Synthesis and Charge-Discharge Properties of Organometallic Copolymers of Ferrocene and Triphenylamine as Cathode Active Materials for Organic-Battery Applications

KGaA. Two new organometallic copolymers (PVFVM1 and PVFVM1-1) bearing different molar ratios of ferrocene and triphenylamine pendants were successfully designed and synthesized as cathode active materials for organic-battery applications. Their structural and thermal characteristics were determined by1H NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, size exclusion chromatography (SEC), and thermogravimetric analysis (TGA). Cyclic voltammograms of the as-prepared polymers show that the electrochemical reactions of the ferrocene and triphenylamine moieties are reversible after the first cycle. A composite electrode based on copolymer PVFVM1 exhibits an initial specific discharge capacity of 102 mA h g-1, which corresponds to 98 % of its theoretical capacity (104 mA h g-1). The cycle endurances for both polymers have been evaluated for over 50 cycles. Our results show that both copolymers are good candidates as a new class of cathode active materials and charge-storage materials for rechargeable batteries.