With increasing demand of high-capacity, safe, rechargeable energy storage systems for efficient use of fossil and renewable energy, the development of alternative battery systems has been strongly motivated . The concept of battery systems based on anion transport was introduced more than half-century ago , and the fluoride ion, as the most chemically stable shuttle anion, has been widely investigated for use in fluoride-ion batteries (FIBs) . Recent demonstrations of high-energy-density rechargeable FIBs have significantly boosted interest in this field . Most research has focused on improving conductivity of electrolytes at room temperature as well as developing high-performance electrode materials .