Abstract
A systematic investigation of the factors that affect lithium diffusion coefficient measurements in the Atlung Method for Intercalant Diffusion (AMID) is carried out. Single crystal LiNi0.6Mn0.2Co0.2O2 is used for method development. The factors include electrode mass loading, separator thickness, electrolyte solvent choice and salt molarity, voltage interval sizes, open circuit relaxation time, C-rate choice, and charge vs discharge direction. In an ideal diffusivity measurement method, none of these factors listed should impact the true material diffusivity since it should be a purely material property. However, as we demonstrate here, all these experimental parameters should be selected carefully to minimize cell and electrode resistance contributions so that one can measure true lithium diffusivity in a material that is independent of current direction. We propose a low electrode loading cell design that is applicable for all diffusion measurement methods consisting of an ultrathin electrode coating (0.2 mAh cm−2), thin separator and 1.5 M LiPF6 ethylene carbonate: dimethyl carbonate 1:1 electrolyte. Additionally, we show diffusivity is not dependent on charge or discharge direction in NMC622, and we compare AMID results to Galvanostatic Intermittent Titration. Specific to AMID 15 min OCV time with 0.1 V intervals are suitable for this measurement.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.