Re-understanding the galvanostatic intermittent titration technique: Pitfalls in evaluation of diffusion coefficients and rational suggestions

The chemical diffusion coefficient (D), as an intuitive indicator for diffusion kinetics of ions in electrode materials, plays an essential role in determining material selection and predicting electrochemical properties. However, there are always some loopholes in the application of galvanostatic intermittent titration technique (GITT) as a conventional tool for testing the D value. Research has shown that the improper use of the GITT model and the wrong selection of important parameters of equations are the critical factors causing the order of magnitude difference in the results. To improve the accuracy of the D value, we have formulated the standards for the above issues, and analyzed the assumptions under different conditions. Moreover, a series of special measures that can improve the test results and new methods derived from GITT are rationally integrated. The GITT's suitability analysis and usage standards will enhance the efficiency and accuracy in obtaining the D values towards the effective optimization of electrode materials for advanced electrochemical energy storage devices.

Automated summary

The chemical diffusion coefficient (D) is an important indicator for the diffusion kinetics of ions in electrode materials. However, there are flaws in the conventional tool, galvanostatic intermittent titration technique (GITT), used to test the D value, such as improper model usage and selection of parameters leading to significant differences in results. To improve accuracy, we have formulated standards and analyzed assumptions under different conditions. In addition, we have integrated special measures and new methods derived from GITT to enhance the test results.