Battery, gas sensing material and preparation method therefor, sensor, and electrical device

Abstract

A battery, a gas sensing material and a preparation method therefor, a sensor, and an electrical device. The battery (100) comprises a gas sensor; the gas sensor comprises a gas sensing material; the gas sensing material comprises a palladium-carbon nanotube composite material; a response gas of the palladium-carbon nanotube composite material under an oxygen-free condition comprises at least one of hydrogen, carbon monoxide and ammonia. The battery can achieve high-sensitivity response and rapid recovery of a target gas in an oxygen-free environment, so that the safety performance of the battery is improved.

Description

Battery, gas sensing material and preparation method thereof, sensor and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202311649340.2, filed on December 1, 2023, entitled “Gas Sensing Materials, Preparation Methods Thereof, Sensors, Batteries and Electrical Equipment,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of new energy technology, and in particular to batteries, gas sensing materials and preparation methods thereof, sensors and electrical equipment. Background Art

[0004] As global energy and environmental issues continue to intensify, new energy, as one of the areas of sustainable development, is developing rapidly. Batteries are becoming more and more widely used as a new energy source. Among them, the problem of battery gas production has always attracted much attention. The gas produced by the battery is prone to cause safety problems such as explosion and fire. By detecting the gas situation in the battery, timely warnings can be provided. The sensing principles of existing gas sensors mostly rely on oxygen and have a low response speed, so they have limitations in terms of application environment and response effect. The above statements are only used to provide background technical information related to this application and do not necessarily constitute prior art.

[0005] Summary of the Invention

[0006] The main technical problem solved by this application is to provide a battery, a gas sensing material and a preparation method thereof, a sensor and an electrical device, which have the advantage of rapid response of gas sensing under anaerobic conditions.

[0007] To address the above technical issues, this application employs a technical solution: providing a battery comprising a gas sensor, the gas sensor comprising a gas sensing material, the gas sensing material comprising a palladium-carbon nanotube composite material, and the palladium-carbon nanotube composite material responding to at least one of hydrogen, carbon monoxide, and ammonia in an oxygen-free environment. This arrangement enables the battery to achieve highly sensitive response and rapid recovery to target gases in an oxygen-free environment, thereby improving the battery's safety performance.

[0008] In one embodiment, the gas sensor is used to detect gas inside the battery, and can timely monitor gas production inside the battery, thereby improving the safety performance of the battery.

[0009] In one embodiment, the palladium-carbon nanotube composite material further includes a second metal. By introducing the second metal, the synergistic effect of two or more metals can improve the gas response value.

[0010] In one embodiment, the second metal includes one or more of copper, silver, gold, and nickel. By introducing the second metal, the synergistic effect of two or more metals can improve the gas response value.

[0011] In one embodiment, the second metal forms an alloy with palladium or the second metal is a single metal. By forming an alloy with the above metals or attaching the second metal single metal to the surface of the carbon nanotubes, the gas response value can be improved.

[0012] In one embodiment, the palladium content is greater than 0 and less than or equal to 50% based on the total mass of the palladium-carbon nanotube composite material. By controlling the palladium content within the above range, the gas response value can be improved.

[0013] In one embodiment, the palladium content of the palladium-carbon nanotube composite material is greater than 1% and less than or equal to 20% based on the total mass of the palladium-carbon nanotube composite material. By controlling the palladium content within the above range, the gas response value can be further improved.

[0014] In one embodiment, the carbon nanotubes include single-walled carbon nanotubes and / or multi-walled carbon nanotubes.

[0015] In one embodiment, the carbon nanotubes are single-walled carbon nanotubes.

[0016] In one embodiment, the carbon nanotubes further include inorganic non-metallic elements. By selecting or doping the carbon nanotubes with non-metallic elements, the gas response value can be improved.

[0017] In one embodiment, the inorganic non-metallic element includes at least one of N, S, B, P, and F.

[0018] In order to solve the above technical problems, another technical solution adopted by the present application is: to provide a gas sensing material, including a palladium-carbon nanotube composite material, wherein the response gas of the palladium-carbon nanotube composite material under oxygen-free conditions includes at least one of hydrogen, carbon monoxide and ammonia. The composite material combines the gas sensitivity of palladium metal with the high conductivity and high stability of carbon nanotubes, and can effectively adsorb gas molecules. At the same time, it can accelerate the diffusion rate of gas on the sensing material and accelerate the charge transfer caused by gas adsorption, so that the composite material can perform rapid gas sensing under oxygen-free conditions. Palladium can react specifically with the above gases, expanding the scope of application. At the same time, it has a strong specific reaction to hydrogen, and therefore, the anti-interference performance of the gas sensing material can be improved.

[0019] In one embodiment, by introducing a second metal, the synergistic effect of two or more metals can improve the gas response value.

[0020] In one embodiment, by controlling the palladium content within the above range, the gas response value can be improved.

[0021] To solve the above technical problems, another technical solution adopted in this application is: providing a method for preparing a gas sensing material, comprising: mixing a palladium precursor and a carbon nanotube solution to obtain a mixed solution; drying the mixed solution to obtain a powder; calcining the powder to obtain a palladium-carbon nanotube composite material, wherein the response gas of the palladium-carbon nanotube composite material under oxygen-free conditions includes at least one of hydrogen, carbon monoxide and ammonia.

[0022] The palladium-carbon nanotube composite material combines the gas sensitivity of palladium metal with the high conductivity and high stability of carbon nanotubes. It can effectively adsorb gas molecules, while accelerating the diffusion rate of gas on the sensing material and accelerating the charge transfer caused by gas adsorption, enabling the composite material to respond quickly to gas sensing under oxygen-free conditions.

[0023] In one embodiment, during the step of mixing the palladium precursor with the carbon nanotubes, the mixed solution further comprises a second metal precursor, which forms a palladium alloy or a second metal element with the metal palladium.

[0024] In one embodiment, in the step of mixing the palladium precursor with the carbon nanotubes, the mixed solution further includes a linker, which can promote the binding of the metal palladium and / or the second metal to the carbon nanotubes.

[0025] In one embodiment, the linker includes any one of dopamine and hexadecyltrimethylammonium bromide. By defining the linker, the combination of metal palladium and carbon nanotubes can be promoted.

[0026] To solve the above technical problems, another technical solution adopted in this application is to provide a gas sensor comprising any of the above-mentioned gas sensing materials, or a gas sensing material produced by any of the above-mentioned methods. Through the above-mentioned configuration, a highly sensitive response to a target gas can be achieved in an oxygen-free environment.

[0027] To solve the above technical problems, another technical solution adopted by the present application is to provide an electrical device comprising the above battery. The electrical device has at least the same advantages as the battery.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] FIG1 is a transmission electron microscope (TEM) image of a gas sensing material according to one or more embodiments;

[0031] FIG2 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0032] FIG3 is a scanning electron microscope (SEM) image of a gas sensing material according to one or more embodiments;

[0033] FIG4 is a schematic diagram of a gas sensing performance test of a gas sensing material according to one or more embodiments;

[0034] FIG5 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0035] FIG6 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0036] FIG7 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0037] FIG8 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0038] FIG9 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0039] FIG10 is a schematic diagram illustrating gas response of a gas sensing material according to one or more embodiments;

[0040] FIG11 is a schematic diagram of an exploded structure of a battery according to one or more embodiments;

[0041] FIG12 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0042] FIG13 is a schematic structural diagram of a vehicle according to one or more embodiments.

[0043] In the drawings: 1000, vehicle; 300, motor; 200, controller; 100, battery; 10, housing; 11, first part; 12, second part; 20, battery cell; 21, end cap; 21a, electrode terminal; 22, housing; 23, electrode assembly. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and effect of this application clearer and more specific, the following embodiments of the technical solution of this application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0046] In the description of the embodiments of the present application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two (including two), and "multiple pieces" refers to more than two (including two), unless otherwise clearly and specifically defined.

[0047] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0049] Amounts, ratios, and other numerical values ​​are presented herein in a range format. It should be understood that such range format is used for convenience and brevity and should be interpreted flexibly to include not only the values ​​explicitly specified as range limits, but also all individual values ​​or sub-ranges encompassed within the range, as if each value and sub-range were explicitly specified.

[0050] If not otherwise specified, all steps of the present application may be performed sequentially, randomly, or in parallel, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially, or may include steps (a) and (b) performed simultaneously in parallel. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b), and (c), or may include steps (a), (c), and (b), or may include steps (c), (a), and (b), etc.

[0051] Under the new round of technological change, the new energy industry is experiencing rapid development. As a key component of this sector, the power battery industry is also experiencing rapid growth. Currently, power batteries are widely used in electric vehicles, energy storage systems, and renewable energy. With the growing demand for clean energy and sustainable development, the application of batteries in the new energy sector will continue to expand, driving further progress in the energy transition. With the new development of power batteries in my country, power batteries are bound to achieve multiple improvements. From a technical perspective, "high safety," "high efficiency," "long life," and "low cost" will be the core solutions and goals for the development of power battery technology.

[0052] As the battery charges and discharges, some side reactions generate gases. If these gases are not promptly discharged, the internal pressure of the battery will rise, exceeding normal levels. Excessive internal pressure can negatively impact the battery's performance and appearance. In severe cases, these can have devastating effects, such as leakage, bulging, increased internal resistance, and shortened discharge time and cycle life. Furthermore, batteries can be subject to abnormal operation during use, including overcharging, over-discharging, and internal faults. In these cases, the chemical reactions within the battery may become uncontrolled, accompanied by a violent release of gas, and even trigger thermal runaway. Battery thermal runaway refers to a chain reaction phenomenon triggered by various factors. The large amount of heat and harmful gases released during thermal runaway can cause the battery to catch fire and explode.

[0053] To monitor battery gas production in real time, a gas sensor can be installed inside the battery. Different batteries produce different characteristic gases, and the composition of the gas sensing material can be adjusted to make it selective for different characteristic gases, thereby achieving adaptive application for different batteries. However, existing gas sensors have shortcomings in detecting battery gas production. Application environments such as battery packs are often low in oxygen or oxygen-free, making electrochemical sensors and resistive sensors that rely on oxygen unable to function properly.

[0054] Palladium metal has been shown to have a specific response to hydrogen, independent of oxygen. However, pure palladium has a slow adsorption rate for hydrogen, resulting in low sensitivity and slow response in gas sensing.

[0055] Based on the above considerations, the present application designs a battery, which includes a gas sensor, and the gas sensor includes a gas sensing material. This gas sensing material is a chemical resistance sensing material, which relies on the change in the surface resistance of the sensor when the gas-sensitive material palladium metal interacts with the target gas to achieve the detection purpose. No oxygen is involved in the reaction process. At the same time, carbon nanotubes with semiconductor properties are used as the substrate of the gas-sensitive material palladium metal, so that the above-mentioned gas sensing material can respond to hydrogen in an oxygen-free environment, and has high sensitivity and fast response speed.

[0056] According to some embodiments of the present application, the present application discloses a battery, which includes a gas sensor, the gas sensor includes a gas sensing material, the gas sensing material includes a palladium-carbon nanotube composite material, and the response gas of the palladium-carbon nanotube composite material under oxygen-free conditions includes at least one of hydrogen, carbon monoxide and ammonia.

[0057] Please refer to Figure 1, which is a transmission electron microscope (TEM) image of a gas sensing material according to one or more embodiments of the present application. As shown in the figure, in the palladium-carbon nanotube composite material, palladium nanoparticles are randomly distributed on the surface of the carbon nanotubes.

[0058] Carbon nanotubes (CNTs) are one-dimensional materials with a special structure. They are coaxial hollow seamless tubular structural materials formed by curling single or multiple layers of graphene sheets around the center at a certain angle. Their tube walls are mostly composed of hexagonal carbon atom grids. Depending on the number of tube wall layers, they can be divided into single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). Single-walled carbon nanotubes are composed of a single layer of graphene sheets. The typical diameter and length of single-walled carbon nanotubes are 0.75-3nm and 1-50μm, respectively. Thanks to their special structure, single-walled carbon nanotubes have a high specific surface area and excellent electron transport properties. Compared with multi-walled carbon nanotubes, they have a higher current carrying capacity and can respond quickly to external stimuli. At the same time, single-walled carbon nanotubes also have rich functional groups, which can be easily chemically modified and functionalized to meet the needs of specific applications.

[0059] Due to the extremely small diameter and high aspect ratio of single-walled carbon nanotubes, the specific surface area of ​​single-walled carbon nanotubes is extremely large, which makes the corresponding gas sensor respond faster to hydrogen and can achieve stable readings in a short time.

[0060] Thanks to their unique surface structure, single-walled carbon nanotubes and palladium metal can form a composite. Palladium (Pd) is a transition metal in the Group VIII platinum series of Period VIII. Its surface contains numerous defects, providing numerous active sites for gas adsorption. Furthermore, palladium's 4d electron layer lacks two electrons, allowing it to form chemical bonds with gas molecules.

[0061] In one embodiment, the palladium-carbon nanotube composite material has a nanoscale dimension. The nanoscale refers to the dimension of objects between the molecular and micron scales; the linear dimensions of these materials 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, nanobelts, and nanometer-sized pores.

[0062] Palladium-carbon nanotube composites combine the gas sensitivity of palladium metal with the high conductivity and stability of carbon nanotubes. They effectively adsorb gas molecules and accelerate the diffusion rate of gas on the sensing material. When gas molecules interact with the surface of the gas sensing material, the surface resistance of the material changes, generating a significant electrical signal. This process does not require the participation of oxygen, thus achieving a highly sensitive response to target gases in an oxygen-free environment.

[0063] According to some embodiments of the present application, the palladium-carbon nanotube composite material further includes a second metal, which can improve the gas response value.

[0064] According to some embodiments of the present application, the second metal includes one or more of copper, silver, gold, and nickel. The second element includes one or more of copper (Cu), silver (Ag), gold (Au), and nickel (Ni). By introducing the above metals, the gas response value can be improved.

[0065] According to some embodiments of the present application, the second metal forms an alloy with palladium or the second metal is a single metal. By forming an alloy with the above metals or attaching the second metal single metal to the surface of the carbon nanotubes, the gas response value can be improved.

[0066] In some embodiments, the basic principle of palladium metal alloying is to mix two or more different metal elements together through atomic interactions to form new alloy materials, such as palladium-gold alloy (Pb-Au), palladium-silver alloy (Pb-Ag), palladium-copper alloy (Pb-Cu), etc. By doping these metals to form alloys, gas response values ​​can be improved.

[0067] By introducing a second metal and alloying palladium, the palladium's response to hydrogen can be altered, helping to improve and control the hydrogen adsorption behavior of gas sensing materials. For example, Pb-Au alloys exhibit higher hydrogen solubility than pure Pd, accelerating hydrogen adsorption and increasing the sensitivity and response speed of gas sensing materials. Pb-Ag alloys have strong hydrogen absorption capabilities, resulting in gas sensing materials with high sensitivity and good response repeatability. Pb-Cu alloys have strong selective hydrogen permeability, which helps improve the selectivity of gas sensing materials.

[0068] According to some embodiments of the present application, based on the total mass of the palladium-carbon nanotube composite material, the palladium content is greater than 0 and less than or equal to 50%. By controlling the palladium content within the above range, the gas response value can be improved.

[0069] According to some embodiments of the present application, based on the total mass of the palladium-carbon nanotube composite material, the palladium content is greater than or equal to 1% and less than or equal to 20%. By controlling the palladium content within the above range, the gas response value can be further improved.

[0070] In theory, the higher the palladium content in the gas sensing material, the better the sensing performance. This is because increasing the content of palladium nanoparticles in the palladium-carbon nanotube composite material can increase the gas adsorption sites. However, when there are too many palladium nanoparticles, the sp 2 The structure will be destroyed, thus hindering the efficient and free movement of electrons within the tube, making the conductivity of carbon nanotubes worse. Therefore, it is necessary to control the content of palladium nanoparticles within an appropriate range to achieve the optimal response effect in terms of gas sensing sensitivity and response speed.

[0071] According to some embodiments of the present application, the carbon nanotubes include single-walled carbon nanotubes and / or multi-walled carbon nanotubes. Through the above configuration, the material selection range of the palladium-carbon nanotube composite material can be broadened to meet different application requirements.

[0072] According to some embodiments of the present application, the carbon nanotubes are single-walled carbon nanotubes, which have a high specific surface area and excellent electron transport properties, a higher current carrying capacity than multi-walled carbon nanotubes, and the ability to quickly respond to external stimuli.

[0073] According to some embodiments of the present application, the carbon nanotubes further include inorganic non-metallic elements. The gas response value can be improved by selecting or doping the carbon nanotubes.

[0074] According to some embodiments of the present application, the inorganic non-metallic element includes at least one of N, S, B, P, and F. The gas response value can be improved by selecting or doping the carbon nanotubes.

[0075] Some embodiments of the present application also provide a gas sensing material comprising a palladium-carbon nanotube composite material. The palladium-carbon nanotube composite material responds to at least one of hydrogen, carbon monoxide, and ammonia in the absence of oxygen. Refer to Figure 2, which is a schematic diagram of the gas response of a gas sensing material according to one or more embodiments. Figure 2 illustrates the response of the palladium-carbon nanotube composite material to different gases at 1000 ppm.

[0076] The following uses hydrogen as an example. When palladium is exposed to an H₂ atmosphere, H₂ molecules physically adsorb to the palladium surface through van der Waals forces. The H₂ molecules then dissociate into H atoms on the palladium surface and diffuse into the interstices of the palladium lattice, causing the palladium lattice to expand and undergo a phase transition, forming palladium hydride, which in turn changes the electrical signal. This process occurs spontaneously and is independent of oxygen.

[0077] Furthermore, palladium can react specifically with hydrogen, thus avoiding interference from other gases to a certain extent, giving the palladium-carbon nanotube composite material good selectivity for hydrogen detection and improving the accuracy of gas detection. This is because when Pd is exposed to an H2 atmosphere, H2 molecules are physically adsorbed on the Pd surface through van der Waals forces. The H2 molecules then dissociate into H atoms on the Pd surface and form Pd-H chemical bonds with the Pd atoms. They then diffuse into the gaps in the Pd lattice to form a solid solution, causing the Pd lattice to expand and undergo a phase transition to form a β phase that can absorb more H2 molecules, forming palladium hydride.

[0078] Palladium can react specifically with the other substances mentioned above, expanding its adaptability. At the same time, it has a strong specific reaction to hydrogen, thus improving the anti-interference performance of gas sensing materials.

[0079] In some embodiments of the present application, the palladium in the palladium-carbon nanotube composite material is combined with carbon nanotubes in the form of palladium nanoparticles, palladium alloy nanoparticles or second metal nanoparticles. Palladium nanoparticles or palladium alloy nanoparticles have an extremely high specific surface area and therefore can provide more adsorption sites for gas molecules. Taking hydrogen (H2) as an example, H2 molecules are physically adsorbed on the palladium surface by van der Waals forces, and then the H2 molecules dissociate into H atoms on the palladium surface and diffuse into the lattice gaps of palladium to form palladium hydride, causing a change in electrical signals. The palladium in nanoparticle form can increase the contact area with hydrogen molecules, provide more abundant hydrogen adsorption sites, and therefore can improve the response speed of the gas sensor.

[0080] According to some embodiments of the present application, the palladium-carbon nanotube composite material further includes a second metal, which can improve the gas response value.

[0081] According to some embodiments of the present application, based on the total mass of the palladium-carbon nanotube composite material, the palladium content is greater than 0 and less than or equal to 50%. By controlling the palladium content within the above range, the gas response value can be improved.

[0082] Some embodiments of the present application also provide a method for preparing a gas sensing material, comprising: mixing a palladium precursor and a carbon nanotube solution to obtain a mixed solution; drying the mixed solution to obtain a powder; and calcining the powder to obtain a palladium-carbon nanotube composite material. The palladium-carbon nanotube composite material has a nanoscale scale.

[0083] The palladium-carbon nanotube composite material combines the gas sensitivity of palladium metal with the high conductivity and high stability of carbon nanotubes. It can effectively adsorb gas molecules, while accelerating the diffusion rate of gas on the sensing material and accelerating the charge transfer caused by gas adsorption, enabling the composite material to respond quickly to gas sensing under oxygen-free conditions.

[0084] The palladium precursor is a form of palladium metal before obtaining the target product palladium metal nanoparticles, usually a divalent palladium compound, including palladium salts such as palladium chloride (PdCl2) or palladium nitrate (Pd(NO3)2); organic palladium compounds such as palladium acetylacetonate (PdA) and palladium nitrate (Pd(NO3)2). 10 H 14 O4Pd), palladium acetate (Pd(OAc)2) or palladium aryl compounds; and colloidal palladium, etc.

[0085] In the step of mixing the palladium precursor with the carbon nanotubes, the mixed solution further includes a second metal precursor, which is conducive to forming a palladium alloy or a second metal element with the metal palladium.

[0086] The second metal precursor may be chloroauric acid (HAuCl4), silver nitrate (AgNO3), copper nitrate (Cu(NO3)2), nickel nitrate (Ni(NO3)2), or the like.

[0087] The process of mixing the palladium precursor, the second metal precursor, and the carbon nanotube solution, drying, and calcining is called carbon nanotube functionalization, which involves introducing functional groups onto the surface of the carbon nanotubes. Purification and acidification of the carbon nanotubes are typically required before functionalization.

[0088] Taking single-walled carbon nanotubes as an example, single-walled carbon nanotubes often contain impurities, which may affect subsequent research and applications, and therefore need to be purified. Please refer to Figure 3, which is a scanning electron microscope image (SEM) of single-walled carbon nanotubes before and after purification of one or more embodiments of the present application. As shown in the figure, many impurities are attached to the surface of the single-walled carbon nanotubes before purification, while the impurities disappear after purification. The purification method can be divided into physical purification method, chemical purification method and comprehensive purification method. In some embodiments of the present application, the specific purification method is to add 600mg of unloaded single-walled carbon nanotubes to 300mL of concentrated hydrochloric acid and ultrasonically clean for 30min. Use 500mg of deionized water to ultrasonically clean the mixture for another 30min. The cleaned mixture is placed in a drying oven and dried at 150°C for 10h to obtain purified unloaded single-walled carbon nanotubes. The above method mainly utilizes the stability of single-walled carbon nanotubes, which are resistant to corrosion by strong acids and alkalis. Other impurities, such as graphite particles, carbon nanoparticles, and fullerenes, are far less stable than carbon nanotubes and can be removed by acid (such as hydrochloric acid).

[0089] Acidification can increase the active functional groups on the surface of carbon nanotubes, which is actually an oxidation treatment of the carbon nanotubes. During the oxidation process, functional groups such as hydroxyl (-OH) and carboxyl (-COOH) on the surface of the carbon nanotubes will increase, resulting in changes in the chemical properties and surface properties of the carbon nanotubes, making them have good hydrophilicity, higher reactivity and easier properties to form composite materials. In some embodiments of the present application, the specific acidification method is to add 400 mg of purified unloaded single-walled carbon nanotubes to 50 mL of concentrated sulfuric acid and 20 mL of concentrated nitric acid, and heat and stir at 80°C for 4 hours. After the mixture is cooled, it is diluted with 60 mL of deionized water. The mixture is filtered through a microporous membrane with a pore size of 0.45 μm and repeatedly washed with deionized water until the pH = 7. After drying at 80°C for 12 hours, acidified single-walled carbon nanotubes are obtained. Through the above method, abundant carboxyl and hydroxyl active groups are introduced on the surface of the single-walled carbon nanotubes, which is conducive to the subsequent functionalization of the single-walled carbon nanotubes.

[0090] Specifically, in some embodiments of the present application, the functionalization method of single-walled carbon nanotubes is to dissolve 200 mg of single-walled carbon nanotubes in 50 mL of isopropanol and ultrasonicate for 20 minutes to improve the dispersion of the single-walled carbon nanotubes. 4 mg of PdCl2 is dissolved in 3 mL of ammonia water. The PdCl2 solution is added dropwise to the SWCNTs / isopropanol mixed solution and stirred at high speed for 2 hours. The resulting suspension is placed in a drying oven and dried at 80°C for 2 hours. The obtained powder is placed in a calcination furnace at 600°C for 2 hours. Finally, a 1wt% palladium-single-walled carbon nanotube composite material is synthesized.

[0091] Furthermore, when a second metal is present, taking gold as an example, the functionalization method of single-walled carbon nanotubes is to add PdCl2 solution dropwise to the SWCNTs / isopropanol mixed solution, and then add 50 μL of 0.01 g / mL HAuCl4 solution to the solution, and the subsequent steps are the same as above.

[0092] During the functionalization process, palladium nanoparticles react chemically with active functional groups (such as carboxyl, hydroxyl, etc.) on the surface of single-walled carbon nanotubes to form stable chemical bonds, thereby realizing the composite of palladium nanoparticles and single-walled carbon nanotubes.

[0093] To enhance the bonding strength between the palladium nanoparticles and the carbon nanotubes, in one embodiment, the palladium precursor is mixed with a linker prior to mixing with the carbon nanotubes. The addition of the linker can facilitate bonding between the palladium metal and the carbon nanotubes. The linker can facilitate bonding between the palladium metal and the carbon nanotubes. The linker can facilitate bonding between the palladium metal and / or the second metal to the carbon nanotubes.

[0094] The role of a linker is to connect different molecules or materials together. Different linkers have different properties and applications, so choosing the right linker is key to achieving efficient connection between palladium and carbon nanotubes.

[0095] In one embodiment, the linker includes any one of dopamine and hexadecyltrimethylammonium bromide. By defining the linker, the combination of metal palladium and carbon nanotubes can be promoted.

[0096] The linking principle of dopamine (DA) is based on the interaction between the catechol group in the dopamine molecule and various metal ions (such as palladium, copper, zinc, iron, etc.). The catechol group can form stable chelates with metal ions, thereby connecting the metal ions with other molecules or materials.

[0097] Cetyltrimethylammonium bromide (CTAB) is a cationic surfactant whose bonding principle is based on the interaction between the cations in the CTAB molecule and various materials (such as silicates, aluminates, phosphates, etc.). The cations can interact with the negatively charged groups on the surface of the materials, thereby connecting the materials together.

[0098] In some embodiments of the present application, a gas sensor based on a palladium-carbon nanotube composite material is also provided, which includes any of the above-mentioned gas sensing materials; or includes a gas sensing material prepared using any of the above-mentioned methods.

[0099] Specifically, a palladium-carbon nanotube composite material is used as a gas sensing material. This material responds to the induced gas based on the change in the surface resistance of the sensor when palladium interacts with the target gas, and accelerates the charge transfer through carbon nanotubes, which can achieve gas response under anaerobic conditions. A gas sensor that can respond quickly to gas under anaerobic conditions and has high detection sensitivity is prepared.

[0100] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0101] 1. Preparation of gas sensing materials

[0102] Example 1:

[0103] 1. Add 600 mg of unloaded SWCNTs to 300 mL of concentrated hydrochloric acid and ultrasonically clean for 30 minutes. Use 500 mg of deionized water to ultrasonically clean the mixture for another 30 minutes. Place the cleaned mixture in a drying oven and dry it at 150°C for 10 hours to obtain purified unloaded SWCNTs.

[0104] 2. Add 400 mg of purified unloaded single-walled carbon nanotubes to 50 mL of concentrated sulfuric acid and 20 mL of concentrated nitric acid and heat with stirring at 80°C for 4 h. After the mixture is cooled, dilute it with 60 mL of deionized water. Filter the mixture through a microporous membrane with a pore size of 0.45 μm and wash it repeatedly with deionized water until the pH reaches 7. After drying at 80°C for 12 h, acidified single-walled carbon nanotubes are obtained;

[0105] 3. Dissolve 200 mg of single-walled carbon nanotubes in 50 mL of isopropanol and sonicate for 20 minutes. Dissolve 4 mg of PdCl₂ in 3 mL of aqueous ammonia. Add the PdCl₂ solution dropwise to the SWCNTs / isopropanol mixture and stir at high speed for 2 hours. Place the resulting suspension in a drying oven and dry at 80°C for 2 hours. The resulting powder is calcined in a 600°C furnace for 2 hours. This results in the synthesis of a 1 wt% palladium-single-walled carbon nanotube composite, Pb / SWCNT-1.

[0106] Example 2-4:

[0107] Based on Example 1, the palladium content was changed to 12 mg, 40 mg, and 80 mg, respectively. Palladium-single-walled carbon nanotube composite materials Pb / SWCNT-2, Pb / SWCNT-3, and Pb / SWCNT-4 were prepared, with corresponding palladium contents of 3%, 10%, and 20%, respectively. Table 1 lists the reaction parameters and performance parameters of each example.

[0108] Example 5:

[0109] On the basis of Example 2, the type of carbon nanotubes was changed to multi-walled carbon nanotubes instead of single-walled carbon nanotubes to prepare a palladium-multi-walled carbon nanotube composite material Pb / MWCNT-5. The specific reaction conditions are shown in Table 1.

[0110] Example 6:

[0111] The type of carbon nanotubes was changed based on Example 2. The difference was that the single-walled carbon nanotubes were modified by inorganic non-metal doping.

[0112] Examples 7-9:

[0113] On the basis of Example 2 and step 3, a precursor of a second metal is added.

[0114] Example 10:

[0115] Based on Example 2 and step 3, a linker was added.

[0116] Comparative Example:

[0117] 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 thoroughly by ultrasonication in an ice bath for 30 min.

[0118] 2. Place the above solution in an 80°C oil bath for 4 hours, then centrifuge the reaction solution at 10,000 rpm for 30 minutes to obtain a black product;

[0119] 3. Wash the above black product with anhydrous ethanol three times, centrifuge at 10000 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 and dry it for 12 h to obtain palladium metal nanosheets Pb-0.

[0120] 2. Preparation of gas sensors

[0121] A palladium-carbon nanotube composite material at a concentration of 10 mg / L was added to terpineol and ultrasonicated at 40 kHz for 10 minutes to uniformly disperse the composite material in the terpineol, thereby obtaining a palladium-carbon nanotube dispersion. Gold electrodes were fabricated using micromachining techniques, with a spacing of 800 μm between the positive and negative electrodes and 300 μm between adjacent electrodes. Five μL of the dispersion was dropwise applied to the interdigitated electrodes. The sample was then vacuum-dried at 60°C for 1 hour to obtain a palladium-carbon nanotube hydrogen sensor.

[0122] 3. Gas Sensing Performance Test

[0123] Please refer to Figure 4. The gas sensor is placed in the test chamber. At room temperature, the target gas is introduced using a static gas distribution method. The resistance change of the sensor in an inert gas environment and under different target gas concentrations is monitored in real time using an Agilent 4156C semiconductor parameter analyzer. A constant operating voltage of 500mV is applied between the sensor electrodes. The test is performed in accordance with the standard GB / T3634-1995 4.5. Before the target gas is introduced, the chamber is purged with dry compressed argon (MFC3) to stabilize the baseline signal. Compressed argon (MFC2) is used as a carrier gas to dilute the target gas of different concentrations. The target gas is controlled by a mass flow controller (MFC1). The difference in resistance of the sensor in dry argon and the target gas is related to the resistance ratio in dry argon (|R a -R g | / R a The response time and recovery time are defined by reaching 90% saturation of the response and recovery curves. The test results are shown in Table 1.

[0124] 4. Preparation of batteries

[0125] 1. The positive electrode active material lithium iron phosphate, the conductive agent acetylene black, and the binder PVDF were weighed in a weight ratio of 97.5:1.5:1, fully stirred and mixed in an N-methylpyrrolidone solvent system, and then coated on an Al foil by extrusion coating or transfer coating, dried, and cold pressed to obtain a positive electrode sheet.

[0126] 2. The negative electrode active material artificial graphite, the conductive agent acetylene black, the binder carboxymethyl cellulose, and the dispersant styrene-butadiene rubber are fully stirred and mixed in a deionized water solvent system in a weight ratio of 96:2:1:1, and then coated on a Cu foil, dried, and cold pressed to obtain a negative electrode sheet.

[0127] 3. Using a PE porous polymer film as a separator, the positive electrode sheet, separator, and negative electrode sheet are wound in order and size to form a battery cell. After packaging, liquid injection, formation, and exhaust processes, a gas sensor is placed in the battery casing to obtain a lithium-ion battery.

[0128] 1. Comparison of different embodiments

[0129] Please refer to Table 1 first, which shows the reaction parameters and performance parameters of each embodiment and comparative example.

[0130] Table 1 Reaction parameters and performance parameters of various embodiments and comparative examples

[0131] Note: "Pd content" in the table refers to the total mass of Pd-carbon nanotube composites and the proportion of Pd in ​​the composites. "Single-walled" refers to semiconductor single-walled carbon nanotubes, "multi-walled" refers to multi-walled carbon nanotubes, and single-walled (B-doped) refers to non-metallic B-modified single-walled carbon nanotubes. The gas used for the response value and response time tests is 1000 ppm hydrogen.

[0132] By comparing Examples 1-4 and 6-10 with the comparative example, it can be seen that the response value of palladium-carbon nanotubes is higher.

[0133] By comparing Example 5 with the comparative example, it can be seen that the response time and recovery time of the palladium-carbon nanotubes are both faster.

[0134] 2. H2 response and recovery dynamic test

[0135] As shown in Figures 5-9, the responses of the sensors of the gas sensing materials prepared in different embodiments and comparative examples of the present application to hydrogen were tested at room temperature.

[0136] 3. H2 cycle stability test

[0137] The palladium-carbon nanotube gas sensor material prepared in Example 2 of the present invention was subjected to multiple response and recovery tests to 1000 ppm hydrogen at room temperature. Argon was used as the background gas during the tests, and data was acquired and analyzed. The results are shown in Figure 10 , where the horizontal axis represents acquisition time and the vertical axis represents device sensitivity. After three response-recovery cycles, the sensor's response remained essentially unchanged, exceeding 3.4%, while the response time remained essentially unchanged at approximately 100 seconds. These results demonstrate that the sensor prepared in the aforementioned example exhibits good cyclic stability during the H2 response recovery process.

[0138] 4. Gas selectivity test

[0139] Please refer to Figure 2, which shows the response of a palladium-carbon nanotube gas sensor material to different gases at the same concentration, according to one or more embodiments of the present application. As can be seen from the figure, the gas sensor material exhibits similar responses to hydrogen, carbon monoxide, and ammonia. However, it exhibits excellent selectivity for hydrogen.

[0140] In some embodiments of the present application, the gas sensor can be used to detect gas inside a battery. That is, the present application provides a battery comprising the gas sensor of the above embodiment.

[0141] Please refer to Figure 11, which is a schematic diagram of an exploded structure of a battery according to one or more embodiments. Battery 100 includes a housing 10 and battery cells 20, which are housed within housing 10. Housing 10 provides storage space for battery cells 20 and can have various structures. In some embodiments, housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for battery cells 20. Second portion 12 can be a hollow structure with one end open. First portion 11 can be a plate-like structure, overlapping the open side of second portion 12, so that the first and second portions 11 and 12 together define a storage space. Alternatively, first portion 11 and second portion 12 can each be a hollow structure with one end open, with the open side of first portion 11 overlapping the open side of second portion 12. Housing 10 formed by first portion 11 and second portion 12 can also have various shapes, such as a cylinder or a rectangular parallelepiped.

[0142] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0143] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0144] Please refer to Figure 12, which is a schematic diagram of the exploded structure of a battery cell according to one or more embodiments. A battery cell 20 is the smallest unit that makes up a battery. As shown in Figure 12, a battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0145] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. The end cap 21 can be provided with functional components such as electrode terminals 21a. The electrode terminals 21a can be used to electrically connect to the electrode assembly 23 for inputting or outputting electrical energy from the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0146] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0147] The electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 23a. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs 23a connect the electrode terminals to form a current loop.

[0148] In one embodiment, the positive electrode sheet includes a current collector and a positive active layer disposed on the current collector.

[0149] 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-containing phosphates 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 traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. 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 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05O2) and its modified compounds. Examples of olivine-structured lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), 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 iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0150] In one embodiment, the positive electrode active layer also includes a conductive agent, thereby giving the electrode conductivity. The positive electrode conductive material can include any conductive material as long as it does not cause chemical changes. Non-limiting examples of positive electrode conductive materials include carbon-based materials (e.g., natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, etc.), metal-based materials (e.g., metal powder, metal fiber, etc., including, for example, copper, nickel, aluminum, silver, etc.), conductive polymers (e.g., polyphenylene derivatives) and mixtures thereof. Alternatively, the conductive agent includes one or more of conductive carbon black, conductive graphite, carbon fiber, carbon nanotubes, graphene, Ketjen black and acetylene black.

[0151] 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 shedding. The binder can 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). Alternatively, the binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, acrylate, and polyurethane.

[0152] In one embodiment, the positive electrode active layer further includes other optional additives, which may be thickening and dispersing agents (such as sodium carboxymethyl cellulose CMC-Na) and PTC thermistor materials.

[0153] In some embodiments, the negative electrode sheet includes a current collector and a negative active layer disposed on the current collector.

[0154] The negative electrode active layer includes a negative electrode active material, which includes but is 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 includes but is not limited to graphite materials, silicon-carbon materials, graphite-silicon oxide materials, nano-silicon materials, silicon oxide materials and tin-based materials; more specifically includes natural graphite, artificial graphite, mesophase microcarbon beads (abbreviated as MCMB), hard carbon, soft carbon, silicon, silicon-carbon composites, Li-Sn alloys, Li-Sn-O alloys, Sn, SnO, SnO2, spinel structured lithiated TiO2-Li4Ti5O 12 , one or more of Li-Al alloys.

[0155] In some embodiments, the negative electrode active layer may further include a binder, a conductive agent, and other optional additives. For 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. For 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). For example, other optional additives may include thickening and dispersing agents (e.g., sodium carboxymethyl cellulose (CMC-Na)) and PTC thermistor materials.

[0156] In some embodiments, the material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can 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 can be the same or different, without particular limitation.

[0157] In one embodiment, the electrolyte includes one or more of carbonate solvents and ether solvents.

[0158] Carbonates are generally small molecule cyclic or chain carbonates; including but not limited to one or more of ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, methylpropyl carbonate, dipropyl carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and fluorocarbonates; and may also be at least one ester solvent selected from γ-butyrolactone, dimethyl sulfite, ethyl acetate, methyl acetate, methyl butyrate, ethyl butyrate, methyl propionate, ethyl propionate, propyl acetate, and fluorocarboxylic acid esters.

[0159] Ether solvents include, but are not limited to, one or more of dimethyl ether, diethyl ether, tetrahydrofuran, methyltetrahydrofuran, ethylene oxide, 1,3-dioxolane, fluoroether, 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.

[0160] In other embodiments, the electrolyte may also include any one or a mixture of several of an amine solvent, a sulfone solvent, and a nitrile solvent. The amine solvent includes at least one of N-methylacetamide, N-methylformamide, dimethylformamide, and diethylformamide. The sulfone solvent includes at least one of dimethyl sulfoxide, cyclopentane sulfone, diphenyl sulfoxide, thionyl chloride, and dipropyl sulfone. The nitrile solvent includes at least one of acetonitrile, succinonitrile, adiponitrile, and glutaronitrile. The electrolyte is preferably a high-voltage resistant electrolyte, which has reduced acidity under high voltage, can facilitate the transmission of active ions, significantly reduce side reactions on the electrode surface, and improve battery stability.

[0161] In some embodiments, the electrolyte further includes an electrolyte salt, which 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 difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0162] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, and additives that improve battery high or low temperature performance.

[0163] The battery disclosed in the embodiments of the present application can be used in electrical devices that use the battery as a power source or various energy storage systems that use the battery as an energy storage element. That is, a power device is provided. In some embodiments, the power device of the present application can be used for, but is not limited to, laptop computers, pen-type computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo headphones, video recorders, LCD televisions, portable cleaners, portable CD players, mini-discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, ships, spacecraft, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.

[0164] The battery disclosed in the embodiments of the present application can be used for various energy storage systems that use batteries as power supplies or use batteries as energy storage elements. That is, the present application provides an electric device, and the electric device includes the battery of the above embodiment. In some embodiments, the electric device of the present application can be used for, 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, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, ships, spacecraft, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.

[0165] Electrical equipment can choose battery cells, battery modules or battery packs according to its usage requirements.

[0166] Please refer to Figure 13, which 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 provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0167] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0168] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery, wherein: Including gas sensors; The gas sensor comprises a gas sensing material, wherein the gas sensing material comprises a palladium-carbon nanotube composite material, and the response gas of the palladium-carbon nanotube composite material under oxygen-free conditions comprises at least one of hydrogen, carbon monoxide and ammonia.

2. The battery according to claim 1, wherein The gas sensor is used for detecting the gas inside the battery.

3. The battery according to claim 1 or 2, wherein: The palladium-carbon nanotube composite material also includes a second metal.

4. The battery according to claim 3, wherein The second metal includes one or more of copper, silver, gold and nickel.

5. The battery according to claim 3 or 4, wherein The second metal forms an alloy with palladium or the second metal is a single metal.

6. The battery according to any one of claims 1 to 5, wherein: Based on the total mass of the palladium-carbon nanotube composite material, the content of palladium is greater than 0 and less than or equal to 50%.

7. The battery according to claim 6, wherein Based on the total mass of the palladium-carbon nanotube composite material, the content of palladium is greater than or equal to 1% and less than or equal to 20%.

8. The battery according to any one of claims 1 to 7, wherein: The carbon nanotubes include single-walled carbon nanotubes and / or multi-walled carbon nanotubes.

9. The battery according to any one of claims 1 to 8, wherein: The carbon nanotubes are single-walled carbon nanotubes.

10. The battery according to any one of claims 1 to 9, wherein: The carbon nanotubes also include inorganic non-metallic elements.

11. The battery according to claim 10, wherein The inorganic non-metallic element includes at least one of N, S, B, P and F.

12. A gas sensing material, wherein: The gas sensing material comprises a palladium-carbon nanotube composite material, and the response gas of the palladium-carbon nanotube composite material under oxygen-free conditions comprises at least one of hydrogen, carbon monoxide and ammonia.

13. The gas sensing material according to claim 12, wherein: The palladium-carbon nanotube composite material also includes a second metal.

14. The gas sensing material according to claim 12 or 13, wherein: Based on the total mass of the palladium-carbon nanotube composite material, the content of palladium is greater than 0 and less than or equal to 50%.

15. A method for preparing a gas sensing material, wherein: include: mixing a palladium precursor and a carbon nanotube solution to obtain a mixed solution; Drying the mixed solution to obtain powder; The powder is calcined to obtain a palladium-carbon nanotube composite material.

16. The method for preparing a gas sensing material according to claim 15, wherein: In the step of mixing the palladium precursor with the carbon nanotubes, the mixed solution further includes a second metal precursor.

17. The method for preparing a gas sensing material according to claim 15 or 16, wherein: In the step of mixing the palladium precursor with the carbon nanotubes, the mixed solution further includes a linker.

18. The method for preparing a gas sensing material according to claim 17, wherein: The linking agent includes any one of dopamine and hexadecyltrimethylammonium bromide.

19. A gas sensor, wherein: The method comprises the gas sensing material as claimed in any one of claims 12 to 14; or comprises the gas sensing material prepared by the method as claimed in any one of claims 15 to 18.

20. An electrical device, wherein: A battery comprising any one of claims 1 to 11.

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