Multi-mode sensitive element, preparation method and application thereof and multi-mode sensor

Abstract

The invention provides a multi-mode sensitive element, a preparation method and application thereof and a multi-mode sensor, and belongs to the technical field of sensors. The multi-mode sensitive element provided by the invention comprises a flexible substrate, and a temperature receptor, a gas receptor and a mechanical force receptor which are arranged on the surface of the flexible substrate, the temperature sensor comprises a first linear copper electrode and a linear nickel electrode, and one end of the first linear copper electrode is in contact with one end of the linear nickel electrode; the gas receptor comprises a first comb-shaped copper electrode and a palladium / yttrium alloy-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode; the mechanical force receptor comprises a second comb-shaped copper electrode and a mechanical force sensitive layer arranged on the comb-shaped surface of the second comb-shaped copper electrode, and the mechanical force sensitive layer is made of polydimethylsiloxane and nano barium carbonate and nano aluminum nitride dispersed in the polydimethylsiloxane. The multi-mode sensitive element provided by the invention has low crosstalk among multiple signals.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a multimodal sensitive element, a preparation method and application thereof, and a multimodal sensor. Background Art

[0002] With the development of science and technology, lithium batteries have become the mainstream. Lithium batteries have the advantages of high energy density, light weight, and long cycle life, and have important applications in many fields such as electronic products, transportation, and medical devices. However, lithium batteries often face various possible failures during use, such as internal short circuit, overcharging, over-discharging, and thermal runaway, etc., which will seriously affect the performance and use of lithium batteries. Therefore, it is necessary to monitor lithium batteries.

[0003] These failure phenomena are usually accompanied by changes in temperature, strain, and gas generation. Traditional monitoring instruments usually monitor a single parameter, but a single parameter cannot accurately reflect the operating state of the battery. Therefore, it is necessary to combine sensors with different monitoring functions to monitor lithium batteries. However, loading too many single-function sensors on lithium batteries has two problems. One is that the volume is relatively large, and the other is that the wiring is complex. Most importantly, the electrical signals of the functional sensors in the prior art are all voltage signals, and there is coupling between the voltage signals generated by simultaneously loading multiple single-function sensors, with serious crosstalk and difficult decoupling problems, which seriously affect the measurement accuracy. Summary of the Invention

[0004] The purpose of the present invention is to provide a multimodal sensitive element, a preparation method and application thereof, and a multimodal sensor. The multimodal sensitive element provided by the present invention can simultaneously monitor changes in temperature, gas, and mechanical force, with low crosstalk between multiple signals, and effectively reduces the volume of the multimodal sensor composed of it and simplifies the wiring of the multimodal sensor.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a multimodal sensitive element, including a flexible substrate and a temperature sensor, a gas sensor, and a mechanical force sensor disposed on the surface of the flexible substrate;

[0007] The temperature sensor includes a first linear copper electrode and a linear nickel electrode, and one end of the first linear copper electrode is in contact with one end of the linear nickel electrode;

[0008] The gas sensor includes a first comb-shaped copper electrode and a palladium / yttrium alloy-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode;

[0009] The mechanical force sensor includes a second comb-shaped copper electrode and a mechanical force sensitive layer disposed on the comb-shaped surface of the second comb-shaped copper electrode. The material of the mechanical force sensitive layer includes polydimethylsiloxane, nano-barium carbonate, and nano-aluminum nitride dispersed in the polydimethylsiloxane.

[0010] Preferably, the mass ratio of palladium / yttrium alloy to nano-tungsten oxide in the palladium / yttrium alloy - nano-tungsten oxide layer is (1 - 3):(7 - 9); the mass ratio of palladium to yttrium in the palladium / yttrium alloy is (1 - 5):(5 - 9).

[0011] Preferably, the mass ratio of polydimethylsiloxane, nano-barium carbonate, and nano-aluminum nitride in the mechanical force sensitive layer is 7:(0.5 - 1.5):(1.5 - 2.5).

[0012] Preferably, the thickness of the mechanical force sensitive layer is 0.2 - 1.5 mm.

[0013] Preferably, the gas sensor further includes a second linear copper electrode and a third linear copper electrode electrically connected to both ends of the first comb-shaped copper electrode.

[0014] Preferably, the mechanical force sensor further includes a fourth linear copper electrode and a fifth linear copper electrode electrically connected to both ends of the second comb-shaped copper electrode.

[0015] The present invention also provides a preparation method of the multi-modal sensitive element described in the above technical solution, including:

[0016] Using laser direct writing technology to prepare a copper conductive layer and a nickel conductive layer on the surface of a flexible substrate respectively; the copper conductive layer includes a first linear copper electrode, a second linear copper electrode, a third linear copper electrode, a fourth linear copper electrode, a fifth linear copper electrode, a first comb-shaped copper electrode, and a second comb-shaped copper electrode; the nickel conductive layer includes a linear nickel electrode;

[0017] Using a coating method to prepare a palladium / yttrium - nano-tungsten oxide alloy layer on the comb-shaped surface of the first comb-shaped copper electrode;

[0018] Pouring and curing a mechanical force sensitive layer colloidal solution on the comb-shaped surface of the second comb-shaped copper electrode to obtain a mechanical force sensitive layer.

[0019] The present invention also provides an application of the multi-modal sensitive element described in the above technical solution or the multi-modal sensitive element prepared by the preparation method described in the above technical solution in lithium battery monitoring.

[0020] The present invention also discloses a multi-modal sensor, including the multi-modal sensitive element described in the above technical solution or the multi-modal sensitive element prepared by the preparation method described in the above technical solution, and a conversion element electrically connected to the multi-modal sensitive element.

[0021] Preferably, the multimodal sensing element and the conversion element are connected by an FPC connector.

[0022] The present invention provides a multimodal sensing element, which includes a flexible substrate, and a temperature sensor, a gas sensor, and a mechanical force sensor disposed on the surface of the flexible substrate; the temperature sensor includes a first linear copper electrode and a linear nickel electrode, and one end of the first linear copper electrode is in contact with one end of the linear nickel electrode; the gas sensor includes a first comb-shaped copper electrode and a palladium / yttrium alloy-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode; the mechanical force sensor includes a second comb-shaped copper electrode and a mechanical force sensitive layer disposed on the comb-shaped surface of the second comb-shaped copper electrode, and the material of the mechanical force sensitive layer includes polydimethylsiloxane, nano barium carbonate, and nano aluminum nitride dispersed in the polydimethylsiloxane. The multimodal sensing element provided by the present invention uses the palladium / yttrium-nano tungsten oxide alloy layer as the gas sensor. The free electrons in the conduction band of tungsten oxide will be captured by oxygen molecules in the air to obtain oxygen ions, forming a depletion layer that increases the resistance. Palladium and yttrium in the alloy layer will further catalyze the dissociation of oxygen molecules and form a deeper depletion layer, further increasing the resistance; when there is hydrogen around the sensing element, causing a gas change, the hydrogen will react with the oxygen atoms in the depletion layer to promote the consumption of the depletion layer, effectively reducing the resistance. At the same time, palladium and yttrium will further promote the dissociation of hydrogen and promote its reaction with oxygen atoms, adding to the reduction of the resistance. Thus, the palladium / yttrium-nano tungsten oxide alloy layer is used as the gas sensor to output a resistance signal; the polydimethylsiloxane in the mechanical force sensor has good flexibility and elasticity, and it can be tightly combined with the interdigital electrodes. When an external force is applied, it will cause a change in the interdigital spacing and a change in the dielectric constant of the interdigital electrodes. The addition of nano barium carbonate can effectively improve the sensitivity of the mechanical force sensor, making the change in the interdigital spacing of the interdigital electrodes more obvious. According to the capacitance formula, a change in the electrode spacing will cause a change in capacitance. Thus, the mechanical force sensor is used to output a capacitance signal. At the same time, under the action of an external force, the interaction force between polydimethylsiloxane, nano barium carbonate, and nano aluminum nitride in the mechanical force sensitive layer is enhanced, reducing the polarization degree of the material. Using the high dielectric constant performance of nano barium carbonate, a change in the dielectric constant is caused, further strengthening the capacitance signal; moreover, the introduction of nano aluminum nitride neutralizes the change in the dielectric constant caused by nano barium carbonate under temperature changes, reducing the temperature sensitivity; the temperature sensor is composed of two different electrodes, and at the same temperature, different electron energy distributions and electron mobilities will be generated, resulting in the accumulation of charges and generating a potential difference, and outputting a voltage signal based on the Seebeck effect; different changes are represented by three different signals to achieve simultaneous monitoring of gas, mechanical force, and temperature changes. Moreover, the signals represented by the three changes are different, effectively reducing the crosstalk between signals; and because the multimodal sensing element realizes simultaneous monitoring of multiple changes, the use of multiple sensors is avoided, reducing the area of the sensor in the lithium battery and greatly reducing the wiring complexity.The results of the examples show that the multi-modal sensitive element provided by the present invention has simple wiring and can simultaneously monitor changes in temperature, gas, and mechanical force. There is low crosstalk between multiple signals, and the volume of the multi-modal sensitive element and the sensor is effectively reduced. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the multi-modal sensitive element of Example 1, where 1 is the gas-sensitive layer, 2 is the mechanical-force sensitive layer, 3 is the temperature sensor, 4 is the polyimide film substrate, 5 is the linear copper electrode, and 6 is the linear nickel electrode;

[0024] Figure 2 It is a schematic diagram of the copper conductive layer prepared in Example 1;

[0025] Figure 3 It is a schematic diagram of the nickel conductive layer prepared in Example 1;

[0026] Figure 4 It is a schematic diagram of the detection process of the multi-modal sensor of Example 2;

[0027] Figure 5 It is a response performance graph of the mechanical force sensor to strain in the multi-modal sensor of Example 2;

[0028] Figure 6 It is a response performance graph of the temperature sensor to strain in the multi-modal sensor of Example 2;

[0029] Figure 7 It is a response performance graph of the gas sensor to strain in the multi-modal sensor of Example 2;

[0030] Figure 8 It is a response performance graph of the gas sensor to different hydrogen concentrations in the multi-modal sensor of Example 2;

[0031] Figure 9 It is a response performance graph of the temperature sensor to different hydrogen concentrations in the multi-modal sensor of Example 2;

[0032] Figure 10 It is a response performance graph of the mechanical force sensor to different hydrogen concentrations in the multi-modal sensor of Example 2;

[0033] Figure 11 It is a response performance graph of the temperature sensor to different hydrogen concentrations in the multi-modal sensor of Example 2;

[0034] Figure 12 It is a response performance graph of the gas sensor to different hydrogen concentrations in the multi-modal sensor of Example 2;

[0035] Figure 13Response performance diagram of the mechanoreceptor in the multimodal sensor of Example 2 to different hydrogen concentrations;

[0036] Figure 14 Response performance diagram of the gas sensor in the multimodal sensor of Example 2 to 1000 ppm hydrogen;

[0037] Figure 15 Response performance diagram of the gas sensor in the multimodal sensor of Comparative Example 3 to 1000 ppm hydrogen;

[0038] Figure 16 Response performance diagram of the gas sensor in the multimodal sensor of Comparative Example 4 to 1000 ppm hydrogen. Detailed implementation manners

[0039] The present invention provides a multimodal sensitive element, comprising a flexible substrate and a temperature sensor, a gas sensor and a mechanoreceptor disposed on the surface of the flexible substrate;

[0040] The temperature sensor includes a first linear copper electrode and a linear nickel electrode, and one end of the first linear copper electrode is in contact with one end of the linear nickel electrode;

[0041] The gas sensor includes a first comb-shaped copper electrode and a palladium / yttrium alloy-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode;

[0042] The mechanoreceptor includes a second comb-shaped copper electrode and a mechanosensitive layer disposed on the comb-shaped surface of the second comb-shaped copper electrode, and the material of the mechanosensitive layer includes polydimethylsiloxane and nano barium carbonate and nano aluminum nitride dispersed in the polydimethylsiloxane.

[0043] The multimodal sensitive element provided by the present invention includes a flexible substrate.

[0044] As an implementation manner of the present invention, the flexible substrate may be a polyimide film, a polyethylene terephthalate film, a polyvinyl alcohol film or a polyethylene naphthalate film; the thickness of the flexible substrate may be 0.01-0.1 mm, may also be 0.02-0.08 mm, or may also be 0.05-0.06 mm. In the present invention, by defining the type and thickness of the flexible substrate, the support for the electrodes in the multimodal sensitive element is realized, and the performance of the multimodal sensitive element is further improved; at the same time, the change in the spacing of the interdigital electrodes can be supported to realize the detection of the deformation change of the multimodal sensitive element.

[0045] The sensitive element provided by the present invention further includes a temperature sensor disposed on the flexible substrate.

[0046] In the present invention, the temperature sensor includes a first linear copper electrode and a linear nickel electrode, and one end of the first linear copper electrode is in contact with one end of the linear nickel electrode. In the present invention, a temperature sensor is formed by contacting two different materials. At the same temperature, the two electrodes will have different electron energy distributions and electron mobilities, which can form a charge accumulation and generate a potential difference, thereby outputting a voltage signal based on the Seebeck effect.

[0047] The present invention has no special limitation on the shapes and sizes of the first linear copper electrode and the linear nickel electrode, and they can be selected according to the usage conditions.

[0048] The sensitive element provided by the present invention further includes a gas sensor disposed on the flexible substrate.

[0049] In the present invention, the gas sensor includes a first comb-shaped copper electrode and nano-aluminum nitride coated on the comb-shaped surface of the first comb-shaped copper electrode.

[0050] As an embodiment of the present invention, the mass ratio of palladium-yttrium alloy to nano-tungsten oxide in the palladium / yttrium-nano-tungsten oxide alloy layer can be (1-3):(7-9), or (1.5-2.5):(7.5-8.5), or (1.8-2):(8-8.2); the mass ratio of palladium to yttrium in the palladium-yttrium alloy can be (1-5):(5-9), or (2-4.5):(6-8.5), or (3-4):(7-8). In the present invention, by defining the composition of the alloy layer, tungsten oxide in the alloy layer can react with oxygen to form a high-resistance depletion layer. When the hydrogen concentration changes, the depletion layer will react with hydrogen to consume the depletion layer, and palladium and yttrium in the alloy will accelerate the effect of the depletion layer, causing a resistance change, thereby enabling the gas sensor to output a resistance signal.

[0051] As an embodiment of the present invention, a polytetrafluoroethylene film can be pasted on the surface of the gas sensor; a heat insulation layer can be pasted on the back of the substrate corresponding to the gas sensor; the material of the heat insulation layer can be aerogel or foamed polyurethane. In the present invention, by coating the gas sensor, the temperature of the object to be measured and the influence of water and oil stains on the detection of the gas sensor can be isolated.

[0052] The sensitive element provided by the present invention further includes a mechanical force sensor disposed on the flexible substrate.

[0053] In the present invention, the mechanical force sensor includes a second comb-shaped copper electrode and a mechanical force sensitive layer disposed on the comb-shaped surface of the second comb-shaped copper electrode. The material of the mechanical force sensitive layer includes polydimethylsiloxane and nano-barium carbonate and nano-aluminum nitride dispersed in the polydimethylsiloxane.

[0054] As an embodiment of the present invention, the mass ratio of the polydimethylsiloxane, the nano-barium carbonate and the nano-aluminum nitride can be 7:(0.5 - 1.5):(1.5 - 2.5), or 7:(0.8 - 1.4):(1.8 - 2.4), or 7:(1.0 - 1.2):(2.0 - 2.2). In the present invention, by defining the composition of the mechanical force sensitive layer, the close combination of the mechanical force sensitive layer and the interdigital electrodes is realized, so that the external force received is converted into the change of the interdigital electrode spacing and its sensitivity is effectively improved. The change of the interdigital electrode spacing is converted into a capacitance signal output by using the capacitance formula.

[0055] As an embodiment of the present invention, the thickness of the mechanical force sensitive layer can be 0.2 - 1.5 mm, or 0.5 - 1.2 mm, or 0.8 - 1 mm. In the present invention, by defining the thickness of the mechanical force sensitive layer, it is ensured that it can play its role fully.

[0056] As an embodiment of the present invention, the exposed parts of the linear copper electrode and the linear nickel electrode can be pasted with PET tape to avoid the oxidation of the electrodes by air.

[0057] The sensitive element provided by the present invention can simultaneously monitor the changes of temperature, gas and mechanical force, and output voltage, resistance and capacitance signals respectively, effectively reducing the crosstalk between signals.

[0058] The present invention also provides a preparation method of the multi-modal sensitive element described in the above technical solution, including:

[0059] Using laser direct writing technology to prepare a copper conductive layer and a nickel conductive layer on the surface of the flexible substrate respectively; the copper conductive layer includes a first linear copper electrode, a second linear copper electrode, a first comb-shaped copper electrode and a second comb-shaped copper electrode; the nickel conductive layer includes a linear nickel electrode;

[0060] Using the coating method to prepare a palladium / yttrium-nano tungsten oxide alloy layer on the comb-shaped surface of the first comb-shaped copper electrode;

[0061] Pouring and curing the colloidal solution of the mechanical force sensitive layer on the comb-shaped surface of the second comb-shaped copper electrode to obtain the mechanical force sensitive layer.

[0062] The present invention uses laser direct writing technology to prepare a copper conductive layer and a nickel conductive layer on the surface of the flexible substrate respectively.

[0063] As an embodiment of the present invention, the copper precursor can be reduced by laser direct writing to obtain the copper conductive layer.

[0064] As an embodiment of the present invention, the preparation method of the copper precursor includes:

[0065] Copper nitrate hexahydrate and ethylene glycol are stirred and mixed and then heated to obtain a copper precursor.

[0066] As an embodiment of the present invention, the mass ratio of copper nitrate hexahydrate to the volume of ethylene glycol can be (1 - 3) g:(2 - 3) mL, can also be (1.2 - 2.5) g:(2.2 - 2.8) mL, and can also be 2 g:2.5 mL. In the present invention, by limiting the dosage ratio of the raw materials, the sufficient reaction between the raw materials is realized.

[0067] As an embodiment of the present invention, the stirring and mixing can be magnetic stirring and mixing; the time of the stirring and mixing can be 10 - 30 min, can also be 12 - 28 min, and can also be 20 - 26 min; the rate of the stirring and mixing can be 200 - 1000 rpm / min, can also be 400 - 800 rpm / min, and can also be 500 - 600 rpm / min. In the present invention, by limiting the process parameters of the stirring and mixing, the sufficient contact of the reaction raw materials is ensured.

[0068] As an embodiment of the present invention, the heating temperature can be 110 - 130 °C, can also be 115 - 125 °C, and can also be 120 - 122 °C; the heating time can be 5 - 15 min, can also be 8 - 13 min, and can also be 10 - 12 min. In the present invention, by limiting the process parameters of the heating process, the activity of the reaction raw materials can be improved, and the reaction degree between the reaction raw materials can be further improved.

[0069] As an embodiment of the present invention, the laser wavelength of the laser direct writing can be 355 nm, 266 nm, 375 nm or 395 nm; the laser frequency of the laser direct writing can be 10 - 15 Hz, can also be 11 - 14 Hz, and can also be 12 - 13 Hz; the device for the laser direct writing is a pulsed laser; the power of the laser direct writing can be 3 - 5 W, can also be 4 W; the scanning speed of the laser direct writing can be 15 - 20 mm / s, can also be 16 - 19 mm / s, and can also be 17 - 18 mm / s. In the present invention, by limiting the process parameters of the laser direct writing, the sufficient reduction of the copper precursor is realized.

[0070] As an embodiment of the present invention, the nickel precursor can be reduced by laser direct writing to obtain a nickel conductive layer.

[0071] As an embodiment of the present invention, the nickel precursor can be nano nickel oxide; the particle size of the nano nickel oxide can be 5 - 15 nm, can also be 8 - 14 nm, and can also be 10 - 12 nm.

[0072] As an embodiment of the present invention, the preparation method of the nickel precursor includes:

[0073] Mix nano-nickel oxide, polyvinylpyrrolidone and n-pentanol and then perform ultrasonic treatment to obtain the nickel precursor.

[0074] As an embodiment of the present invention, the mass ratio of the nano-nickel oxide, polyvinylpyrrolidone and n-pentanol can be (3 - 5):(1 - 2):(10 - 15), or can be 4:1:12. In the present invention, by limiting the dosage ratio of the reaction raw materials, it is ensured that the reaction raw materials can react fully, avoiding incomplete reaction due to too little raw materials and also avoiding side reactions caused by too much raw materials.

[0075] As an embodiment of the present invention, the ultrasonic time can be 10 - 15 h, or can be 11 - 14 h, or can also be 12 - 13 h; the ultrasonic power is 500 - 600 W. In the present invention, by limiting the process parameters of the ultrasonic treatment, the contact opportunity of the raw materials is effectively increased, and the reaction degree is further improved.

[0076] As an embodiment of the present invention, the laser wavelength of the laser direct writing can be 355 nm; the laser frequency of the laser direct writing can be 20 - 25 KHz, or can be 21 - 24 KHz, or can also be 22 - 23 KHz; the power of the laser direct writing can be 1 - 3 W, or can be 2 W; the scanning speed of the laser direct writing can be 50 - 60 mm / s, or can be 52 - 58 mm / s, or can also be 55 - 56 mm / s. In the present invention, by limiting the process parameters of the laser direct writing, the full reduction of the nickel precursor is realized.

[0077] After obtaining the copper conductive layer, the present invention uses the coating method to prepare a palladium / yttrium-nano tungsten oxide alloy layer on the comb-shaped surface of the first comb-shaped copper electrode.

[0078] As an embodiment of the present invention, the preparation method of the palladium / yttrium-nano tungsten oxide alloy layer includes:

[0079] Mix nano tungsten oxide, yttrium chloride, palladium chloride and a metal chelating agent and then perform sintering to obtain palladium / yttrium-nano tungsten oxide alloy powder;

[0080] Mix the palladium / yttrium-nano tungsten oxide alloy powder and a solvent, grind them and then coat them on the comb-shaped surface of the first comb-shaped copper electrode, and perform heat treatment to obtain the palladium / yttrium-nano tungsten oxide alloy layer.

[0081] As an embodiment of the present invention, the metal chelating agent can be o-phenanthroline.

[0082] As an embodiment of the present invention, the mass ratio of the nano-tungsten oxide, yttrium chloride, palladium chloride and metal chelating agent can be (0.1-0.3):(0.01-0.03):(0.01-0.03):0.005, or (0.2-0.25):(0.02-0.025):(0.01-0.02):0.005. In the present invention, the palladium / yttrium-nano-tungsten oxide alloy layer of the required composition is obtained by limiting the amount ratio of the reaction raw materials.

[0083] As an embodiment of the present invention, the sintering temperature can be 600-700°C, 620-680°C, or 650-660°C; the sintering heating rate can be 5-15°C / min, 8-13°C / min, or 10-12°C / min; the sintering time can be 1-5h, 2-4h, or 2.5-3h; the sintering pressure can be 50-100Pa, 55-90Pa, or 60-80Pa. In the present invention, the reaction raw materials are fully contacted, and coordination bonds are formed between yttrium chloride, palladium chloride and metal chelating agent. Under the action of high temperature, metal ions will be decomposed to obtain corresponding metal elements; by limiting the sintering process parameters, the sintering effect is further improved, and the performance of the alloy layer is further improved.

[0084] As an embodiment of the present invention, the mass ratio of the palladium / yttrium-nano tungsten oxide alloy to the solvent can be 1:(1-5) or 1:(2-3). In the present invention, by limiting the amount ratio of the reaction raw materials, the viscosity of the mixed solution is regulated while the alloy is evenly dispersed, thereby ensuring the subsequent combination of the alloy and the copper interdigital electrode.

[0085] As an embodiment of the present invention, the temperature of the heat treatment can be 200-250°C, 210-240°C, or 220-230°C; the time of the heat treatment can be 1-5 minutes, 2-4.5 minutes, or 3-4 minutes. In the present invention, by limiting the process parameters of the heating operation, the solvent in the mixed solution is fully removed to achieve full combination of the alloy and the interdigital electrodes.

[0086] After obtaining the copper conductive layer, the present invention pours a colloidal solution of a mechanical force sensitive layer on the comb-shaped surface of the second comb-shaped copper electrode and solidifies the colloidal solution to obtain the mechanical force sensitive layer.

[0087] As an embodiment of the present invention, the method for preparing the mechanical force sensitive layer comprises:

[0088] The prepolymer of polydimethylsiloxane, a cross-linking agent, nano-barium carbonate and nano-aluminum nitride are mixed and ultrasonicated to obtain a colloidal solution;

[0089] Pour the colloidal solution onto the comb-shaped surface of the second comb-shaped copper electrode for curing to obtain a mechanical force sensitive layer.

[0090] As an embodiment of the present invention, the mass ratio of the prepolymer of polydimethylsiloxane to the crosslinking agent can be (5-10):1, or can be (6-8):1. As an embodiment of the present invention, the total mass ratio of the prepolymer of polydimethylsiloxane and the crosslinking agent to barium carbonate nanoparticles and aluminum nitride nanoparticles can be (3.5-9):1:1, or can be (6-8):1:1, or can also be 7:1:1. In the present invention, by limiting the dosage ratio of the reaction raw materials, it is beneficial to achieve the full crosslinking of the polydimethylsiloxane prepolymer and the full contact of barium carbonate nanoparticles and aluminum nitride nanoparticles with the crosslinking network in the subsequent process, further improving the performance and sensitivity of the mechanical force sensitive layer.

[0091] The present invention has no special limitation on the crosslinking agent, and the crosslinking agents commonly used by those skilled in the art can be adopted.

[0092] As an embodiment of the present invention, the frequency of the ultrasonic wave can be 100KHz-1MHz, or can be 200-800KHz, or can also be 500-600KHz; the time of the ultrasonic wave can be 5-15min, or can be 6-13min, or can also be 8-10min. In the present invention, by limiting the process parameters of the ultrasonic treatment, the uniform dispersion and full contact of the reaction raw materials are realized.

[0093] As an embodiment of the present invention, the temperature of the curing can be 50-80°C, or can be 55-75°C, or can also be 60-70°C; the time of the curing can be 2-5h, or can be 3-4h. In the present invention, by limiting the process parameters of the curing treatment, the reaction raw materials react fully, the prepolymer of polydimethylsiloxane and the crosslinking agent react fully to obtain a crosslinking network, and barium carbonate nanoparticles and aluminum nitride nanoparticles are fully dispersed in the crosslinking network.

[0094] The preparation method provided by the present invention can achieve the tight combination of the detection sensitive layer and the electrode, effectively improve the monitoring accuracy, and realize the simultaneous detection of gas, temperature and deformation.

[0095] The present invention also provides the application of the multimodal sensitive element described in the above technical solution or the multimodal sensitive element prepared by the preparation method described in the above technical solution in the monitoring of lithium batteries.

[0096] The present invention also provides a multimodal sensor, including the multimodal sensitive element described in the above technical solution or the multimodal sensitive element prepared by the preparation method described in the above technical solution, and a conversion element electrically connected to the multimodal sensitive element.

[0097] As an embodiment of the present invention, the conversion element may include a resistance processing module, a voltage processing module, and a capacitance processing module.

[0098] As an embodiment of the present invention, the resistance processing module includes a resistance signal port, a voltage dividing circuit, an electrostatic amplifier, a data converter, a main control chip, and a terminal machine connected in sequence; the resistance signal port is connected to the second linear copper electrode and the third linear copper electrode in the multimodal sensitive element;

[0099] The voltage processing module includes a voltage signal port, a data converter, a main control chip, and a terminal machine connected in sequence; the voltage signal port is connected to the ports of the first linear copper electrode and the linear nickel electrode in the multimodal sensitive element;

[0100] The capacitance processing port includes a capacitance digital converter, a main control chip, and a terminal machine; the capacitance signal port is connected to the ports of the fourth linear copper electrode and the fifth linear copper electrode in the multimodal sensitive element.

[0101] As an embodiment of the present invention, the multimodal sensitive element and the conversion element can be connected through an FPC connector. In the present invention, by defining the connection method, the tight connection between the multimodal sensitive element and the conversion element is realized, and the conversion element processes the signals of the multimodal sensitive element to realize the monitoring of gas, temperature, and mechanical force.

[0102] The multimodal sensor provided by the present invention can detect changes in temperature, gas, and mechanical force, and convert them into digital information to effectively monitor the battery usage.

[0103] In order to further illustrate the present invention, the following will describe in detail the multimodal sensitive element provided by the present invention, its preparation method and application, and the multimodal sensor in combination with embodiments, but they cannot be understood as limiting the protection scope of the present invention.

[0104] Example 1

[0105] A multimodal sensitive element is as Figure 1 shown, and is composed of a polyimide film with a thickness of 0.05 mm and a temperature sensor, a gas sensor, and a mechanical force sensor disposed on the surface of the polyimide film;

[0106] The temperature sensor includes a first linear copper electrode and a linear nickel electrode, and one end of the first linear copper electrode is in contact with one end of the linear nickel electrode;

[0107] The gas sensor includes a first comb-shaped copper electrode and a palladium / yttrium alloy-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode;

[0108] The composition of the palladium / yttrium alloy-nano tungsten oxide layer is a palladium-yttrium alloy and nano tungsten oxide with a mass ratio of 2:8; the mass ratio of palladium to yttrium in the palladium / yttrium alloy is 5:5;

[0109] Paste a layer of polytetrafluoroethylene film on the surface of the gas sensor, and paste a layer of foamed polyurethane flexible heat-insulating material on the back of the polyimide film corresponding to the gas sensor;

[0110] The mechanical force sensor includes a second comb-shaped copper electrode and a mechanical force sensitive layer arranged on the comb-shaped surface of the second comb-shaped copper electrode. The material of the mechanical force sensitive layer includes polydimethylsiloxane and nano barium carbonate and nano aluminum nitride dispersed in the polydimethylsiloxane;

[0111] The mass ratio of polydimethylsiloxane, nano barium carbonate and nano aluminum nitride in the mechanical force sensitive layer is 7:1.5:1.5;

[0112] The preparation method of the multimodal sensitive element includes:

[0113] Use laser direct writing technology to prepare a copper conductive layer on the surface of the flexible substrate as Figure 2 shown and a nickel conductive layer as Figure 3 shown; the copper conductive layer includes a first linear copper electrode, a second linear copper electrode, a first comb-shaped copper electrode and a second comb-shaped copper electrode; the nickel conductive layer includes a linear nickel electrode;

[0114] Among them, the preparation method of the copper conductive layer is:

[0115] Mix 2.5 g of copper nitrate hexahydrate and 2 mL of ethylene glycol (the mass ratio of copper nitrate hexahydrate to the volume of ethylene glycol is 2.5 g:2 mL), and magnetically stir at 500 rpm for 10 min, and then heat at 120 °C for 10 min to obtain a copper precursor;

[0116] Use laser direct writing with a laser wavelength of 355 nm, a laser frequency of 10 Hz, a laser power of 3 W, and a scanning speed of 15 mm / s to reduce the copper precursor until the entire pattern is scanned by the laser to obtain a copper conductive layer;

[0117] Among them, the preparation method of the nickel conductive layer is:

[0118] Mix nano nickel oxide, polyvinylpyrrolidone and n-pentanol with a mass ratio of 4:1:12, and perform ultrasonic oscillation at a power of 500 W for 10 h to obtain a nickel precursor with a particle size of 8 nm;

[0119] Reducing the nickel precursor by laser direct writing with a laser wavelength of 355 nm, a laser frequency of 20 KHz, a laser power of 2 W, and a scanning speed of 50 mm / s until the entire pattern is scanned by the laser to obtain a nickel electrode;

[0120] Preparing a palladium / yttrium alloy-nano tungsten oxide layer on the comb-shaped surface of the first comb-shaped copper electrode by a coating method, including:

[0121] (1) Mixing tungsten oxide nanoparticles, phenanthroline, ethanol, and water with a mass ratio of 0.2048:0.005:5:5, and performing the first ultrasonic treatment at 50 °C and a power of 500 W for 30 min to obtain a mixed solution;

[0122] (2) Adding yttrium chloride and palladium chloride (the mass ratio of tungsten oxide nanoparticles, yttrium chloride, and palladium chloride is 0.2048:0.0232:0.0177) to the mixed solution obtained in step (1), performing the second ultrasonic treatment at 50 °C and a power of 500 W for 15 min, and then drying at 80 °C to obtain a mixed powder; ultrasonically cleaning the quartz boat with ethanol and acetone at a power of 500 W for 15 min and then drying at 82 °C for 2 h; transferring the mixed powder to the quartz boat and placing the quartz boat 20 cm outside the tube furnace;

[0123] (3) Flowing argon with a flow rate of 100 sccm in the tube furnace for 30 min and then sweeping the tube, evacuating the tube furnace to a pressure of -0.1 MPa, heating it at a heating rate of 10 °C / min to 650 °C, and pushing the quartz boat containing the mixed powder obtained in step (2) into the center of the hot zone within 1 s for sintering for 2 h to obtain a palladium / yttrium alloy-nano tungsten oxide;

[0124] Mixing and grinding the palladium / yttrium alloy-nano tungsten oxide, terpineol, butyl carbitol acetate, and dibutyl phthalate with a mass ratio of 1:3:1.5:0.5, and then coating it on the comb-shaped surface of the first comb-shaped copper electrode with a coating thickness of 0.01 cm; then heating at 200 °C for 2 min to obtain a palladium / yttrium alloy-nano tungsten oxide layer;

[0125] Pouring a colloidal solution of a mechanical force-sensitive layer on the comb-shaped surface of the second comb-shaped copper electrode and then curing it to obtain a mechanical force-sensitive layer, including:

[0126] Mixing the prepolymer of polydimethylsiloxane, polydimethyl-methylhydrogensiloxane, nano barium carbonate, and nano aluminum nitride with a mass ratio of 6.36:0.64:1.5:1.5 and performing ultrasonic treatment at a power of 500 W for 10 min to obtain a colloidal solution;

[0127] Place a mold with a thickness of 1 cm on the interdigital surface of the other interdigital electrode of the composite copper electrode, pour the colloidal solution into the mold, and cure it at 80 °C for 5 h to obtain a mechanical force sensitive layer.

[0128] Example 2

[0129] A multimodal sensor is composed of the multimodal sensitive element of Example 1 and a conversion element (as Figure 4 shown) that is electrically connected to the multimodal sensitive element;

[0130] The conversion element is composed of a resistance processing module, a voltage processing module, and a capacitance processing module;

[0131] The resistance processing module is composed of a resistance signal port, a voltage dividing circuit, an electrostatic amplifier, a data converter, a main control chip, and a terminal machine connected in sequence; the resistance signal port is connected to the second linear copper electrode and the third linear copper electrode in the multimodal sensitive element of Example 1;

[0132] The voltage processing module is composed of a voltage signal port, a data converter, a main control chip, and a terminal machine connected in sequence; the voltage signal port is connected to the ports of the first linear copper electrode and the linear nickel electrode in the multimodal sensitive element of Example 1;

[0133] The capacitance processing port is composed of a capacitance digital converter, a main control chip, and a terminal machine; the capacitance signal port is connected to the ports of the fourth linear copper electrode and the fifth linear copper electrode in the multimodal sensitive element of Example 1.

[0134] Under room temperature and normal environment, clamp both ends of the multimodal sensor prepared in Example 2 on a Mark10 horizontal tensile tester for stretching. During the stretching process, collect the signals of the mechanical, temperature, and gas concentration three channels through the acquisition module and output the results, as shown in Figures 5 - 7 shown. It can be seen from the figure that: the capacitance signal of the mechanical force sensor in the multimodal sensor prepared by the present invention increases with the increase of strain; while the voltage signal of the temperature sensor in the multimodal sensor prepared by the present invention hardly changes with the increase of strain; however, the resistance signal of the gas sensor in the multimodal sensor prepared by the present invention increases with the increase of strain. Thus, it can be seen that there is low crosstalk between the temperature sensor and the mechanical force sensor in the multimodal sensor prepared by the present invention; there is crosstalk between the gas sensor and the mechanical force sensor, and generally, the crosstalk can be removed by a simple mathematical decoupling method.

[0135] Fix the multimodal sensor prepared in Example 2 by pasting and place it in a sealed gas chamber for experiments. Introduce hydrogen with a concentration of 0 - 1000 ppm with air as the background gas into the sealed gas chamber, and collect the signals of the gas concentration, temperature, and mechanical three channels through the acquisition module and output the results. The results are asFigures 8 - 10 As shown in the figure. It can be seen from the figure that: the resistance signal of the gas sensor in the multimodal sensor prepared by the present invention increases with the increase of hydrogen concentration; the capacitance signal of the mechanical force sensor and the voltage signal of the temperature sensor in the multimodal sensor prepared by the present invention change irregularly with the increase of hydrogen concentration. Thus, it can be seen that the temperature sensor and the mechanical force sensor in the multimodal sensor prepared by the present invention are not affected by crosstalk from the gas sensor, and the gas sensor is affected by crosstalk from the temperature sensor and the mechanical force sensor, and generally, the crosstalk can be removed by a simple mathematical decoupling method.

[0136] The multimodal sensor prepared in Example 2 was fixed on a high-precision heating table by pasting for heating. During the heating process, signals of three paths, namely temperature, gas concentration, and mechanical, were respectively collected by the acquisition module, and the results were output, as shown respectively in Figures 11 - 13 As shown in the figure. It can be seen from the figure that: the voltage signal of the temperature sensor in the multimodal sensor prepared by the present invention increases with the increase of temperature; while the capacitance signal of the mechanical force sensor in the multimodal sensor prepared by the present invention hardly changes with the increase of temperature; however, the resistance signal of the gas sensor in the multimodal sensor prepared by the present invention decreases with the increase of temperature. Thus, it can be seen that there is low crosstalk between the temperature sensor and the mechanical force sensor in the multimodal sensor prepared by the present invention; there is crosstalk between the gas sensor and the temperature sensor, and generally, the crosstalk can be removed by a simple mathematical decoupling method.

[0137] Comparative Example 1

[0138] The difference between Comparative Example 1 and Example 1 is only that the gas sensor includes a first comb-shaped copper electrode and a nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode; the rest is the same as in Example 1.

[0139] Comparative Example 2

[0140] The difference between Comparative Example 2 and Example 1 is only that the gas sensor includes a first comb-shaped copper electrode and a palladium-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode;

[0141] The composition of the palladium-nano tungsten oxide layer is palladium and nano tungsten oxide with a mass ratio of 2:8; the rest is the same as in Example 1.

[0142] Comparative Example 3

[0143] The difference between Comparative Example 3 and Example 2 is only that the multimodal sensor is composed of the multimodal sensitive element of Comparative Example 1 and a conversion element electrically connected to the multimodal sensitive element, and the rest is the same as in Example 2.

[0144] Comparative Example 4

[0145] The difference between Comparative Example 4 and Example 2 lies only in the multimodal sensor, which is composed of the multimodal sensitive element of Comparative Example 2 and a conversion element electrically connected to the multimodal sensitive element, and the rest is the same as in Example 2.

[0146] The multimodal sensors prepared in Example 2, Comparative Example 3, and Comparative Example 4 were fixed in a self-developed sealed air chamber by pasting for experiments. Hydrogen with an air background of 1000 ppm was introduced into the sealed air chamber. The gas concentration path signal was collected through the acquisition module, and the results were output, as shown respectively in Figures 14 - 16 the figure. It can be seen from the figure that the gas sensor of the multimodal sensor prepared by the present application can respond to the discharged hydrogen. However, for the gas sensors of the multimodal sensors prepared in Comparative Example 3 and Comparative Example 4, when the concentration of the discharged hydrogen increases, there is a response. However, after the hydrogen decreases, its response cannot be restored to the initial value and cannot be used for gas sensing.

[0147] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A multi-modal sensitive element, characterized in that: It comprises a flexible substrate and a temperature sensor, a gas sensor and a mechanical force sensor arranged on the surface of the flexible substrate; The temperature sensor comprises a first linear copper electrode and a linear nickel electrode, wherein one end of the first linear copper electrode is in contact with one end of the linear nickel electrode; The gas sensor comprises a first comb-shaped copper electrode and a palladium / yttrium alloy-nano tungsten oxide layer coated on the comb-shaped surface of the first comb-shaped copper electrode; The mechanical force receptor comprises a second comb-shaped copper electrode and a mechanical force sensitive layer arranged on the comb-shaped surface of the second comb-shaped copper electrode. The material of the mechanical force sensitive layer comprises polydimethylsiloxane and nano-barium carbonate and nano-aluminum nitride dispersed in the polydimethylsiloxane.

2. The multi-modal sensor according to claim 1, characterized in that: The mass ratio of palladium-yttrium alloy and nano-tungsten oxide in the palladium / yttrium alloy-nano-tungsten oxide layer is (1-3):(7-9); the mass ratio of palladium and yttrium in the palladium-yttrium alloy is (1-5):(5-9).

3. The multi-modal sensor according to claim 1, characterized in that: The mass ratio of polydimethylsiloxane, nano-barium carbonate and nano-aluminum nitride in the mechanical force sensitive layer is 7:(0.5-1.5):(1.5-2.5).

4. The multi-modal sensing element according to claim 1 or 3, characterized in that: The thickness of the mechanical force sensitive layer is 0.2-1.5 mm.

5. The multi-modal sensor according to claim 1, characterized in that: The gas sensor further includes a second linear copper electrode and a third linear copper electrode electrically connected to both ends of the first comb-shaped copper electrode.

6. The multi-modal sensor according to claim 1, characterized in that: The mechanical force receptor further includes a fourth linear copper electrode and a fifth linear copper electrode electrically connected to both ends of the second comb-shaped copper electrode.

7. The method for preparing the multimodal sensing element according to claims 1 to 6, comprising: A copper conductive layer and a nickel conductive layer are prepared on the surface of a flexible substrate by laser direct writing technology; the copper conductive layer comprises a first linear copper electrode, a second linear copper electrode, a third linear copper electrode, a fourth linear copper electrode, a fifth linear copper electrode, a first comb-shaped copper electrode and a second comb-shaped copper electrode; the nickel conductive layer comprises a linear nickel electrode; Preparing a palladium / yttrium-nano tungsten oxide alloy layer on the comb-shaped surface of the first comb-shaped copper electrode by a coating method; The mechanical force sensitive layer is obtained by pouring a colloidal solution of the mechanical force sensitive layer on the comb-shaped surface of the second comb-shaped copper electrode and then solidifying the solution.

8. Use of the multimodal sensitive element according to any one of claims 1 to 6 or the multimodal sensitive element prepared by the preparation method according to claim 7 in lithium battery monitoring.

9. A multimodal sensor, comprising the multimodal sensitive element according to any one of claims 1 to 6 or the multimodal sensitive element prepared by the preparation method according to claim 7, and a conversion element electrically connected to the multimodal sensitive element.

10. The multimodal sensor according to claim 9, characterized in that: The multimodal sensing element and the conversion element are connected via an FPC connector.

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