192 results about "Charge transfer resistance" patented technology

A system and method for estimating internal parameters of a lithium-ion battery to provide a reliable battery state-of-charge estimate. The method uses a two RC-pair equivalent battery circuit model to estimate the battery parameters, including a battery open circuit voltage, an ohmic resistance, a double layer capacitance, a charge transfer resistance, a diffusion resistance and a diffusion capacitance. The method further uses the equivalent circuit model to provide a difference equation from which the battery parameters are adapted, and calculates the battery parameters from the difference equation.

An apparatus is disclosed that includes a resistance measuring unit operable to determine a solution resistance Rsol and a charge transfer resistance Rest of a battery; and at least one computer-readable non-transitory storage medium comprising code, that, when executed by at least one processor, is operable to provide an estimate of the present value of the battery by: comparing Rsol and Rct to historical deterioration transition information; estimating the number of remaining charge cycles before a discharge capacity lower limit is reached by the battery using the comparison; and estimating the number of remaining charge cycles before a discharge time lower limit is reached by the battery using the comparison. The estimate of the present value of the battery includes the smaller of the number of remaining charge cycles before a discharge capacity lower limit is reached or the number of remaining charge cycles before a discharge time lower limit is reached.

The invention belongs to the field of electrocatalysts, and specifically relates to a preparation method and application of a mesoporous bi-metal phosphide electrocatalyst for electrochemically decomposing water to generate hydrogen with high performance. A hydroxide precursor is synthesized through hydrothermal reaction and is further subjected to low-temperature phosphating reaction to obtain aNixMn1P porous nanosheet array electrocatalyst. The series of bi-metal phosphides have relatively low charge transfer resistance and reaction barrier of hydrogen evolution reaction, and have excellentperformances in electro-catalytic hydrogen evolution reaction. The catalyst is low in cost, is simple and convenient in operation, is simple in process, is excellent in catalysis performance, and provides basic application research, in the electro-catalysis field, of the materials.

The invention belongs to the field of nanomaterials, and discloses a nickel-cobalt bimetallic phosphide electrocatalyst as well as a synthesis method and an application thereof. The Prussian blue analogue precursor synthesized through simple aging reaction is further subjected to low-temperature phosphating reaction, and a NiCoP multi-hollow porous nanocube electrocatalyst is obtained. The seriesof bimetallic phosphides have lower charge transfer resistance and reaction barrier for oxygen evolution reaction, and have superior performance in electrocatalytic oxygen evolution reaction. Besides,the catalyst is low in cost and convenient to operate, adopts a simple process and has superior catalytic performance, and basic application research is provided for the materials in the field of electrocatalysis.

The invention relates to a battery ageing state estimation method considering different battery states, which comprises the following steps of: 1, establishing an equivalent circuit model for fittingan electrochemical impedance spectroscopy of a single battery; 2, according to the equivalent circuit model, acquiring charge transfer resistance values at different temperatures and charge states soas to obtain a fit data set; 3, constructing a calculation model f (T, SOC) between a charge transfer resistance and the battery temperature as well as the charge state, and according to the fit dataset, determining parameters of an expression; 4, carrying out correction on the calculation model after determining the parameters through fitting; 5, defining a battery standard state, and accordingto the corrected calculation model g (T, SOC), calculating a charge transfer resistance value in the battery standard state; and 6, according to relative growth of the charge transfer resistance converted into the standard state, estimating an ageing state of the battery. Compared to the prior art, the battery ageing state estimation method has the advantages of simplicity and convenience for calculation, reliability for estimation and the like.

The present invention relates to a preparation method of a solid state lithium battery composite cathode film, belonging to the technical field of battery cathode materials. In order to solve the problems that sintering aids are required being added and the internal resistance of the interface is high in the prior art, the present invention provides a preparation method of a solid state lithium battery composite cathode film. The method comprises the steps of: performing uniform mixing and ball milling of active cathode particles and LLZO solid electrolyte particles in proportion, then dryingthe mixture to obtain composite cathode powder body particles, wherein the mass content of the LLZO solid electrolyte particles in the composite cathode powder body particles is 5.0-35wt%; mixing thecomposite cathode particles, a binder, adhesives, a dispersing agent, a plasticizer and a solvent to form a composite cathode slurry; and performing tape casting of the composite cathode slurry to prepare a composite cathode blank film, performing drying and rubber discharging of the composite cathode blank film, and performing low-temperature sintering processing at a temperature of 650-850 DEG Cto obtain a composite cathode film. The preparation method of the solid state lithium battery composite cathode film can effectively improve the interface densification, can reduce the interface impedance and can reduce the interface charge transfer resistance.

The invention provides preparation of a carnation-shaped p-n heterojunction copper sulfide nanometer material, and belongs to the technical field of nanometer materials. The preparation includes the steps that melamine is used as a raw material, carbon-doped graphene carbon nitrogen C-g-C3N4(CCN) is synthesized through hydro-thermal treatment and high-temperature calcination, and the carbon-doped graphene carbon nitrogen, copper chloride dihydrate and thiourea are further subjected to a hydrothermal reaction to synthesize a CCN-CuS p-n heterojunction; the p-n heterostructure reduces charge transfer resistance, enables photoinduced charges to be effectively separated and can effectively improve activity of photocatalyst. It is indicated through experiments that the prepared CCN-CuS p-n heterojunction nanometer material shows excellent visible-light catalytic activity and good cycling stability, and the degradation rate of rhodamin B can reach 92.6%. Therefore, the nanometer material can be used for degradation treatment on organic dyestuff waste water.

The invention provides a lithium precipitation forecast method of a lithium ion battery. The lithium precipitation forecast method comprises the steps of S1) performing linear fitting on a positive potential and a charging current or charging rate to obtain slope during the charging process of the lithium ion battery; and S2) performing linear fitting on charge transferring resistance and the slope of the lithium ion battery, obtaining a condition model of the charging current or the charging rate of the lithium ion battery and a temperature according to a relation between the charge transferring resistance and the temperature T, and forecasting critical lithium precipitation charging current or charging rate according to the condition model. Compared with the prior art, the lithium precipitation critical condition of the lithium ion battery under different ambient temperatures can be quantitatively judged by a modeling mode according to Arrhenius formula, a battery cell is not neededto be disassembled, time and labor are saved, resources are saved, quantization is achieved, and high accuracy is achieved.

The invention provides a method for preparing a MnO2/carbon composite material for a super-capacitor. The method includes the steps of step one, dissolving glucose or sucrose or fructose in deionized water, stirring until a settled solution is obtained, transferring the settled solution into a hydrothermal reaction kettle, performing centrifugation, water washing, alcohol washing and drying on an obtained polymeric pecursor solution to prepare monodisperse carbon spheres; step two, taking the monodisperse carbon spheres, performing heat treatment on the monodisperse carbon spheres in a NaOH solution, then performing centrifugation, water washing and alcohol washing on a mixture solution three times, conducting drying, and performing calcination treatment in vacuum or inert atmosphere; step three, using the carbon spheres experiencing modified treatment in the step two as a template, placing the template in a KMnO4 aqueous solution, stirring and aging at the room temperature, obtaining a sediment, performing centrifugation, water washing and alcohol washing on the sediment, performing drying in a vacuum oven, and obtaining CS@MnO2 coated powder. Obtained MnO2/carbon sphere composite powder is of a core-shell structure, the specific surface area of the powder can reach more than 778m<2>/g, the specific capacity of the powder can reach more than 439F/g, charge transfer resistance is lower than 2.1 omega, and the powder is a novel super-capacitor electrode material.

A difunctional negative electrode for an all-vanadium redox energy storage battery negative electrode includes a carbon matrix material and a Bi-containing electro-catalyst modifying the surface of the carbon matrix material. The negative electrode is suitable for being used as the negative electrode of the all-vanadium redox energy storage battery, can greatly improve the electrocatalytic activity and electrochemical reversibility of an electrode material on a V<2+>/V<3+> redox reaction, and decreases the charge transfer resistance; and the negative electrode has high hydrogen evolution overpotential, can inhibit a hydrogen evolution reaction, and prolongs the work life of the battery. The difunctional negative electrode improves the voltage efficiency and energy efficiency of the all-vanadium redox energy storage battery, so the working current density of the battery is improved, and the weight, the size and the cost of the battery with same output power are greatly reduced.

The present invention relates to a method for estimating the remaining useful life of a battery, comprising the steps of: providing a single battery; performing multiple charging-discharging cycles ona single battery; performing measurement of electrochemical impedance spectroscopy on the single battery during at least a part of the charging-discharging cycles, and obtaining charge transfer resistance and surface layer resistance of the single battery through the fitting of an equivalent circuit model; establishing the relationship between the capacity of a single battery and the cycling times by means of the charge transfer resistance and the surface layer resistance and capacity obtained by multiple cycles; predicting the remaining battery capacity or the number of remaining cycles of the battery by means of the already-established relationship between the capacity and the cycling times. The present invention also proposes a method for estimating the remaining useful life of a batchof batteries.

The invention provides a porous carbon fiber paper electrode material for an all-vanadium redox flow battery. The porous carbon fiber paper electrode material has a thickness of 50 to 1000 [mu]m and is composed of a carbon fiber with a diameter of 5 to 20 [mu]m; porous carbon fiber paper has a porosity of 60 to 90%; the surface of the carbon fiber is of a porous structure, and the carbon fiber has a specific surface area of 5 to 50 m<2>/g and a pore size of 50 to 2000 nm. By the porous carbon fiber paper, the specific surface area and oxygen-containing function groups are increased, and the electrocatalytic activity of carbon fiber material to an oxidation reduction reaction of vanadium ions can be substantially improved. The electrode material provided by the invention is applicable to the all-vanadium redox flow battery, and can reduce space between the electrodes and internal resistance of the battery, lower charge transfer resistance and improve the voltage efficiency and energy efficiency of the all-vanadium redox flow battery, so the working current density of the battery is improved, and battery weight, size and cost are greatly reduced under the condition of same output power.

The invention discloses a porous carbon nanofiber electrode used for a redox flow battery, and a preparation method of the porous carbon nanofiber electrode. The electrode is 20-500[mu]m in thickness and formed by porous carbon nanofibers with diameter of 50-500nm; the porous carbon nanofiber electrode is prepared by the steps of taking a high-molecular polymer as a precursor, preparing into nanofibers through electrostatic spinning, and then performing high temperature carbonization and next, carrying out high-temperature activation through CO<2> or vapor. The prepared porous carbon nanofiber electrode, with obviously enlarged specific surface area and improved oxygen-containing functional group, has high electrocatalytic activity and electrochemical reversibility when the porous carbon nanofiber electrode is used for the redox flow battery; the redox flow battery has the advantages of simple preparation method, easily available raw material, low cost and the like; the electrode material is applicable to the redox flow battery; due to the ultra-thin electrode thickness, space between electrodes of the battery can be reduced, and internal resistance of the battery can be lowered; and in addition, charge transfer resistance can be lowered, the voltage efficiency and energy efficiency of the all-vanadium redox flow battery are improved, and the weight and the volume of the battery are reduced.

The invention relates to a lithium-rich material/conductive organic polymer composite positive material and an electrode preparation method. A one-step oxalate coprecipitation- solvothermal method isadopted to obtain the lithium-rich positive material of a nano/micron rodlike hierarchical structure; an in-situ polymerization method is performed on a conductive organic polymer to coat the lithium-rich positive material, and the lithium-rich material/conductive organic polymer composite positive material is obtained. The prepared lithium-rich material/conductive organic polymer composite positive material can be used for preparing a positive electrode. According to the preparation method, by synthesizing the lithium-rich layered oxide positive material of the nano/micron rodlike hierarchical structure, the positive material has dual advantages of nano and micron structures, the diffusion path of lithium ions is short, the material structure has good stability, the positive material is coated with the conductive organic polymer, the electron transfer rate of the lithium-rich material is improved, the charge transfer resistance is reduced, the cycling stability is improved, and the rate capability of the material is greatly improved.

The invention belongs to the technical field of electrocatalysis, and discloses a cobalt zinc bimetallic sulfide based composite electrocatalyst, and a preparation method and applications thereof, andmore specifically relates to a cobalt zinc bimetallic sulfide/nickel iron layered bimetallic hydroxide/foam nickel composite electrocatalyst, and a preparation method and applications thereof. The cobalt zinc bimetallic sulfide/nickel iron layered bimetallic hydroxide/foam nickel composite electrocatalyst is prepared through three-step hydro-thermal method, is low in charge transfer resistance and hydrogen evolution reaction barrier, possesses excellent performance in electrocatalysis hydrogen evolution reaction, is low in cost, simple in operation and technology, and excellent in catalytic performance, and base application research on the material kind in electrocatalysis field is realized.

An LFP electrode material is provided which has improved impedance, power during cold cranking, rate capacity retention, charge transfer resistance over the current LFP based cathode materials. The electrode material comprises crystalline primary particles and secondary particles, where the primary particle is formed from a plate-shaped single-phase spheniscidite precursor and a lithium source. The LFP includes an LFP phase behavior where the LFP phase behavior includes an extended solid-solution range.

The invention discloses a method for realizing the on-line estimation of the equivalent temperature of a lithium ion battery. The method includes the following steps that: the relationship model of the charge transfer resistance Rct_0 of the lithium ion battery and the real temperature Tr of the battery is established according to electrochemical impedance spectroscopy under different real temperatures of the lithium ion battery; under an actual working condition, an SOC correction factor fs and a current ratio correction factor fi are introduced so as to be used correcting the influence of aSOC and a current ratio on charge transfer resistance respectively, and the relationship model of charge transfer resistance Rct and battery temperature T, which is suitable for the working condition,is established; and the model is substituted into a battery equivalent circuit model, and with the battery temperature T used as a state variable, the extended Kalman filter algorithm is used to estimate the battery temperature T which is used as an equivalent temperature under the working condition of the battery, and therefore, the online estimation of the equivalent temperature of the batteryis realized.

The invention discloses a preparation method for NiTe2 used for the electrode material of a supercapacitor. The preparation method includes the following steps that: a tellurium source and a nickel source are mixed, an obtained mixture is arranged in a reactor, a reducing agent and a solvent are added into the mixture, and an obtained mixture is stirred so as to form a mixed solution; a foamed nickel sheet is e arranged in the mixed solution; and the reactor is arranged into a heating furnace, the foamed nickel sheet reacts with the mixed solution for some time; the nickel sheet is removed out; absolute ethyl alcohol and deionized water are adopted to repeatedly wash the nickel sheet, and then, the washed nickel sheet is arranged in a drying oven of a temperature of 60 DEG C so as to be dried, and finally, a dried nickel sheet can be obtained, and the NiTe2 material can be finally formed on the surface of the nickel sheet. The NiTe2 material used for the electrode of the supercapacitor which is prepared by using the preparation method of the invention has high specific capacitance and very excellent cyclic stability; the charge transfer resistance of the NiTe2 is as low as 0.021 ohm; and the NiTe2 can keep 100% capacitance after having been subjected to 1000 times of cyclic distance-current discharge.

The invention provides a method for preparing a bimetal/organic framework/bismuth vanadate composite photoanode material. A metal framework NiCo-MOFs with a three-dimensional rhombic tetragonal structure is formed by a hydrothermal process in a mixed solution of N,N-dimethylformamide, anhydrous ethanol and distilled water with CoCl2.6H2O and NiCl2.6H2O as raw materials, phthalic acid as a ligand framework and a BiVO4 electrode as a matrix, and the metal framework NiCo-MOFs is loaded on a BiVO4 film to obtain the photoanode material NiCo-MOFs/BiVO4. The coupling effect of the bimetal center promotes the transfer of electrons from the organic ligand to the metal center in order to promote charge separation. Additionally, the three-dimensional rhombic tetragonal metal framework structure andthe sufficiently large contact area make lights effectively captured, the charge transfer resistance reduced and the rapid migration of carriers accelerated, so the recombination of electron hole pairs is inhibited, thereby the electrochemical performances of BiVO4 are effectively improved.

The invention belongs to the energy storage material technical field, and relates to a graphene/nitrogen doped carbon/nickel/nickel oxide composite material preparation method; the method is applied to a super capacitor electrode material preparation occasion, and solves the problems that an existing process is complex in preparation steps, long in time consumption, low in compound specific capacitance, and hard in material applications. The method comprises the following steps: employing a reduction oxidation graphene/crosslinking polyacrylamide/nickel salt aerogel as a precursor; calcining same to realize carbon material in situ nitrogen doping, carbon hot reduction, and catalysis graphitization; and compositing same with the reduction oxidation graphene to form a 3D structure graphene/nitrogen doped carbon/nickel/nickel oxide quaternary nano composite material. The preparation process is simple, and reliable in principles; the composite material can serve as the super capacitor electrode material, is low in equivalent resistance, low in interface charge transfer resistance and Warburg impedance, high in product specific capacitance, excellent in electrochemistry performance, andhas excellent economic benefits and application prospects.

An embodiment of the present application provides a negative electrode and a lithium ion battery including the negative electrode, the negative electrode includes a negative electrode current collector, and a negative electrode active material layer arranged on the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material and a dispersant, and the dispersant includes lithium carboxymethylcellulose, wherein the mass ratio of the negative electrode active material to the dispersant being ≥18.74. The present application greatly reduces the DC resistance of the lithium ion battery and the charge transfer resistance at the interface without losing the energy density of the lithium ion battery, without affecting the cycle life of the lithium ion battery or causing cyclic expansion, which avoids the lithium precipitation phenomenon of the lithium ion battery during the cycle of charge and discharge.

The invention belongs to the field of electrocatalysts, and particularly relates to a preparation method and applications of a high-performance carbon-based composite catalyst for producing hydrogen by electrochemically decomposing water, wherein the Ru/NC electrocatalyst is obtained by using nitrogen-doped carbon (NC) synthesized through complexing, calcining and acid washing as a substrate material and using ethylene glycol as a reducing agent under a reflux condition. According to the invention, the electrocatalyst material has low charge transfer resistance and reaction barrier of hydrogenevolution reaction, and has excellent performance in electrocatalytic hydrogen evolution reactions; Ru has the lowest price in Pt series precious metal materials, so that the catalyst is low in cost;and the obtained catalyst is simple and convenient in experimental operation, simple in process and excellent in catalytic performance, and provides the basic application research for the materials in the field of electro-catalysis.

The invention provides an electrochemical detection method for dihydrogen phosphate ions in a water system, which comprises the steps: inserting a gold electrode the surface of which is self-assembled with a porphyrin monolayer, a reference electrode and a counter electrode into an electrochemical detection cell of potassium hexafluorophosphate electrolyte solution containing red potassium prussiate/potassium ferrocyanide probe molecules, performing scanning by an electrochemical workstation, and obtaining a charge transfer resistance value (Rct) of the self-assembled porphyrin monolayer; and then jointly inserting the gold electrode modified by porphyrin, the reference electrode and the counter electrode into the electrochemical detection cell of the electrolyte solution which contains an object to be detected, namely the dihydrogen phosphate ions, performing scanning by the electrochemical workstation, and obtaining a charge transfer resistance value (Rct) of the self-assembled porphyrin monolayer, wherein the charge transfer resistance values (Rct) and the concentrations (C) of the dihydrogen phosphate ions have corresponding relation. The method detects the dihydrogen phosphate ions on the surface of the gold electrode modified by thiol-porphyrin, is convenient and quick, and realizes the selective detection of the dihydrogen phosphate ions in the water system.

The invention relates to a superhydrophilic material modified electrode material for an energy-storing flow battery as well as a preparation method and application thereof. The electrode material takes a carbon-based material as a matrix; and the matrix comprises a graphene oxide superhydrophilic material which is formed by graphene oxide and phytic acid and has a three-dimensional structure. In the electrode material, the graphene oxide increases the reaction active sites and the specific surface area of graphite felt fiber, and the phytic acid with six phosphate groups are crosslinked with different graphene oxide layers to form a three-dimensional structure, so that the electric conductivity of the system is improved, transmission of protons and vanadium ions on graphite felt is benefited, charge transfer resistance and mass transfer resistance are reduced, the electrocatalytic activity of the whole electrode is improved, and the energy efficiency and the discharging capacity of thewhole battery are greatly improved.