspective in Embodiment 1.

[0036] Figure 8 This is a schematic diagram of the exploded structure of the end cap assembly in Embodiment 1.

[0037] Figure 9This is a schematic diagram of a half-section of the end cap assembly in Embodiment 1.

[0038] Figure 10 This is a schematic diagram of the adapter, bimetallic strip, and pressure ring structure in Example 1.

[0039] Figure 11 This is a schematic diagram of the bimetallic sheet structure in Example 1.

[0040] Figure 12 This is a magnified view of the bimetallic strip in the first working position in Embodiment 1.

[0041] Figure 13 This is a partially enlarged view of the bimetallic strip in the second working position in Embodiment 1.

[0042] Figure 14 This is a schematic diagram of the end cap assembly structure in Embodiment 2.

[0043] Figure 15 This is a schematic diagram of the exploded structure of the end cap assembly in Embodiment 2.

[0044] Figure 16 This is a cross-sectional view of the end cap assembly in Embodiment 2.

[0045] Figure 17 This is a schematic diagram of the adapter structure in Embodiment 2.

[0046] Figure 18 This is a magnified view of the bimetallic strip in its flat state in Example 2.

[0047] Figure 19 This is a magnified view of the bimetallic strip bent upwards in Example 2.

[0048] Figure 20 This is a schematic diagram of a half-section of the end cap assembly in Embodiment 3.

[0049] Figure 21 This is a schematic diagram of the end cap substrate structure in Example 3.

[0050] Figure 22 This is a schematic diagram of the bending state of the end cap base in Example 3.

[0051] Explanation of reference numerals in the attached drawings: 100, cabinet; 200, cover plate; 300, electrochemical cell; 10, shell; 20, electrode assembly; 30, electrode tab connector; 31, reduction section; 40, end cap assembly; 41, end cap base; 411, end cap connecting part; 412, first mounting groove; 413, first through hole; 414, annular weakening part; 42, electrode terminal; 421, first connecting part; 422, first welding surface; 423, second connecting part; 4 24. Second welding surface; 425. Third connecting part; 43. Insulating component; 44. Sealing ring; 45. Adapter; 451. Second through hole; 452. Third welding surface; 453. Through hole; 454. Inner boss; 455. Pressure ring; 456. Fourth welding surface; 457. Thinned part; 458. Cut; 459. Active metal layer; 46. Bimetallic strip; 461. Tongue; 47. Passive metal layer; 471. Rivet; 472. Buckle. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] The following is in conjunction with the appendix Figures 1 to 22 This application will be described in further detail.

[0054] This application discloses a safety protection device for a supercapacitor.

[0055] Example 1 Reference Figures 1 to 13 A safety protection device for a supercapacitor includes a supercapacitor module. The supercapacitor module includes a cabinet 100, an electrochemical cell 300 disposed inside the cabinet 100, a control module, a voltage detection module, and an isolation actuator. Cover plates 200 are installed on the cabinet 100 and interlock with each other to form a closed space inside the cabinet 100.

[0056] Electrochemical cell 300 is a supercapacitor, and multiple units can be configured, providing more electrical energy compared to a single supercapacitor. The supercapacitors in a supercapacitor module can be electrically connected in series, parallel, or mixed connections to achieve larger capacity or power. For example, refer to... Figure 2 The supercapacitors are placed vertically, with their height aligned with the vertical direction. The supercapacitors in the supercapacitor module are arranged side by side along the width direction of the supercapacitor.

[0057] The electrochemical cell 300 includes a housing 10, an electrode assembly 20, a tab connector 30, and an end cap assembly 40.

[0058] The housing 10 is used to house the electrode assembly 20 and to provide protection for the electrode assembly 20. The end of the housing 10 has an opening, and the end cap assembly 40 covers the opening of the housing 10, so that a sealed space for housing the electrode assembly 20 is formed inside the housing 10.

[0059] The electrode assembly 20, used to generate electrical energy, is formed by stacking or winding a first electrode, a second electrode, and an insulating spacer located between the first and second electrodes. One of the first and second electrodes is a positive electrode, and the other is a negative electrode. Both have a coated portion with an active material and an uncoated tab extending outward from the coated portion. The electrical energy generated by the electrode assembly 20 is transferred outward through the tabs. The tab corresponding to the positive electrode is called the positive tab, and the tab corresponding to the negative electrode is called the negative tab. The positive tab extends from the coated portion of the positive electrode, and the negative tab extends from the coated portion of the negative electrode.

[0060] The tab connector 30 is located in the housing 10 and between the electrode assembly 20 and the end cap assembly 40, for realizing the electrical connection between the electrode assembly 20 and the electrode terminals 42 of the end cap assembly 40.

[0061] The end cap assembly 40 includes a positive terminal and a negative terminal, and the electrochemical monomer 300 includes two tab connectors 30. The two tab connectors 30 are electrically connected to the positive tab and the negative tab. The two tab connectors 30 correspond one-to-one with the positive and negative terminals, realizing the electrical connection between the positive terminal and the positive tab, and the electrical connection between the negative terminal and the negative tab.

[0062] The adapter 45 and end cap assembly 40 are pre-integrated. The tab connector 30 and the liquid injection part are welded to the electrode assembly 20. Then, the end cap assembly 40 is welded to the tab connector 30 through the adapter 45. Subsequently, the liquid injection part is welded to the housing 10, and the outer periphery of the end cap base 41 is welded to seal the opening end of the housing 10. The electrolyte is injected through the liquid injection part and then sealed.

[0063] The end cap assembly 40 includes an end cap base 41, an insulating component 43, an electrode terminal 42, a sealing ring 44, and an adapter 45.

[0064] The end cap base 41 has an end cap connecting part 411 on its outer edge, which is an outward protrusion on the outer edge, used to cover the end opening of the housing 10. The end cap connecting part 411 is engaged with the opening, and the end cap base 41 provides an installation base for other structural parts of the end cap assembly 40.

[0065] The end cap base 41 is provided with a pressure relief component. When the internal pressure of the electrochemical monomer 300 reaches the threshold, the pressure relief component is destroyed to release the seal on the internal space of the electrochemical monomer 300, release the internal pressure of the electrochemical monomer 300, and play a safety and explosion-proof role.

[0066] The end cap assembly 40 has a certain anti-rotation capability. Knurling, grooves or bosses are added to the side wall of the opening. Correspondingly, the outer ring of the end cap base 41 has corresponding knurling, grooves or bosses, forming an anti-rotation structure with the housing 10 and strengthening the connection of the end cap assembly 40.

[0067] The end cap base 41 typically requires high resistance to deformation and has a thickness greater than that of the shell 10. In order to reduce the space occupied by the end cap assembly 40 while ensuring strength, a first mounting groove 412 is provided on the end cap base 41, and a first through hole 413 is coaxially provided in the first mounting groove 412.

[0068] The electrode terminal 42 has a first connecting portion 421, a second connecting portion 423, and a third connecting portion 425, wherein the third connecting portion 425 has a larger size than the first through hole 413, providing more reliable support. The first connecting portion 421 is used to connect to an external interface, such as a bus, providing a mounting base and a first welding surface 422. The second connecting portion 423 has a smaller size than the first through hole 413, providing a mounting base for the adapter 45 and a second welding surface 424. Both the first connecting portion 421 and the second connecting portion 423 are bosses, and both the first welding surface 422 and the second welding surface 424 are longitudinal annular surfaces for welding.

[0069] The insulating member 43 forms a wrap around the lower part and outer periphery of the third connecting part 425 of the electrode terminal 42, and is spaced apart from the end cap base 41 by the circuit and accommodated in the first mounting groove 412 of the end cap base 41. The insulating member 43, together with the sealing ring 44, separates the circuit between the electrode terminal 42 and the end cap base 41.

[0070] After the electrode terminal 42 passes through the first through hole 413, there is a gap in the circumference between the electrode terminal 42 and the first through hole 413 to accommodate the L-shaped sealing ring 44. The foot of the L-shaped sealing ring 44 is placed on the lower surface of the end cap base 41. The sealing ring 44 achieves sealing and insulation between the end cap base 41 and the electrode terminal 42.

[0071] The adapter 45 has a second through hole 451 at its center. The second connecting part 423 of the electrode terminal 42 passes through the first through hole 413 and is inserted into the second through hole 451 for a tight fit. The mating surface is the second welding surface 424. The assembly of the rear end cover assembly 40 is completed by welding. The outer dimension of the adapter 45 is slightly smaller than the inner diameter of the opening at the end of the housing 10. Figure 5So that after the adapter 45 and the tab connector 30 are assembled, they have an outer peripheral transverse gap, i.e., the third welding surface 452. After welding, the first electrical channel is formed by the upper end of the electrode assembly 20 - tab - tab connector 30 - third welding surface 452 - adapter 45 - second welding surface 424 - electrode terminal 42, and the second electrical path is formed by the lower end of the electrode assembly 20 - tab - tab connector 30 - housing 10 - end cap base 41.

[0072] The adapter 45 is also provided with a bimetallic strip 46 mounting part, which includes multiple through holes 453 opened along the circumferential direction on the adapter 45. An annular inner boss 454 (only one is shown in the figure) is provided in the inner circle of the through hole 453. The temperature memory element is a bimetallic strip 46. The bimetallic strip 46 is mounted on the inner boss 454 in the through hole 453, and a pressure ring 455 is installed on the bimetallic strip 46 for pressing. The pressure ring 455 is flush with the upper surface of the adapter 45 to facilitate welding. The contact surface between the pressure ring 455 and the adapter 45 is the fourth welding surface 456 for welding and fixing. On the one hand, the pressure ring 455 and the adapter 45 are made of the same material (e.g., aluminum), giving them good weldability and avoiding problems such as incomplete welding (due to different materials) or deformation (due to high temperature deformation) that can occur when directly welding the bimetallic strip 46 to the adapter 45. On the other hand, the pressure ring 455 is pressed tightly against the adapter 45, increasing their contact area and enhancing current carrying capacity. After assembly, the bimetallic strip 46 is connected to the electrical channel between the adapter 45 and the second welding surface 424.

[0073] Reference Figure 11 The bimetallic strip 46 is disc-shaped, with a tongue 461 in the middle. The tongue 461 bends in the overlapping direction. The bimetallic strip 46 has internal stress. Before the set temperature threshold is reached, the deformation of the bimetallic strip 46 can keep the external force and internal stress in balance and maintain the original position. When the temperature reaches or exceeds the threshold, the bimetallic strip 46 suddenly deforms, realizing the instantaneous action of the relay. The tongue 461 increases the overlapping strength and the deformation connection stroke.

[0074] Reference Figure 12 Under normal operating conditions, the bimetallic strip 46 is in its original position (first working position); such as Figure 13 When the electrochemical monomer 300 is operating under abnormal conditions and its temperature rises, causing the bimetallic strip 46 to reach the temperature threshold, the bimetallic strip 467 is in the second operating position, such as... Figure 13At this point, the bimetallic strip 46 overlaps with the end cap substrate 41 with opposite polarity. That is, when the electrochemical monomer 300 is in an abnormal operating condition and the temperature rises to the set threshold of the bimetallic strip 46, the bimetallic strip 46 deforms rapidly and overlaps with the end cap substrate 41, realizing a short circuit between the first and second electrical paths and releasing the stored electrical energy. The bimetallic strip 46 is designed to be reusable, that is, it can automatically reset after the temperature drops, that is, the bimetallic strip 46 returns to the first working position, which has the ability to provide repeatable protection, improving the economy and applicability of the product.

[0075] Reference Figure 1 When the bimetallic strip 46 inside an electrochemical cell 300 overheats and causes a short circuit between the positive and negative electrodes, its terminal voltage will drop sharply or return to zero within a very short time. The voltage detection module detects this abnormal voltage drop (e.g., falling below 50% of the rated voltage or below a preset extremely low voltage threshold within milliseconds) and sends this signal to the control module. The control module then issues a disconnect command to the isolator connected in series with the faulty electrochemical cell 300. The isolator responds to the command and quickly disconnects the series path between the faulty electrochemical cell 300 and other electrochemical cells 300 in the supercapacitor module, thus achieving electrical isolation. Afterward, the current in the electrochemical cell 300 will bypass the faulty cell through other paths (such as a synchronously conducting bypass switch, if designed), maintaining the continued operation of the electrochemical cell 300 (despite the overall voltage reduction).

[0076] Example 2 Reference Figures 14 to 19 Another short-connection form is disclosed, in which the adapter 45 has a thinned portion 457, which is a cutting groove opened on the adapter 45, and cuts 458 are made on both sides of the thinned portion 457, so that one end of the thinned portion 457 is free and becomes the active metal layer 459. The thinned portion 457 can accommodate the passive metal layer 47 with a smaller temperature volume change rate. The inner ends of the passive metal layer 47 and the active metal layer 459 are riveted by rivets 471, and the outer ends are fixed by a buckle 472 at the outer end of the passive metal layer 47. The passive metal layer 47 and the active metal layer 459 form a bimetallic strip 46. The buckle 472 has a cut-off portion 31 in the longitudinal projection of the tab connector 30 to avoid the buckle 472. When the temperature has not reached the threshold, it is in a flat state, and when the temperature reaches the threshold, it is in an upward bending state, such as Figure 19 As shown, the active metal layer 459 with a higher temperature volume change rate extends more than the passive metal layer 47, but its end is restricted by the snap 472. Therefore, the outer end of the bimetallic strip 46 bends upward and shorts with the end cap substrate 41, realizing the short circuit of the first and second electrical paths and releasing the stored electrical energy.

[0077] Example 3 Reference Figures 20 to 22The lower surface of the end cap base 41 is provided with an annular weakening portion 414, which consists of two weakening grooves. Due to the increased temperature inside the electrochemical monomer 300, the electrolyte vaporizes, and the pressure continuously increases. The middle part of the end cap base 41, which is farther from the end cap connection portion 411, is more prone to deformation and upward bending, while the edges bend downwards. Figure 22 As shown, the adapter 45 short-circuits with the end cap base 41. That is, the end cap base 41, which is provided with an annular weakening part 414, deforms under air pressure and overlaps with the adapter 45, thereby achieving a short circuit between the first and second electrical paths and releasing the stored electrical energy. The presence of the weakening part makes this process more favorable, causing an internal short circuit before the opening pressure of the explosion-proof valve is reached.

[0078] In Example 3, the annular weakening portion 414 of the end cap substrate 41 can also be used simultaneously with the bimetallic strip 46 of Example 1 or 2. In addition, the end cap substrate 41 in Example 3 is irreversibly deformed under pressure. When the bimetallic strip 46 is provided at the same time, the threshold for deformation of the end cap substrate 41 is higher than the threshold of the bimetallic strip 46, which is beneficial to the lifespan and reusability of the electrochemical monomer 300.

[0079] In the description of this invention, it should be understood that the terms "inner end," "outer end," "one side," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise specified and limited, it should be noted that the term "connection" should be interpreted broadly, for example, it can be a mechanical connection or an electrical connection, or it can be a connection within two elements, a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0080] The above are merely preferred embodiments of the invention and are not intended to limit the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A safety protection device for a supercapacitor, comprising an electrochemical cell (300), characterized in that, It also includes a supercapacitor module, which contains an electrochemical cell (300), a control module, a voltage detection module, and an isolation actuator. The electrochemical monomer (300) is provided with a temperature memory element electrically connected to one electrode of the electrochemical monomer (300), and the temperature memory element is disconnected from and in contact with the other electrode in low temperature memory mode and high temperature memory mode, respectively. The temperature memory element can be transformed from low temperature memory mode to high temperature memory mode when the internal temperature of the electrochemical monomer (300) is higher than the preset temperature control threshold. The voltage detection module is used to detect whether the temperature memory element of the electrochemical cell (300) is short-circuited with another electrode, and sends this signal to the control module. The control module controls the start of the isolation actuator to cut off the electrical connection between the electrochemical cell (300) and other electrochemical cells (300) in the supercapacitor module.

2. The safety protection device for a supercapacitor according to claim 1, characterized in that, The electrochemical monomer (300) also includes a housing (10), an electrode assembly (20), a tab connector (30), and an end cap assembly (40). The electrode assembly (20) is disposed inside the housing (10) and outputs electrical energy through the positive and negative electrodes. The end opening of the housing (10) is closed by the end cap base (41). The electrode connector (30) is located inside the housing (10) and is connected to the positive electrode and the negative electrode respectively, so as to realize the electrical connection between the electrode assembly (20) and the electrode terminal (42); The end cap assembly (40) includes an end cap base (41) and an adapter (45). The electrode terminal (42) is disposed on the end cap base (41) and is insulated from the end cap base (41). The adapter (45) is located on the side of the end cap base (41) close to the electrode assembly (20) and is spaced apart from the end cap base (41). The adapter (45) is connected to the electrode terminal (42) and the tab connector (30). The electrode terminal (42) on the end cap base (41) is connected to the positive electrode tab, and the end cap base (41) is connected to the negative electrode tab of the electrode assembly (20) through the housing (10) and the electrode tab connector (30); The temperature memory element is disposed on the adapter (45), and under high temperature memory mode, the temperature memory element deforms and comes into contact with the end cap substrate (41).

3. A safety protection device for a supercapacitor according to claim 2, characterized in that, The end cap assembly (40) also includes an insulating element (43) and a sealing ring (44). The end cap base (41) is provided with a first mounting groove (412), and a first through hole (413) is coaxially opened in the first mounting groove (412). The electrode terminal (42) is disposed in the first mounting groove (412). An insulating member (43) is provided between the electrode terminal (42) and the first mounting groove (412), and the bottom end of the electrode terminal (42) passes through the first through hole (413). A sealing ring (44) is provided between the electrode terminal (42) and the first through hole (413). The bottom end of the electrode terminal (42) is inserted into the adapter (45). The electrode terminal (42) has a first connecting part (421), a second connecting part (423), and a third connecting part (425). The first connecting part (421) is a first welding surface (422) for electrical connection with the outside. The second connecting part (423) is smaller than the first through hole (413) and is used to be installed with the adapter (45) and is a second welding surface (424). The third connecting part (425) is larger than the size of the first through hole (413).

4. A safety protection device for a supercapacitor according to claim 3, characterized in that, The insulating component (43) wraps around the lower part and outer periphery of the third connecting part (425) of the electrode terminal (42), and is separated from the end cap base (41) by a circuit and accommodated in the first mounting groove (412) of the end cap base (41); After the electrode terminal (42) passes through the first through hole (413), an L-shaped sealing ring (44) is provided in the gap between the circumferential part and the first through hole (413), and the foot of the L-shaped sealing ring (44) is placed on the lower surface of the end cap base (41), so as to achieve sealing and insulation between the end cap base (41) and the electrode terminal (42).

5. A safety protection device for a supercapacitor according to claim 3, characterized in that, The adapter (45) has a second through hole (451). The bottom end of the electrode terminal (42) passes through the first through hole (413) and is inserted into the second through hole (451) for a tight fit. The outer ring of the adapter (45) is slightly smaller than the inner diameter of the end opening of the housing (10), and the outer ring of the adapter (45) contacts the tab connector (30) to form a third welding surface (452).

6. A safety protection device for a supercapacitor according to claim 3, characterized in that, The adapter (45) has a through hole (453) and an annular inner boss (454) in the inner ring of the through hole (453). The temperature memory element includes a bimetallic strip (46) with a tongue (461) on it. The tongue (461) is bent toward the end cap base (41). The bimetallic strip (46) is mounted on the inner boss (454) and is pressed by a mounting ring (455). The ring (455) and the adapter (45) form a fourth welding surface (456) for welding and fixing.

7. A safety protection device for a supercapacitor according to claim 2, characterized in that, The adapter (45) has a cutting groove, and cuts (458) are made on both sides of the cutting groove, so that the adapter (45) at the cutting groove becomes an active metal layer (459); a passive metal layer (47) with a smaller temperature volume change rate is set in the cutting groove, the inner end of the passive metal layer (47) is fixed to the inner end of the active metal layer (459), and the outer end of the passive metal layer (47) is fixed by the outer end of the passive metal layer (47); when the high temperature threshold is reached, the outer ends of the two metal layers bend upward and contact the end cap substrate (41).

8. A safety protection device for a supercapacitor according to claim 3, characterized in that, The lower surface of the end cap substrate (41) is provided with an annular weakening part (414). When the internal pressure of the electrochemical monomer (300) continues to increase, the middle part of the end cap substrate (41) deforms and bends upward, and the edge bends downward, and the adapter (45) comes into contact with the end cap substrate (41).

9. A safety protection device for a supercapacitor according to claim 2, characterized in that, An explosion-proof valve is provided on the end cap base (41).

10. A safety protection device for a supercapacitor according to claim 1, characterized in that, The supercapacitor module includes a cabinet (100) and a cover plate (200). The electrochemical cell (300), control module, voltage detection module and isolation actuator are all installed inside the cabinet (100). The cover plate (200) is installed on the cabinet (100) to form a closed space inside the cabinet (100).

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