Fe/Zn co-doped MnO₂ nanoflowers for high-performance aqueous zinc-ion batteries

Fe/Zn bimetallic co-doped layered manganese dioxide (FZMO) nanoflowers were synthesised using a one-step solvothermal method. The incorporation of iron and zinc cations stabilises the structure by generating oxygen vacancies, reducing the dimensions of the nanoflowers while increasing the interlayer spacing. This synergistic effect significantly enhances electrical conductivity and shortens ion migration pathways, thereby improving ion diffusion kinetics. Electrochemical tests showed that the FZMO cathode exhibited an improved capacity of 432.5 mAh g^-1 at 0.2 A g^-1 and superior rate capability. Notably, it retained 90.16% of its capacity over 1000 cycles at a high current density of 1 A g^-1, highlighting its exceptional stability.