Electrochemical devices and electronic devices

Abstract

The present application provides an electrochemical device and an electronic device, wherein the electrochemical device comprises a packaging bag, an electrode assembly and a detection assembly, wherein the packaging bag is provided with a receiving space, wherein the electrode assembly and the detection assembly are received in the receiving space, and wherein the detection assembly comprises a hydrogen storage metal assembly, wherein when the hydrogen storage metal assembly encounters hydrogen, the internal resistance of the hydrogen storage metal assembly changes. Through the above structure, the electrochemical device can monitor the content of hydrogen in the receiving space in real time, thereby improving the safety of the electrochemical device.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of energy storage power supply, and in particular to an electrochemical device and an electronic device. Background Art

[0002] Lithium batteries are a type of battery that uses lithium metal or lithium alloy as positive / negative electrode materials and non-aqueous electrolyte solutions. With the development of science and technology and new energy industries, lithium batteries have become the mainstream of energy storage power sources, especially soft-pack lithium batteries, which are widely used due to their good safety performance, light weight, large capacity, low internal resistance and flexible design.

[0003] At present, lithium plating is a common problem in soft-pack lithium batteries. In addition to a sharp decline in the life of the lithium battery after lithium plating, the probability of safety problems will also be greatly increased, such as high-temperature fire, internal short-circuit fire, violent reaction explosion, etc. Summary of the invention

[0004] The main technical problem solved by the embodiments of the present application is to provide a battery device and an electronic device that can monitor hydrogen in the battery device, thereby promptly processing the electrochemical device where lithium deposition occurs, thereby improving the safety of the battery device.

[0005] In order to solve the above technical problems, a technical solution provided in an embodiment of the present application is: providing an electrochemical device, comprising an electrode assembly, a packaging bag and a detection assembly, wherein the packaging bag is provided with a receiving space, and the electrode assembly is received in the receiving space; the detection assembly comprises a hydrogen storage metal assembly, and the hydrogen storage metal assembly comprises a hydrogen storage metal wire; the hydrogen storage metal assembly is arranged in the receiving space, wherein when the hydrogen storage metal assembly encounters hydrogen, the internal resistance of the hydrogen storage metal assembly changes.

[0006] Optionally, the detection component also includes a first joint and a second joint; one end of the hydrogen storage metal component is connected to one end of the first joint, and the other end of the first joint extends out of the packaging bag, and the other end of the hydrogen storage metal component is connected to one end of the second joint, and the other end of the second joint extends out of the packaging bag.

[0007] Optionally, the electrode assembly is provided with a wide surface, and the hydrogen storage metal assembly is arranged between the wide surface of the electrode assembly and the packaging bag.

[0008] Optionally, the hydrogen storage metal component further includes a polymer material layer, and the porosity K of the polymer material layer satisfies: 10%≤K≤50%.

[0009] Optionally, the polymer material layer includes a first polymer material layer and a second polymer material layer; the first polymer material layer is arranged between the hydrogen storage metal wire and the electrode assembly, and the second polymer material layer is arranged between the hydrogen storage metal wire and the packaging bag.

[0010] Optionally, the hydrogen storage metal wire satisfies at least one of the following conditions: (1) the ratio A of the area of ​​the minimum circumscribed rectangle of the hydrogen storage metal wire to the area of ​​the wide surface satisfies: 20%≤A≤40%; (2) the cross-sectional area D of the hydrogen storage metal wire satisfies: 20 square microns≤D≤8000 square microns; (3) the length L of the hydrogen storage metal wire satisfies: 5 mm≤L≤1000 mm; (4) the hydrogen storage metal wire is prepared from palladium metal; (5) the hydrogen storage metal wire is patterned and bent.

[0011] Optionally, the outer side of the electrode assembly is a separation membrane, and at least one of the first polymer material layer and the second polymer material layer includes the separation membrane.

[0012] Optionally, the detection component further includes a first seal and a second seal, wherein the first seal seals a connection between the first joint and the packaging bag, and the second seal seals a connection between the second joint and the packaging bag.

[0013] Optionally, the first joint and the second joint include at least one of aluminum or nickel.

[0014] In order to solve the above technical problem, an embodiment of the present application provides another technical solution: providing an electronic device, including the electrochemical device as described above.

[0015] The beneficial effects of the embodiment of the present application are: the electrochemical device includes an electrode assembly, a packaging bag and a detection assembly, the packaging bag is provided with a receiving space, the electrode assembly is received in the receiving space, the detection assembly includes a hydrogen storage metal assembly, the hydrogen storage metal assembly includes a hydrogen storage metal wire; the hydrogen storage metal assembly is arranged in the receiving space, wherein when the hydrogen storage metal assembly encounters hydrogen, the internal resistance of the hydrogen storage metal assembly changes. Through the above structure, the electrochemical device can monitor the hydrogen content in the receiving space in real time, thereby improving the safety of the electrochemical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0017] Figure 1 is a schematic diagram of an electrochemical device from one perspective of an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of the electrochemical device of an embodiment of the present application from another perspective;

[0019] Figure 3 is a schematic diagram of a detection component from one perspective in an electrochemical device according to an embodiment of the present application;

[0020] Figure 4 is a cross-sectional view of a wound electrode assembly of an electrochemical device according to an embodiment of the present application along a first direction;

[0021] Figure 5 is a cross-sectional view of another wound electrode assembly of the electrochemical device according to an embodiment of the present application along a first direction;

[0022] Figure 6 is a cross-sectional view of another wound electrode assembly of the electrochemical device according to an embodiment of the present application along the first direction;

[0023] Figure 7 It is a cross-sectional view of a stacked electrode assembly of an electrochemical device according to an embodiment of the present application along a first direction. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on another element or there can be one or more centered elements therebetween. When an element is described as "connected" to another element, it can be directly connected to another element or there can be one or more centered elements therebetween. The orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. used in this specification is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0026] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0027] Lithium deposition is a common problem in lithium batteries. In addition to a sharp decline in the service life of the electrochemical device after lithium deposition, the probability of safety problems will also increase greatly, such as high-temperature fire, internal short circuit fire and explosion. After lithium deposition in the electrochemical device, lithium will react with the electrolyte or other substances inside the electrochemical device to generate hydrogen. Large amounts of lithium deposition will cause more hydrogen to be generated inside the battery, posing a serious safety hazard to the battery. If it is possible to detect whether hydrogen exists inside the electrochemical device and the amount of hydrogen, it is possible to make a relatively quick and accurate judgment on the state of the electrochemical device, and take safety measures for the electrochemical device to avoid safety accidents.

[0028] See also Figure 1 and Figure 2 The electrochemical device 100 includes a packaging bag 10, an electrode assembly 20, a detection assembly 30, and an electrolyte 40. The packaging bag 10 is provided with a receiving space, the electrode assembly 20 and the detection assembly 30 are both received in the receiving space, the electrolyte 40 is filled in the receiving space, and soaks the electrode assembly 20 and the detection assembly 30, and the detection assembly 30 is used to detect hydrogen and the content of hydrogen in the receiving space.

[0029] It is worth noting that the electrochemical device 100 can be a soft-pack battery, that is, the packaging bag 10 is made of a flexible material, such as an aluminum-plastic film. The electrochemical device 100 can also be a hard-shell battery, and the hard shell is made of a hard material, such as metal.

[0030] See also Figures 3 to 7 , viewed along the first direction R, the electrode assembly 20 includes a positive electrode sheet 21, a negative electrode sheet 22, and a separator 23, the separator 23 is disposed between the positive electrode sheet 21 and the negative electrode sheet 22, and the separator 23 is used to separate the positive electrode sheet 21 and the negative electrode sheet 22 to prevent the positive electrode sheet 21 and the negative electrode sheet 22 from contacting and causing a short circuit in the electrochemical device 100. The electrolyte 40 is used to provide an environment for ion transfer between the positive electrode sheet 21 and the negative electrode sheet 22.

[0031] The electrode assembly 20 is provided with a wide surface 24, and the detection assembly 30 is disposed between the wide surface 24 and the packaging bag 10. It is worth noting that when the electrode assembly 20 is a winding structure, the wide surface 24 is disposed on the flat portion of the electrode assembly 20, and when the electrode assembly 20 is a laminated structure, the wide surface 24 is disposed on the outermost surface of the electrode assembly 20, and the wide surface 24 is perpendicular to the direction in which the electrode assembly 20 is stacked.

[0032] See also Figure 3The detection assembly 30 includes a first joint 31, a second joint 32, a hydrogen storage metal assembly 33, a first seal 34 and a second seal 35. The first joint 31 and the second joint 32 both extend outward from the receiving space, the hydrogen storage metal assembly 33 includes a hydrogen storage metal wire 331 and a polymer material layer 332, the polymer material layer 332 includes a first polymer material layer 3321 and a second polymer material layer 3322, the first surface of the first polymer material layer 3321 is bonded to the electrode assembly 20, the hydrogen storage metal wire 331 is arranged on the second surface of the first polymer material layer 3321, wherein the first surface and the second surface are arranged opposite to each other, one end of the hydrogen storage metal wire 331 is electrically connected to the first joint 31, and the other end of the hydrogen storage metal wire 331 is electrically connected to the second joint 32. The first seal 34 is disposed between the first joint 31 and the packaging bag 10, and the first seal 34 seals the gap between the first joint 31 and the packaging bag 10. The second seal 35 is disposed between the second joint 32 and the packaging bag 10, and the second seal 35 seals the gap between the second joint 32 and the packaging bag 10. The first seal 34 and the second seal 35 prevent leakage of the electrolyte 40 in the receiving space.

[0033] In some other embodiments, the distance between the first joint 31 and the second joint 32 can be adjusted according to actual needs, and the first joint 31 and the second joint 32 include at least one of aluminum or nickel.

[0034] In this embodiment, the hydrogen storage wire 331 is a palladium wire. When lithium is precipitated in the electrode assembly 20, the precipitated lithium reacts with the electrolyte 40 to generate hydrogen. The hydrogen contacts the palladium wire, and the palladium wire can catalyze the decomposition of hydrogen into hydrogen atoms, and adsorb the hydrogen atoms inside the palladium wire. After the hydrogen atoms enter the palladium wire, the original lattice of the palladium wire expands, weakening the metal bond, resulting in a decrease in the conductivity of the palladium wire and an increase in the resistance value of the palladium wire. The resistance value of the palladium wire can be measured by electrically connecting the first connector 31 and the second connector 32 through an external resistance measuring device, so that it can be determined whether there is hydrogen inside the electrochemical device 100, and the hydrogen content can be determined according to the change in the resistance value of the palladium wire. The palladium wire has a high sensitivity to hydrogen and can detect the hydrogen content at the ppm level. In addition, the palladium metal only reacts with the hydrogen in the receiving space, which can effectively eliminate the interference of other gases.

[0035] The porosity K of the polymer material layer 332 satisfies: 10%≤K≤50%. The polymer material layer 332 is used to support the hydrogen storage metal wire 331. If the porosity K is too low, it is easy to prevent hydrogen from contacting the hydrogen storage metal wire 331, reducing the sensitivity of the detection component 30. If the porosity K is too high, it may cause the polymer material layer 332 to reduce its support for the hydrogen storage metal wire 331, causing the hydrogen storage metal wire 331 to contact the electrode assembly 20, causing a short circuit in the electrode assembly 20. In addition, if the porosity K is too high, it will also cause the mechanical strength of the polymer material layer 332 to decrease. During the processing and assembly process, the polymer material layer 332 is easily damaged.

[0036] The polymer material layer 332 is used to enhance the strength of the detection component 30, which can reduce the probability of deformation of the hydrogen storage metal wire 331 leading to internal short circuit of the hydrogen storage metal wire 331, and reduce the probability of breakage of the hydrogen storage metal wire 331. The polymer material layer 332 is immersed in the electrolyte 40, and the trace hydrogen dissolved in the electrolyte 40 can be transferred to the hydrogen storage metal wire 331 through the pores of the polymer material layer 332.

[0037] See also Figures 4 to 7 The polymer material layer 332 includes a first polymer material layer 3321 and a second polymer material layer 3322. The first polymer material layer 3321 is arranged between the hydrogen storage metal wire 331 and the electrode assembly 20. The first polymer material layer 3321 is used to isolate the hydrogen storage metal wire 331 from the electrode assembly 20 to prevent the hydrogen storage metal wire 331 and the electrode assembly 20 from directly contacting each other and causing a short circuit. The second polymer material layer 3322 is arranged between the hydrogen storage metal wire 331 and the packaging bag 10. The second polymer material layer 3322 is used to isolate the hydrogen storage metal wire 331 from the packaging bag 10 to reduce the safety risks caused by direct contact between the hydrogen storage metal wire 331 and the packaging bag 10.

[0038] When the outermost layer of the electrode assembly 20 is the separator 23, the separator 23 and the polymer material layer 332 are an integrally formed structure, or at least one of the first polymer material layer 3321 or the second polymer material layer 3322 includes a separator. When the outermost layer of the electrode assembly 20 is not the separator 23, the first polymer material layer 3321 is directly attached to the positive electrode sheet 21 or the negative electrode sheet 22 of the electrode assembly 20.

[0039] The hydrogen storage metal wire 331 is patterned and bent on the polymer material layer 332. In the present embodiment, the hydrogen storage metal wire 331 is in a serpentine shape. In other embodiments, the hydrogen storage metal wire 331 may also be in a circular, rectangular, polygonal, wavy or other shapes, as long as the hydrogen storage metal wire 331 does not short-circuit and can effectively contact the hydrogen.

[0040] The ratio A of the minimum circumscribed rectangle of the patterned hydrogen storage metal wire 331 to the wide surface 24 satisfies: 10%≤A≤70%. In the present embodiment, the ratio A satisfies: 20%≤A≤40%. The minimum circumscribed rectangle of the patterned hydrogen storage metal wire 331 is too small, resulting in a decrease in the sensitivity of the detection component 30, making it difficult to detect the small amount of hydrogen generated in the electrochemical device 100. The minimum circumscribed rectangle of the patterned hydrogen storage metal wire 331 is too large, resulting in excessively high costs and reducing the practicability of the electrochemical device 100.

[0041] It is worth noting that when the electrode assembly 20 is a winding structure or a stacked structure, there will be two relatively wide surfaces 24. In the present embodiment, the ratio A of the minimum circumscribed rectangle of the patterned hydrogen storage metal wire 331 to the wide surface 24 refers to: the area ratio of the minimum circumscribed rectangle of the patterned hydrogen storage metal wire 331 to a wide surface 24 on the side where the detection assembly 30 is located.

[0042] The cross-sectional area D of the hydrogen storage wire 331 satisfies: 20 square microns ≤ D ≤ 8000 square microns, and the cross-sectional area of ​​the hydrogen storage wire 331 is perpendicular to the extension direction of the hydrogen storage wire 331. The cross-sectional area D of the hydrogen storage wire 331 is related to the detection accuracy and detection range of the detection component 30. Specifically, the smaller the cross-sectional area of ​​the hydrogen storage wire 331 (the thinner the hydrogen storage wire 331), the higher the detection accuracy of the detection component 30, but the smaller the detection range, the hydrogen storage wire 331 is too thin and easy to break, and it is not conducive to the processing of the hydrogen storage wire 331; the larger the cross-sectional area of ​​the hydrogen storage wire 331 (the thicker the hydrogen storage wire 331), the lower the detection accuracy of the detection component 30, but the larger the detection range, the hydrogen storage wire 331 is too thick, resulting in an increase in manufacturing costs. Therefore, it is necessary to comprehensively consider the selection of the cross-sectional area of ​​the hydrogen storage wire 331.

[0043] In some embodiments, the cross-sectional area of ​​the hydrogen storage wire 331 may be circular, elliptical, rectangular, polygonal, etc. In this embodiment, the cross-sectional area of ​​the hydrogen storage wire 331 is circular, and the cylindrical hydrogen storage wire 331 is easy to process.

[0044] The length L of the hydrogen storage metal wire 331 satisfies: 5 mm ≤ L ≤ 1000 mm. The longer the length of the hydrogen storage metal wire 331, the larger the patterned area that can be enclosed, and the faster the reaction time between the hydrogen storage metal wire 331 and hydrogen. When the area of ​​the minimum circumscribed rectangle after the hydrogen storage metal wire 331 is patterned is the same, the longer the length of the hydrogen storage metal wire 331, the larger the effective area ratio of the hydrogen storage metal wire 331, so that the contact area between the hydrogen storage metal wire 331 and hydrogen increases, and the reaction time between the hydrogen storage metal wire 331 and hydrogen is faster. Among them, the effective area ratio of the hydrogen storage metal wire 331 is: the ratio of the area of ​​the vertical projection of the hydrogen storage metal wire 331 on the wide surface 24 to the area of ​​the minimum circumscribed rectangle after the hydrogen storage metal wire 331 is patterned.

[0045] In addition, in order to facilitate readers to understand the technical effects brought about by the technical solution, the embodiments of the present application also carried out comparative tests, wherein the embodiments and comparative examples in the present application are all made by packaging the electrode assembly in the shell aluminum-plastic film, perfusing the electrolyte, and then packaging it into a lithium-ion battery. Of course, the embodiment of the present application is not limited to this, and the test process is as follows:

[0046] Preparation of test components:

[0047] (1) Hydrogen storage metal wire: The two ends of the palladium metal wire are respectively welded to the root of the nickel joint, and a sealing member for packaging is welded thereon. The palladium metal wire is bent into a serpentine shape, and the palladium metal wire is fixed to the polymer material layer with an electrolyte-resistant glue (one of polyvinylidene fluoride, polypropylene or polyethylene). The thickness of the polymer material layer is 5 to 15 microns. When the thickness is less than 5 microns, the polymer material layer is easy to break and has poor mechanical strength. When the thickness is greater than 15 microns, the polymer material layer loses energy density.

[0048] (2) Vacuum deposition method: palladium metal wire of a certain thickness and shape is deposited on the polymer material layer by vacuum deposition method, and the two ends of the palladium metal wire are welded to the root of the nickel joint. The thickness of the palladium metal is 5 microns to 100 microns, the width is 5 microns to 500 microns, and the length is 5 mm to 1000 mm.

[0049] Preparation of electrode assembly:

[0050] (1) Preparation of negative electrode

[0051] The negative electrode active material graphite, conductive carbon black (Super P), and styrene-butadiene rubber (SBR) were mixed in a weight ratio of 96:1.5:2.5, and deionized water (H2O) was added as a solvent to prepare a slurry with a solid content of 0.7, and stirred evenly. The slurry was evenly coated on the negative electrode current collector copper foil. The weight of the effective material on the electrode sheet was 95g / m 2After drying at 110°C, the negative electrode sheet is obtained. After the above steps are completed, the single-sided coating of the negative electrode sheet is completed. After that, the above steps are also completed on the back of the electrode sheet in the same way to obtain a negative electrode sheet with double-sided coating. After coating, the negative electrode sheet is cold pressed to 1.7g / cm 3 The compaction density is achieved, which completes the entire preparation process of the negative electrode sheet.

[0052] (2) Preparation of positive electrode

[0053] The positive electrode active material lithium cobalt oxide (LiCoO2), conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) were mixed at a weight ratio of 97.5:1.0:1.5, and N-methylpyrrolidone (NMP) was added as a solvent to prepare a slurry with a solid content of 0.75, and stirred evenly. The slurry was evenly coated on the positive electrode current collector aluminum foil, and the weight of the effective material on the pole piece was 180g / m 2 After drying at 90°C, the positive electrode sheet is obtained. After the above steps are completed, the single-sided coating of the positive electrode sheet is completed. After that, the above steps are also completed on the back of the electrode sheet in the same way to obtain a double-sided coated positive electrode sheet. After coating, the positive electrode sheet is cold pressed to 4.1g / cm 3 The compaction density is achieved, which completes the entire preparation process of the positive electrode.

[0054] Preparation of electrolyte:

[0055] In a dry argon atmosphere, organic solvents ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) are first mixed in a mass ratio of EC:EMC:DEC=30:50:20, and then lithium salt lithium hexafluorophosphate (LiPF6) is added to the organic solvent to dissolve and mix evenly to obtain an electrolyte with a lithium salt concentration of 1.15M.

[0056] Preparation of lithium-ion batteries:

[0057] A polyethylene (PE) with a thickness of 15 microns was selected as the separator. The positive electrode sheet, separator, and negative electrode sheet were stacked in order so that the separator was in the middle. The stacked electrode sheet and separator were then rolled into an electrode assembly, and the detection assembly was placed in the electrode assembly. After being packaged with aluminum-plastic film, the top and side seals were completed, and then the electrolyte was added. The lithium-ion battery after the injection was formed (charged to 3.3V at a constant current of 0.02C, and then charged to 3.6V at a constant current of 0.1C), and then the performance of the lithium-ion battery was preliminarily tested, and finally a soft-pack lithium-ion battery was obtained.

[0058] Test method:

[0059] (1) Calibration of detection components: Place detection components of different models in standard gas samples containing different hydrogen concentrations, record the change of the internal resistance of the detection components with the change of hydrogen concentration and the conversion relationship between the two, record the detection accuracy and detection range of different detection components, and maintain the temperature at 20°C throughout the calibration process.

[0060] (2) Hydrogen detection of lithium-ion batteries: Overcharging will cause lithium precipitation, and the precipitated lithium metal will react with the electrolyte and residual water inside to generate hydrogen. Charge the lithium-ion battery at 0.02C constant current to 5V, then stop charging and start timing. Record the time it takes for the detection component to respond after charging is cut off (the time from charging cut off to the time when the resistance of the detection component begins to change). The temperature is maintained at 20°C throughout the process.

[0061] Example 1

[0062] A palladium metal wire with a diameter of 10 microns and a length of 100 millimeters is folded in a serpentine shape on a polymer material layer with a porosity of 40%, thereby manufacturing a detection component in which the ratio of the area of ​​the minimum circumscribed rectangle of the palladium metal wire to the area of ​​the wide surface is 20%; after calibration of the detection component, it is found that the detection accuracy of the detection component is 0.1ppm, and the detection range is 0.1ppm to 100ppm; hydrogen detection of lithium-ion batteries is performed, and the response time of the detection component is 3min.

[0063] Example 2 to Example 16

[0064] The differences from Example 1 and the test results are shown in Table 1.

[0065] Table 1

[0066]

[0067] From the data results in the above table, we can see that:

[0068] (1) Under the premise that the length of the palladium wire remains unchanged, the increase in the diameter of the palladium wire will reduce the detection accuracy of the detection component and prolong the response time, but the detection range of the detection component can be widened accordingly.

[0069] (2) Under the premise that the diameter of the palladium metal wire remains unchanged, increasing the length of the palladium metal wire can increase the overall area of ​​the detection component, thereby increasing the ratio of the area of ​​the minimum circumscribed rectangle of the palladium metal wire to the area of ​​the wide surface of the electrode component, which can reduce the response time.

[0070] (3) Under the premise that the diameter of the palladium wire remains unchanged, the length of the palladium wire is too short, the ratio of the area of ​​the minimum circumscribed rectangle of the palladium wire to the area of ​​the wide surface of the electrode assembly is small, and the response time is long, which is not conducive to the detection of hydrogen.

[0071] (4) Under the premise that other factors of the palladium metal wire are the same, the greater the porosity K of the polymer material layer, the shorter the response time of the detection component to hydrogen.

[0072] (5) Under the premise that the diameter of the palladium wire and the area ratio of the electrochemical device covered are the same, the longer the length of the palladium wire, the larger the effective area ratio of the palladium wire, and the shorter the response time of the detection component to hydrogen.

[0073] Embodiment 17

[0074] A palladium metal wire with a thickness of 5 microns, a width of 30 microns and a length of 100 mm is prepared on a polymer material layer with a porosity of 40% by a vacuum deposition method, and a detection component is obtained in which the ratio of the area of ​​the minimum circumscribed rectangle of the palladium metal wire to the area of ​​the wide surface is 20%; after calibration of the detection component, the detection accuracy of the detection component is obtained to be 0.2ppm, and the detection range is 0.2ppm to 200ppm; hydrogen detection of lithium-ion batteries is carried out, and the response time of the detection component is obtained to be 5min.

[0075] Example 18 to Example 32

[0076] The differences from Example 17 and the test results are detailed in Table 2.

[0077] Table 2

[0078]

[0079]

[0080] From the data results in the above table, we can see that:

[0081] (1) Under the premise that the length of the palladium metal wire remains unchanged, the cross-sectional area of ​​the palladium metal wire is controlled within the scope of the present application, so that the detection accuracy, response time and detection range of the detection component can be within a reasonable required range.

[0082] (2) Under the premise that the cross-sectional area of ​​the palladium metal wire remains unchanged, increasing the length of the palladium metal wire can increase the overall area of ​​the detection assembly, thereby increasing the ratio of the area of ​​the minimum circumscribed rectangle of the palladium metal wire to the area of ​​the wide surface of the electrode assembly, which can reduce the response time.

[0083] (3) Under the premise that the cross-sectional area of ​​the palladium wire remains unchanged, the length of the palladium wire is too short, the ratio of the area of ​​the minimum circumscribed rectangle of the palladium wire to the area of ​​the wide surface of the electrode assembly is small, and the response time is long, which is not conducive to the detection of hydrogen.

[0084] (4) Under the premise that other factors of the palladium metal wire are the same, the greater the porosity K of the polymer material layer, the shorter the response time of the detection component to hydrogen.

[0085] (5) Under the premise that the cross-sectional area of ​​the palladium metal wire and the area covered by the electrochemical device are in the same ratio, the longer the length of the palladium metal wire, the larger the effective area ratio of the palladium metal wire, and the shorter the response time of the detection component to hydrogen.

[0086] The beneficial effects of the embodiment of the present application are as follows: the electrochemical device 100 includes a packaging bag 10, an electrode assembly 20 and a detection assembly 30, the packaging bag 10 is provided with a receiving space, the electrode assembly 20 and the detection assembly 30 are received in the receiving space, the detection assembly 30 includes a first joint 31, a second joint 32 and a hydrogen storage metal assembly 33, the hydrogen storage metal assembly 33 is arranged in the receiving space, one end of the hydrogen storage metal assembly 33 is connected to one end of the first joint 31, the other end of the first joint 31 extends from the packaging bag 10, the other end of the hydrogen storage metal assembly 33 is connected to one end of the second joint 32, the other end of the second joint 32 extends from the packaging bag 10, wherein when the hydrogen storage metal assembly 33 encounters hydrogen, the internal resistance of the hydrogen storage metal assembly 33 changes. Through the above structure, the electrochemical device 100 can detect the content of hydrogen in the receiving space, and can process the hydrogen in time, thereby improving the safety of the electrochemical device 100.

[0087] The present application also provides an embodiment of an electronic device, which includes the electrochemical device 100 as described above. The function and structure of the electrochemical device 100 can be found in the above embodiments, and will not be described in detail here.

[0088] The above descriptions are merely embodiments of the present application and are not intended to limit the scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the protection scope of the present application.

Claims

1. An electrochemical device, comprising an electrode assembly and a packaging bag, wherein the packaging bag is provided with a receiving space, and the electrode assembly is received in the receiving space, characterized in that: The electrochemical device further comprises a detection component, the detection component comprises a hydrogen storage metal component, the hydrogen storage metal component is located in the receiving space, the electrode component is provided with a wide surface, and the hydrogen storage metal component is arranged between the wide surface of the electrode component and the packaging bag; The hydrogen storage metal component comprises a hydrogen storage metal wire and a polymer material layer, wherein the hydrogen storage metal wire is arranged on the polymer material layer, and the porosity K of the polymer material layer satisfies: 10%≤K≤50%; When the hydrogen storage metal wire encounters hydrogen, the internal resistance of the hydrogen storage metal wire changes.

2. The electrochemical device according to claim 1, characterized in that The detection assembly also includes a first connector and a second connector; One end of the hydrogen storage metal component is connected to one end of the first joint, and the other end of the first joint extends out of the packaging bag. The other end of the hydrogen storage metal component is connected to one end of the second joint, and the other end of the second joint extends out of the packaging bag.

3. The electrochemical device according to claim 1, characterized in that The polymer material layer comprises a first polymer material layer and a second polymer material layer; The first polymer material layer is disposed between the hydrogen storage metal wire and the electrode assembly, and the second polymer material layer is disposed between the hydrogen storage metal wire and the packaging bag.

4. The electrochemical device according to claim 1, characterized in that The hydrogen storage metal wire satisfies at least one of the following conditions: (1) The ratio A of the area of ​​the minimum circumscribed rectangle of the hydrogen storage metal wire to the area of ​​the wide surface satisfies: 20%≤A≤40%; (2) The cross-sectional area D of the hydrogen storage metal wire satisfies: 20 square microns ≤ D ≤ 8000 square microns; (3) The length L of the hydrogen storage metal wire satisfies: 5 mm ≤ L ≤ 1000 mm; (4) The hydrogen storage metal wire is prepared from palladium metal; (5) The hydrogen storage metal wire is arranged in a patterned bending manner.

5. The electrochemical device according to claim 3, characterized in that The outer side of the electrode assembly is a separator, and at least one of the first polymer material layer and the second polymer material layer includes the separator.

6. The electrochemical device according to claim 2, characterized in that The detection assembly further includes a first seal and a second seal. The first seal seals a connection between the first joint and the packaging bag, and the second seal seals a connection between the second joint and the packaging bag.

7. The electrochemical device according to claim 2, characterized in that The first joint and the second joint include at least one of aluminum or nickel.

8. An electronic device, characterized in that: Comprising the electrochemical device according to any one of claims 1 to 7.

Images