title: Dithiophenedione-containing polymers for battery application.
abstract: Redox-active polymers have received recently significant interest as active materials in secondary organic batteries. We designed a redox-active monomer, namely 2-vinyl-4,8-dihydrobenzo[1,2-b:4,5-b']dithiophene-4,8-dione that exhibits two one-electron redox reactions and has a low molar mass, resulting in a high theoretical capacity of 217 mAh/g. The free radical polymerization of the monomer was optimized by variation of solvent and initiator. The electrochemical behavior of the obtained polymer was investigated using cyclic voltammetry. The utilization of lithium salts in the supporting electrolyte leads to a merging of the redox waves accompanied by a shift to higher redox potentials. Prototype batteries manufactured with 10 wt % polymer as active material exhibit full material activity at the first charge/discharge cycle. During the first 100 cycles, the capacity drops to 50%. Higher contents of polymer (up to 40 wt %) leads to a lower material activity. Furthermore, the battery system reveals a fast charge/discharge ability, allowing a maximum speed up to 10C (6 min) with only a negligible loss of capacity.
authors.affiliation: Laboratory of Organic and Macromolecular Chemistry, Friedrich Schiller University Jena , Humboldtstraße 10, 07743 Jena, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Häupler
authors.forename: Tino
authors.initials: T
authors.lastname: Hagemann
authors.forename: Christian
authors.initials: C
authors.lastname: Friebe
authors.forename: Andreas
authors.initials: A
authors.lastname: Wild
authors.forename: Ulrich S
authors.initials: US
authors.lastname: Schubert
keywords: cathode material; organic battery; polymer; quinone; redox-active