Ion Transport in Lithium Electrochemical Systems: Problems and Solutions
Aleksandr V. Ivanishchev, И. А. Иванищева
Abstract
Abstract The realizing of new electrode materials and the modification of existing ones are important trends in the development of lithium-ion batteries. Of particular importance is the assessment of their diffusion ability, that is, the ability to provide transport of the electroactive component. For this purpose, electrochemical methods such as cyclic voltammetry, electrochemical impedance spectroscopy, potentiostatic intermittent titration, and galvanostatic intermittent titration techniques are used. The chemical diffusion coefficient D estimated in such electrode materials is shown to have a spread in values by several orders of magnitude. The main reasons for this rather significant dispersion are discussed, including the uncertainty of the estimates of the diffusion surface area and the using of various approaches to the obtaining of equations for the calculating of D. The conclusions are illustrated by examples of the D estimates in LixC6-, LixSn-, LixTiO2-, LixWO3-, LiMyMn2 – yO4-, and LiFePO4-based electrode materials.