Poly(anthraquinonyl imide) as a high capacity organic cathode material for Na-ion batteries

Abstract

Redox-active organic imides are potential alternatives to transition-metal based cathodes for material-sustainable and environmentally friendly Na-ion batteries; however, their poor cyclability remains a challenge for battery applications. To address this issue, we use a redox-active anthraquinone to link the small carbonyl molecules to obtain a conjugated polymer with multiple redox-active centers. Herein, we synthesize four cathode-active poly(anthraquinonyl imide)s (PAQIs) from pyromellitic dianhydride (or 1,4,5,8-naphthalenetetracarboxylic dianhydride) and 1,4-diaminoanthraquinone (or 1,5-diaminoanthraquinone). The as-prepared PAQI materials exhibit a high reversible capacity of 190 mA h g⁻¹ and a stable cyclability with 93% capacity retention over 150 cycles, suggesting a possible use of these organic cathode materials for high capacity Na-ion batteries.