38 results about "Polarization impedance" patented technology

The invention relates to a preparation method of a solid oxide fuel cell cathode by utilizing an electrical spinning method, belonging to the technological field of function materials. The preparation method is characterized in that cathode material metal cations containing the stoichiometric ratio and the precursor solution or colloidal sol of the appropriate amount of polymerizer is subjected to electrical spinning on a substrate; then the spinning precursor sample is dried and sintered to prepare the solid oxide fuel cell cathode materials with a porous structure and controllable microstructure and thickness. The SOFC (Solid Oxide Fuel Cell) cathode prepared by utilizing the electrical spinning method has the advantages of large specific surface area, high porosity, adjustable aperture and good structure homogeneity; the oxygen transmission characteristic and the catalytic activity of the cathode can be enhanced; the polarization impedance is reduced; the performance in intermediate and low temperature solid oxide fuel cells is excellent; the simple, convenient and low-cost preparation of the solid oxide fuel cell cathode is realized by omitting a powder synthesis step and reducing a high-temperature sintering step; and the method comprises the preparation of perovskite structure oxide, class perovskite structure oxide and composite cathode materials.

The invention discloses a measurement method of the electrical conductivity of a solution stimulated by sine wave superimposed signals of two frequencies. Two sine wave superimposed signals are used to stimulate an electrode. Electrode response current is filtered through two channels. One channel carries out low pass filtering to precipitate a sine wave signal of a low frequency component. The other channel carries out high pass filtering (or band pass filtering) to precipitate a sine wave signal of a high frequency component. Amplitude and phase detection are respectively carried out on the sine wave signal of the low frequency component and the sine wave signal of the high frequency component, wherein the signals are precipitated by two channels. By combining the parameters of the stimulating signals and detected amplitude and phase of the response current with an electrical conductivity cell equivalent physical model, a joint equation is listed and is solved to acquire Rx, wherein the resistance Rx of the solution to be measured, the electrode distribution capacitance Cp, the electrode polarization impedance, the double electrical layer capacitance Cx of the electrode are unknowns of the joint equation. Electrode constants are combined to calculate the electrical conductivity of the solution. According to the technical scheme, the effects of the electrode distribution capacitance, the electrode polarization impedance and the double electrical layer capacitance of the electrode on measurement can be removed.

The invention relates to an A-bit Pr-surplus solid oxide fuel cell cathode material and a preparation method thereof. The composition molecular formula of the cathode material is Pr1+xBaCo2O6-delta, wherein x represents Pr-surplus amount, x is greater than or equal to 0 and less than or equal to 0.1, and delta represents the content of oxygen vacancy; the invention belongs to the technical field of solid oxide fuel cell cathode materials. The electrochemical performance of PrBaCo2O6-delta is improved by means of A-bit Pr surplus in the perovskite material PrBaCo2O6-delta. The electrical conductivity, oxygen diffusion capacity and oxygen exchange capacity of the A-bit Pr-surplus Pr1+xBaCo2O6-delta material are improved to a certain extent, the polarization resistance at the temperature of 600 DEG C is only 0.046 omega cm <2>, and the maximum power output of a corresponding single cell at the temperature of 650 DEG C reaches up to 1503mW.cm<-2>. The A-bit Pr-surplus solid oxide fuel cellcathode material can obviously reduce the polarization resistance of a PrBaCo2O6-delta cathode, thus contributing to the industrial application of medium and low temperature solid oxide fuel cells.

The invention relates to the field of medical instruments, discloses a dual-electrode combined member and a stimulation system, and aims at stimulating deep tissues, controllably stimulating two tissues and reducing tissue reaction and polarization impedance. The dual-electrode combined member comprises a screw type electrode or a spindle type electrode and a spiral electrode. The dual-electrode combined member, a stimulation generator and lead bodies form the stimulation system. The stimulation generator comprises a dual pulse output circuit (simply named "dual-core" heart pacemaker when it is used for the heart), and a new simulation mode through which electric pulses of opposite directions are alternately emitted is provided. The dual-electrode combined member and the stimulation system are preferably used for the ventricular septum to perform cardiac resynchronization therapy; and two brand-new cardiac synchronization modes are put forward: one mode is that left and right ventricular electrical stimulation pulses are emitted to control double ventricular electro-mechanical activity; and the other mode is that the cardiac muscle between the cathode and the anode in the ventricular septum is stimulated so that excitation is enabled to be spread to both ventricles from the ventricular septum.

The invention discloses an energy storage power station battery cluster inconsistency online evaluation method based on polarization impedance voltage rises. The method comprises the steps: screening battery pack boxes based on two parameter indexes which are available capacity and DC internal resistance, and selecting characterization monomers; acquiring voltage rises [delta]Up and [delta]up, caused by polarization impedance, of the battery clusters and the characterization monomers in real time; acquiring a linear fitting relation f(n*[delta]up, [delta]Up), and performing derivation on the linear fitting relation to obtain a change rate k(n*[delta]up, [delta]Up), with n being the number of battery pack boxes. If the k(n*[delta]up, [delta]Up) is in an increasing trend along with the proceeding of the circulation, it shows that the inconsistency of the battery clusters is intensified. The method is low in implementation cost and easy in practical application, and online evaluation of the inconsistency of the battery clusters is effectively carried out.

Methods and apparatus for controlling a catalytic layer deposition process are provided. A feed stream comprising a carbon source is provided to a catalyst layer. An asymmetrical alternating current is applied to the catalyst layer. A polarization impedance of the catalyst layer is monitored. The polarization impedance can be controlled by varying the asymmetrical alternating current. The controlling of the polarization impedance provides control over the structure and amount of carbon particles deposited on the catalyst layer. The carbon particles may be in the form of nanotubes, fullerenes, and / or nanoparticles.

The present invention provides methods and apparatus for controlling catalytic processes, including catalyst regeneration and soot elimination. An alternating current is applied to a catalyst layer and a polarization impedance of the catalyst layer is monitored. The polarization impedance may be controlled by varying the asymmetrical alternating current. At least one of water, oxygen, steam and heat may be provided to the catalyst layer to enhance an oxidation reaction for soot elimination and / or to regenerate the catalyst.

The invention discloses a lithium ion power battery cell grouping method, and the method comprises the following steps: charging and discharging cells, acquiring charging and discharging polarization voltage, and calculating a polarization resistance ratio; grading the battery cells according to the polarization resistance ratio r of the battery cells; removing the abnormal points of the inventory, the alternating-current internal resistance and the self-discharge parameters of the graded battery cells; and automatically grouping the cells of the same level through series-parallel connection. According to the method, the polarization impedance in the actual charging and discharging process of the battery cell is considered and is added to matching, compared with a method of grouping by capacity, the overall capacity exertion of the battery cell pack is remarkably improved, the capacity conversion rate is improved to 93%-95% from the original 85%-92%, module heat production is reduced, and internal friction is reduced. The operation is simple and feasible.

The invention discloses a novel high-performance solid oxide electrolytic tank support which belongs to the technical field of a solid oxide electrolytic tank. The support is provided with a continuous gradient porous structure with the porosity of 60%-80%. A support preparation method comprises the following steps of: preparing water-based paste by using 8YSZ powder or NiO-8YSZ as a solid material and an ammonium polyacrylate dispersing agent and a water-based emulsion bonding agent, molding through the combination of a freezing pouring process and a freeze drying method, and finally sintering at high temperature to obtain the target support. As the support is provided with the continuous gradient porous structure, the area of the three-phase interface is greatly enlarged, meanwhile, the resistance of gas diffusing toward the surface of electrolyte from the surface of an electrode is reduced, and therefore, the polarization impedance of a solid oxide battery can be greatly reduced, thus the performance of the solid oxide battery is improved. The method has the advantages of simple operation, flexibility, controllable pore passage morphology and the like.

The invention relates to a preparation method of a nanofiber composite negative electrode of an intermediate-temperature solid oxide fuel cell, belonging to the technical field of energy materials. The preparation method comprises the following steps: firstly preparing a mixed spinning solution containing perovskite structured oxide components and oxygen ion conductor electrolyte components, spinning the mixed solution by virtue of an electrospinning technique to prepare composite fiber, drying and carrying out high-temperature sintering, so as to obtain nanofiber structured composite negative electrode. The diameter of the composite negative electrode fiber is 100-600 nanometers; nanofiber is formed by virtue of agglomeration of perovskite oxide components and electrolyte component nano-particles, wherein the mass percent of the perovskite oxide components is 45%-65%. Components in the nanofiber negative electrode are uniformly distributed, so that the transmission of ions and electrons is benefited; the activation area of electrochemical reaction and the interface of three-phase reaction are large, so that the oxygen reduction catalytic activity of the negative electrode is improved, and the polarization impedance of the negative electrode is reduced; furthermore, the preparation process is simple, the operation is easy, and the cost is low.

The invention discloses an impedance measurement system and method for secondary batteries and belongs to a battery measurement technology. The system comprises a battery module, a charging and discharging module, an alternating current frequency scanning module and a signal collecting and processing module. A 203c point of a 203 three-position switch of the charging and discharging circuit is connected with the negative electrode of the battery module 1, and by selecting a switch arm connected with the 203c point, the negative electrode of the battery module 1 is connected with a 202 electronic load and the positive electrode of the battery module 1 through a 203a point to form a discharging circuit. The impedance measurement system and method for the secondary batteries are applied to tests on impedance of the secondary batteries in the working state and can be used for measuring all the single secondary batteries contained in a secondary battery pack in parallel through multiple channels. The Ohm internal resistance, the electrochemical polarization impedance and the concentration polarization impedance of each secondary battery are tested out, the impedance of each secondary battery is analyzed, and the impedance measurement system and method are used for analyzing the charging and discharging performance of the batteries. The service life of the batteries is estimated, and the batteries can run more safely, stably and reliably.

The invention discloses a porous separation membrane and a preparation method thereof, and a battery manufactured by using the porous separation membrane. The raw material of the porous separation membrane includes the following substances in mass fractions: 9.8-60 wt% of the membrane base material, 0.1-18 wt% of the conductive agent , solvent 20-90wt%, dispersant 0.1-2wt%. The preparation method includes the following steps: (1) mixing the film base material, conductive agent, solvent, and dispersant, and stirring and grinding at 20-60°C to obtain a slurry; (2) extruding the slurry through a spinneret, Perform phase inversion molding with water or ethanol, and solidify to obtain a porous separation membrane blank; (3) drying and cutting the porous separation membrane blank to prepare a porous separation membrane. The battery is made using a porous separation membrane. The porous separation membrane of the invention has good mechanical properties and is simple to prepare; in addition, the mass transfer resistance used as a battery diaphragm is small, and the ohmic impedance and polarization impedance of the battery can be effectively reduced.

The invention relates to an electrochemical device and an electronic device comprising the same. The electrochemical device comprises an electrolyte, a positive electrode and a negative electrode. Thenegative electrode comprises a negative electrode active material layer, the negative electrode active material layer includes a negative electrode active material, and the electrolyte includes fluoroethylene carbonate, wherein the electrochemical device satisfies the following relational expressions: 0.5 < Rct / Rcp < 1.5, both Rct and Rcp are less than 35 milliohms, and 0.005 <= A / B <= 0.1; Rct represents the charge transfer impedance in a 50% state of charge at 25 DEG C, and Rcp represents the concentration polarization impedance in a 50% state of charge at 25 DEG C; the mass of the fluoroethylene carbonate corresponding to 1g of the negative electrode active material is Ag, and the specific surface area of the negative electrode active material is B m <2> / g. The invention aims to improve the quick charging performance of the electrochemical device while maintaining the cycle performance of the electrochemical device.

The invention discloses a measurement method of the electrical conductivity of a solution stimulated by sine wave superimposed signals of two frequencies. Two sine wave superimposed signals are used to stimulate an electrode. Electrode response current is filtered through two channels. One channel carries out low pass filtering to precipitate a sine wave signal of a low frequency component. The other channel carries out high pass filtering (or band pass filtering) to precipitate a sine wave signal of a high frequency component. Amplitude and phase detection are respectively carried out on the sine wave signal of the low frequency component and the sine wave signal of the high frequency component, wherein the signals are precipitated by two channels. By combining the parameters of the stimulating signals and detected amplitude and phase of the response current with an electrical conductivity cell equivalent physical model, a joint equation is listed and is solved to acquire Rx, wherein the resistance Rx of the solution to be measured, the electrode distribution capacitance Cp, the electrode polarization impedance, the double electrical layer capacitance Cx of the electrode are unknowns of the joint equation. Electrode constants are combined to calculate the electrical conductivity of the solution. According to the technical scheme, the effects of the electrode distribution capacitance, the electrode polarization impedance and the double electrical layer capacitance of the electrode on measurement can be removed.