ИСТИНА

Electrochemical methods are widely applied in fundamental and practical studies of intercalating materials for metal ion batteries. In most studies researchers make use of galvanostatic charge-discharge techniques (to determine practical capacity of the material under study), potentiostatic and galvanostatic intermittent titration (to determine the variation of diffusion coefficient with composition) and electrochemical impedance spectroscopy (to evaluate the dependence of the charge transfer resistance on various factors). Cyclic voltammetry (CV) is rarely applied to characterize kinetic properties of intercalating materials, in spite of a number of benefits that are provided by this classical technique [1]. This tutorial will demonstrate the possibility to apply CV method to distinguish between three common regimes of metal ion insertion/extraction process: thermodynamic, kinetic and mixed (diffusion and kinetic) control [2]. The shapes of the CV curves that are characteristic for each regime will be discussed and the analytical schemes for the treatment of experimental data for phase-transforming and single-phase intercalating materials will be suggested. Other aspects of interest include the influence of broad particle size distribution on the shape of the CV curve, the effect of SEI (or CEI) layer on the ion-transfer kinetics and the kinetics of systems with slow nucleation of a new phase.