Rapid determination of solid-state diffusion coefficients in Li-based batteries via intermittent current interruption method
Yu‐Chuan Chien, Haidong Liu, Ashok S. Menon, William R. Brant, Daniel Brandell, Matthew J. Lacey
Abstract
Abstract The galvanostatic intermittent titration technique (GITT) is considered the go-to method for determining the Li + diffusion coefficients in insertion electrode materials. However, GITT-based methods are either time-consuming, prone to analysis pitfalls or require sophisticated interpretation models. Here, we propose the intermittent current interruption (ICI) method as a reliable, accurate and faster alternative to GITT-based methods. Using Fick’s laws, we prove that the ICI method renders the same information as the GITT within a certain duration of time since the current interruption. Via experimental measurements, we also demonstrate that the results from ICI and GITT methods match where the assumption of semi-infinite diffusion applies. Moreover, the benefit of the non-disruptive ICI method to operando materials characterization is exhibited by correlating the continuously monitored diffusion coefficient of Li + in a LiNi 0.8 Mn 0.1 Co 0.1 O 2 -based electrode to its structural changes captured by operando X-ray diffraction measurements.