The network pathway shown in Figure has the 12th lowest cost with only Li + and EC as starting species (no CO 2 ) at +0.0V vs. Li/Li + . In this pathway, Li + coordinates with EC, and the Li + EC reduces twice. The doubly reduced Li + EC 2-then ring-opens at the shoulder bond, after which this shoulder-ringopened species can abstract a proton from an additional Li + EC, forming LFEO with a Li + EC-H -as a byproduct. The identified elementary mechanism follows this path exactly, with two TS -one for the ring-opening of Li + EC 2-with a barrier ∆G ‡ = 0.10 eV and one for proton abstraction from EC to form LFEO with ∆G ‡ = 0.11 eV.