Flash graphene induced low-temperature synthesis of a single-crystalline Na2.72Fe1.64(SO4)3 cathode for boosted sodium storage

A single-crystalline Na 2.72 Fe 1.64 (SO 4 ) 3 @FG cathode material was successful fabricated for the first time, which exhibits a high-rate performance of 81 mA h g −1 at 15C and maintains an excellent capacity retention of 80.7% after 15 000 cycles.