203 results about "Cell impedance" patented technology

The invention discloses a Fourier transform and S transform combined battery impedance spectroscopy measurement method and device, and aims to improve the precision, speed and reliability of impedance measurement of a battery energy storage system. According to the method, a multi-frequency component excitation signal is generated through a controllable current source, and current and voltage response signals of a battery are synchronously acquired and are respectively input into a Fourier transform module and an S transform module for frequency domain analysis. The Fourier transform module extracts impedance spectrums of low and medium frequency bands, and the S transform module extracts impedance spectrums of medium and high frequency bands through Gaussian window time-frequency analysis. And a data fusion algorithm is adopted to perform composite processing on results of the two modules, including a direct selection method, an arithmetic average method, an amplitude and phase calibration method and a weighted average method, so that smooth transition and optimization between frequency bands are realized, and finally the electrochemical impedance spectrum is generated. Through collaborative analysis of Fourier transform and S transform, parameter optimization and a fusion algorithm, the efficiency and accuracy of impedance spectroscopy measurement are remarkably improved, and the method is suitable for rapid monitoring and diagnosis of the battery state.

The invention provides an intelligent battery sorting method integrating impedance characteristics and deep learning. The method comprises the following steps: acquiring battery impedance data through an electrochemical workstation, drawing an electrochemical impedance spectroscopy (EIS), and extracting impedance characteristics of a medium-frequency region; a 25-dimensional impedance coupling feature space is innovatively constructed, a dual-network differentiated feature selection strategy (IC-GRU) is adopted, a main network selects 12 features with the highest correlation, a boundary expert network selects 10 features with the highest correlation and additionally constructs 5 boundary sensitive features, and finally, the main network selects 12 features with the highest correlation. And establishing an impedance coupling sensing gating circulation unit network to realize accurate prediction of the state of health (SOH). And performing four-stage sorting on the SOH result predicted by the IC-GRU through a random forest algorithm (RF). According to the method, more accurate SOH prediction is realized through deep learning guided by a physical mechanism, the battery pack health state sorting precision and consistency are improved, and an intelligent solution is provided for new energy automobile battery life management.

The invention discloses a secondary battery, and belongs to the technical field of batteries, according to the secondary battery, cyclic sulfate is introduced into an electrolyte, and meanwhile, the content of the cyclic sulfate in the electrolyte, the nuclear magnetic displacement value of central carbon atoms of the electrolyte and the passivation capability of a negative pole piece are cooperatively regulated and controlled, so that the first-effect performance of the secondary battery can be effectively improved; and meanwhile, the low level of battery impedance can also be considered.

The invention relates to the technical field of solid-state battery positive electrode materials, in particular to a double-layer coated halide positive electrode composite material, a preparation method thereof and a solid-state battery. The double-layer coated halide positive electrode composite material comprises a positive electrode material inner core, and a middle layer and an outer layer which sequentially coat the positive electrode material inner core; the material of the intermediate layer comprises a first halide electrolyte with a general formula of LiaMXb; and the material of the outer layer comprises a second halide electrolyte, and the general formula of the second halide electrolyte is LicAGXd or LieAOXf. By utilizing respective advantages of different halide electrolytes, the first halide electrolyte in contact with the positive electrode material is stable to a high-voltage positive electrode, and the second halide electrolyte in contact with the sulfide solid electrolyte layer is stable to a sulfide solid electrolyte; the incompatibility of a high-voltage positive electrode material and a narrow electrochemical window sulfide solid electrolyte can be relieved, the interface side reaction is effectively reduced, the battery impedance is reduced, and the electrochemical performance of a solid-state battery is improved.

The invention provides a positive plate, a battery, a battery pack and electric equipment. The positive plate comprises a positive current collector, a first positive active layer and a second positive active layer, wherein the first positive active layer and the second positive active layer are stacked on at least one side of the positive current collector; the first positive electrode active layer comprises a first positive electrode active material, and the second positive electrode active material comprises a first positive electrode active material and a second positive electrode active material; the first positive electrode active material comprises at least one of a manganese-based positive electrode active material, an iron-based positive electrode active material and a manganese-iron mixed-based positive electrode active material, and the second positive electrode active material comprises at least one of a ternary positive electrode active material, lithium cobalt oxide, lithium nickelate and lithium titanate; the second positive electrode active layer further comprises a second conductive agent, and the second conductive agent comprises at least two linear conductive agents and at least one of a sheet-shaped conductive agent and a point-shaped conductive agent. The positive plate has a special structure and composition, and can effectively improve the impedance increase of the battery and improve the cycle performance of the battery.

The invention provides a decoupling analysis method of a battery medium-high frequency impedance spectroscopy and a battery health diagnosis method, and the decoupling analysis method comprises the steps: building a battery medium-high frequency RQ model, the battery medium-high frequency RQ model comprises at least one RQ link, each RQ link is used for representing an electrochemical process or a conduction characteristic of the battery in a middle-high frequency band in a decoupling manner, and comprises a CPE element and a resistor element which are connected in parallel; and carrying out RQ-DRT transformation on the medium-high frequency impedance spectrum of the battery by using the medium-high frequency RQ model of the battery, and solving to obtain at least one electrochemical process or a characteristic parameter corresponding to a conduction characteristic of the battery in a medium-high frequency band. According to the method used by the invention, the electrochemical process or the conduction characteristic of the high frequency band in the battery impedance spectrum can be quantitatively analyzed in a decoupling manner and can be used as a basis for health diagnosis of the battery.

The invention provides an SOC estimation method and device for a lithium battery, electronic equipment and a storage medium, and belongs to the technical field of battery management, and the method comprises the steps: obtaining a current model parameter of a pre-constructed battery equivalent circuit model and an SOC estimation value at a previous moment; predicting the terminal voltage of the lithium battery at the current moment based on the current model parameter, the current of the lithium battery at the current moment and the SOC estimated value at the previous moment; and estimating the SOC at the current moment based on the SOC estimated value at the previous moment by adopting an SOC estimation algorithm, and correcting the SOC estimated at the current moment based on the deviation between the predicted terminal voltage and the terminal voltage actually measured at the current moment to obtain the optimal SOC estimated value at the current moment. According to the method, the dynamically updated battery equivalent circuit model parameters are introduced, so that the model can reflect the change of the impedance characteristic of the battery in real time, the terminal voltage prediction error is remarkably reduced, and the SOC estimation precision is improved.

The invention provides a battery impedance analysis method and device, a storage medium and computer equipment. When the battery impedance is analyzed, an EIS test is carried out on a target battery, and various electrochemical behaviors of the battery in the test process are captured through dynamic characteristics in test data, so that a DRT map generated by carrying out DRT analysis on the test data can visually display impedance response time corresponding to different electrochemical processes in a time dimension; after the response interval of each electrochemical process is determined, standard charging and discharging circulation can be carried out on the target battery, DCR testing is carried out on the target battery with a plurality of selected turns in the circulation process, impedance decomposition is carried out on DCR data obtained through testing on the basis of each response interval, and therefore real-time subdivision of overall impedance information is achieved. And finally, carrying out comparative analysis on impedance decomposition data obtained after subdividing each selected number of turns, so as to generate a high-quality impedance analysis result.

The embodiment of the invention provides a lithium battery impedance detection method and system, and relates to the technical field of lithium battery impedance detection, and the method comprises the steps: firstly obtaining high-frequency voltage fluctuation as an AC excitation signal of a lithium battery pack; obtaining a target voltage fluctuation signal and a target current fluctuation signal according to the alternating current excitation signal; performing spectral analysis on the target voltage fluctuation signal and the target current fluctuation signal to obtain a spectral analysis result; calculating a first complex impedance value corresponding to the high-frequency voltage fluctuation according to the spectral analysis result; identifying the current collector corrosion characteristics of the lithium battery pack according to the first complex impedance value and preset time; and according to the current collector corrosion characteristics and a preset battery aging index, distinguishing the aging mechanism of the lithium battery pack. According to the embodiment of the invention, the overall health state of the battery can be comprehensively known, and different aging mechanisms can be distinguished.

The invention provides a negative electrode plate, a battery, a battery pack and electric equipment, the negative electrode plate comprises a negative electrode current collector and a negative electrode coating located on at least one side surface of the negative electrode current collector, the negative electrode coating comprises non-coated graphite, and the OI value of the non-coated graphite in the negative electrode coating is 0.06-2. The battery impedance can be reduced, and the cycle life of the battery can be prolonged.

The invention discloses an energy storage battery aging evaluation method and device under an immersed liquid cooling condition, terminal equipment and a storage medium, and belongs to the field of battery testing. The method comprises the steps of obtaining a first active lithium ion loss change rate and a first active substance loss change rate according to a battery voltage and a first battery capacity identification characteristic peak in a to-be-tested battery test, and calculating a battery capacity loss change rate according to a first battery capacity and a second battery capacity before the test; determining a second active lithium ion loss change rate, a second active material loss change rate and a battery impedance change rate based on the electrochemical impedance spectrogram and the pre-test impedance, and determining the battery capacity loss change rate and the battery impedance change rate according to the determined active lithium ion loss, the active material loss, the battery capacity loss change rate and the battery impedance change rate. The resistance, the moisture content and the dielectric loss change rate of the cooling liquid to be measured construct an analytic hierarchy model, the battery aging condition is determined according to the calculated aging evaluation value, and the problem that deviation exists in single evaluation in the prior art is solved.

The objective of the present invention is to evaluate a battery with high accuracy using a simple method. A battery evaluation device (100) is provided with an impedance real part measuring unit for measuring the real part of the impedance of a battery, for each of a first frequency and a second frequency. The battery evaluation device (100) obtains an evaluation value indicating the state of the battery on the basis of the real part of the impedance of the battery obtained for each of the first frequency and the second frequency, a temperature coefficient and a capacity deterioration coefficient acquired in advance for the first frequency, and a temperature coefficient and a capacity deterioration coefficient acquired in advance for the second frequency. The evaluation value is at least one of a metal deposition amount and a temperature.

A battery state diagnosis apparatus includes a processor configured to extract battery impedance by obtaining voltage and current signals outputted from a battery management system of an electric vehicle, removing noise by performing first signal processing on the voltage and current signals outputted from the battery management system, and extracting a frequency characteristic by performing second signal processing on the voltage and current signals from which the noise has been removed, and a storage configured to store data and algorithms driven by the processor.

Disclosed are an internal temperature measurement method and apparatus for a battery, and an electronic device and a storage medium. The method comprises: acquiring a surface temperature of a battery, and determining a temperature interval in which the surface temperature is located; when the surface temperature is in a first temperature interval, selecting from an excitation frequency selection section an excitation frequency corresponding to the surface temperature, wherein the excitation frequency selection section includes a plurality of excitation frequencies; generating an excitation signal on the basis of the excitation frequency corresponding to the surface temperature, and outputting the excitation signal to the battery, so as to acquire a response signal fed back by the battery in response to the excitation signal; determining a battery impedance of the battery on the basis of the excitation signal and the response signal; and determining an internal temperature on the basis of the battery impedance.

A method for estimating battery impedance and remaining energy in a battery system, including a group of battery cells, includes periodically measuring current and voltages of all battery cells in the group of batter cells for a time period. The method also includes determining a present current value in accordance with averaging the measured current and voltages over the time period. The method further includes detecting a step change in a current based on a comparison of the present current value with one or more previously stored current vales. The method still further includes initiating an impedance measurement event in accordance with validating the step change.

According to the battery state monitoring method and system based on the battery impedance chip, battery internal resistance data are collected in real time through the battery impedance chip, and high precision and reliability of the data are ensured in combination with temperature compensation processing. The internal resistance data is deeply analyzed by using a support vector machine (SVM) model, so that the health state of the battery can be accurately evaluated, and the attenuation trend of the battery can be predicted. According to the method, the accuracy of battery health state evaluation is improved, and the safety of a battery system is enhanced through a real-time monitoring and early warning mechanism.

The invention discloses a lithium ion pool charge state detection method and system based on an electrochemical impedance spectroscopy, by obtaining impedance spectroscopy measurement data in a full charge state range, the data integrity of model construction is ensured, a foundation is laid for later model construction, a fractional order equivalent circuit model is adopted to fit impedance spectroscopy data, and the lithium ion pool charge state detection method and system based on the electrochemical impedance spectroscopy are obtained. According to the method, the actual electrochemical behavior of the battery can be described more accurately, the defects of a traditional integer order model during fitting of a non-ideal semicircular structure are overcome, the parameter identification precision is improved, SEI film resistance RSEI and a battery impedance value are screened out to serve as characteristic parameters to construct a battery SOC estimation model, the state estimation reliability is improved, and the reliability of the state estimation is improved. According to the method, the SOC of the to-be-detected battery is estimated based on the battery SOC estimation model, lossless, rapid and online detection of the battery is realized, and the method disclosed by the invention does not need complex iterative calculation or large-current pulse test and is high in parameter identification precision.

The invention relates to a battery and an electric device, and belongs to the technical field of batteries. The cyclic sulfate and the lithium difluorophosphate are added into the electrolyte, and the mass ratio m of the lithium difluorophosphate to the cyclic sulfate in the electrolyte, the liquid retention coefficient n of the battery cell and the absolute value of the difference value of the particle sizes Dv50 of the positive electrode and the negative electrode are controlled to meet the specific relationship, so that the lithium difluorophosphate can be ensured to participate in film formation well in the initial stage and the later stage of circulation; the side reaction between the electrolyte and the positive and negative pole pieces in the long-cycle process is inhibited, and the cycle stability of the battery is ensured; meanwhile, the transmission performance of lithium ions at the positive electrode and the negative electrode is improved, the battery impedance is reduced, the cycle performance and the fast charge performance are cooperatively improved, and the battery has excellent and balanced cycle and fast charge characteristics.

A battery impedance measuring device 1 measures the AC impedance of a battery pack 3. FETs 5 and 6 are arranged in a path through which an excitation current flows from the battery pack 3, and a shunt resistor 7 is energized with the excitation current through the FETs 5 and 6. An excitation current control unit 13 and a diagnosis control unit 14 control the turning on and off of the FETs 5 and 6, respectively, and a current detection circuit 15 measures the voltage of the shunt resistor 7. An error determination circuit 16 diagnoses the conduction state of the FETs 5 and 6, on the basis of the on / off state of the FETs 5 and 6 controlled by the control units 13 and 14 and the result of energization of the shunt resistor 7.

This application discloses a portable online electrochemical impedance spectroscopy measurement system and method for lithium-ion batteries, relating to the field of lithium-ion battery technology. The system includes: a power supply system for powering a power transmission system and an online measurement system, connected in parallel with a charger connected to the battery pack to achieve synchronous charging and impedance measurement; a power transmission system for converting direct current into a step function current, which is superimposed on the DC charging current and injected into the battery pack as an excitation signal; a control system for adjusting the frequency of the step function current using pulse width modulation technology; a measurement circuit module for acquiring the current and voltage signals of the battery pack; and a data analysis module for processing the time-domain signal using wavelet transform to calculate the electrochemical impedance spectrum. This application achieves low-cost, portable online measurement, enabling monitoring of the battery impedance spectrum during charging and providing support for safety early warning.

In order to solve the technical problem that battery impedance is increased due to the fact that a high-temperature performance additive is added into an existing lithium ion battery, the invention provides a non-aqueous electrolyte and a lithium battery, the non-aqueous electrolyte comprises a solvent, an electrolyte salt and an additive, the additive comprises a first additive and a second additive, the first additive comprises at least one of compounds shown in a structural formula 1: A-D-B-E-C structural formula 1; the second additive comprises at least one of compounds shown in a structural formula 2: the non-aqueous electrolyte with the structural formula 2 meets the following relational expressions: 0.15 < b / (a + b) < 0.65, 0.1% < = a < = 3%, and 0.1% < = b < = 1%. According to the non-aqueous electrolyte provided by the invention, the high-temperature cycle capacity retention rate and the high-temperature storage performance of the battery can be improved, impedance increase in the high-temperature cycle and high-temperature storage processes is effectively inhibited, gas production is reduced, and the high-temperature performance of the electrolyte is remarkably improved.

This invention relates to a method for predicting the internal temperature of a battery based on variable frequency impedance measurement, belonging to the field of battery thermal management technology. The invention measures the impedance of the battery in its offline state at different temperatures and at different excitation frequencies, plots the battery excitation frequency-impedance relationship at different temperatures, divides temperature ranges according to the test accuracy, finds the optimal excitation frequency for each temperature range, and fits the battery impedance-temperature function relationship at the optimal excitation frequency for each temperature range. Using the one-dimensional heat transfer principle, the measured battery surface temperature and ambient temperature are used as inputs to perform the first estimation of the battery's internal temperature, obtaining the internal temperature T. in 1; Based on the internal temperature T in 1. Select the optimal excitation frequency for the corresponding temperature range, i.e., the internal temperature T. in The optimal excitation frequency for the specified temperature range is used to perform a second estimation based on the battery impedance-temperature function relationship at the optimal excitation frequency, thus obtaining the battery internal temperature T. in 2. This invention can more accurately predict the internal temperature of a battery.

An impedance calculation apparatus applicable to a power source system provided with a storage battery, applying an AC signal to the storage battery to calculate an impedance of the storage battery, during a predetermined impedance calculation period, the impedance calculation apparatus includes: an error calculation unit that applies the AC signal having a specified frequency at which at least either a real part component or an imaginary part component of an impedance of the storage battery is a specific value, to calculate an impedance error of the storage battery, during an error calculation period different from the impedance calculation period; an impedance calculation unit that calculates an impedance of the storage battery during the impedance calculation period; and a correction unit that corrects, based on the impedance error, the impedance of the storage battery calculated by the impedance calculation unit.

This application provides a battery impedance analysis method, apparatus, storage medium, and computer equipment. When analyzing battery impedance, an EIS test is performed on the target battery to capture various electrochemical behaviors of the battery during the test process through the dynamic characteristics in the test data. Therefore, the DRT spectrum generated by DRT analysis of the test data can intuitively display the impedance response time corresponding to different electrochemical processes in the time dimension. After determining the response range of each electrochemical process, standard charge-discharge cycles can be performed on the target battery. During the cycle, DCR tests are performed on the target battery for multiple selected cycles, and impedance decomposition is performed on the obtained DCR data based on each response range to achieve real-time subdivision of the overall impedance information. Finally, the impedance decomposition data obtained after subdivision for each selected cycle number are compared and analyzed to generate high-quality impedance analysis results.

The application discloses an integrated electrode and a preparation method and application thereof, wherein the preparation method comprises the following steps: uniformly mixing a positive electrode active material, LiOH and a metal conductive agent, and then press-forming into a sheet to obtain a positive electrode sheet; uniformly mixing one or more of oxide solid electrolytes and LiOH, and then press-forming into a sheet to obtain an electrolyte sheet; uniformly mixing a negative electrode active material and a metal conductive agent, and then press-forming into a product to obtain a negative electrode sheet; sequentially stacking the positive electrode sheet, the electrolyte sheet and the negative electrode sheet, and then performing cold isostatic pressing treatment to obtain a mixed stack; and performing sintering treatment on the mixed stack in an oxygen atmosphere to obtain the integrated electrode. The integrated electrode prepared by the application greatly eliminates the interface problems existing in traditional oxide battery materials and the influence of glue in the electrode on the impedance of the battery, and the integrated electrode has high compactness and higher energy density; and the integrated electrode is used for preparing a solid battery, so that the rate and cycle performance of the battery can be effectively improved.

The invention relates to a high-throughput cell electric signal exporting device based on an analog switch, a cell impedance detection system and a detection method, and belongs to the technical field of biomedical detection equipment. The system achieves the functions of image observation and cell electric signal export at the same time, and is characterized in that a more complex circuit layout is achieved by using a smaller PCB size. According to the system, by integrating temperature control and electric signal conduction, the function of an existing microscope is utilized, electric signal conduction is completed, and a brand new technical scheme is provided for biological experiments such as analysis of the growth state, the adhesion degree and the migration ability of cells.

This invention relates to the field of battery technology, specifically to a composite negative electrode current collector, its preparation method, and its application. The composite negative electrode current collector of this invention includes a polymer material layer, a lithium replenishment layer, and a conductive metal layer. The lithium replenishment layer is located on at least one surface of the polymer material layer, and the conductive metal layer is located on the surface of the lithium replenishment layer away from the polymer material layer. The lithium replenishment layer includes a composite lithium material comprising a lithium metal core and a lithium compound coating layer covering the surface of the lithium metal core. The conductive metal layer has multiple through-hole structures. The composite negative electrode current collector of this invention, through the coordination of its various layer structures, is beneficial for improving the storage performance of the negative electrode, reducing battery impedance, shortening the electrolyte wetting time, enhancing lithium replenishment capacity, preventing the formation of lithium dendrites, and improving battery safety performance.

The application discloses an excitation current generating circuit and a control method for battery impedance spectrum measurement, and belongs to the field of battery impedance spectrum detection. The excitation current generating circuit generates an excitation current with a set frequency and amplitude on the connected battery system to perform battery impedance spectrum measurement. The excitation current generating circuit is connected in parallel with the battery system, an energy storage converter or a load. A mathematical model, an equivalent circuit model and a control method of the excitation current generating circuit are provided. Through closed-loop control of the port current of the excitation current generating circuit and the DC side capacitor voltage, the excitation current with controllable frequency and amplitude is generated by periodic energy exchange with the battery system. Compared with the prior art, the excitation current generating circuit provided by the application does not need to make any adjustment to the existing equipment in the energy storage system, adopts a battery system self-energy supply mode, and generates an excitation current for impedance spectrum measurement under low power consumption.

The invention provides an intelligent battery management system and method for electric vehicle charging, and relates to the technical field of intelligent battery management, working condition parameters of a target electric vehicle battery are collected, and battery impedance multi-mode sensing is performed on the target electric vehicle battery according to the working condition parameters to obtain a multi-source heterogeneous parameter set; acquiring historical charging data, performing inferior electricity prediction on the target electric vehicle battery according to the multi-source heterogeneous parameter set and the historical charging data to obtain a battery class loss set, and determining an inferior loss response according to the battery class loss set; determining an inferior electricity index through the inferior damage response, and performing intelligent charging management on the target electric vehicle battery according to the inferior electricity index and a preset charging strategy to obtain a charging strategy; and the target electric vehicle battery is intelligently charged according to the charging strategy, and intelligent charging strategy management is completed. According to the invention, the deterioration state of the rechargeable battery of the automobile can be accurately identified, and the charging safety and efficiency are improved.

The present application belongs to the technical field of fuel cell, and particularly relates to a kind of fuel cell impedance spectrum fast measurement system and measurement method, system is divided into excitation current injection part, data acquisition part and host computer, host computer uses DIBS signal with excellent peak suppression ability and flexible amplitude frequency design ability as test excitation, uses electronic load as excitation source.Host computer can control electronic load to generate current excitation waveform for impedance test based on DIBS signal, and electronic load injects excitation current into the output current of the measured stack, and host computer can also read the sampling data of data acquisition part, and the collected excitation current and response voltage data are subjected to fast Fourier transform to obtain electrochemical impedance spectrum.The present application improves the impedance measurement efficiency, the hardware structure is simple, has good on-site application prospect, and the measured object can be extended to other electrochemical systems including electrolytic cell, and has good expandability.