An electrochemical device

Abstract

The utility model relates to the technical fields of electrochemical device discloses an electrochemical device, including casing, pole and explosion -proof sealing sheet, casing is equipped with cavity and along first direction's first through -hole, first through -hole communicates with the cavity, and pole is used for connecting with the electric core through the first through -hole and stretches into the cavity, and pole and casing insulate to set up, and pole is equipped with along first direction's liquid injection channel, and explosion -proof sealing sheet is connected in the one end of pole and seals the liquid injection channel away from the cavity and covers, and explosion -proof sealing sheet and liquid injection channel limit form the explosion -proof chamber of opening towards the cavity, and explosion -proof sealing sheet is equipped with thinning portion, and the position of thinning portion in first direction corresponds with the setting of liquid injection channel, the utility model discloses electrochemical device, electric connection, liquid injection and explosion -proof function integration, simplify structure, improve the leakproofness and security.

Description

Technical Field

[0001] This utility model relates to the technical field of electrochemical devices, and in particular to an electrochemical device. Background Technology

[0002] In existing battery structures, terminals typically only serve as electrical connections for current inflow or outflow, while electrolyte filling and safety pressure relief rely on independent structures on the casing. Specifically, traditional batteries generally have separate electrolyte filling holes and explosion-proof valve mounting holes on the casing: the electrolyte filling hole is used to inject electrolyte after battery encapsulation and is subsequently sealed by sealing pins, adhesive sealing, or other methods; the explosion-proof valve is a separate safety element located on the top or side wall of the casing, which ruptures or opens to release pressure and prevent the casing from exploding when internal pressure abnormally increases.

[0003] However, the multiple openings penetrating the casing significantly increase the difficulty of sealing, which can easily lead to electrolyte leakage or external moisture intrusion, affecting the battery's cycle life and safety. The additional explosion-proof valve and liquid injection sealing structure occupy casing space, which is not conducive to improving the battery's energy density. The response speed of the external explosion-proof valve is limited by the path length of gas conduction from the cell cavity to the pressure relief position, and it may fail due to corrosion, oxidation or mechanical fatigue during long-term use, posing a safety hazard. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. It provides an electrochemical device that integrates electrical connection, liquid injection, and explosion-proof functions, simplifying the structure and improving sealing and safety.

[0005] To achieve the above objectives, this utility model provides an electrochemical device having a first direction, including a housing, an electrode post, and an explosion-proof sealing sheet. The housing has a cavity and a first through hole extending along the first direction, the first through hole communicating with the cavity. The electrode post extends into the cavity through the first through hole for connection with a battery cell. The electrode post is insulated from the housing. The electrode post has a liquid injection channel extending along the first direction. The explosion-proof sealing sheet is connected to the end of the electrode post away from the cavity and covers the liquid injection channel. The explosion-proof sealing sheet and the liquid injection channel define an explosion-proof cavity with an opening facing the cavity. The explosion-proof sealing sheet has a thinning portion, the thinning portion being positioned in the first direction corresponding to the liquid injection channel.

[0006] As a preferred embodiment, the end of the electrode away from the cavity is provided with a step, the step is arranged around the injection channel, and the edge of the explosion-proof sealing sheet is connected to the step.

[0007] As a preferred embodiment, the electrode post is provided with a connecting piece for connecting with the battery cell. The connecting piece is located in the cavity. The connecting piece is provided with a connecting through hole that extends along the first direction. The electrode post passes through the connecting through hole. The outer peripheral surface of the electrode post is connected to the inner wall of the connecting through hole. The connecting piece is insulated from the housing.

[0008] As a preferred embodiment, the outer peripheral surface of the pole protrudes radially to form a limiting portion, the limiting portion being located at the end of the pole away from the explosion-proof sealing sheet, and in the first direction, the connecting piece is connected between the housing and the limiting portion, and the connecting piece is engaged with the limiting portion.

[0009] As a preferred embodiment, the electrode post is provided with insulating adhesive, and a pressure relief channel is formed between the outer periphery of the electrode post and the housing. The insulating adhesive fills the pressure relief channel, and the electrode post is sealed to the housing through the insulating adhesive.

[0010] As a preferred embodiment, the electrode includes an extension and a main body. The extension is connected to the outer periphery of the main body and to the outer side of the housing. The injection channel extends through the main body along the first direction. The explosion-proof sealing sheet is connected to the end of the main body away from the cavity. At least a portion of the main body extends into the cavity. The extension, the main body, and the housing define the pressure relief channel.

[0011] As a preferred embodiment, the extension is sealed to the housing via the insulating adhesive, and / or the outer peripheral surface of the main body is sealed to the housing via the insulating adhesive.

[0012] As a preferred embodiment, the extension and the housing are filled with the insulating adhesive between them in the first direction to form a first insulating ring, the first insulating ring being located outside the housing; or, The connecting piece and the housing are filled with insulating adhesive in the first direction to form a second insulating ring, which is located inside the cavity.

[0013] As a preferred embodiment, the height of the pole post in the first direction is set at 1mm-2.4mm, the extension is connected to the end of the main body away from the cavity, and the height of the extension in the first direction is set at 0.2mm-0.5mm.

[0014] As a preferred embodiment, the explosion-proof sealing sheet includes a first thermally conductive layer and a second thermally conductive layer, the first thermally conductive layer and the second thermally conductive layer are stacked and connected sequentially along the first direction, the second thermally conductive layer is arranged towards the injection channel, and the thermal expansion coefficient of the second thermally conductive layer is greater than that of the first thermally conductive layer.

[0015] Compared with existing technologies, the electrochemical device of this utility model has the following advantages: The electrode extends into the cavity through a first through-hole for connection with the battery cell, and the electrode is insulated from the housing. As a key conductive component for current extraction or introduction, the electrode passes through the first through-hole in the housing into the cavity and is electrically connected to the battery cell inside the cavity. Simultaneously, it is insulated from the housing, ensuring electrical isolation between the electrode and the housing and preventing short circuits. The electrode has a liquid injection channel extending along a first direction, allowing electrolyte to be injected into the cavity through the channel without the need for an additional independent injection hole, simplifying the housing structure, reducing potential leakage points, and improving sealing reliability. Sharing the same physical structure, the electrode, for the liquid injection path and the electrical connection path achieves a high degree of integration of space and function. An explosion-proof sealing plate is connected to the end of the electrode furthest from the cavity and covers the liquid injection channel. The explosion-proof sealing plate and the liquid injection channel define an explosion-proof cavity with an opening facing the cavity. The explosion-proof sealing plate has a thinned portion, which is positioned in the first direction corresponding to the pressure relief channel. An explosion-proof sealing plate seals the outer end of the injection channel, and the sealing plate and the inner wall of the injection channel together form an explosion-proof cavity with an opening facing the internal structure. When high-pressure gas is generated inside the battery due to thermal runaway or overcharging, the gas can enter the explosion-proof cavity through the injection channel and exert pressure on the explosion-proof sealing plate. The thinned section is a pre-designed weak area that will preferentially rupture or deform when the internal gas pressure reaches a set threshold, thereby opening the pressure relief channel, releasing the overpressure gas inside the cavity, and preventing the casing from exploding. The pressure relief function is directly integrated into one end of the injection channel, eliminating the need for an additional pressure relief valve or safety diaphragm. The thinned section is positioned in the first direction corresponding to the position of the injection channel, shortening the pressure transmission path, improving response speed, and enhancing pressure relief reliability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model.

[0017] Figure 2 This is a cross-sectional view of the internal structure of an embodiment of this utility model.

[0018] Figure 3 This is an embodiment of the present utility model. Figure 2 A magnified structural diagram of point B in the diagram.

[0019] Figure 4 This is a schematic diagram of the structure of the pole post in an embodiment of this utility model.

[0020] Figure 5 This is a schematic diagram of the connecting piece in an embodiment of the present invention.

[0021] Figure 6 This is an embodiment of the present utility model. Figure 1 A magnified structural diagram of point A in the diagram.

[0022] Figure 7 This is a structural schematic diagram of the pressure relief path in an embodiment of this utility model.

[0023] In the picture: X, first direction; 20. Shell; 21. Cavity; 22. First through hole; 30. Pole post; 31. Injection channel; 32. Explosion-proof cavity; 33. Step; 34. Connecting piece; 35. Connecting through hole; 36. Limiting part; 37. Insulating adhesive; 38. Pressure relief channel; 39. Extension part; 40. Main body part; 41. First insulating ring; 42. Second insulating ring; 50. Explosion-proof sealing sheet; 51. Thinning section; 52. First heat-conducting layer; 53. Second heat-conducting layer; Detailed Implementation

[0024] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0026] In the description of this utility model, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] like Figures 1 to 3As shown, a preferred embodiment of the present invention provides an electrochemical device having a first direction X, including a housing 20, an electrode 30, and an explosion-proof sealing sheet 50. The housing 20 has a cavity 21 and a first through hole 22 extending along the first direction X, which communicates with the cavity 21. The electrode 30 extends into the cavity 21 through the first through hole 22 for connection with a battery cell. The electrode 30 is insulated from the housing 20. The electrode 30 has a liquid injection channel 31 extending along the first direction X. The explosion-proof sealing sheet 50 is connected to the end of the electrode 30 away from the cavity 21 and covers the liquid injection channel 31. The explosion-proof sealing sheet 50 and the liquid injection channel 31 define an explosion-proof cavity 32 with its opening facing the cavity 21. The explosion-proof sealing sheet 50 has a thinning portion 51, which is positioned in the first direction X corresponding to the liquid injection channel 31.

[0028] In this electrochemical device, the electrode post 30 extends into the cavity 21 through a first through-hole 22 for connection with the battery cell. The electrode post 30 is insulated from the housing 20. As a key conductive component for current inflow or outflow, the electrode post 30 passes through the first through-hole 22 on the housing 20 into the cavity 21 and is electrically connected to the battery cell inside the cavity 21. Simultaneously, it is insulated from the housing 20, ensuring electrical isolation between the electrode post 30 and the housing 20 and preventing short circuits. The electrode post 30 has a liquid injection channel 31 extending along a first direction X, allowing electrolyte to be injected into the cavity 21 through the liquid injection channel 31. This eliminates the need for a separate liquid injection hole, simplifying the structure of the housing 20, reducing potential leakage points, and improving sealing reliability. By sharing the same physical structure, the electrode post 30, for both the liquid injection path and the electrical connection path, a high degree of integration of space and function is achieved. An explosion-proof sealing sheet 50 is connected to the end of the terminal post 30 away from the cavity 21 and covers the liquid injection channel 31. The explosion-proof sealing sheet 50 and the liquid injection channel 31 define an explosion-proof cavity 32 with its opening facing the cavity 21. The explosion-proof sealing sheet 50 has a thinning portion 51, which is positioned in the first direction X corresponding to the pressure relief channel. The explosion-proof sealing sheet 50 blocks the outer end of the liquid injection channel 31, and the explosion-proof sealing sheet 50 and the inner wall of the liquid injection channel 31 together form an explosion-proof cavity 32 with its opening facing the cavity 21. When high-pressure gas is generated inside the battery due to thermal runaway or overcharging, the gas can enter the explosion-proof cavity 32 through the liquid injection channel 31 and exert pressure on the explosion-proof sealing sheet 50. The thinning portion 51 is a pre-designed weak area that will preferentially rupture or deform when the internal gas pressure reaches a set threshold, thereby opening the pressure relief channel, releasing the overpressure gas inside the cavity 21, and preventing the casing 20 from exploding. The pressure relief function is directly integrated into one end of the liquid injection channel 31, eliminating the need for an additional pressure relief valve or safety membrane. The thinning section 51 is positioned in the first direction X corresponding to the position of the injection channel 31, which shortens the pressure transmission path, improves the response speed, and enhances the reliability of pressure relief.

[0029] As one embodiment, such as Figure 6As shown, the thinned portion 51 is a scoring groove. The opening of the scoring groove can face the cavity 21 or face away from the cavity 21. The scoring groove can be of any shape.

[0030] As one embodiment, such as Figure 6 As shown, the width of the groove is greater than or equal to 0.11 mm. The depth of the groove in the first direction X is a, and the thickness of the explosion-proof sealing sheet 50 in the first direction X is b, where a / b = 0.4-0.8, to ensure that the groove can respond promptly under pressure.

[0031] Furthermore, such as Figure 4 As shown, the end of the electrode post 30 furthest from the cavity 21 has a step 33, which surrounds the injection channel 31. The edge of the explosion-proof sealing sheet 50 is connected to the step 33. The step 33 provides a clear and stable mounting surface for the explosion-proof sealing sheet 50, which helps to improve the connection strength and sealing performance between the explosion-proof sealing sheet 50 and the electrode post 30. The step 33 can limit the radial and axial displacement of the explosion-proof sealing sheet 50, making it easier to position the connection position of the explosion-proof sealing sheet 50 during assembly and improving positioning accuracy. When pressure relief is triggered, because the edge of the explosion-proof sealing sheet 50 is limited by the step 33, cracking or deformation is mainly concentrated in the preset thinning part 51 area, thereby ensuring the accuracy and consistency of the pressure relief action and improving the reliability of the safety response.

[0032] As one embodiment, such as Figures 3 to 4 As shown, the explosion-proof sealing sheet 50 is located inside the step 33, and the height of the explosion-proof sealing sheet 50 in the first direction X does not exceed the upper end face of the step 33, which can avoid the loss of cell energy density.

[0033] In one embodiment, the explosion-proof sealing sheet 50 is connected to the step 33 by a polymer adhesive. Preferably, the polymer adhesive is PP adhesive.

[0034] Furthermore, such as Figures 3 to 5 As shown, the terminal 30 is provided with a connecting piece 34 for connecting to the battery cell. The connecting piece 34 is located inside the cavity 21 and has a connecting through hole 35 extending along the first direction X. The terminal 30 passes through the connecting through hole 35, and the outer peripheral surface of the terminal 30 is connected to the inner wall of the connecting through hole 35. The connecting piece 34 is insulated from the housing 20. The terminal 30 is connected to the battery cell through the connecting piece 34. The connecting piece 34, as an intermediate conductive component between the terminal 30 and the battery cell, can flexibly adapt to the position and shape of the battery cell tabs, improving assembly compatibility and process tolerance. The connecting piece 34 is kept insulated from the housing 20, avoiding safety hazards caused by the metal housing 20 being energized or short-circuited, and ensuring the reliability of electrical isolation inside the battery.

[0035] In one embodiment, the connecting piece 34 is connected to the battery cell via a wire.

[0036] Furthermore, such as Figures 3 to 4 As shown, a limiting portion 36 protrudes radially from the outer peripheral surface of the electrode post 30. The limiting portion 36 is located at the end of the electrode post 30 away from the explosion-proof sealing sheet 50. In the first direction X, a connecting piece 34 connects the housing 20 and the limiting portion 36, and the connecting piece 34 is engaged with the limiting portion 36. By providing a radially protruding limiting portion 36 at one end of the electrode post 30 inside the cavity 21, and engaging the connecting piece 34 between the limiting portion 36 and the housing 20, the positioning and mechanical limiting of the connecting piece 34 in the first direction X are achieved. This prevents the connecting piece 34 from axially shifting or falling off due to vibration, impact, or thermal expansion during battery assembly, transportation, or use. By positioning the upper limit of the connecting piece 34 in the first direction X between the limiting portion 36 and the housing 20, the structural rigidity and connection reliability are improved. Since the connecting piece 34 is constrained between the limiting portion 36 and the housing 20, the connection area between the connecting piece 34 and the outer peripheral surface of the electrode post 30 experiences more uniform stress, which helps to reduce local stress concentration and improve the stability of current transmission.

[0037] Furthermore, such as Figures 3 to 4 as well as Figure 7 As shown, the terminal post 30 is provided with insulating adhesive 37, forming a pressure relief channel between the outer periphery of the terminal post 30 and the housing 20. The insulating adhesive 37 fills the pressure relief channel, and the terminal post 30 is sealed to the housing 20 through the insulating adhesive 37. The insulating adhesive 37 fills the pressure relief channel between the outer periphery of the terminal post 30 and the housing 20, blocking the electrical contact between the terminal post 30 and the metal housing 20, keeping the terminal post 30 and the housing 20 insulated, and preventing the risk of short circuit. Under normal operating conditions, the insulating adhesive 37 has airtight and liquid-tight properties, preventing electrolyte leakage or external moisture intrusion, improving the environmental adaptability and long-term reliability of the battery. When the internal temperature softens the insulating adhesive 37 and opens the pressure relief channel, the pressure relief path is temporarily opened, which, together with the thinned part 51 of the explosion-proof sealing sheet 50, achieves multi-stage or coordinated pressure relief, enhancing the overall safety redundancy.

[0038] As one embodiment, the softening or loss of tack temperature of the insulating adhesive 37 is 90°C to 130°C.

[0039] Furthermore, such as Figures 3 to 4 as well as Figure 7As shown, the electrode post 30 includes an extension 39 and a main body 40. The extension 39 is connected to the outer periphery of the main body 40 and to the outer side of the housing 20. The injection channel 31 extends through the main body 40 along a first direction X. The explosion-proof sealing plate 50 is connected to the end of the main body 40 away from the cavity 21. At least a portion of the main body 40 extends into the cavity 21. The extension 39, the main body 40, and the housing 20 define a pressure relief channel. The main body 40 integrates the functions of the injection channel 31, connecting the battery cell, and supporting the explosion-proof sealing plate 50, ensuring a high degree of integration of electrical connection, injection, and pressure relief functions. The extension 39 extends outward from the outer periphery of the main body 40 and connects to the outer side of the housing 20, providing mechanical support and a mounting reference for the main body 40.

[0040] As one embodiment, the integrated arrangement of the main body 40 and the extension 39 enhances the overall structural rigidity and torsional resistance of the pole post 30.

[0041] Furthermore, such as Figures 3 to 4 as well as Figure 7 As shown, the extension 39 is sealed to the housing 20 via insulating adhesive 37, and / or the outer peripheral surface of the main body 40 is sealed to the housing 20 via insulating adhesive 37, achieving electrical insulation, mechanical fixation, and airtight sealing between the terminal post 30 and the housing 20. The insulating adhesive 37 isolates the electrical contact between the extension 39 and the main body 40 and the conductive housing 20, ensuring the battery's insulation safety under high-voltage conditions. The insulating adhesive 37 fills the gap between the terminal post 30 and the housing 20, improving the overall sealing performance of the battery housing 20 and preventing electrolyte leakage or external moisture intrusion. In the event of thermal abuse of the battery cell generating high-temperature and high-pressure gases, the high-temperature gases soften the insulating adhesive 37 through the sidewall of the cavity 21, causing defects in the sealing interface originally maintained by the insulating adhesive 37. This provides an additional safe emission path for the high-temperature and high-pressure gases, increasing the safety and reliability of the battery cell.

[0042] Furthermore, such as Figure 3 As shown, an insulating ring 41 is formed by filling the space between the extension 39 and the housing 20 in the first direction X with insulating adhesive 37. The first insulating ring 41 is located outside the housing 20, blocking the axial and radial conductive paths between the extension 39 and the metal housing 20. Alternatively, a second insulating ring 42 is formed by filling the space between the connecting piece 34 and the housing 20 in the first direction X with insulating adhesive 37. The second insulating ring 42 is located inside the cavity 21. The second insulating ring 42 being located inside the cavity 21 ensures electrical isolation between the connecting piece 34 and the housing 20, preventing short circuits.

[0043] Furthermore, such as Figures 3 to 4As shown, the height H0 of the terminal post 30 in the first direction X is set between 1mm and 2.4mm. The extension 39 is connected to the end of the main body 40 away from the cavity 21, and the height H1 of the extension 39 in the first direction X is set between 0.2mm and 0.5mm. Controlling the total height of the terminal post 30 within the range of 1mm to 2.4mm reduces the space occupied at the top of the battery while ensuring the unobstructed flow of the liquid injection channel 31. Limiting the height of the extension 39 to the range of 0.2mm to 0.5mm reduces the external protrusion size while ensuring a stable connection and reliable seal with the outside of the casing 20. This reduces the risk of interference or damage caused by the excessive height of the terminal post 30 extension structure during battery stacking or packaging.

[0044] As one embodiment, such as Figures 3 to 4 As shown, the height H2 of step 33 in the first direction X is set at 0.1mm-0.3mm.

[0045] In one embodiment, the height H3 from the root of step 33 to the other end face of pole post 30 is set at 0.7mm-2.3mm.

[0046] Furthermore, such as Figure 3 As shown, the explosion-proof sealing sheet 50 includes a first thermally conductive layer 52 and a second thermally conductive layer 53. The first thermally conductive layer 52 and the second thermally conductive layer 53 are stacked and connected sequentially along the first direction X. The second thermally conductive layer 53 is arranged facing the liquid injection channel 31, and the coefficient of thermal expansion of the second thermally conductive layer 53 is greater than that of the first thermally conductive layer 52. When the battery cell overheats abnormally, the heat is conducted to the explosion-proof sealing sheet 50 through the liquid injection channel 31, and first acts on the second thermally conductive layer 53 facing the cavity 21. Since the second thermally conductive layer 53 has a higher coefficient of thermal expansion, it will undergo greater expansion deformation than the first thermally conductive layer 52 after being heated, thereby forming internal stress between the two layers. This causes the explosion-proof sealing sheet 50 to bend away from the cavity 21 or to crack faster at the preset thinning part 51, thus improving the sensitivity and timeliness of the safety response.

[0047] As one embodiment, such as Figure 3 As shown, both the first heat-conducting layer 52 and the second heat-conducting layer 53 are metal layers. The coefficient of expansion of the first heat-conducting layer 52 is a1, and the coefficient of expansion of the second heat-conducting layer 53 is a2, where a2 ≥ (1.35~3.03)*a1.

[0048] As one embodiment, such as Figure 6 As shown, the burst gas pressure response range of the groove is 0.1MPa to 10MPa.

[0049] As one embodiment, such as Figure 6 As shown, the materials of the explosion-proof sealing sheet 50 include, but are not limited to, nickel, aluminum, and copper.

[0050] In summary, this embodiment of the invention provides an electrochemical device. The electrode post 30 extends into the cavity 21 through a first through-hole 22 for connection to the battery cell. The electrode post 30 is insulated from the housing 20. As a key conductive component for current extraction or introduction, the electrode post 30 passes through the first through-hole 22 on the housing 20 into the cavity 21 and is electrically connected to the battery cell within the cavity 21. Simultaneously, it is insulated from the housing 20, ensuring electrical isolation between the electrode post 30 and the housing 20 and preventing short circuits. The electrode post 30 has a liquid injection channel 31 extending along a first direction X, allowing electrolyte to be injected into the cavity 21 through the liquid injection channel 31. This eliminates the need for a separate liquid injection hole, simplifying the structure of the housing 20, reducing potential leakage points, and improving sealing reliability. By sharing the same physical structure, the electrode post 30, for both the liquid injection path and the electrical connection path, a high degree of integration of space and function is achieved. An explosion-proof sealing sheet 50 is connected to the end of the terminal post 30 away from the cavity 21 and covers the liquid injection channel 31. The explosion-proof sealing sheet 50 and the liquid injection channel 31 define an explosion-proof cavity 32 with its opening facing the cavity 21. The explosion-proof sealing sheet 50 has a thinning portion 51, which is positioned in the first direction X corresponding to the pressure relief channel. The explosion-proof sealing sheet 50 blocks the outer end of the liquid injection channel 31, and the explosion-proof sealing sheet 50 and the inner wall of the liquid injection channel 31 together form an explosion-proof cavity 32 with its opening facing the cavity 21. When high-pressure gas is generated inside the battery due to thermal runaway or overcharging, the gas can enter the explosion-proof cavity 32 through the liquid injection channel 31 and exert pressure on the explosion-proof sealing sheet 50. The thinning portion 51 is a pre-designed weak area that will preferentially rupture or deform when the internal gas pressure reaches a set threshold, thereby opening the pressure relief channel, releasing the overpressure gas inside the cavity 21, and preventing the casing 20 from exploding. The pressure relief function is directly integrated into one end of the liquid injection channel 31, eliminating the need for an additional pressure relief valve or safety membrane. The thinning section 51 is positioned in the first direction X corresponding to the position of the injection channel 31, which shortens the pressure transmission path, improves the response speed, and enhances the reliability of pressure relief.

[0051] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.

Claims

1. An electrochemical device having a first orientation, characterized in that: The device includes a housing, an electrode post, and an explosion-proof sealing sheet. The housing has a cavity and a first through hole extending along a first direction. The first through hole communicates with the cavity. The electrode post extends into the cavity through the first through hole for connection with a battery cell. The electrode post is insulated from the housing. The electrode post has a liquid injection channel extending along the first direction. The explosion-proof sealing sheet is connected to the end of the electrode post away from the cavity and covers the liquid injection channel. The explosion-proof sealing sheet and the liquid injection channel define an explosion-proof cavity with an opening facing the cavity. The explosion-proof sealing sheet has a thinning portion, which is positioned in the first direction corresponding to the liquid injection channel.

2. The electrochemical device according to claim 1, characterized in that: The end of the electrode column away from the cavity is provided with a step, the step is arranged around the injection channel, and the edge of the explosion-proof sealing sheet is connected to the step.

3. The electrochemical device according to claim 1, characterized in that: The electrode post is provided with a connecting piece for connecting with the battery cell. The connecting piece is located in the cavity. The connecting piece is provided with a connecting through hole that extends along the first direction. The electrode post passes through the connecting through hole. The outer peripheral surface of the electrode post is connected to the inner wall of the connecting through hole. The connecting piece is insulated from the housing.

4. The electrochemical device according to claim 3, characterized in that: The outer peripheral surface of the pole protrudes radially to form a limiting part, which is located at the end of the pole away from the explosion-proof sealing sheet. In the first direction, the connecting piece connects the housing and the limiting part, and the connecting piece is engaged with the limiting part.

5. The electrochemical device according to claim 3, characterized in that: The electrode post is provided with insulating adhesive, and a pressure relief channel is formed between the outer periphery of the electrode post and the housing. The insulating adhesive fills the pressure relief channel, and the electrode post is sealed to the housing through the insulating adhesive.

6. The electrochemical device according to claim 5, characterized in that: The electrode includes an extension and a main body. The extension is connected to the outer periphery of the main body and to the outer side of the housing. The injection channel extends through the main body along the first direction. The explosion-proof sealing sheet is connected to the end of the main body away from the cavity. At least a portion of the main body extends into the cavity. The extension, the main body, and the housing define the pressure relief channel.

7. The electrochemical device according to claim 6, characterized in that: The extension is sealed to the housing via the insulating adhesive, and / or the outer peripheral surface of the main body is sealed to the housing via the insulating adhesive.

8. The electrochemical device according to claim 6, characterized in that: The extension and the housing are filled with the insulating adhesive between them in the first direction to form a first insulating ring, the first insulating ring being located outside the housing; or... The connecting piece and the housing are filled with insulating adhesive in the first direction to form a second insulating ring, which is located inside the cavity.

9. The electrochemical device according to claim 6, characterized in that: The height of the pole post in the first direction is set at 1mm-2.4mm, and the extension is connected to the end of the main body away from the cavity. The height of the extension in the first direction is set at 0.2mm-0.5mm.

10. The electrochemical device according to claim 1, characterized in that: The explosion-proof sealing sheet includes a first thermally conductive layer and a second thermally conductive layer. The first thermally conductive layer and the second thermally conductive layer are stacked and connected sequentially along the first direction. The second thermally conductive layer is arranged towards the injection channel. The thermal expansion coefficient of the second thermally conductive layer is greater than that of the first thermally conductive layer.

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