A novel polyquinone cathode material for rechargeable lithium batteries

A novel polymer, poly(5-amino-1,4-dyhydroxy anthraquinone) (PADAQ) as the cathode material of lithium batteries is synthesized by a facile oxidation process and characterized by FT-IR, MS, elementary analysis, XRD, SEM and electrochemical method. The results show that the as-prepared polymer solves the problems of dissolution and crystallization of its monomer, 5-amino-1,4-dyhydroxy anthraquinone (ADAQ), thus maintains the stability of the electrode structure successfully. At the cutoff voltage of 1.5 -3.7 V, the initial discharge capacity of PADAQ is 101 mAh g(-1) at the current density of 400 mAh g(-1). After 14 cycles, the capacity increases to 143 mAh g(-1), and maintains 129 mAh g(-1) after 50 cycles, which shows an improved cycle performance compared to its monomer. Even at the high current density of 1400 mAh g(-1), its capacity still reaches 95 mAh g(-1), indicating a high rate capacity. The results also show that PADAQ is sensitive to discharge depth. When discharged to 1.0 V, its cycle performance is poor. (C) 2013 Elsevier B.V. All rights reserved.