Fabrication of Zn-doped Co3O4 as cathode material for aqueous rechargeable Zn-ion batteries

The increasing demand for advanced energy-storage systems have led to extensive research on Co3O4//Zn batteries because of their high theoretical capacity, low cost, and environment friendliness. However, the capacity of Co3O4//Zn batteries is decreased by the volume change of Co3O4 cathode in practical application, so its advantages are not fully utilised. To improve the capacity of Co3O4 cathode, a cathode of Zn-doped Co3O4 based on carbon cloth with zeolite imidazole-67 (ZIF-67) precursor in aqueous zinc-ion battery was successfully prepared. The Zn-doped Co3O4 cathode had a uniform arrangement in mild aqueous electrolyte, The battery had a high charge/discharge voltage of 2.2 V, a high specific capacity of 196 mA h/g at 1 A/g, outstanding rate capability, and superior cycle stability of 93.2 % capacity retention over 1000 cycles at 5 A/g. The improvement in electrode material provided a new idea for preparing rechargeable aqueous Zn-ion batteries.