Zinc-ion batteries (ZIBs) are deemed as a prospective battery technology in virtue of their intrinsic safety, low cost and environmental friendliness. Nevertheless, the sluggish ion transport kinetics is an important factor constraining the practical viability of ZIBs. Herein, porous MnO₂ was synthesized by a self‑assembly assisted hydrothermal process to facilitate ion diffusion. The electrochemical results show that porous MnO₂ outlines extraordinary electrochemical performance with an exceptional capacity of 207 mAh g^-1 at 0.2 A g^-1 after 100 cycles, significantly outperforming Mn₂O₃ (85 mAh g^-1) and MnO (28 mAh g^-1). Furthermore, the charge storage process of porous MnO₂ was investigated, which is dominated by the dissolution/deposition of MnO₂ mechanism, providing new insights into the rational design of advanced manganese oxides.