Related Experiment Video
Updated: Sep 24, 2025

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery
Published on: February 13, 2017
An Energy-Dense, Powerful, Robust Bipolar Zinc-Ferrocene Redox-Flow Battery
1Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322, USA.
Abstract:
Zinc metal represents a low-cost, high-capacity anode material to develop energy-dense aqueous redox-flow batteries (RFB). However, the energy-storage applications of traditional inorganic Zn halide flow batteries are primarily plagued by the material challenges of traditional halide cathode electrolytes (e.g., bromine), including corrosion, toxicity, and severe crossover. Herein, we report a bipolar zinc-ferrocene salt compound, zinc 1,1'-bis(3-sulfonatopropyl)ferrocene, Zn[Fc(SPr)2 ] (1.80 M solubility or 48.2 Ah L- charge storage capacity)-a robust, energy-dense, bipolar redox-active electrolyte material for RFBs. Zn[Fc(SPr)2 ]-based redox-flow batteries operated at high current densities of up to 200 mA cm-2 and delivered an energy efficiency of up to 81.5 % and a power density of up to 270.5 mW cm-2 . A Zn[Fc(SPr)2 ] flow battery demonstrated an energy density of 20.2 Wh L-1 and displayed nearly 100 % capacity retention for 2000 cycles (1284 h or 53.5 days).
Related Concept Videos
Batteries and Fuel Cells
Voltaic/Galvanic Cells
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
DC Battery
Electromotive Force
Standard Electrode Potentials
Electrolysis

