A high surface area tunnel-type α-MnO2 nanorod cathode by a simple solvent-free synthesis for rechargeable aqueous zinc-ion batteries

Tunnel-type α-MnO2 with a nanorod morphology was prepared via a simple solvent-free synthesis method for use in aqueous zinc-ion battery (ZIB). This synthesis method produced α-MnO2 with a high BET surface area of 153 m2 g−1. α-MnO2 electrode demonstrated remarkable zinc storage properties (first and second discharge capacities of 323 and 270 mAh g−1 at 16 mA g−1) with good capacity retentions and rate capability. After charging within only 60 s, the α-MnO2 nanorod cathode delivered a considerable discharge capacity of 115 mAh g−1 when cycled at current density of 16 mA g−1.