Electrochemical Preparation of Poly(N-anthraquinoyl pyrrole) as High-Performance Cathode Materials for Organic Lithium-Ion Batteries

Anthraquinone and its derivatives show compelling electrochemical activities in lithium-ion batteries due to their abundant redox-active carbonyl groups and desirable π -conjugated structures. However, anthraquinone-based compounds often suffer from inferior material utilization, a low-capacity retention rate, and short cycle life due to poor conductivities and unexpected dissolution properties in supporting electrolytes during the charge/discharge cycles. To solve these problems, a novel grafted polymer, poly(N-anthraquinoyl pyrrole) (e-PAQPy), containing redox-active anthraquinone subunits and conductive polypyrrole groups, is prepared by an electrochemical polymerization method and employed as the cathode material for organic lithium-ion batteries. Polypyrrole backbone chain in e-PAQPy is utilized both to bring into high electronic conductivity and to decrease the solubility of the anthraquinone subunits. As expected, the e-PAQPy exhibits a high specific capacity (196.2 mAh g −1 at 0.1 C), good rate performance (70.8 mAh g −1 at 3 C), and long cycle stability (79% of the initial capacity after 500 cycles).