ИСТИНА

The method of the distribution of relaxation times (DRT) is a relatively new approach to the analysis of electrochemical impedance spectra of various systems [1–3]. Its main advantage is that, unlike traditional impedance fitting, it does not require a-priori selection of an equivalent circuit, which may be a quite controversial choice for many systems and may even compromise the validity of the results obtained using such analysis. Whereas the theoretical basis of the DRT method is quite well substantiated in the works of various authors, there is still lack of studies that could provide further validation of this method by applying it to practical systems and checking if the results obtained using this method have a clear physical meaning and agree with the existing data. In this work, we applied the DRT method to the analysis of the impedance data for lithium-ion batteries. The impedance spectra were obtained for several practical systems by varying such factors as the composition of the electrodes, methods of their preparation, battery state of charge, etc. The experimental impedance spectra were then analyzed using the DRT method and the results were compared with the data known for such systems from the literature and general considerations. The comparison shows that the results of the DRT analysis agree quite well with the available literature data and therefore this method can be recommended as a valuable tool for the analysis of the impedance data for batteries and similar practical systems. The work was supported by the Russian Science Foundation, project 17-73-30006-P. References: 1. Wan, T.H.; Saccoccio, M.; Chen, C.; Ciucci, F. // Electrochimica Acta. 2015, 184, 483. 2. Chen, C.; Ciucci, F. // Electrochimica Acta. 2015. 167, 439. 3. Effat, M.B.; Ciucci, F. // Electrochimica Acta. 2017, 247, 1117.