The working electrode was prepared by mixing 60 wt. % of the active material, 30 wt. % of Printex XE2 carbon black, and 10 wt. % of polytetrafluoroethylene (PTFE) binder (60 wt. % water dispersion, Aldrich) in 2-propanol. The mixture was ball milled in a planetary ball mill (Retsch PM100) at 300 rpm for 30 min in an ambient atmosphere. The obtained slurry was rolled into a thin film, pressed onto an Al-mesh (mesh size 100) current collector, and cut into circular discs (ϕ = 12 mm), which were afterward dried at 50 °C for 1 day. For ex-situ FT-IR measurements, the slurry was rolled on glass and cut into free-standing electrodes (ϕ = 12 mm). Swagelok-type battery cells were assembled in an argon-filled glovebox (O2 < 1 ppm, H2O < 1 ppm) by separating working electrodes and lithium foil discs (ϕ = 12 mm) with 2 pieces (ϕ = 13 mm) of Celgard 2320 separators wetted with 3 drops of 1 M LiTFSI in 1:1 (v/v) DOL and DME.