Successive Cationic and Anionic (De)‐Intercalation/ Incorporation into an Ion‐Doped Radical Conducting Polymer

Abstract The further development of conducting polymers (CPs) as electrode materials is restricted by the limited doping level, solely ionic reaction as well as the insufficient reversibility and stability. In order to overcome the deficiency of intrinsic properties, a combined strategy is adopted to modify a p‐type CP (polythiophene, PTh) through grafting a radical pendant (2,2,6,6‐tetramethylpiperidinyl‐1‐oxyl, TEMPO) and incorporating a redox‐active dopant (Fe(CN)₆³⁻) into the π‐conjugated backbone of PTh. TEMPO group works as the electron donor allowing anionic incorporation (PF₆⁻, ClO₄⁻) and Fe(CN)₆³⁻ doping in the conducting matrixes of PTh combines with cations (Li⁺) to deliver extra capacity, leading to the final composite shows a successive cationic and anionic (de)‐intercalation behavior. This dual‐ion transportation mechanism of Fe(CN)₆³⁻ doped P(Th‐TEMPO) facilitates the enhanced electrochemical performance, including two significant voltage plateaus (3.6 V and 2.9 V), a reversible capacity from 76 mAh g⁻¹ to 135 mAh g⁻¹ at an ultra‐high coulombic efficiency (more than 99 %), which result in a high energy density.