Performance gains in single flow zinc-nickel batteries through novel cell configuration

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 20 mA cm−2 to 80 mA cm−2 for the first time. Compared to traditional structure cell, the energy efficiency is improved 10.3% reaching to 75.2% at 80 mA cm−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.