How did you define “volume change” in the battery explorer app?
I was playing around with the pymatgen’s MPRester and tried to calculate volume change for “Ca_0-0.5_FeO2” electrode system. (https://materialsproject.org/batteries/mvc-2000025690/). I got volumes for FeO2 and Ca(FeO2)2 as 279.0727Å^3 and 309.1910Å^3, respectively. However, (309.1910-279.0727)/279.0727 gives 10.79% of volume change, not 13%.
Similarly for the LiCoO2 system (https://materialsproject.org/batteries/mp-300024850/), how was the overall volume change of 4% calculated?