Regaining Potential: Studies Concerning 2-Ferrocenylethyl Methacrylate, Its Polymers, and Application in Redox Flow Batteries

A concise synthesis for the monomer 2-ferrocenylethyl methacrylate is presented. This versatile monomer can be homopolymerized to yield highly lipophilic, stimuli-responsive homopolymers and can also be used to further synthesize water-soluble copolymers. For the first time, the X-ray crystal structure of this monomer is shown. The copolymerization with two different ionic monomers was thoroughly investigated at various temperatures. Electrochemical investigations were performed with a well-established viologen to assess the viability of the new material for possible energy storage scenarios. Charge storage experiments at ambient and elevated temperature point toward a satisfying stability of the new materials, with charge recoveries of approximately 95%. The Coulombic efficiency of the materials was determined via galvanostatic cycling and was found to be above 99%, which is comparable to other suitable redox-active polymers for charge storage studies.