The hollandite-type β-FeOOH(Cl) as a new cathode material for chloride ion batteries

β-FeOOH is utilized as a new cathode material for rechargeable chloride ion batteries for the first time. β-FeOOH has superior rate capabilities and a high reversible capacity of 122 mA h g−1 after 100 cycles. This work opens up new possibilities for the development of anion batteries.