Electrochemical device and electric equipment

Abstract

The invention provides an electrochemical device and electric equipment, the electrochemical device comprises a packaging bag, an electrode assembly, a first tab, a second tab and a deformation piece, the packaging bag is provided with a sealing part, the electrode assembly is accommodated in the packaging bag, one end of the first tab and one end of the second tab are respectively connected with the electrode assembly, and the other end of the first tab and the other end of the second tab respectively extend out of the packaging bag from the sealing part; at least part of the deformation piece is made of memory alloy, the deformation piece is in heat conduction connection with the electrode assembly, and at least part of the deformation piece is arranged on the sealing part; the electrode assembly comprises a first pole piece, a second pole piece and an isolating membrane arranged between the first pole piece and the second pole piece; the deformation piece is connected with the first pole piece. The deformation part can quickly sense abnormal temperature change in the electrochemical device and generate deformation, so that the packaging bag is helped to be broken to release heat and pressure of the electrochemical device, the probability of safety accidents caused by too high temperature of the electrochemical device can be reduced, and the safety of the electrochemical device can be improved.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202310303045.5, entitled “Electrochemical Device and Electrical Equipment”, filed on March 27, 2023. Technical Field

[0002] This application relates to the field of battery technology, and more specifically, to an electrochemical device and an electrical appliance. Background Technology

[0003] With the rapid development of mobile terminals, electric vehicles, and other technologies, the demands for battery charging speed and capacity are increasing, leading to higher requirements for battery safety and increasingly stringent requirements for battery thermal testing. Therefore, improving battery safety has become a pressing issue in the battery industry.

[0004] Currently, when batteries are fast-charged or tested in a hot box, a large amount of heat is generated inside the battery in a short period of time, causing the electrolyte to decompose into gas. This results in a rapid increase in the internal pressure of the battery. Existing pressure relief structures cannot react to the high temperature inside the battery in time to relieve the pressure, which can lead to explosions and other safety hazards. Summary of the Invention

[0005] The purpose of this application is to provide an electrochemical device and an electrical appliance to improve battery safety.

[0006] In a first aspect, this application provides an electrochemical device, comprising: The packaging bag has a sealing part; the electrode assembly is housed inside the packaging bag; The first electrode tab and the second electrode tab, one end of which are respectively connected to the electrode assembly, and the other end of which protrude from the sealing part of the packaging bag; The deformable element is at least partially made of shape memory alloy and is thermally connected to the electrode assembly. At least a portion of the deformable element is located in the sealing portion.

[0007] In the above technical solution, a deformation element made of at least part of shape memory alloy is provided, and the deformation element is thermally connected to the electrode assembly. At least part of the deformation element is located in the sealing part of the packaging bag. When the temperature of the electrode assembly is high, the deformation element can quickly sense abnormal temperature changes inside the electrochemical device and deform, thereby helping to break open the packaging bag to release the heat and pressure of the electrochemical device. This can reduce the probability of safety accidents caused by excessive temperature of the electrochemical device and improve the safety of the electrochemical device.

[0008] In some embodiments, the deformable member includes a first segment and a second segment connected to each other. The first segment is made of shape memory alloy and at least a portion of the first segment is disposed in the sealing portion. The second segment is also connected to the electrode assembly for conducting heat from the electrode assembly to the first segment.

[0009] In the above technical solution, the deformable part is divided into a first section and a second section. The first section is made of shape memory alloy and is at least partially located in the sealing part. It can deform to break the packaging bag and release the heat and pressure of the electrochemical device. The second section is also connected to the electrode assembly to conduct the heat of the electrode assembly to the first section, so that the first section can be deformed by heat.

[0010] In some embodiments, the thermal conductivity of the material in the second segment is greater than that of the material in the first segment.

[0011] In the above technical solution, the thermal conductivity of the material in the second section is greater than that in the first section, which allows the second section to transfer heat to the first section more quickly, enabling the first section to deform under heat more quickly to break open the packaging bag and release the heat and pressure of the electrochemical device.

[0012] In some embodiments, along the extension direction of the deformable member, the length of the first segment is a1 and the length of the deformable member is a2, satisfying 1:10≤a1:a2<1:1.

[0013] In the above technical solution, along the extension direction of the deformable element, the length of the first segment is a1, and the length of the deformable element is a2, satisfying 1:10 ≤ a1:a2 < 1:1. On the one hand, the deformable element can generate sufficient deformation to break the packaging bag and release the heat and pressure of the electrochemical device. On the other hand, the second segment can accelerate the heat conduction speed of the deformable element, thereby generating deformation more quickly to break the packaging bag and further improving the safety of the electrochemical device. If a1:a2 is small (e.g., less than 1:10), the size of the first segment made of shape memory alloy is too small, resulting in a small deformation of the first segment, which may not be able to break the packaging bag and affect the pressure relief. If a1:a2 is large (e.g., equal to 1:1), the deformable element is entirely composed of shape memory alloy, which has poor heat conduction and will affect the deformation speed of the deformable element, causing the packaging bag to not be broken in time, resulting in excessively high temperature or pressure in the electrochemical device, increasing safety hazards, and also increasing costs. It is worth noting that the above-mentioned ratio range of a1:a2 is the preferred solution of this application. Even if a1:a2 is not within the above range, at least part of the deformable part is provided in the sealing part, which can play a basic role in heat deformation and help to break the packaging bag to achieve pressure relief.

[0014] In some embodiments, the deformable part is made entirely of shape memory alloy.

[0015] In the above technical solution, the deformable part is made entirely of shape memory alloy, which can reduce the difficulty of manufacturing the deformable part and improve the manufacturing efficiency of the deformable part.

[0016] In some embodiments, the cross-section of the deformable element is polygonal or elliptical.

[0017] In the above technical solution, the cross-section of the deformable part is polygonal or elliptical, which makes it easier for the deformable part to break open the packaging bag when heated, so as to release the heat and pressure of the electrochemical device.

[0018] In some embodiments, the recovery stress of the shape memory alloy is F, which satisfies 100MPa≤F≤500MPa.

[0019] In the above technical solution, the recovery stress of the shape memory alloy is F, which satisfies 100MPa≤F≤500MPa. On the one hand, the deformable component can generate sufficient force on the packaging bag to break it open, thereby releasing the heat and pressure of the electrochemical device. On the other hand, the force exerted by the deformable component on the packaging bag will not be too large, reducing the probability of damaging other components inside and outside the electrochemical device. If F is small (e.g., less than 100MPa), it may not be able to break the packaging bag, affecting the reliability of the deformable component; if F is large (e.g., greater than 500MPa), it may damage other components inside and outside the electrochemical device while breaking the packaging bag, causing other safety problems.

[0020] In some embodiments, the thickness of the deformable element is less than the thickness of the first tab and the thickness of the second tab, respectively.

[0021] In the above technical solution, the thickness of the deformable component is smaller than that of the first tab and the second tab, making it easier for the deformable component to deform to break the packaging bag and release the heat and pressure of the electrochemical device. At the same time, it makes the first tab and the second tab less prone to deformation, making the internal structure of the electrochemical device more stable and the reliability of the connection with the external device higher.

[0022] In some embodiments, the first tab, the second tab, and the deformation element are located at the same end along the length of the electrochemical device.

[0023] In the above technical solution, the first tab, the second tab, and the deformable element are arranged at the same end along the length of the electrochemical device. This facilitates the thermal connection of the deformable element to the electrode assembly while simultaneously connecting the first tab and the second tab to the electrode assembly. Furthermore, the deformable element is encapsulated while encapsulating the first tab and the second tab, which simplifies the connection and encapsulation process of the deformable element and improves the preparation efficiency of the electrochemical device.

[0024] In some embodiments, the first tab and the second tab are spaced apart along the width direction of the electrochemical device, and the deformable element is located between the first tab and the second tab.

[0025] In the above technical solution, the first electrode and the second electrode are spaced apart along the width direction of the electrochemical device, and the deformable element is located between the first electrode and the second electrode, which facilitates the connection and encapsulation of the deformable element and the electrode assembly.

[0026] In some embodiments, the distance between the first tab and the second tab along the width direction of the electrochemical device is b1, and the dimension of the deformable element along the width direction of the electrochemical device is b2, satisfying that b2≤b1-2mm.

[0027] In the above technical solution, the distance between the first and second electrodes along the width direction of the electrochemical device is b1, and the dimension of the deformable element along the width direction of the electrochemical device is b2, satisfying that b2 ≤ b1 - 2 mm, which facilitates the placement of the deformable element between the first and second electrodes. If b2 is greater than b1 - 2 mm, it is not convenient to place the deformable element between the first and second electrodes, and the distance between the deformable element and the first and second electrodes is too small, which may cause the deformable element to directly contact the first and / or second electrodes, resulting in a short circuit and reducing the safety of the electrochemical device.

[0028] In some embodiments, the first tab and the deformation element are spaced apart along the width direction of the electrochemical device, and the second tab is located between the first tab and the deformation element.

[0029] In the above technical solution, the first electrode tab and the deformable element are spaced apart along the width direction of the electrochemical device, and the second electrode tab is located between the first electrode tab and the deformable element, which facilitates the connection and encapsulation of the deformable element and the electrode assembly.

[0030] In some embodiments, the electrode assembly includes a first electrode, a second electrode, and a separator, with the separator disposed between the first and second electrodes; the deformable element is connected to the first electrode.

[0031] In the above technical solution, the electrode assembly includes a first electrode, a second electrode, and a separator, with the separator disposed between the first and second electrodes; the deformation element is connected to the first electrode, enabling the heat from the first electrode to be directly transferred to the deformation element, which can quickly conduct heat to generate deformation, break open the packaging bag, and realize the release of heat and pressure from the electrochemical device.

[0032] In some embodiments, the first electrode includes a coating area with active material layers on both sides and an empty current collector area with an active material layer on one side and no active material layer on the other side, and the deformation member is connected to the side of the empty current collector area without an active material layer.

[0033] In the above technical solution, the first electrode includes a coating area with active material layers on both sides and an empty current collector area with an active material layer on one side and no active material layer on the other side. The deformation element is connected to the side of the empty current collector area without an active material layer, which enables the heat of the first electrode to be transferred to the deformation element through the empty current collector area. The deformation element can further conduct heat quickly to generate deformation, break the packaging bag, and realize the release of heat and pressure of the electrochemical device.

[0034] In some embodiments, the deformable element passes through the seal and is connected to the seal by an adhesive.

[0035] In the above technical solution, the deformable element passes through the sealing part, making it easier for the deformable element to break through the sealing part when it deforms due to heat, thereby releasing heat and pressure from the electrochemical device and further improving its safety. The deformable element and the sealing part are connected by an adhesive, which improves the sealing performance between them, reduces the possibility of electrolyte leakage, and further enhances the safety of the electrochemical device.

[0036] In some embodiments, the portion of the deformable part located inside the packaging bag is covered with a thermally conductive insulating layer.

[0037] In the above technical solution, the portion of the deformable component located inside the packaging bag is covered with a thermally conductive insulating layer, which can achieve insulation between the deformable component and other components inside the packaging bag, reduce the probability of short circuit caused by direct contact between the deformable component and other components inside the packaging bag, and further improve the safety of the electrochemical device. Its impact on the thermal conductivity of the deformable component is relatively small.

[0038] Secondly, this application provides an electrical device, including the electrochemical device described above. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the main structure of an electrochemical device provided in an embodiment of this application; Figure 2 This is a schematic front view of the deformable component of an electrochemical device provided in an embodiment of this application; Figure 3 This is a cross-sectional structural schematic diagram of a deformable component of an electrochemical device provided in an embodiment of this application; Figure 4 This is a cross-sectional structural schematic diagram of a deformable component of another electrochemical device provided in the embodiments of this application; Figure 5 This is a cross-sectional structural schematic diagram of a deformable component of another electrochemical device provided in the embodiments of this application; Figure 6 This is a cross-sectional structural schematic diagram of a deformable component of another electrochemical device provided in the embodiments of this application; Figure 7This is a schematic diagram of the main structure of a deformable component of another electrochemical device provided in the embodiments of this application; Figure 8 This is a schematic diagram of the main structure of another electrochemical device provided in the embodiments of this application; Figure 9 This is a side view schematic diagram of a partial structure of an electrochemical device provided in an embodiment of this application; Figure 10 This is a front view schematic diagram of a partial structure of an electrochemical device provided in an embodiment of this application; Figure 11 This is a side view schematic diagram of a partial structure of another electrochemical device provided in the embodiments of this application.

[0041] Icons: 10-Electrochemical device; 100-Packaging bag; 110-Sealing part; 200-Electrode assembly; 210-First electrode; 211-First substrate layer; 212-First active material layer; 213-Coated area; 214-Vacuum current collector area; 220-Second electrode; 221-Second substrate layer; 222-Second active material layer; 300-First tab; 310-First colloid; 400-Second tab; 410-Second colloid; 500-Deformable part; 510-First section; 520-Second section; 530-Colloid. Detailed Implementation

[0042] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following embodiments are provided as examples to more clearly illustrate the technical solution of this application, and should not be used to limit the scope of protection of this application. Those skilled in the art will understand that, without conflict, the following embodiments and features described herein can be combined with each other.

[0043] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "connection" can refer to 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 in the embodiments of this application according to the specific circumstances.

[0044] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In this application, "multiple" refers to two or more.

[0045] Currently, the application of rechargeable batteries is becoming increasingly widespread. They are widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in power tools, drones, energy storage devices, and many other fields. With the continuous expansion of the application areas of rechargeable batteries, the market demand is also constantly increasing.

[0046] The inventors noted that, to improve battery safety, batteries are typically equipped with a pressure relief mechanism that can open the battery casing or packaging when the internal pressure is too high, thus preventing safety accidents caused by excessive internal pressure or temperature. However, this pressure relief mechanism does not open when the internal temperature of the battery is high but the pressure has not reached a threshold, therefore it cannot only relieve pressure when the internal temperature of the battery is too high, and a safety hazard still exists.

[0047] Based on the above considerations, and in order to improve the safety of existing batteries, the inventors, after in-depth research, have developed an electrochemical device including a packaging bag, an electrode assembly, a first tab and a second tab, and a deformation element. The packaging bag has a sealing portion, and the electrode assembly is housed within the packaging bag. One end of the first tab and the second tab are respectively connected to the electrode assembly, and the other end extends out of the packaging bag from the sealing portion. At least a portion of the deformation element is made of shape memory alloy and is thermally connected to the electrode assembly. At least a portion of the deformation element is located within the sealing portion. When the temperature of the electrode assembly is high, the deformation element can quickly sense abnormal temperature changes within the electrochemical device and deform, thereby helping to break open the packaging bag to release the heat and pressure of the electrochemical device. This reduces the probability of safety accidents caused by excessively high temperatures in the electrochemical device and improves the safety of the electrochemical device.

[0048] This application provides an electrical device that uses an electrochemical device as a power source. The electrical device can be, but is not limited to, drones, electric vehicles, power tools, and energy storage devices. Drones can include agricultural drones, industrial drones, consumer drones, etc., and electric vehicles can include electric cars, electric motorcycles, electric bicycles, electric boats, etc.

[0049] like Figure 1 As shown, this application provides an electrochemical device 10, which includes a packaging bag 100, an electrode assembly 200, a first tab 300, a second tab 400, and a deformable element 500. The packaging bag 100 has a sealing portion 110. The electrode assembly 200 is housed inside the packaging bag 100. One end of the first tab 300 and the second tab 400 are respectively connected to the electrode assembly 200, and the other end extends out of the packaging bag 100 from the sealing portion 110. At least a portion of the deformable element 500 is made of shape memory alloy. The deformable element 500 is thermally connected to the electrode assembly 200, and at least a portion of the deformable element 500 is disposed in the sealing portion 110.

[0050] Shape memory alloys are materials composed of two or more metallic elements that exhibit shape memory effects through thermoelasticity and martensitic phase transformation and its inverse. For example, in the embodiments of this application, the shape memory alloy can be formed into a first state at a high temperature, deformed into a second state at room temperature, and installed in an electrochemical device 10. After being heated, it can deform back to the first state to break open the packaging bag.

[0051] A deformable element 500, at least partially made of shape memory alloy, is provided and is thermally connected to the electrode assembly 200. At least a portion of the deformable element 500 is located in the sealing portion 110 of the packaging bag 100. When the temperature of the electrode assembly 200 is high, the deformable element 500 can quickly sense abnormal temperature changes inside the electrochemical device 10 and deform, thereby helping to break open the packaging bag 100 to release the heat and pressure of the electrochemical device 10. This reduces the probability of safety accidents caused by excessive temperature of the electrochemical device 10 and improves the safety of the electrochemical device 10.

[0052] like Figure 2 As shown, in some embodiments, the deformable member 500 includes a first segment 510 and a second segment 520 connected to each other. The first segment is made of shape memory alloy. At least a portion of the first segment 510 is disposed in the sealing portion 110. The second segment 520 is also connected to the electrode assembly 200 for conducting heat from the electrode assembly 200 to the first segment 510.

[0053] The deformable element 500 is divided into a first segment 510 and a second segment 520. The first segment 510 is made of shape memory alloy and is at least partially disposed in the sealing part 110. It can deform to break the packaging bag 100 and release the heat and pressure of the electrochemical device 10. The second segment 520 is also connected to the electrode assembly 200 to conduct the heat of the electrode assembly 200 to the first segment 510, so that the first segment 510 can be deformed by heat.

[0054] In some embodiments, the thermal conductivity of the material in the second segment 520 is greater than that of the material in the first segment 510.

[0055] The thermal conductivity of the material in the second segment 520 is greater than that of the material in the first segment 510, which allows the second segment 520 to transfer heat to the first segment 510 more quickly. This allows the first segment 510 to deform more quickly due to heat, thus breaking open the packaging bag 100 and releasing the heat and pressure of the electrochemical device 10.

[0056] In some embodiments, along the extension direction X of the deformable member 500, the length of the first segment 510 is a1 and the length of the deformable member 500 is a2, satisfying 1:10≤a1:a2<1:1.

[0057] Along the extension direction of the deformable element 500, the length of the first segment 510 is a1, and the length of the deformable element 500 is a2, satisfying 1:10 ≤ a1:a2 < 1:1, for example, a1:a2 is 1:10, 1:2, or 9:10, etc. On the one hand, the deformable element 500 can generate sufficient deformation to break the packaging bag 100, realizing the release of heat and pressure from the electrochemical device 10. On the other hand, the second segment 520 can accelerate the heat conduction rate of the deformable element 500, thereby generating deformation more quickly to break the packaging bag 100, further improving the safety of the electrochemical device 10. If a1:a2 is small (e.g., less than 1:10), the size of the first segment 510 made of shape memory alloy will be too small, resulting in an insufficient deformation of the first segment 510, which may prevent it from breaking the packaging bag 100, affecting pressure relief. If a1:a2 is large (e.g., equal to 1:1), the deformable part 500 is entirely made of shape memory alloy, which has poor thermal conductivity and will affect the deformation speed of the deformable part 500. This may cause the packaging bag 100 to fail to be broken in time, resulting in excessive temperature or pressure in the electrochemical device 10, increasing safety hazards, and also increasing costs.

[0058] In some embodiments, the first segment 510 and the second segment 520 can be integrally formed. For example, the integral forming of the first segment 510 and the second segment 520 can be achieved by processing methods such as powder metallurgy, 3D printing, and metal powder sintering.

[0059] The integrated molding of the first section 510 and the second section 520 makes the structure of the deformable part 500 more stable and the deformable part 500 more reliable in breaking through the packaging bag 100.

[0060] In other embodiments, the first segment 510 and the second segment 520 can also be fixedly connected by welding.

[0061] In other embodiments, the deformable element 500 may also be made entirely of shape memory alloy, and this is not a limitation.

[0062] The deformable part 500 is made entirely of shape memory alloy, which reduces the difficulty of manufacturing the deformable part 500 and improves the manufacturing efficiency of the deformable part 500.

[0063] In some embodiments, the cross-section of the deformable member 500 is polygonal or elliptical. The cross-section of the deformable member 500 is a cross-section on a plane perpendicular to the extending direction X of the deformable member 500. For example... Figure 3 As shown, the cross-section of the first segment 510 can be rectangular. For example... Figure 4 As shown, the cross-section of the first segment 510 can be hexagonal. For example... Figure 5 As shown, the cross-section of the first segment 510 can be trapezoidal. For example... Figure 6 As shown, the cross-section of the first segment 510 can be elliptical.

[0064] The cross-section of the deformable element 500 is polygonal or elliptical, which makes it easier for the deformable element 500 to break the packaging bag 100 when heated, so as to release the heat and pressure of the electrochemical device 10.

[0065] like Figure 7 As shown, in some embodiments, the deformable element 500 includes a first segment 510 and a second segment 520. The first segment 510 is made of shape memory alloy, and the cross-section of the first segment 510 on the vertical plane along the thickness direction of the deformable element 500 is triangular, which further facilitates breaking open the packaging bag 100 when deformation occurs. The thickness direction of the deformable element 500, the length direction X of the electrochemical device 10, and the width direction Y of the electrochemical device 10 are perpendicular to each other.

[0066] In some embodiments, the recovery stress of the shape memory alloy is F, which satisfies 100MPa≤F≤500MPa.

[0067] The recovery stress of the shape memory alloy is F, which satisfies 100MPa≤F≤500MPa. On the one hand, the deformable component can generate sufficient force on the packaging bag 100 to break it open, thereby releasing the heat and pressure of the electrochemical device 10. On the other hand, the force exerted by the deformable component 500 on the packaging bag 100 will not be excessive, reducing the probability of damaging other components inside and outside the electrochemical device 10. If F is small (e.g., less than 100MPa), it may not be able to break the packaging bag 100, affecting the reliability of the deformable component 500. If F is large (e.g., greater than 500MPa), it may damage other components inside and outside the electrochemical device 10 while breaking the packaging bag 100, causing other safety problems.

[0068] In some embodiments, the thickness of the deformable member 500 is less than the thickness of the first tab 300 and the thickness of the second tab 400, respectively.

[0069] The thickness of the deformable element 500 is smaller than that of the first tab 300 and the second tab 400, making it easier for the deformable element 500 to deform and break the packaging bag 100 to release the heat and pressure of the electrochemical device 10. At the same time, it makes the first tab 300 and the second tab 400 less prone to deformation, making the internal structure of the electrochemical device 10 more stable and the reliability of its connection with external devices higher.

[0070] like Figure 1 As shown, in some embodiments, the first tab 300, the second tab 400, and the deformer 500 are located at the same end along the length of the electrochemical device 10.

[0071] By placing the first tab 300, the second tab 400, and the deformable element 500 at the same end along the length of the electrochemical device 10, it is possible to connect the first tab 300 and the second tab 400 to the electrode assembly 200 while simultaneously making the deformable element 500 thermally connected to the electrode assembly 200. Furthermore, by encapsulating the first tab 300 and the second tab 400, the deformable element 500 can be encapsulated at the same time, which simplifies the connection and encapsulation process of the deformable element 500 and improves the preparation efficiency of the electrochemical device 10.

[0072] In other embodiments, the first tab 300 and the second tab 400 may be located at one end of the electrochemical device 10 along the length direction X, and the deformable element 500 may be located at the other end of the electrochemical device 10 along the length direction X. Alternatively, the first tab 300 and the second tab 400 may be located at one end of the electrochemical device 10 along the length direction X, and the deformable element 500 may be located on one side of the electrochemical device 10 along the width direction Y.

[0073] In some embodiments, the first tab 300 and the second tab 400 are spaced apart along the width direction of the electrochemical device 10, and the deformable member 500 is located between the first tab 300 and the second tab 400.

[0074] In the above technical solution, the first tab 300 and the second tab 400 are spaced apart along the width direction Y of the electrochemical device 10, and the deformable element 500 is located between the first tab 300 and the second tab 400, which facilitates the connection and encapsulation of the deformable element 500 with the electrode assembly 200.

[0075] In some embodiments, the distance between the first tab 300 and the second tab 400 along the width direction Y of the electrochemical device 10 is b1, and the dimension of the deformable member 500 along the width direction Y of the electrochemical device 10 is b2, satisfying that b2≤b1-2mm.

[0076] The distance between the first tab 300 and the second tab 400 along the width direction Y of the electrochemical device 10 is b1, and the dimension of the deformable element 500 along the width direction Y of the electrochemical device 10 is b2. The condition b2 ≤ b1 - 2 mm is met, which facilitates the placement of the deformable element 500 between the first tab 300 and the second tab 400. If b2 is greater than b1 - 2 mm, it is not convenient to place the deformable element 500 between the first tab 300 and the second tab 400, and the distance between the deformable element 500 and the first tab 300 and the second tab 400 is too small. This could lead to direct contact between the deformable element 500 and the first tab 300 and / or the second tab 400, causing a short circuit and reducing the safety of the electrochemical device 10.

[0077] like Figure 8As shown, in some other embodiments, the first tab 300 and the deformable element 500 are spaced apart along the width direction Y of the electrochemical device 10, and the second tab 400 is located between the first tab 300 and the deformable element 500.

[0078] The first tab 300 and the deformable element 500 are spaced apart along the width direction Y of the electrochemical device 10. The second tab 400 is located between the first tab 300 and the deformable element 500, which facilitates the connection and encapsulation of the deformable element 500 and the electrode assembly 200.

[0079] like Figure 9 As shown, in some embodiments, the electrode assembly 200 includes a first electrode 210, a second electrode 220, and a separator (not shown), with the separator disposed between the first electrode 210 and the second electrode 220. A deformable member 500 is connected to the first electrode 210.

[0080] The electrode assembly 200 includes a first electrode 210, a second electrode 220, and a separating membrane. The separating membrane is disposed between the first electrode 210 and the second electrode 220, and between two adjacent second electrodes 220 in the middle. The deformation element 500 is connected to the first electrode 210, enabling the heat from the first electrode 210 to be directly transferred to the deformation element 500. The deformation element 500 can quickly conduct heat to generate deformation, breaking open the packaging bag 100 and releasing the heat and pressure of the electrochemical device 10.

[0081] In some embodiments, the first electrode 210 is a positive electrode and the second electrode 220 is a negative electrode.

[0082] In some embodiments, the first electrode 210 includes a first substrate layer 211 and a first active material layer 212 disposed on both sides of the first substrate layer 211.

[0083] like Figure 10 As shown, in some embodiments, the first electrode 210 includes a coating area 213 with a first active material layer 212 on both sides and an empty current collector area 214 with a first active material layer 212 on one side and no active material layer on the other side, and the deformable member 500 is connected to the side of the empty current collector area 214 without an active material layer.

[0084] The first electrode 210 includes a coating area 213 with a first active material layer 212 on both sides and an empty current collector area 214 with a first active material layer 212 on one side and no active material layer on the other side. The deformation element 500 is connected to the side of the empty current collector area 214 without an active material layer, which allows the heat of the first electrode 210 to be transferred to the deformation element 500 through the empty current collector area 214. The deformation element 500 can further conduct heat quickly to generate deformation, break the packaging bag 100, and realize the release of heat and pressure of the electrochemical device 10.

[0085] In some embodiments, the empty current collector region 214 may be formed by cleaning a portion of the coating region 213 to facilitate the coating of the first active material layer 212.

[0086] like Figure 11 As shown, in some embodiments, the electrode assembly 200 includes a first electrode 210, a second electrode 220, and a separator. The separator is disposed between the first electrode 210 and the second electrode 220, and between two adjacent second electrodes 220 in the middle. The second electrode 220 disposed in the middle may include a second substrate layer 221 and a second active material layer 222 disposed on one side of the second substrate layer 221. The deformable member 500 can be connected to the side of the second electrode 220 where the second active material layer 222 is not disposed, which can eliminate the processing of the first electrode 210 or the second electrode 220 (e.g., cleaning to form an empty current collector region 214), reduce the difficulty of fabricating the electrochemical device 10, and improve the fabrication efficiency of the electrochemical device 10.

[0087] like Figure 1 As shown, in some embodiments, the deformable element 500 passes through the sealing portion 110 and is connected to the sealing portion 110 by an adhesive 530.

[0088] The deformable element 500 passes through the sealing portion 110, making it easier for the deformable element 500 to break through the sealing portion 110 when it deforms due to heat, thereby releasing heat and pressure from the electrochemical device 10 and further improving its safety. The deformable element 500 and the sealing portion 110 are connected by an adhesive 530, which improves the sealing performance between them, reduces the possibility of electrolyte leakage, and further enhances the safety of the electrochemical device 10.

[0089] In some embodiments, the first tab 300 passes through the sealing portion 110 and is connected to the sealing portion 110 via a first colloid 310, and the second tab 400 passes through the sealing portion 110 and is connected to the sealing portion 110 via a second colloid 410. This can improve the sealing performance between the first tab 300, the second tab 400 and the sealing portion 110, reduce the possibility of electrolyte leakage, and further improve the safety of the electrochemical device 10.

[0090] In other embodiments, the first tab 300, the second tab 400, the deformable element 500 and the sealing part 110 can also be directly heat-sealed, which is not limited here.

[0091] In some embodiments, the portion of the deformable member 500 located inside the packaging bag 100 is covered with a thermally conductive insulating layer (not shown in the figure).

[0092] The portion of the deformable component 500 located inside the packaging bag 100 is covered with a thermally conductive insulating layer, which can achieve insulation between the deformable component 500 and other components inside the packaging bag 100, reduce the probability of short circuit caused by direct contact between the deformable component 500 and other components inside the packaging bag 100, and further improve the safety of the electrochemical device 10. Its impact on the thermal conductivity of the deformable component 500 is relatively small.

[0093] This application also provides an electrical device, including the electrochemical device 10 provided in any of the above embodiments.

[0094] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0095] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

Claims

1. An electrochemical device, characterized in that, include: Packaging bag with a sealing part; The electrode assembly is housed within the packaging bag; First electrode tab and second electrode tab, one end of the first electrode tab and the second electrode tab are respectively connected to the electrode assembly, and the other end of the first electrode tab and the second electrode tab extend out of the packaging bag from the sealing part; A deformable element, at least partially made of shape memory alloy, is thermally connected to the electrode assembly, and at least a portion of the deformable element is disposed in the sealing portion; The electrode assembly includes a first electrode, a second electrode, and a separator, with the separator disposed between the first electrode and the second electrode; the deformable element is connected to the first electrode.

2. The electrochemical device according to claim 1, characterized in that, The deformable component includes a first segment and a second segment connected to each other. The first segment is made of the shape memory alloy and at least a portion of the first segment is disposed in the sealing portion. The second segment is also connected to the electrode assembly for conducting heat from the electrode assembly to the first segment.

3. The electrochemical device according to claim 2, characterized in that, The thermal conductivity of the material in the second segment is greater than that of the material in the first segment.

4. The electrochemical device according to claim 2, characterized in that, Along the extension direction of the deformable component, the length of the first segment is a1, and the length of the deformable component is a2, satisfying 1:10≤a1:a2<1:

1.

5. The electrochemical device according to claim 1, characterized in that, The deformable component is entirely made of the shape memory alloy.

6. The electrochemical device according to claim 1, characterized in that, The cross-section of the deformable part is polygonal or elliptical.

7. The electrochemical device according to claim 1, characterized in that, The recovery stress of the shape memory alloy is F, which satisfies 100MPa≤F≤500MPa.

8. The electrochemical device according to claim 1, characterized in that, The thickness of the deformable element is less than the thickness of the first electrode and the thickness of the second electrode, respectively.

9. The electrochemical device according to claim 1, characterized in that, The first tab, the second tab, and the deformation element are located at the same end along the length of the electrochemical device.

10. The electrochemical device according to claim 9, characterized in that, The first tab and the second tab are spaced apart along the width direction of the electrochemical device, and the deformable element is located between the first tab and the second tab.

11. The electrochemical device according to claim 10, characterized in that, The distance between the first tab and the second tab along the width direction of the electrochemical device is b1, and the dimension of the deformable element along the width direction of the electrochemical device is b2, satisfying that b2≤b1-2mm.

12. The electrochemical device according to claim 9, characterized in that, The first electrode tab and the deformation element are spaced apart along the width direction of the electrochemical device, and the second electrode tab is located between the first electrode tab and the deformation element.

13. The electrochemical device according to claim 1, characterized in that, The first electrode includes a coating area with active material layers on both sides and an empty current collector area with an active material layer on one side and no active material layer on the other side. The deformation member is connected to the side of the empty current collector area without an active material layer. The deformation member passes through the sealing part and is connected to the sealing part by an adhesive.

14. The electrochemical device according to claim 1, characterized in that, The portion of the deformable component located inside the packaging bag is covered with a thermally conductive insulating layer.

15. An electrical appliance, characterized in that, Includes the electrochemical device as described in any one of claims 1-14.

Images