Gas sensing material and preparation method thereof, sensor, battery and electric equipment

Abstract

The invention discloses a gas sensing material and a preparation method thereof, a sensor, a battery and electric equipment. Wherein the gas sensing material comprises a palladium metal nanosheet with a two-dimensional nanostructure, the gas sensing effect is realized by virtue of the change of the surface resistance of the gas sensing material when palladium metal interacts with target gas, and no oxygen participates in the reaction process. By means of the mode, the target gas can be detected under the oxygen-free or low-oxygen condition, and gas produced in the battery can be detected. Furthermore, the sensitivity and the accuracy of gas response can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of new energy technologies, and particularly to gas sensing materials and their preparation methods, sensors, batteries, and electrical equipment. Background Art

[0002] With the continuous exacerbation of global energy and environmental problems, new energy, as one of the fields of sustainable development, is developing rapidly. Batteries are being applied more and more widely as a new energy source. Among them, the problem of gas generation in batteries has always attracted much attention. The gas generated by the battery is likely to cause safety problems such as explosion and fire. By detecting the gas situation in the battery, early warning can be given in a timely manner. Most of the sensing principles of existing gas sensors rely on oxygen, so there are limitations in the application environment. The above statements are only used to provide background technical information related to this application, and do not necessarily constitute prior art. Summary of the Invention

[0003] The main technical problem to be solved by this application is to provide a gas sensing material and its preparation method, sensor, battery, and electrical equipment, which have the advantage of being able to perform gas sensing response under anaerobic or low-oxygen conditions.

[0004] To solve the above technical problem, a technical solution adopted by this application is: to provide a gas sensing material, the gas sensing material includes palladium metal nanosheets, and the thickness of the palladium metal nanosheets is 0.1 nm - 100 nm. The palladium metal nanosheets rely on the change of the surface resistance of the material when palladium metal interacts with the target gas to achieve the detection purpose. This process is a spontaneous process, and there is no oxygen participating in the reaction process. Therefore, gas response can be carried out under anaerobic or low-oxygen conditions.

[0005] Furthermore, the atomic utilization rate of the palladium metal nanosheets is very high, which can provide more adsorption sites, effectively adsorb gas molecules, and at the same time can accelerate the diffusion rate of the gas on the sensing material, making the resistance change significantly with the change of gas adsorption. Therefore, the sensitivity and accuracy of gas response can be effectively improved.

[0006] In one embodiment, the thickness of the palladium metal nanosheets is 0.5 - 5 nm. Through this setting, the specific surface area of the gas sensing material is extremely high, providing a broader site for the adsorption of gas molecules, thereby improving the sensitivity and speed of gas response.

[0007] In one embodiment, a non-metallic element is doped into the palladium metal nanosheet. Through this arrangement, a non-metallic element or compound can be introduced into the palladium metal nanosheet, which is beneficial to reducing the lattice distortion of the palladium metal nanosheet material, thereby reducing the adsorption strength of gas on the surface of the sensing material, improving the recovery performance of the sensing material, and also capable of affecting the electronic structure and chemical properties of the material, optimizing the response speed and recovery performance of the sensing material to gas, and improving the sensitivity and reliability of the sensor.

[0008] In one embodiment, the non-metallic element includes one or more of carbon, sulfur, phosphorus, nitrogen, boron, and fluorine. By selecting different non-metallic elements to dope the palladium metal nanosheet, it is beneficial to adjust the electronic structure of the palladium metal nanosheet, beneficial to increasing the active sites, and endowing the palladium metal nanosheet with different sensing activities and gas selectivities.

[0009] In one embodiment, the atomic ratio of the non-metallic element to the palladium metal element is (0.02 - 0.30):1. Through this arrangement, it is beneficial to control the electronic structure adjustment ability of the palladium metal nanosheet within a suitable range, beneficial to maintaining the stability of chemical activity, beneficial to the normal progress of the adsorption and desorption processes of molecules such as hydrogen, and thus beneficial to improving the performance of the sensor.

[0010] In one embodiment, the lattice constant of the palladium metal nanosheet is greater than or equal to 3.9 angstroms. Through this arrangement, the gas sensing response speed of the palladium metal nanosheet can be increased, thereby being beneficial to improving the performance of the sensor.

[0011] In one embodiment, the response gas of the gas sensing material includes any one of hydrogen and ammonia. Through this arrangement, the adaptability of the gas sensing material is expanded.

[0012] To solve the above technical problems, another technical solution adopted by this application is: to provide a preparation method of a gas sensing material, including: mixing a palladium precursor, a carbon monoxide source and a solvent to obtain a mixed solution; heating and reacting the mixed solution to obtain palladium metal nanosheets, and the thickness of the palladium metal nanosheets is 0.1 nm - 100 nm. Through the above arrangement, the prepared palladium metal nanosheets rely on the change of the surface resistance of the material when the palladium metal interacts with the target gas to achieve the detection purpose. This process is a spontaneous process and there is no oxygen participating in the reaction process. Therefore, gas response can be carried out under anaerobic or low-oxygen conditions.

[0013] In addition, the atomic utilization rate of the palladium metal nanosheets is very high, which can provide more adsorption sites, effectively adsorb gas molecules, and at the same time can accelerate the diffusion rate of gas on the sensing material, making the resistance change significantly with the change of gas adsorption. Therefore, the sensitivity of gas response and the response recovery speed can be effectively improved.

[0014] In one embodiment, the carbon monoxide source includes metal carbonyl compounds; optionally, the metal carbonyl compounds include one or more of tungsten carbonyl, molybdenum carbonyl, and nickel carbonyl. The decomposition reaction of the metal carbonyl compounds can produce carbon monoxide.

[0015] In one embodiment, in the step of mixing the palladium precursor, the carbon monoxide source, and the solvent, it further includes: one or more of acetic acid and ascorbic acid are further added to the mixture. The synergistic effect of acetic acid, ascorbic acid, and carbon monoxide can regulate the reaction rate and help control the size and morphology of the palladium metal nanosheets.

[0016] In one embodiment, the palladium metal nanosheets are mixed and reacted with a non-metal source to obtain non-metal doped palladium metal nanosheets. Through this setting, non-metal elements or compounds can be introduced into the palladium metal nanosheets, which is beneficial to controlling the lattice constant of the material, thereby reducing the adsorption strength of gas on the surface of the sensing material, improving the recovery performance of the sensing material, and can also affect the electronic structure and chemical properties of the material, optimize the response speed and recovery performance of the sensing material to gas, and improve the sensitivity and reliability of the sensor.

[0017] In one embodiment, the non-metal source includes one or more of anhydrous glucose and sulfur powder. Through the above setting, doping of carbon and sulfur elements into the palladium metal nanosheets can be achieved.

[0018] To solve the above technical problems, another technical solution adopted by this application is: to provide a gas sensor, the sensor includes the gas sensing material of any one of the above; or includes the gas sensing material prepared by the method of any one of the above. Through the above setting, a high-sensitivity response and rapid recovery to the target gas can be achieved.

[0019] To solve the above technical problems, another technical solution adopted by this application is: to provide a battery, the battery includes the gas sensor of any one of the above. Through the above setting, a high-sensitivity response and rapid recovery to the target gas can be achieved.

[0020] To solve the above technical problems, another technical solution adopted by this application is: to provide an electrical device, including the above battery. The electrical device has at least the same advantages as the battery.

[0021] The above description is only an overview of the technical solution of this application. In order to be able to understand the technical means of this application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0023] Figure 1 Scanning electron microscope (SEM) image of a gas sensing material according to one or more embodiments;

[0024] Figure 2 X-ray diffraction (XRD) image of a gas sensing material according to one or more embodiments;

[0025] Figure 3 Scanning electron microscope (SEM) image of a gas sensing material according to one or more embodiments;

[0026] Figure 4 Schematic diagram of the gas sensing performance test of a gas sensing material according to one or more embodiments;

[0027] Figure 5 Schematic diagram of the gas response of a gas sensing material according to one or more embodiments;

[0028] Figure 6 Schematic diagram of the gas response of a gas sensing material according to one or more embodiments;

[0029] Figure 7 Schematic diagram of the gas response of a gas sensing material according to one or more embodiments;

[0030] Figure 8 Schematic diagram of the gas response of a gas sensing material according to one or more embodiments;

[0031] Figure 9 Schematic diagram of the gas response of a gas sensing material according to one or more embodiments;

[0032] Figure 10 Schematic diagram of the gas response of a gas sensing material according to one or more embodiments;

[0033] Figure 11 Schematic diagram of the disassembly structure of a battery according to one or more embodiments;

[0034] Figure 12 Schematic diagram of the disassembly structure of a battery cell according to one or more embodiments;

[0035] Figure 13 Schematic diagram of the structure of a vehicle according to one or more embodiments.

[0036] In the accompanying drawings:

[0037] 1000, vehicle; 300, motor; 200, controller; 100, battery; 10, box body; 11, first part; 12, second part; 20, battery cell; 21, end cap; 21a, electrode terminal; 22, housing; 23, electrode assembly. Detailed implementation manners

[0038] To make the objectives, technical solutions and effects of the present application clearer and more definite, the following will describe in detail the embodiments of the technical solutions of the present application with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, and thus are only examples and cannot be used to limit the protection scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" means two or more (including two). Similarly, "multiple groups" means two or more groups (including two groups), and "multiple pieces" means two or more pieces (including two pieces), unless otherwise specifically defined.

[0041] Referring to "embodiments" herein means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0043] In this document, quantities, ratios, and other numerical values are presented in range format. It should be understood that such range format is for convenience and brevity, and should be interpreted flexibly to include not only the numerical values explicitly specified as range limits, but also all individual numerical values or sub-ranges subsumed within the stated range, as if each numerical value and sub-range were explicitly specified.

[0044] If there is no special instruction, all steps of this application can be carried out sequentially, randomly, or in parallel, and preferably sequentially. For example, the method includes steps (a) and (b), which means the method can include steps (a) and (b) carried out sequentially, or steps (b) and (a) carried out sequentially, or steps (a) and (b) carried out in parallel simultaneously. For example, it is mentioned that the method may further include step (c), which means step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or steps (a), (c), and (b), or steps (c), (a), and (b), etc.

[0045] Under the new round of technological revolution, the new energy industry shows a rapid development trend. As an important part of the new energy industry, the power battery industry has also developed rapidly. Currently, power batteries are widely used in electric vehicles, energy storage systems, and renewable energy fields. With the growing demand for clean energy and sustainable development, the application of batteries in the new energy field will continue to expand and promote the further development of energy transformation. With the new development of power batteries in China, power batteries will surely achieve improvements in many aspects. From a technical perspective, during the improvement process, "high safety", "high efficiency", "long life", and "low cost" will be the core solutions and pursuit goals for the development of power battery technology.

[0046] During the charge and discharge process of the battery, some side reactions will generate gas. If the gas generated by the battery is not discharged in time, it will cause the internal pressure of the battery to rise and exceed the normal level. Excessive internal pressure will have a negative impact on the performance and appearance of the battery. For example, in severe cases, it will have a destructive impact on the performance and appearance of the battery, such as leakage, bottom swelling, increased internal resistance of the battery, shortened discharge time, and reduced cycle life. In addition, there are some abnormal operations during the use of the battery, including overcharging, over-discharging, internal faults, etc. In this case, the chemical reactions inside the battery may get out of control and be accompanied by a violent release of gas, even triggering thermal runaway of the battery. Thermal runaway of the battery refers to a chain reaction phenomenon triggered by various incentives. The large amount of heat and harmful gases emitted during thermal runaway can cause the battery to catch fire and explode.

[0047] To monitor the gas production of the battery in a timely manner, a gas sensor can be installed inside the battery. Along with the charge-discharge cycles during the battery's use, characteristic gases are generated inside the battery. For example, hydrogen gas combines with the gas sensor inside the battery, causing a change in the surface resistance of the gas sensor. When the concentration of hydrogen exceeds the normal level, the surface resistance of the gas sensor reaches a set value, and a reminder is sent or corresponding measures are taken. Different types of characteristic gases are generated in different batteries, and the composition of the gas sensing material can be adjusted to make it selective to different types of characteristic gases, thus achieving adaptive applications for different batteries.

[0048] Specifically, characteristic gases are generated when the battery is working or in thermal runaway. For example, in a lithium-ion battery, when the internal temperature of the battery is too high or there is too much moisture in the electrolyte, the moisture in the electrolyte will be decomposed into hydrogen and oxygen. This process will cause the internal pressure of the battery to increase, and may even cause the battery to explode. By detecting the characteristic gases exceeding the concentration threshold and issuing an alarm in a timely manner, measures can be taken at the initial stage when the internal pressure of the battery exceeds the normal level, reducing the occurrence of safety accidents. However, existing gas sensors have defects in detecting battery gas production. In application environments such as battery packs, they are usually in a low-oxygen or oxygen-free state, making electrochemical sensors and resistive sensors that rely on oxygen unable to work properly.

[0049] Based on the above considerations, in order to solve the problem that gas production detection in the battery relies on oxygen, after in-depth research, a gas sensing material is designed. This gas sensing material is a chemiresistive sensing material, which realizes the detection purpose by relying on the change of the surface resistance of the sensor when palladium metal interacts with the target gas. Without oxygen participating in the reaction process, the above gas sensing material can respond to any one of hydrogen and ammonia in an oxygen-free environment.

[0050] Please refer to Figures 1 to 2 , according to some embodiments of the present application, the present application discloses a gas sensing material, which includes palladium metal nanosheets, and the thickness of the palladium metal nanosheets is 0.1 nm - 100 nm.

[0051] Palladium (Pd), is a platinum group element in Group VIII of the fifth period, belonging to transition metals. There are a large number of defects on the surface of palladium, providing a large number of active sites for gas adsorption. Moreover, the 4d electron layer of palladium lacks two electrons, so chemical bonds can be formed with gas molecules.

[0052] In one embodiment, the palladium metal can be a material with a nanostructure. A nanostructure is the structure of an object with dimensions between those of molecules and the micron scale; the linear dimensions of these substances are generally in the range of 0.1 - 100 nm. Nanostructures include one-dimensional, two-dimensional, and three-dimensional systems, and these material units include nanoparticles, nanotubes, nanorods, nanowires, nanoribbons, and nanoscale pores, etc. Specifically, in this application, the palladium metal is a two-dimensional nanosheet material, which is on the nanoscale in the thickness direction, that is, 0.1 nm - 100 nm, and can reach dozens of nanometers or even hundreds of nanometers in the length and width directions.

[0053] Two-dimensional nanomaterials have a special structure and are in a thermodynamically extremely unstable state, so they have high chemical activity and strong adsorption; specifically for palladium metal nanosheets, there are also a large number of active sites on the surface. Therefore, the atomic utilization rate of palladium metal nanosheets is very high, which can provide more adsorption sites, effectively adsorb gas molecules, and at the same time can accelerate the diffusion rate of gas on the sensing material, making the resistance change significantly with the change of gas adsorption. Therefore, the sensitivity and speed of gas response can be effectively improved.

[0054] Optionally, the thickness of the palladium metal nanosheet is 0.5 - 5 nm. At this time, the thickness of the palladium metal nanosheet is only a few atomic layers, so the specific surface area is extremely high, and the corresponding number of active sites on the surface is more, which can provide a broader site for the adsorption of gas molecules; at the same time, it can accelerate the diffusion rate of gas on the sensing material, making the resistance change significantly with the change of gas adsorption, thereby improving the sensitivity of gas response and shortening the response time and recovery time.

[0055] Please refer to Figure 3 , in some embodiments of this application, carbon elements are also doped in the palladium metal nanosheets.

[0056] Doping non-metallic elements into palladium metal nanosheets means introducing non-metallic elements into palladium metal nanosheets to change their physical and chemical properties and improve the performance of sensing materials. The specific principle and effects are mainly as follows: First, the recovery performance of gas sensing materials is improved by reducing the lattice distortion of palladium metal nanosheets. In palladium metal nanosheet gas sensing materials, lattice distortion refers to the lattice dislocation or deformation caused by the irregularity or distortion of the internal structure of the material. This lattice distortion will cause changes in the resistance on the surface of the sensing material, thus affecting the sensitivity and recovery performance of the sensor. Doping non-metallic elements can reduce the lattice distortion of the material by introducing non-metallic elements or compounds into palladium metal nanosheets, thereby reducing the adsorption strength of gas on the surface of the sensing material and improving the recovery performance of the sensing material. For example, the lattice constant of undoped Pd nanosheets is 3.91 Å; after C doping, the lattice constant can reach 3.999 Å, after N doping, the lattice constant can reach 4.000 Å; after P doping, the lattice constant can reach 3.985 Å, after B doping, the lattice constant can reach 3.979 Å, after F doping, the lattice constant can reach 3.945 Å, and after doping, the lattice constant becomes larger and can reach above 3.9 Å; after S doping, the crystal form is destroyed and becomes amorphous.

[0057] Second, the recovery performance of palladium metal nanosheet sensing materials is improved by adjusting the electronic structure of palladium metal nanosheets. The electronic structure of palladium metal nanosheets has an important influence on the response and recovery performance of sensing materials. Doping non-metallic elements can introduce new energy bands into palladium metal nanosheets, thereby changing the electronic structure and energy state of the material. These new energy bands can provide more gas adsorption sites and improve the hydrogen adsorption and desorption processes on the surface of the sensing material, thus improving the recovery performance of the sensing material. At the same time, doping non-metallic elements can change the position of the Fermi level of palladium metal nanosheets, thereby affecting the electronic structure and chemical properties of the material. By adjusting the position of the Fermi level, the response speed and recovery performance of the sensing material to gas can be optimized, and the sensitivity and reliability of the sensor can be improved.

[0058] Optionally, the non-metallic element includes one or more of carbon, sulfur, phosphorus, nitrogen, boron, and fluorine.

[0059] Taking nitrogen element as an example, nitrogen doping can introduce extra electrons and change its electronic structure by forming bonds with metal atoms in palladium metal nanosheets. This may lead to an increase in the electron density in the nitrogen-doped region, an adjustment of the Fermi level position, and a change in the electron transport performance, thus affecting its electron conduction and sensing performance; nitrogen doping can introduce additional nitrogen atom functional groups on the surface of palladium metal nanosheets, increasing the surface active sites of palladium metal nanosheets, thereby changing the activity and selectivity of palladium metal nanosheets, and can also lead to the formation of surface defects and boundary sites, and these sites may exhibit higher sensing activity.

[0060] In some embodiments of the present application, only one non-metallic element can be doped in the palladium metal nanosheets; or multiple non-metallic elements can be doped simultaneously to form different active centers. Different types of non-metallic elements can endow the palladium metal nanosheets with different electronic structures, and further endow the palladium metal nanosheets with different sensing activities and gas selectivities.

[0061] In some embodiments of the present application, the atomic ratio of the non-metallic element to the palladium metal element is (0.02 - 0.30):1. Specifically, after doping with the non-metallic element, the chemical formula of the obtained compound is PdX a , where X is one or more of C, N, P, S, B, F, and a takes a value of 0.02 - 0.30, that is, the atomic ratio of the non-metallic element to the palladium metal element is a:1 = (0.02 - 0.30):1. During testing, the element ratio can be measured by XPS peak fitting.

[0062] The doping amount of the non-metallic element is controlled by adjusting the mass ratio of the non-metallic element to the palladium metal nanosheets during the preparation process.

[0063] Therefore, adjusting the doping amount of the non-metal is beneficial to controlling the electronic structure adjustment ability of the palladium metal nanosheets within a suitable range, beneficial to maintaining the stability of chemical activity, beneficial to the normal progress of the adsorption and desorption processes of molecules such as hydrogen, and thus beneficial to improving the performance of the sensor.

[0064] In some embodiments of the present application, the lattice constant of the palladium metal nanosheets is greater than or equal to 3.9 Å. By this setting, the gas sensing response speed of the palladium metal nanosheets can be increased, which is beneficial to improving the performance of the sensor.

[0065] In some embodiments of the present application, the response gases of the gas sensing material include any one of hydrogen and ammonia.

[0066] The palladium metal nanosheet gas sensing material shows good selectivity in the gas sensing performance test. For specific details, please refer to the description of the following examples. Please refer to Figure 4 , Figure 4 which is a schematic diagram of the response of the palladium metal nanosheet gas sensing material to different gases at the same concentration. As can be seen from the figure, the gas sensing material has a large response value to hydrogen and also shows a response behavior to ammonia. However, the response values to carbon dioxide, carbon monoxide, and methane are zero, indicating that the gas sensing material has selectivity in the response to hydrogen and ammonia.

[0067] The reason for the above selectivity is as follows: First, hydrogen and ammonia are small molecule gases, which usually have high affinity and can be adsorbed on the surface of palladium metal nanosheet materials through intermolecular forces. In addition, ammonia molecules are polar and are more likely to interact with the charge distribution on the metal surface, so they can be adsorbed by the gas sensing material.

[0068] In chemisorption, when Pd is exposed to an H2 atmosphere, H2 molecules are physically adsorbed on the Pd surface through van der Waals forces. Subsequently, H2 molecules dissociate into H atoms on the Pd surface and form Pd-H chemical bonds with Pd atoms, and then diffuse into the lattice interstitial sites of Pd to form a solid solution, resulting in the expansion of the Pd lattice and a phase change to generate a β-phase that can absorb more H2 molecules, forming palladium hydride and causing a change in the electrical signal. And the above process occurs spontaneously and does not depend on oxygen. Therefore, palladium metal exhibits excellent adsorption activity for hydrogen under anaerobic conditions and can form Pd-H bonds.

[0069] However, carbon monoxide, carbon dioxide, and methane molecules are relatively large in volume and low in polarity, making it difficult to adsorb on the surface of palladium metal nanomaterials, and higher activation energy is required to undergo a chemical reaction on the palladium metal surface.

[0070] Therefore, the responsive gases of the palladium metal nanosheet sensing material include any one of hydrogen and ammonia, which is beneficial to improving the selectivity of the gas sensing material.

[0071] In some embodiments of the present application, a method for preparing a gas sensing material is further provided, including: mixing a palladium precursor, a carbon monoxide source, and a solvent to obtain a mixed solution; heating and reacting the mixed solution to obtain palladium metal nanosheets, and the thickness of the palladium metal nanosheets is at the nanoscale, and the nanoscale is 0.1 nm - 100 nm.

[0072] Among them, the palladium precursor is a form of palladium metal before obtaining the target product palladium metal nanosheets, usually a divalent palladium compound, including palladium salts such as palladium chloride (PdCl2) or palladium nitrate (Pd(NO3)2); organopalladium compounds such as palladium acetylacetonate (C 10 H 14 O4Pd), palladium acetate (Pd(OAc)2), or palladium aryl compounds; and colloidal palladium, etc.

[0073] In some embodiments of the present application, in the step of mixing the palladium precursor, the carbon monoxide source, and the solvent, it further includes: adding one or more of acetic acid and ascorbic acid to the mixed solution.

[0074] When preparing palladium metal nanosheets, the ultimate goal is to convert divalent palladium ions (Pd 2+)It is reduced to the palladium metal (Pd) form, so a reducing agent is required in the preparation process. Commonly used reducing agents include carbon monoxide (CO), hydrogen (H2), sodium hypophosphite (Na2HPO2), and formaldehyde (HCHO), etc. Selecting different reducing agents and synthesis conditions can control the size and shape of the nanosheets.

[0075] In some embodiments of the present application, the palladium precursor of a palladium metal nanosheet can be palladium acetylacetonate, and the reducing agent can be the synergistic action of acetic acid and carbon monoxide. The preparation method of the palladium metal nanosheet can include: adding palladium acetylacetonate, tungsten hexacarbonyl, and acetic acid into a solvent to obtain a mixed solution; heating the mixed solution to 80 °C. Among them, tungsten hexacarbonyl serves as a carbon monoxide source. During the reaction, acetic acid and carbon monoxide act as reducing agents. Carbon monoxide provides electrons to palladium ions, and acetic acid and its conjugate base acetate ion provide electrons and protons to palladium ions, finally reducing palladium ions to metallic palladium, and at the same time generating carbon dioxide and acetate. The specific reaction mechanism is as follows:

[0076] Pd 2+ +CO→Pd+CO2

[0077] Pd 2+ +CH3COOH→Pd+CH3COO - +H +

[0078] Pd 2+ +CH3COO - →Pd+CH3COO 2-

[0079] The synergistic action of acetic acid and carbon monoxide can regulate the reaction rate and help control the size and morphology of the palladium metal nanosheets.

[0080] During the preparation process, the carbon monoxide source includes metal carbonyl compounds; optionally, the metal carbonyl compounds include one or more of tungsten carbonyl, molybdenum carbonyl, and nickel carbonyl. The metal carbonyl compounds can undergo decomposition reactions to produce carbon monoxide.

[0081] After adding the palladium precursor and the reducing agent to the solvent, first ultrasonically mix the mixed solution in an ice bath for 30 min to make it uniform, and then react it in an 80 °C oil bath for 4 h. The ice bath can control the starting conditions of the reaction and slow down side reactions. When the mixed solution is mixed evenly, a certain amount of heat needs to be provided to increase the reaction rate. At this time, a stable and controllable higher temperature is provided by the oil bath, which can promote the reaction and accelerate the reaction rate.

[0082] Subsequently, the reaction solution was centrifuged at 10,000 rpm for 30 min to obtain a black product. The above black product was then washed three times with absolute ethanol, and the centrifugation conditions were the same, with a separation speed of 10,000 rpm and a centrifugation time of 30 min. The washed black product was placed in a vacuum oven at 60 °C and dried for 12 h to obtain palladium metal nanosheets.

[0083] In some embodiments of the present application, palladium metal nanosheets were mixed and reacted with a non-metal source to obtain non-metal doped palladium metal nanosheets.

[0084] The non-metal source refers to a compound or element that is used to introduce doped non-metal elements. It can be a single compound or element, or a product obtained by specific treatment or modification of a metal-organic complex precursor. The choice of non-metal source depends on the desired doping element and the specific application requirements of the material.

[0085] In some embodiments of the present application, the non-metal source includes one or more of anhydrous glucose and sulfur powder. It can achieve the doping of carbon and sulfur elements into palladium metal nanosheets.

[0086] Taking the doping element as carbon as an example, the non-metal source can be anhydrous glucose at this time.

[0087] In some embodiments of the present application, a carbon-doped palladium metal nanosheet was prepared, and the preparation method included: mixing and reacting palladium metal nanosheets with glucose to obtain carbon-doped palladium metal nanosheets.

[0088] By mixing and reacting palladium metal nanosheets with a non-metal source to obtain non-metal doped palladium metal nanosheets, the lattice distortion of the material can be reduced, thereby reducing the adsorption strength of gas on the surface of the sensing material and improving the recovery performance of the sensing material; the position of the Fermi level of palladium metal nanosheets can be changed, thereby affecting the electronic structure and chemical properties of the material, optimizing the response speed and recovery performance of the sensing material to gas, and improving the sensitivity and reliability of the sensor.

[0089] In some embodiments of the present application, a gas sensor based on palladium metal nanosheet material is further provided. The gas sensor includes the gas sensing material of any one of the above; or includes the gas sensing material prepared by using the method of any one of the above.

[0090] Specifically, using palladium metal nanosheets as the gas sensing material, the material realizes the response to the sensed gas based on the change in the surface resistance of the sensor when palladium metal interacts with the target gas, and can achieve gas response under anaerobic conditions. A gas sensor that can quickly respond to gas and has high detection sensitivity under anaerobic conditions was prepared.

[0091] To make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will further elaborate in detail in combination with the embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way constitutes any limitation to the present application and its application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.

[0092] I. Preparation of Gas Sensing Materials

[0093] Example 1:

[0094] 1. Dissolve 10 mg of palladium acetylacetonate, 20 mg of tungsten hexacarbonyl, and 2 mL of acetic acid in 10 mL of N,N-dimethylformamide solution, and mix evenly by ultrasonic bath in an ice bath for 30 min;

[0095] 2. Place the above solution in an oil bath at 80 °C for 4 h, and then centrifuge the reaction solution at 10,000 rpm for 30 min to obtain a black product;

[0096] 3. Wash the above black product with anhydrous ethanol three times, centrifuge at 10,000 rpm for 30 min to obtain a black product, wash it with anhydrous ethanol three times, and then place the product in a vacuum oven at 60 °C for 12 h to obtain palladium metal nanosheets Pb-0.

[0097] Example 2:

[0098] 1. Prepare palladium metal nanosheets, and the steps are the same as those in Example 1.

[0099] 2. Disperse the above palladium metal nanosheets in an oleylamine solution containing anhydrous glucose. After vigorously stirring for 30 min, place the reaction mixture in a magnetic stirring oil bath at 200 °C and heat for 1 h;

[0100] 3. Centrifuge the mixture obtained from the above reaction at 12,000 rpm for 30 min to collect the obtained product, wash it with anhydrous ethanol three times, and then place the obtained product in a vacuum oven at 60 °C for 12 h to obtain carbon-doped palladium metal nanosheets Pb(C)-1.

[0101] Among them, the doping amount of carbon element is 17%. Specifically, disperse 2 mg of the above palladium metal nanosheets in 5 mL of oleylamine solution containing 12 mg of anhydrous glucose. Glucose provides a carbon source to achieve carbon doping, but not all the carbon in glucose is transferred and incorporated into the Pd nanosheets. After doping, the doping amount of carbon element is 17%.

[0102] Examples 3-4:

[0103] Based on Example 2, the preparation of carbon-doped palladium metal nanosheets was changed. The difference lies in changing the doping amount of carbon element, which are 8% and 27% respectively. The difference in the feed is that the amount of glucose is changed to 6 mg and 24 mg; by controlling the amount of glucose, the doping amount of carbon can be controlled.

[0104] Example 5:

[0105] Based on Example 2, the preparation of carbon-doped palladium metal nanosheets was changed. The difference lies in changing anhydrous glucose to sublimed sulfur powder to prepare sulfur-doped palladium metal nanosheet Pb(S)-1. The specific reaction conditions are shown in Table 1.

[0106] Among them, the doping amount of S is 15%. Specifically, on the basis of Example 2, 12 mg of anhydrous glucose was changed to 0.5 mg of sublimed sulfur powder.

[0107] II. Preparation of Gas Sensor

[0108] Using a saturated calomel electrode as the reference electrode, a platinum wire as the comparison electrode, and an interdigital electrode as the working electrode, and a gas sensing material is coated on the interdigital electrode; the gas sensing materials prepared in each example are dispersed in absolute ethanol at 5 mg / mL to prepare a dispersion. Take 5 μL of the above dispersion and drop it onto the surface of the interdigital electrode, and place it in a vacuum oven at 60 °C for 12 h to dry, and then form a gas-sensitive coating.

[0109] III. Gas Sensing Performance Test

[0110] Please refer to Figure 5 , put the gas sensor into the test chamber. Under room temperature conditions, introduce the target gas in a static gas mixing mode. Use an Agilent 4156C semiconductor parameter analyzer to monitor the real-time resistance change of the sensor in an inert gas and in an environment of different concentrations of the target gas. Apply a constant working voltage of 500 mV between the sensor electrodes and perform the test according to Standard GB / T3634 - 19954.5. Before introducing the target gas, use dry compressed argon (MFC3) to purify the chamber to stabilize the baseline signal, use compressed argon (MFC2) as the carrier gas to dilute the target gas of different concentrations, and the target gas is controlled by a mass flow controller (MFC1). The resistance difference between the sensor in dry argon and in the target gas and the current ratio in dry argon (1 - Ia / Ig)*100%

[0111] is the response value of the device to the target gas at this concentration. The response time and recovery time are defined by reaching 90% saturation of the response and recovery curves. The test results are as follows:

[0112] 1. Comparison of Different Examples

[0113] Please refer to Table 1 first. Table 1 is a table of reaction parameters and performance parameters for Examples 1-5.

[0114] Table of reaction parameters and performance parameters for each example in Table 1

[0115]

[0116] In Examples 1-5, the cases of palladium metal nanosheets without doping or with different non-metal doping elements were demonstrated. From the above data, it can be seen that palladium metal nanosheets without doping or with different non-metal doping elements all have a response to hydrogen. Among them, referring to Example 1, the palladium metal nanosheet without doping non-metal elements has a relatively strong response value to hydrogen, but the recovery effect is not good. Referring to Examples 2-5, after non-metal doping of the palladium metal nanosheet, the recovery effect of the hydrogen response becomes better. Referring to Examples 2-4, the doping amount of the non-metal affects the response value to a certain extent, but can improve the recovery effect. By adjusting the doping amount of the non-metal element, a better response value and a better recovery effect can be obtained.

[0117] 2. H2 response and recovery dynamic test

[0118] As Figure 6 and 7 shown, the response of the sensor based on the palladium metal nanosheet gas sensing material prepared in Example 2 of this application to 0.1%-1% hydrogen and 1%-5% hydrogen was tested at room temperature. In the figure, the abscissa is the acquisition time and the ordinate is the device sensitivity. It can be seen from the figure that the response value of the carbon-doped palladium metal nanosheet gas sensing material prepared in Example 2 to 1% hydrogen reached 3.4%, and there was still a response when the hydrogen concentration was 0.1%, and the corresponding response value was 0.3%. As the hydrogen concentration increased, the response value of the sensor to the gas also increased. The response values to 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, and 1% hydrogen were 0.3%, 0.5%, 0.8%, 1.2%, 1.4%, 1.6%, 1.9%, 2.3%, 2.6%, and 3.4% respectively, showing the potential of gas test quantification.

[0119] In addition, the response time of the sensor to the gas is less than 200 s, and the recovery time is extremely short.

[0120] 3. H2 cycle stability test

[0121] At room temperature, the palladium metal nanosheet sensing material prepared in Example 2 of the present invention was subjected to multiple response and recovery tests for 1% hydrogen, and the data was obtained and analyzed. The background gas in the test was argon. The results are as Figure 8 shown, in Figure 8Among them, the abscissa is the acquisition time, and the ordinate is the device sensitivity. After five response-recovery cycles, the response value of the sensor remains basically unchanged, maintaining above 3.1%. At the same time, the response time remains basically unchanged, around 90 s, and the recovery time always remains extremely short during multiple cycles. The above results indicate that the sensor prepared in the foregoing embodiment has good cycle stability during the response and recovery processes to H2.

[0122] 4. Gas selectivity test

[0123] Please refer to Figure 4 , Figure 4 which is a schematic diagram of the responses of the palladium metal nanosheet gas sensing material according to one or more embodiments of the present application to different gases at the same concentration. As can be seen from the figure, the gas sensing material of the target metal nanosheet after doping with a non-metallic element has a large response value to hydrogen, and also shows a response behavior to ammonia. However, the response values to carbon dioxide, carbon monoxide, and methane are zero, indicating that the gas sensing material has selectivity in the responses to hydrogen and ammonia, and particularly shows excellent selectivity to hydrogen.

[0124] Please also refer to Figure 9 and 10 which respectively show the responses of the sensors of the gas sensing materials of the carbon-doped palladium metal nanosheets formed in Example 3 and Example 4 to 1% hydrogen. As can be seen from the figure, for the carbon-doped palladium metal nanosheets, the recovery times are all less than 200 s, and the response values are 3.6% and 1.8% respectively.

[0125] In some embodiments of the present application, the gas sensor can be used for detecting the gas inside the battery. That is, the present application provides a battery, and the battery includes the gas sensor of the foregoing embodiment.

[0126] Please refer to Figure 11 , Figure 11Exploded structural schematic diagram of a battery according to one or more embodiments. The battery 100 includes a box body 10 and battery cells 20, and the battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 are covered with each other, and the first part 11 and the second part 12 jointly define an accommodation space for accommodating the battery cells 20. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure. The first part 11 is covered on the open side of the second part 12 so that the first part 11 and the second part 12 jointly define an accommodation space; the first part 11 and the second part 12 may also both be hollow structures with one side open, and the open side of the first part 11 is covered on the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 may be of various shapes, such as a cylinder, a cuboid, etc.

[0127] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 20 is accommodated in the box body 10; of course, the battery 100 can also be that multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection to form a battery module form, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in the box body 10. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing electrical connection among the multiple battery cells 20.

[0128] Among them, each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but not limited thereto. The battery cell 20 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0129] Please refer to Figure 12 , Figure 12 Exploded structural schematic diagram of a battery cell according to one or more embodiments. A battery cell 20 refers to the smallest unit that makes up a battery. The battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0130] The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to cooperate with the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on the end cap 21. The electrode terminals 21a can be used for electrical connection with the electrode assembly 23 to output or input the electrical energy of the battery cell 20. In some embodiments, a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold can also be provided on the end cap 21. The material of the end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the end cap 21, and the insulating member can be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0131] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 is covered at the opening to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 can also be integrated. Specifically, the end cap 21 and the housing 22 can first form a common connection surface before other components are inserted into the housing, and when it is necessary to encapsulate the inside of the housing 22, the end cap 21 is then covered on the housing 22. The housing 22 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this.

[0132] The electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. The housing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive electrode sheet and the negative electrode sheet having active materials constitute the main body of the electrode assembly, and the portions of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the electrode tabs 23a. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or separately at both ends of the main body. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the electrode tabs 23a are connected to the electrode terminals to form a current loop.

[0133] In one embodiment, the positive electrode sheet includes a current collector and a positive electrode active layer provided on the current collector.

[0134] The positive electrode active layer includes a positive electrode active material, and the positive electrode active material may include at least one of the following materials: lithium phosphate with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be abbreviated as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be abbreviated as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be abbreviated as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be abbreviated as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be abbreviated as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05at least one of O2) and its modified compounds, etc. Examples of the lithium-containing phosphate with olivine structure may include, but are not limited to, lithium iron phosphate (such as LiFePO4 (which can also be abbreviated as LFP for short)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and at least one of a composite material of lithium manganese iron phosphate and carbon.

[0135] In one embodiment, the positive electrode active layer further includes a conductive agent to endow the electrode with conductivity. The positive electrode conductive material can include any conductive material as long as it does not cause chemical changes. Non-limiting examples of the positive electrode conductive material include carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, etc.), metal-based materials (such as metal powder, metal fiber, etc., including, for example, copper, nickel, aluminum, silver, etc.), conductive polymers (such as polyphenylene derivatives), and mixtures thereof. Optionally, the conductive agent includes one or more of conductive carbon black, conductive graphite, carbon fiber, carbon nanotube, graphene, Ketjen black, and acetylene black.

[0136] In one embodiment, the positive electrode active layer further includes a binder to improve the adhesion stability of the active layer and reduce the probability of powder falling off. The binder can be one or several of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyacrylic acid (PAA), carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). Optionally, the binder includes one or several of polyvinylidene fluoride, polytetrafluoroethylene, acrylate, and polyurethane.

[0137] In one embodiment, the positive electrode active layer further includes other optional additives, and the other optional additives can be thickening and dispersing agents (such as sodium carboxymethyl cellulose CMC-Na), PTC thermistor materials.

[0138] In some embodiments, the negative electrode sheet includes a current collector and a negative electrode active layer provided on the current collector.

[0139] The negative electrode active layer includes negative electrode active materials, which include but are not limited to carbon-based negative electrode materials, silicon-based negative electrode materials, tin-based negative electrode materials, lithium titanate negative electrode materials, metallic lithium negative electrode materials, etc.; specifically including but not limited to graphite materials, silicon-carbon materials, graphite-silicon monoxide materials, nano-silicon materials, silicon monoxide materials, and tin-based materials; more specifically including natural graphite, artificial graphite, mesocarbon microbeads (abbreviated as MCMB), hard carbon, soft carbon, silicon, silicon-carbon composites, Li-Sn alloys, Li-Sn-O alloys, Sn, SnO, SnO2, lithiated TiO2-Li4Ti5O with a spinel structure 12 , and one or more of Li-Al alloys.

[0140] In some embodiments, the negative electrode active layer may further include a binder, a conductive agent, and other optional additives. As an example, the conductive agent may be one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, Super P (SP), graphene, and carbon nanofibers. As an example, the binder may be one or more of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyacrylic acid (PAA), carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB). As an example, other optional additives may be thickening and dispersing agents (such as sodium carboxymethyl cellulose CMC-Na), PTC thermistor materials.

[0141] In some embodiments, the material of the separator may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0142] In one embodiment, the electrolyte includes one or more of carbonate solvents and ether solvents.

[0143] Carbonates are usually small-molecule cyclic or chain carbonates; including but not limited to one or more of ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, methyl propyl carbonate, dipropyl carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and fluorinated carbonates; it may also be at least one ester solvent of γ-butyrolactone, dimethyl sulfite, ethyl acetate, methyl acetate, methyl butyrate, ethyl butyrate, methyl propionate, ethyl propionate, propyl acetate, and fluorinated carboxylate.

[0144] Ether solvents include, but are not limited to, one or more of dimethyl ether, diethyl ether, tetrahydrofuran, methyltetrahydrofuran, ethylene oxide, 1,3-dioxolane, fluorinated ether, DME (ethylene glycol dimethyl ether), DEE (ethylene glycol diethyl ether), DEGDME (diethylene glycol dimethyl ether), TRGDME (triethylene glycol dimethyl ether), TEGDME (tetraethylene glycol dimethyl ether), dipropyl ether, and dibutyl ether.

[0145] In other embodiments, the electrolyte may further include a mixture composed of any one or several of amine solvents, sulfone solvents, and nitrile solvents. Amine solvents include at least one of N-methylacetamide, N-methylformamide, dimethylformamide, and diethylformamide. Sulfone solvents include at least one of dimethyl sulfoxide, sulfolane, diphenyl sulfoxide, thionyl chloride, and dipropyl sulfone. Nitrile solvents include at least one of acetonitrile, succinonitrile, adiponitrile, and glutaronitrile. The electrolyte is preferably a high-voltage-resistant electrolyte, whose acidity weakens under high voltage, which is beneficial to the transport of active ions, significantly reduces side reactions on the electrode surface, and improves battery stability.

[0146] In some embodiments, the electrolyte further includes an electrolyte salt, and the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium bis(oxalato)borate, lithium difluoro bis(oxalato)phosphate, and lithium tetrafluorooxalate phosphate.

[0147] In some embodiments, the electrolyte may optionally further include additives. For example, the additives can include negative electrode film-forming additives, positive electrode film-forming additives, and can also include additives that can improve certain battery performances, such as additives for improving battery overcharge performance, additives for improving battery high-temperature or low-temperature performance, etc.

[0148] The battery disclosed in the embodiments of the present application can be used in electrical equipment using the battery as a power source or various energy storage systems using the battery as an energy storage element. That is, an electrical equipment is provided. In some embodiments, the electrical equipment of the present application can be used in, but is not limited to, laptop computers, pen input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo headphones, video recorders, liquid crystal TVs, hand-held cleaners, portable CD players, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, motorized bicycles, bicycles, ships, spacecrafts, lighting appliances, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, and lithium-ion capacitors, etc.

[0149] The battery disclosed in the embodiments of the present application can be used in electrical equipment that uses the battery as a power source or various energy storage systems that use the battery as an energy storage element. That is, the present application provides an electrical equipment, and the electrical equipment includes the battery of the above embodiments. In some embodiments, the electrical equipment of the present application can be used in, but not limited to, laptop computers, pen input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo headphones, video recorders, liquid crystal TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, motorized bicycles, bicycles, ships, spacecrafts, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household storage batteries, and lithium-ion capacitors, etc.

[0150] The electrical equipment can select battery cells, battery modules, or battery packs according to its usage requirements.

[0151] Please refer to Figure 13 , Figure 13 FIG. is a schematic structural diagram of a vehicle according to one or more embodiments. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 100 is disposed inside the vehicle 1000. The battery 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used to supply power to the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0152] In some embodiments of the present application, the battery 100 can not only be used as the operating power source of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0153] The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present application by the same token.

Claims

1. A gas sensing material, characterized in that, Comprising: Palladium metal nanosheets, the thickness of the palladium metal nanosheets being 0.1 nm - 100 nm.

2. The gas sensing material according to claim 1, wherein the thickness of the palladium metal nanosheets is 0.5 - 5 nm.

3. The gas sensing material according to claim 1 or 2, wherein the palladium metal nanosheets are doped with non-metallic elements.

4. The gas sensing material according to claim 3, wherein the non-metallic elements include one or more of carbon, sulfur, phosphorus, nitrogen, boron, and fluorine.

5. The gas sensing material according to claim 3 or 4, wherein the atomic ratio of the non-metallic elements to palladium elements is (0.02 - 0.30):

1.

6. The gas sensing material according to any one of claims 1 to 5, wherein the lattice constant of the palladium metal nanosheets is greater than or equal to 3.9 Å.

7. The gas sensing material according to any one of claims 1 to 6, wherein the response gases of the gas sensing material include at least one of hydrogen and ammonia.

8. A method for preparing a gas sensing material, characterized in that, Comprising: Mixing a palladium precursor, a carbon monoxide source, and a solvent to obtain a mixed solution; Performing a heating reaction on the mixed solution to obtain palladium metal nanosheets, the thickness of the palladium metal nanosheets being 0.1 nm - 100 nm.

9. The method for preparing the gas sensing material according to claim 8, wherein the carbon monoxide source includes metal carbonyl compounds; optionally, the metal carbonyl compounds include one or more of tungsten carbonyl, molybdenum carbonyl, and nickel carbonyl.

10. The method for preparing the gas sensing material according to claim 8 or 9, wherein in the step of mixing the palladium precursor, the carbon monoxide source, and the solvent to obtain a mixed solution, it further includes: one or more of acetic acid and ascorbic acid are further added to the mixed solution.

11. The method for preparing the gas sensing material according to any one of claims 8 to 10, wherein mixing and reacting the palladium metal nanosheets with a non-metal source to obtain non-metal doped palladium metal nanosheets.

12. The method for preparing the gas sensing material according to claim 13, wherein the non-metal source includes one or more of anhydrous glucose and sulfur powder.

13. A sensor, characterized in that, Comprising the gas sensing material according to any one of claims 1 to 7; or comprising the gas sensing material prepared by the method according to any one of claims 8 to 12.

14. A battery, characterized in that, Comprising the gas sensor according to claim 13.

15. An electrical device, characterized in that, Comprising the battery according to claim 14.

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