Conducting Redox Polymer as Organic Anode Material for Polymer‐Manganese Secondary Batteries
Kouki Oka, Rebecka Löfgren, Rikard Emanuelsson, Hiroyuki Nishide, Kenichi Oyaizu, Maria Strømme, Martin Sjödin
Abstract
Abstract Manganese‐based aqueous batteries have attracted significant attention due to their earth‐abundant components and low environmental burden. However, state‐of‐the‐art manganese‐zinc batteries are poorly rechargeable, owing to dendrite formation on the zinc anode. Organic materials could provide a safe and sustainable replacement. In the present work, a conducting redox polymer (CRP) based on a trimer of EPE (E=3,4‐ethylenedioxythiophene; P=3,4‐propylenedioxythiophene) and a naphthoquinone (NQ) pendant group is used as anode in polymer‐manganese secondary batteries. The polymer shows stable redox conversion around+0.05 V vs. Ag/AgCl, and fast kinetics that involves proton cycling during pendant group redox conversion. For the first time, a CRP‐manganese secondary battery was fabricated with pEP(NQ)E as the anode, manganese oxide as the cathode, and manganese‐containing acidic aqueous solution as the electrolyte. This battery yielded a discharge voltage of 1.0 V and a discharging capacity of 76 mAh/g anode over >50 cycles and high rate capabilities (up to 10 C).