Tailoring three-dimensional porous Ni-doped Mn2O3 cathode for high-performance zinc-ion battery

Manganese-based materials are widely regarded as promising cathodes for aqueous zinc-ion batteries (AZIBs) due to their high operating voltage and large specific capacity. Nevertheless, the dissolution of manganese during cycling leads to structural breakdown and poor electrochemical reaction kinetic. Addressing these challenges is critical for the advancement of AZIBs. In this study, three-dimensional porous Ni-doped Mn 2 O 3 spheres (NMO) were prepared to enhance the charge storage capacity of Mn 2 O 3 . The incorporation of Ni 2 + creates oxygen vacancies to stabilize the internal electric field. The enlarged lattice spacing caused by Ni 2+ doping also accelerates the diffusion of H + /Zn 2+ . Moreover, the porous structure facilitates electrolyte penetration, shortening diffusion pathway of Zn 2+ . As expected, the optimized NMO exhibits a significantly higher specific capacity of 512.9 mAh g –1 at 0.1 A g –1 . Additionally, NMO demonstrates outstanding cyclic stability with a capacity retention of 97.3 % after 1000 cycles at 1 A g –1 . This research provides a unique approach for the design and optimization of manganese-based materials. Three-dimensional porous Ni-doped Mn 2 O 3 spheres were synthesized. The doping of Ni 2+ increases oxygen vacancies and enlarges lattice spacing. Excellent electrochemical stability of NMO has been achieved. The charge storage mechanism of NMO is investigated.