35 results about "Double-layer capacitance" patented technology

The invention discloses a working condition monitoring method for a sodium ion battery sodium precipitation behavior based on battery impedance analysis. The core principle of the method is based on the following points: when sodium precipitation occurs, sodium metal is deposited on the surface of hard carbon, so that the physical and chemical properties of the surface of the hard carbon can be changed; the conductivity of sodium metal is obviously different from that of a hard carbon material, so that the charge transfer resistance of hard carbon is obviously changed. In addition, the appearance of the sodium metal also causes the change of the electric double layer capacitance on the hard carbon surface; therefore, whether sodium metal begins to be separated out or not can be accurately judged by detecting the change of the charge transfer resistance and the electric double-layer capacitance on the hard carbon surface; according to the scheme, in-situ monitoring of sodium metal precipitation can be achieved under the condition that the battery structure is not damaged, the sodium metal precipitation situation of the sodium ion battery in the half-battery discharging process can be sensitively captured, and sodium metal deposition of the half battery, the full battery and the soft package battery under the actual operation condition can be monitored in real time.

The invention discloses a flexible pressure sensor based on ionized hydrogel and a preparation method thereof. The sensor adopts a sandwich layered structure of a flexible composite electrode, an ionized water gel dielectric layer and a flexible composite electrode, ionized water gel is used as a dielectric layer, and an upper flexible electrode and a lower flexible electrode are prepared from a multi-walled carbon nanotube / polydimethylsiloxane (MWCNTs / PDMS) composite material; the surface, making contact with the dielectric layer, of the electrode is copied through an abrasive paper template method to form a micron-sized rough structure. Under the action of external pressure, the effective contact area between the microstructure electrode and the ionized water gel dielectric layer and the equivalent electrode distance change, so that the interface electric double-layer capacitance is regulated and controlled, and high-sensitivity conversion from a pressure signal to a capacitance signal is realized. The flexible pressure sensor is simple in structure and excellent in flexibility, can be further integrated into a pressure sensing array, and is suitable for the fields of wearable electronics, electronic skin, man-machine interaction and the like.

The invention discloses a method, a device and equipment for determining electrochemical parameters of a battery, a medium and a product. The method comprises the following steps: acquiring an electrochemical impedance frequency spectrum of the battery; constructing an electrochemical model, wherein the electrochemical model is obtained by adding an electric double-layer capacitance model on the basis of the pseudo two-dimensional model; inputting an electrochemical parameter initial value into the electrochemical model, applying a sinusoidal signal with a preset frequency, and simulating a battery electrochemical experiment process to obtain a simulation voltage value and a simulation current value; performing fitting calculation processing on the simulation voltage value and the simulation current value to obtain a simulation impedance value; and performing iterative adjustment on the initial value of the electrochemical parameter according to the test impedance value and the simulation impedance value to obtain a target value of the electrochemical parameter. According to the scheme, the electrochemical parameters of the battery can be directly obtained by using the pseudo two-dimensional model and the electric double-layer capacitance model, and influences of different physical and chemical processes are distinguished through impedance analysis, so that the accuracy of electrochemical parameter calculation is improved.

The present invention provides a method for testing the electrochemical active area of ​​an electrode, comprising the following steps: S1: preparing a battery with a three-electrode structure; S2: performing cycle activation on the battery; S3: performing an EIS test on the battery to obtain an EIS test curve; S4: performing equivalent circuit fitting using simulation software based on the curve obtained by the EIS test and calculating the double-layer capacitance C according to a formula dl #imgabs0#Where f is the frequency, Z” is the imaginary component of EIS, and n is the degree of non-ideal behavior. S5: Calculate the electrochemically active area ESCS of the electrode using the formula: #imgabs1#Where ECSA is the electrochemical surface area (cm) contained in each geometric area 2 cm ‑2 ), C*=60μF cm ‑2 (surface capacitance of a smooth surface), A is the geometric area of ​​the electrode (cm 2 The method for testing the electrochemically active area of ​​an electrode provided by the present invention overcomes the defect that the existing method for testing the electrochemically active area of ​​an electrode is easily interfered by external factors, and improves the accuracy, reliability and reproducibility of the method for testing the electrochemically active area of ​​an electrode.

The invention discloses a method for predicting the high-temperature storage performance of a battery. The method comprises the following steps: manufacturing a negative plate into a soft package symmetrical battery; measuring the open-circuit voltage of the soft package symmetrical battery; at least three different scanning speeds are selected, a CV curve of the soft package symmetrical battery is made, at each scanning speed, two current values corresponding to the open-circuit voltage are I1 and I2 respectively, and I is recorded as 0.5 * (I1-I2); the scanning speed and the corresponding I value are fitted to obtain an oblique line, the slope of the oblique line is electric double layer capacitance Cdl, and normalization processing is performed according to a formula C = Cdl / S or C = Cdl / m to obtain unit capacitance; testing the high-temperature full-power recovery rate of the soft package symmetrical battery with the known C value at the test temperature after N days; drawing a standard curve by using multiple groups of data; and preparing the negative plate to be measured into a symmetrical battery, and substituting the measured capacitance into the standard curve to obtain the full-charge recovery rate after N days. The method can quickly predict the high-temperature storage performance of the battery.

The invention relates to an IrO2-Ta2O5 titanium anode coating based on graphene doping and temperature programming sintering synergistic enhancement and a preparation method of the IrO2-Ta2O5 titanium anode coating, and belongs to the technical field of electrode material preparation. According to the method, graphene is doped in an IrO2-Ta2O5 coating, the content of the graphene is controlled to be 0.2-0.8 mg / mL, preferably 0.6 mg / mL, the content of iridium is 26 g / m, and a 200-500 DEG C temperature programming sintering process is adopted. By optimizing the graphene dispersing and sintering process, the conductivity, the electrocatalytic activity and the structural stability of the coating are remarkably improved. Experimental results show that the coating has lower charge transfer resistance and higher electric double layer capacitance and oxygen evolution reaction activity, and the strengthening life of the coating exceeds 1100 hours and is far longer than that of a traditional titanium anode coating. The method is suitable for high-requirement electrochemical scenes such as electrolytic copper foil and chlor-alkali industry, and has a good industrial popularization prospect.

A trench capacitor and a manufacturing method therefor. The manufacturing method comprises: providing a substrate; forming a first trench in an insulating layer on a first metal wire, so as to expose the first metal wire; forming a double-layer capacitor on the insulating layer on the periphery of the first trench and in the first trench, and a first electrode being electrically connected to the first metal wire; and forming a fourth metal wire to connect a second metal wire to a second electrode and forming a fifth metal wire to connect a third metal wire to a third electrode. Three electrodes of the double-layer capacitor are led out downwards by using the first to third metal wires in the substrate, which reduces the difficulty of process integration and is conducive to improving the capacitance density and design freedom of the double-layer capacitor.

The invention discloses an MEMS device and a manufacturing method thereof, and the method comprises the steps: forming a first MEMS structure: providing a first substrate, forming a first sensing layer on the first substrate, and sequentially forming a first cavity and a second sensing layer on the first sensing layer; forming a second MEMS structure: providing a second substrate, forming a third sensing layer on the second substrate, and sequentially forming a second cavity and a fourth sensing layer on the third sensing layer; bonding the second sensing layer and the fourth sensing layer to form a common sensing layer; the part, corresponding to the first cavity, of the first substrate is removed, and the first sensing layer forms a movable sensing layer. According to the MEMS device and the manufacturing method thereof provided by the invention, the stacked double-layer capacitor structure is prepared by adopting a heterogeneous bonding mode, the process is simple, the implementation is high, the prepared device structure does not need to be plugged, the problem that the sensing layer is uneven due to hole plugging is avoided, and the reliability of the device is improved. The reliability problems of air leakage and the like of the hole blocking structure caused by repeated pressure measurement motion of the upper-layer pressure sensing film of the sealing cavity are also avoided, and the service life and the yield of the device are improved.

The invention discloses a device for performing direction control and separation on charged particles in electrolyte, which comprises a microfluid channel, the microfluid channel is provided with a sample inlet port and a sample outlet port, a fluid flows from the sample inlet port to the sample outlet port at a speed v0, a separation chamber is formed in the microfluid channel, the fluid contains the charged particles, and the separation chamber is communicated with the sample inlet port and the sample outlet port. Charged particles are separated in the separation chamber; the number of the electrodes in each group of electrodes is the same or different, each electrode is in contact with the fluid, a pseudocapacitor and / or a double-layer capacitor are / is formed on the contact interface of the electrode and the fluid, the electrodes are arranged in the microfluid channel in parallel, and a certain angle can be formed between the arrangement direction and the flowing direction of the fluid; a plurality of conductor leads; and each driving power supply is connected with one group of electrodes, the driving power supplies generate periodic voltage or current excitation, and the voltage excitation or the current excitation output by the driving power supplies in an output period is in a changing state.

The present invention belongs to the technical field of electrochemical catalysts, and specifically relates to a porous carbon nanotube-supported high entropy alloy and its preparation method and application. The porous carbon nanotube-supported high entropy alloy is a porous nanoflower network structure; the nanosheet structure formed by iron, aluminum, nickel, cobalt and manganese elements is evenly distributed on the surface of the multi-walled carbon nanotube; and the average pore size of the porous carbon nanotube-supported high entropy alloy is 10nm-11nm, and the average pore volume is 0.25cm 3 / g‑0.3cm 3 / g, specific surface area is 50m 2 / g‑54m 2 / g, the effective surface area of ​​the double layer capacitor is 6.2mF / cm 2 ‑6.5mF / cm 2 , the Tafel slope is 46mV / dec‑47mV / dec. Compared with existing catalysts and high entropy alloys, it has a smaller Tafel slope, stronger OER activity, a larger double-layer capacitor effective surface area, and a faster electron transfer reaction rate, that is, it has stronger electrocatalytic performance.

The invention provides a trench capacitor and a manufacturing method thereof. The manufacturing method comprises the following steps: providing a substrate; forming a plurality of first grooves to expose the first metal wires and a plurality of second grooves to expose the second metal wires; a single-layer capacitor is formed on the first groove and the insulating layer around the first groove, a double-layer capacitor is formed on the second groove and the insulating layer around the second groove, the second electrode is connected with the first metal wire through the first groove, and the first electrode is connected with the second metal wire through the second groove; forming a through hole in the insulating layer on the third metal wire to expose the third metal wire; and forming a fourth metal wire which is electrically connected with the third electrode and the third metal wire. According to the invention, the three electrodes of the double-layer capacitor and the single-layer capacitor are led out downwards by using the first metal wire, the second metal wire and the third metal wire in the substrate, so that the capacitance density of the trench capacitor is increased, the process integration difficulty is reduced, and the freedom degree of the design of the trench capacitor is improved.

The present invention relates to a method for treating a surface (10a) of a part (10) of an implantable medical device (1), the method comprising the steps of: providing the part (10), the part (10) comprising a surface (10a) comprising titanium, exposing the surface to a gas (G) containing nitrogen, and applying laser light (L) to the surface (10a) to create a titanium nitride (TiN) layer (11) on the surface (10a) having an increased double layer capacitance compared to the untreated surface (10a).

The invention relates to a high-modulation-efficiency phase modulator based on a silicon nitride-lithium niobate waveguide. The modulator comprises an optical transmission unit and an electric transmission unit, the optical transmission unit comprises a quartz substrate layer, a silicon dioxide buffer layer arranged above the quartz substrate layer, a composite waveguide arranged above the middle position of the silicon dioxide buffer layer, and a silicon dioxide cladding covering the outer side of the composite waveguide; the electric transmission unit comprises a metal traveling wave electrode, and the metal traveling wave electrode adopts an embedded double-layer capacitor microstructure load traveling wave electrode. By optimizing the design of the electrode structure and the waveguide structure, the modulation efficiency is remarkably improved, broadband response and low optical loss are considered at the same time, and the device is suitable for application scenes sensitive to phase modulation efficiency and power consumption, such as high-speed optical fiber communication, coherent optical transmission systems, optical phased arrays and quantum optical experiments.

The invention belongs to the technical field of resource recycling, and particularly relates to an energy storage bearing material and a preparation method thereof, and a structural electrode and a preparation method and application thereof. The energy storage bearing material provided by the invention has good bearing capacity and energy storage capacity and high compressive strength. The structural electrode provided by the invention has bearing capacity and energy storage capacity at the same time, and is high in compressive strength, high in cycle retention rate, good in stability and good in compatibility with buildings, and the retention rate of 5000 cycles is 93% or above. According to the structural electrode provided by the invention, the electric quantity is stored by adopting a double-electric-layer capacitance principle, and the structural electrode has good stability and durability; meanwhile, hidden dangers of liquid leakage and fire outbreak of a traditional pseudocapacitor can be avoided, the treatment problem caused by scrapping of a chemical battery can be solved, and environmental friendliness and sustainable development are achieved. The structural electrode provided by the invention can be applied to the field of energy development and utilization, and is wide in application scene.

A capacitive sensing film, a smart diaper and a wetness detection system device including the capacitive sensing film. The capacitive sensing film includes a metal film electrode, a flexible substrate, and a waterproof protective layer; the metal film electrode is deposited on the flexible substrate, and the waterproof protective layer covers the metal film electrode and forms an interlayer, adapted to protect the metal film electrode; the metal film electrode has a smooth surface and a nanoscale thickness, adapted to reduce the surface area in contact with a liquid through the gap of the interlayer; when the capacitive sensing film is wetted by the liquid containing electrolyte, the electric double layer capacitance generated between the metal film electrode and the liquid is smaller than the electrolytic capacitance generated between the metal film electrode and the liquid, thus a wetness detection function based on electrolytic capacitance is realized.

This invention relates to a method for operating an electric vehicle and an electric vehicle comprising: an electrical drive unit for the vehicle's driving motion; a control unit for controlling the vehicle's driving motion; a first energy storage device, particularly configured as a rechargeable battery device, for supplying a first DC voltage to the control unit; a second energy storage device, particularly configured as a double-layer capacitor device, and / or the second energy storage device charging and discharging faster than the first energy storage device, for supplying a second DC voltage to the drive unit; and a power supply unit, particularly intermittently providing a DC output voltage, wherein the first energy storage device is connected to the second energy storage device, particularly electrically, via a conversion device, wherein the connection between the first energy storage device and the power supply unit, particularly an electrical connection, is such that the DC output voltage is substantially equal to the first DC voltage, wherein the conversion device converts the first DC voltage to the second DC voltage, and wherein power flow from the second energy storage device to the first energy storage device is prevented.

The present disclosure relates to the technical field of electrode materials and provides a titanium-based platinum-nickel electrode material, a preparation method, and an application thereof. The method includes: performing a first anodic oxidation and a second anodic oxidation sequentially on a titanium sheet in an ammonium fluoride solution to obtain an oxidized titanium sheet; performing calcination on the oxidized titanium sheet to obtain a titanium sheet containing a titanium dioxide layer; and performing electrodeposition on the titanium sheet containing the titanium dioxide layer in a platinum-based electrolyte to obtain the titanium-based platinum-nickel electrode material. The prepared titanium-based platinum-nickel electrode material effectively reduces the usage amount of Pt-based precious metals and can maintain high activity and stability to generate hydrogen peroxide on-line under the neutral condition; its cathode current density efficiency reaches 76.40%, the anode current density efficiency reaches 70.23%, and the bilayer capacitance value is 1.33 mF·cm−2, which is 4.2 times the bilayer capacitance value of the titanium-based platinum-nickel electrode material obtained without anodic oxidation, and has a very good industrial application prospect.

A device for estimating electrical properties of an electrolyzer (103) includes a data processing system (102) for estimating electrical values ​​of the electrolyzer, such as membrane resistance, based on the initial value and decay time constant of the electrolyzer's differential voltage, current (I), and double-layer capacitance voltage during shutdown of the electrolyzer. The differential voltage is the difference between the electrolyzer's voltage (U) and the electrolyzer's total reversible voltage. The initial value and decay time constant of the double-layer capacitance voltage are estimated based on the value of the differential voltage when the current is zero and the differential voltage is equal to the double-layer capacitance voltage. The electrical values ​​can be estimated even if a gradual interruption of the electrolyzer's current is not possible.

The application relates to the preparation and application of a capacitive deionization electrode for treating low-concentration fluoride ion wastewater, and belongs to the technical field of capacitive deionization. A cerium-nitrogen co-modified turbo layered carbon material prepared by taking a supramolecule as a precursor, forming a carbon skeleton through pyrolysis and then performing metal modification control is used as an anode, carboxyl activated carbon is used as a cathode, and the cathode and the anode jointly form a capacitive deionization system. The cerium-nitrogen co-modified turbo layered carbon material electrode has a layered loose controllable mesoporous structure, a large number of active sites caused by unsaturated coordination vacancies and excellent electric double-layer capacitive behavior. The cerium-nitrogen co-modified turbo layered carbon material electrode has excellent fluoride ion adsorption capacity in low-concentration fluoride-containing wastewater, specifically, the adsorption rate is fast and the adsorption capacity is large, and the effluent concentration can reach below the relevant standard. The capacitive deionization electrode material has a good engineering application prospect in actual wastewater treatment.

The invention relates to the technical field of sensing of aquatic water ion detection, and discloses a solid-state contact layer of an all-solid-state ion selective electrode, FeCoNi-coated ZIF-8 doped with three transition metals of iron, cobalt and nickel is synthesized through a one-pot method, nano porous carbon based on ZIF-8 is generated through pyrolysis, and finally a transition metal doped ZIF-8-derived carbon nanomaterial is obtained. And mixing the carbon nanomaterial with a hydrophobic material and an ionic liquid to construct an ion-electron transduction layer of the all-solid-state ion selective electrode with excellent hydrophobic performance. The solid-state contact layer prepared by the invention not only can effectively inhibit the formation of a water layer between an ion sensitive film and a conductive substrate and solve the problem of potential drift of an ion selective electrode in measurement, but also has the advantages that the electric double-layer capacitance effect of the carbon nanomaterial and the synergistic pseudocapacitance effect among various transition metals act together; and the ion-electron transduction capability of the electrode is improved.

The invention provides a double-layer capacitor and a manufacturing method thereof. The manufacturing method comprises the following steps: providing a substrate; forming a groove in the insulating layer on the second metal wire to expose the second metal wire; a double-layer capacitor is formed on the insulating layer on the periphery of the groove and in the groove, a part of the surfaces of the second electrode and the third electrode are exposed, and the first electrode is electrically connected with the second metal wire; forming a third dielectric layer to cover the double-layer capacitor, and forming a first through hole to expose the second electrode and the third electrode; forming a second through hole in the insulating layer to expose the first metal wire and the third metal wire; and forming a fourth metal wire to connect the first metal wire and the second electrode and a fifth metal wire to connect the third metal wire and the third electrode. In the invention, the three electrodes of the double-layer capacitor are led out downwards by using the first metal wire, the second metal wire and the third metal wire in the substrate, so that the process integration difficulty is reduced, and the capacitance density and the design freedom degree of the double-layer capacitor can be improved.

The present invention relates to a method for assessing the corrosive state of a reinforced-concrete component (1) comprising reinforcing steel (5), comprising the steps: providing a first conductor (LA) and establishing an electrical connection between the first conductor (LA) and a first section of the reinforcing steel (5) for the use thereof as an anode (100), and providing a second conductor (LK) and establishing an electrical connection between the second conductor (LK) and a second section, the second section being a section of the reinforcing steel (5) which is spatially separated from the first section, or a section of a steel element present outside the reinforced-concrete component (1), for the use thereof as a cathode (110); establishing a disconnectable electrical connection between the first conductor (LA) and the second conductor (LK) outside the reinforced-concrete component (1); determining the double-layer capacitance (CDL,A, CDL,K) of the anode (100) and of the cathode (110) and / or of the surface (AA, AK) of the anode (100) and of the cathode (110) on which the double-layer capacitance (CDL,A, CDL,K) is based; forming a mathematical relation of the double-layer capacitances (CDL,A, CDL,K) to one another or of the surfaces (AA, AK) to one another; and assessing the formed relation on the basis of exactly one or at least one predetermined criterion.

A method of detecting a state of a lipid membrane in a cell of a nanopore based sequencing chip is disclosed. A lipid membrane is coupled with an integrating capacitor, wherein the lipid membrane is between a working electrode and a counter electrode. An alternating current (AC) voltage is applied to the counter electrode. A voltage across the integrating capacitor is periodically sampled by an analog-to-digital converter (ADC). A change in the sampled voltage across the integrating capacitor in response to an intermediate change in the AC voltage is determined. A state of the lipid membrane is determined based on the determined change in the sampled voltage across the integrating capacitor in response to the intermediate change in the AC voltage.

An apparatus for performing direction control and separation on particles in an electrolyte. The apparatus comprises: a microfluidic channel (1), wherein the microfluidic channel (1) has a sample inlet (11) and a sample outlet (12), such that a fluid flows at a velocity V0 through the sample inlet (11) toward the sample outlet (12), a separation chamber is formed inside the microfluidic channel (1), and the fluid contains charged particles, which are separated inside the separation chamber; two or more groups of electrodes (2), wherein the number of electrodes in each group of electrodes (2) is the same or different, each electrode (2) is in contact with the fluid and forms a pseudocapacitor and / or a double-layer capacitor on the interface where the electrode (2) is in contact with the fluid, the electrodes (2) are arranged in parallel inside the microfluidic channel (1), and there may be a certain angle between the arrangement direction of the electrodes (2) and the flowing direction of the fluid; a plurality of conductor leads (3); and two or more driving power sources (4), wherein each driving power source (4) is connected to one group of electrodes (2), the driving power sources (4) generate periodic voltages or current excitations, and voltage excitations or current excitations output by the driving power sources (4) within one output period are in a changing state.

The invention discloses a preparation method for quickly preparing an efficient hydrogen evolution catalyst on carbon steel. The method is prepared by treating empty carbon steel, preparing an electroplating solution and an electrodeposited catalyst. The preparation method is simple, the process is easy to control, the raw material source is wide, the cost is low, and the preparation cycle is short. In the preparation process, a dynamic hydrogen bubble template method is used to quickly and firmly grow a NiCoFe catalyst on a carbon steel substrate under a large current, which not only enhances the hydrophilicity and gas repellency of the carbon steel, but also improves the double electric layer capacitance of the material, reduces the hydrogen evolution overpotential of the material, and the prepared catalyst particle size is 1 μm, and the morphology is a three-dimensional porous spherical structure, which lays a foundation for its excellent hydrogen evolution catalytic performance. The catalyst prepared by the invention can be mass-produced, has good economic benefits, and is suitable for industrial application.

The present application is generally directed to an ultrapure polymer gel comprising carbon, hydrogen, oxygen and a total impurity content of less than 500 ppm of elements having atomic numbers ranging from 11 to 92 as measured by proton induced x-ray emission. The disclosed ultrapure polymer gel find utility in any number of devices, for example, in electric double layer capacitance devices and batteries.

The present invention proposes an improved method for the DC model of a liquid-gated graphene field-effect transistor, which includes three steps: improving the traditional GFET model by combining electrochemical theory, introducing the direction of the concentration parameter variable for further improvement, and finally verifying. By introducing the electric double-layer capacitance, the present invention accurately describes the electrode physical effect in the liquid gate, first corrects the DC model of the traditional GFET, overcomes its disadvantage of not being applicable to LG-GFET, and combines the principle of chemical reaction equilibrium to deduce the influence of the analyte concentration on graphene doping. The relationship between the analyte concentration and the carrier mobility is fitted using the relaxation time function, and finally a concentration-related DC model of LG-GFET is established, improving the application scope of the model. At the same time, by introducing the analyte concentration as an independent variable, the concentration of the analyte can be directly obtained using this model while detecting the electrical signal, improving the detection efficiency in the field of biological detection.

The present invention relates to the field of material science and technology, and specifically to a performance evaluation method and system for porous carbon materials for negative electrodes of lithium-ion batteries. By measuring physical performance indicators such as specific surface area, total pore volume, average pore size and graphitization degree of porous carbon materials, using electrochemical impedance spectroscopy to test electrochemical performance indicators such as ohmic resistance, charge transfer resistance, double layer capacitance and diffusion coefficient of porous carbon materials, constructing a two-dimensional matrix of physical performance and electrochemical performance to analyze the correlation, and drawing a radar chart of physicochemical performance to evaluate the comprehensive performance, a comprehensive, efficient and visual performance evaluation method is provided for the application of porous carbon materials in negative electrodes of lithium-ion batteries.

The present invention belongs to the field of pressure sensors, and discloses a flexible pressure sensor based on the synergistic effect of double-layer capacitance and intrinsic pseudocapacitance, which is a stacked structure, which is an upper electrode layer, an adhesive layer, a pseudocapacitance layer, a double-layer capacitance layer, a pseudocapacitance layer, an adhesive layer and a lower electrode layer from top to bottom, and a packaging layer is wrapped around the flexible pressure sensor as a whole, wherein: the upper electrode layer and the lower electrode layer are a pair of circular electrodes of different sizes, and the lower electrode layer has a larger diameter than the upper electrode layer; the double-layer capacitance layer is in the shape of a disc, and the diameter is the same as that of the upper electrode layer, and a plurality of annular protrusions concentric with the double-layer capacitance layer are symmetrically arranged on the upper and lower surfaces of the double-layer capacitance layer; the pseudocapacitance layer is evenly sprayed on the upper and lower surfaces of the double-layer capacitance layer. The capacitive flexible pressure sensor prepared by the present invention has ultra-high sensitivity, high durability, excellent biocompatibility and environmental friendliness.

The invention discloses a VO (OH) 2 / g-C3N4 nano composite material for a supercapacitor and a preparation method of the VO (OH) 2 / g-C3N4 nano composite material, and belongs to the technical field of nano composite material preparation. The preparation method comprises the following steps: firstly, preparing g-C3N4 by adopting a calcination method, adding PVP and anhydrous VOSO4 into deionized water, then adding a NaOH solution to adjust the pH value, then adding g-C3N4, uniformly mixing by adopting a magnetic stirrer, then carrying out ultrasonic dispersion, then pouring a mixed solution into a reaction kettle, setting the temperature to be 100 DEG C, and carrying out sealed storage for 48 hours; after the reaction is finished, naturally cooling to the room temperature, cleaning, drying and grinding a product to obtain VO (OH) 2 / g-C3N4 solid powder, wrapping g-C3N4 nanosheets with VO (OH) 2 nanoribbons, and stacking the g-C3N4 nanosheets together to form a staggered network. The VO (OH) 2 / g-C3N4 composite material has a unique low-resistance characteristic, and shows excellent electrochemical performance due to the synergistic effect of a double-layer capacitor and an embedded pseudo capacitor. The prepared nano composite material has good stability and reusability, the preparation process is simple, economical and efficient, and the nano composite material has good application prospects.