Amorphous aluminum-doped manganese oxide cathode with strengthened performance for aqueous zinc-ion batteries

Aqueous zinc-ion batteries have been regarded as owning substantial potential for applications on account of their notable safety, low cost, environmental-friendly economy and high theoretical capacity. However, the long-term service lifespan and high-capacity retention of aqueous zinc-ion batteries are still obstructed by the ion/electronic conductivity and constructional durability of cathode materials. Heteroatom doping strategy is an effective method for enhancing the conductivity and stability of cathodes. Herein, porous amorphous aluminum-doped manganese oxide (a-AMO) is prepared through hydrothermal and high-temperature annealing means. The porous structure shortens the transmission distance of zinc ions, contributing to reduce the ion diffusion path as well as promote the mass transmission. The incorporation of aluminum ions is a key step for maintaining the structural integrity and reducing manganese leaching reaction of manganese oxide cathodes. The obtained a-AMO cathode exhibits superior long-term cycling stability in contrast to the control sample without aluminum ions doping. Specifically, the capacity of a-AMO cathode can stable at 104.2 mAh g⁻¹ after 1000 cycles at 1.0 A g⁻¹. This method offers new possibilities to produce perdurable cathodes for long service life zinc-ion batteries.