Table 1. Projected Concentrations of LiPF₆ and Li Ion Vacancies in FePO₄ within the Battery Electrodes Used in This Study^a.

% active material in electrode	LiPF6 soaked in electrode void space/mol dm–3	Li ion vacancies in FePO4/mol dm–3
50	0.2	6.52
25	0.2	2.85

^aCalculated assuming that the solid material is approximately 80% of the volume and that the free space (filled with electrolyte) is 20% (approximated from ref (48)). Densities were taken as 3.6, 2, and 2.2 g cm^–3 for LiFePO₄, carbon black, and PTFE, respectively. It was also assumed that changes in composition of the active material did not change the packing of the solids and therefore the occupied volume. The concentration of the LiPF₆ in the electrolyte solution used was 1 M.