“…Recently, with the rapid development of electric vehicles and electronic equipment, developing solid state rechargeable batteries with high density, 1–3 high voltage, 4,5 ultrahigh-rate, 6,7 safety 8,9 and long-life 10,11 has become an important strategic goal. Among various kinds of solid state rechargeable batteries, fluoride ion batteries (FIBs) 12,13 usually have multi-electron transfer characteristics, which makes them possess a high energy density of 5000 W h L −1 .…”