Electrode sheets were coated in air on carbon-coated Al foil using a doctor blade set to a height of 100 µm from a slurry of positive electrode material, carbon black, and PVDF at an 80:10:10 mass ratio in NMP (Sigma-Aldrich). Electrode sheets were dried at 65 °C in air for at least 1 h, then at 60 °C under active vacuum overnight. In an Ar-filled glovebox, 1 cm 2 electrodes were assembled into 2032-type 316 stainless steel coin cells separated from a Li foil counter electrode by a celguard separator. Cells were flooded with excess 1 M LiPF 6 EC: DEC (1:1 w/w) (LP40, Gotion). Typical active material loading was 3 mg/cm 2 . The exact cycling protocol -in summary: slow formation, followed by extended activation, a rate test, and an additional 70 cycles at moderate rate -is described in SI Table .