Manuscript "Towards carbon-free cathodes for fluoride ion batteries: deconvoluting effects of active material and conductive additive on charging and cyclic stability" Page 5 of 18 2 hours without intermediate rest in a 50 ml stainless steel ball milling jar with 100 g of 5 mm diameter stainless steel balls in argon atmosphere. After milling, the powder was heated to 600 °C for 4 h with a heating/cooling rate of 3 °C min -1 under 10 sscm pure oxygen flow to oxidize the SnO formed after ball-milling to SnO2 and decompose the ammonium fluoride to enable fluorination using the gaseous HF obtained in the process. The calcined powder mixture was then dispersed in deionized water to dissolve the sodium chloride and the remaining solid was centrifuged out. After decanting the clear supernatant and adding fresh deionized water, the dispersion was sonicated using a Hielscher 200S ultrasonic probe to disperse the particles.