Rapid charge–discharge rate is an important feature of energy storage devices, but causes dramatic reduction in battery performance. In single flow zinc–nickel batteries (ZNBs), large polarization of nickel hydroxide electrode is an obstacle to realizing high charge–discharge rate without compromising battery performance. A novel cell structure with a serpentine flow field is designed to reduce the polarization of the positive electrode through enhancing mass transport. The power density is improved nearly fourfold by elevating charge–discharge current density from 20mAcm−2 to 80mAcm−2 for the first time. Compared to traditional structure cell, the energy efficiency is improved 10.3% reaching to 75.2% at 80mAcm−2, which has a remarkable improvement. No obvious decrease of efficiencies is presented in the 70 charge–discharge cycles. This provides a feasible method to improve the charge–discharge rate with high performance and boosts the practical application progress of ZNBs.