Optimizing ammonium vanadate crystal structure by facile in situ phase transformation of VO2/NH4V4O10 with special micro–nano feature for advanced aqueous zinc ion batteries

NH 4 + -defected NH 4 V 4 O 10 with microflower morphology was synthesized via hydrothermal method and in situ phase transition to improve specific capacity (494.0 mA h g −1 ), Zn 2+ diffusion efficiency and structural stability (71.8% for 2000 cycles).