30 results about "Ac impedance spectra" patented technology

The invention belongs to the technical field of electrochemistry, and in particular relates to a preparation method of a sulfide ore working electrode used for measuring electrochemical signals under pressure leaching process conditions of sulfide ore, a sulfide ore working electrode, and the application of the working electrode to sulfide ore working electrodes. Methods for the study of pressure leaching processes. It solves the problems of lack of devices and methods for measuring dynamic high temperature and high pressure electrochemical signals and the lack of representativeness of using natural bulk electrodes in the prior art. The sulfide ore working electrode is made of carbon powder and mineral powder mixed in a certain proportion and added with a binder (PVDF). Through the open circuit potential test, polarization curve test and AC impedance spectrum test technology, the electrochemical mechanism of chalcopyrite leaching at different temperatures is tested; with the help of AC impedance technology, the number of sub-processes in the leaching process can be distinguished, and the equivalent circuit simulation The kinetic parameters of each sub-process were obtained by methods such as the following methods, and the formation and growth mechanism of the passivation film on the chalcopyrite surface were determined.

The invention discloses a lithium-ion battery consistency evaluation method and system, belonging to the technical field of power battery detection, including carrying out chemical composition and capacity processing on a plurality of lithium-ion batteries with the same nominal capacity, and obtaining lithium batteries after preliminary classification. Ion battery; carry out AC impedance spectrum test under the low temperature to the lithium ion battery after preliminary classification, obtain the charge transfer impedance of the lithium ion battery after this preliminary classification; According to the size of charge transfer impedance, after described preliminary classification Consistency evaluation of lithium-ion batteries. The invention increases the AC impedance test of the battery at low temperature to improve the problem that the battery has good consistency in electrical performance at room temperature but poor consistency at low temperature, so as to realize reasonable matching of batteries and ensure battery The group has excellent performance at low temperature and normal temperature charge and discharge.

The present invention relates to a lithium-ion battery modeling method based on relaxation time distribution, the method comprising the following steps: S1, performing an AC impedance spectrum test on a lithium-ion battery sample at a specific SOC and temperature T; S2, calculating the AC impedance; S3. Using the Debye relaxation time formula to establish a relaxation time distribution function of the AC impedance; S4. Determine the battery RC model order and model parameters according to the AC impedance relaxation time distribution function; S5. Determine the lithium-ion battery model. Compared with the prior art, the present invention eliminates the influence of subjective factors on model establishment, and the established model has high precision.

The invention provides a fuel cell diagnosis method and diagnosis system, including: injecting synchronous multi-frequency current excitation into the fuel cell; collecting the time domain current excitation signal and voltage feedback signal of the fuel cell, and calculating the AC current at different frequency points Impedance spectrum data; construct the AC impedance spectrum model of the fuel cell, and convert the nonlinear model equation of the AC impedance spectrum model into a linear model equation; fit the AC impedance spectrum data and the linear model equation according to the principle of least squares, and obtain the AC The parameter values ​​of the impedance spectrum model; the eigenvectors of the fuel cell are obtained according to the parameter values; the fault classification algorithm is used to classify the eigenvectors, and the working status of the fuel cell is diagnosed according to the classification results, thereby greatly reducing the calculation by fitting the linear model equation The complexity and amount of calculation, and also avoid the problem that the nonlinear least squares method is easy to fall into local optimum and low precision.

The invention relates to a method for detecting the degree of influence of recycled aggregate on the concrete interface transition zone, which is obtained by making a finished test block of recycled aggregate and a finished product test block of acrylic aggregate with conductive properties; and performing an AC impedance spectrum test on the two test blocks. The complex plane plot of the electrochemical impedance, obtained by least squares fitting of the equivalent circuit, R 1 , R 1 * and R 2 , R 2 * ; where R 1 and R 2 are the minimum value and maximum value of the real part of the impedance complex plane diagram of a typical recycled aggregate concrete test block, R 1 * and R 2 * are the minimum value and maximum value of the real part in the impedance complex plane diagram of a typical acrylic concrete test block; the influence factor is calculated by the formula. When the influence factor is larger, it indicates that the recycled aggregate has a greater influence on the interface transition zone, and vice versa . Through the above tests, relatively effective impact test results can be obtained, which can be widely used in the test of the impact of recycled aggregate on the concrete interface transition zone.