A fixed-bed zinc/nickel redox flow battery (RFB) is designed and developed. The proposed cell has been established in the form of a fixed bed RFB. The zinc electrode is immersed in an aqueous NaOH solution (anolyte solution) and the nickel electrode is immersed in the catholyte solution which is a mixture of potassium ferrocyanide, potassium ferricyanide and sodium hydroxide as the supporting electrolyte. In the present work, the electrode area has been maximized to 1500 cm 2 to enforce an increase in the energy efficiency up to 77.02% at a current density 0.06 mA/cm 2 using a flow rate 35 cm 3 /s, a concentration of the anolyte solution is 1.5 mol L -1 NaOH and the catholyte solution is 1.5 mol L -1 NaOH as a supporting electrolyte mixed with 0.2 mol L -1 equimolar of potassium ferrocyanide and potassium ferricyanide. The outlined results from this study are described on the basis of battery performance with respect to the current density, velocity in different electrolytes conditions, energy efficiency, voltage efficiency and power of the battery.