In-situ polymerization of an organic cathode for highly efficient Li-ion batteries

Abstract

An organic polymer cathode called poly(anthraquinone-alt-benzene) (PAQB) is in-situ synthesized between the monomers of 2,6-dibromoanthraquinone and 1,4-benzenediboronic acid bis(pinacol) ester based on the matrix of carbon nanotube (CNT), leading to the growth of a polymer on CNT (PAQB@C) and the better formation of electron transportation network. After optimization, the sample (PAQB@C) of PAQB grown on 2 wt% CNT shows the best results in Li-ion batteries. In half cells, PAQB@C shows the average discharge potential around 2.2 V (vs. Li+/Li) and peak discharge capacity of 184 mAh g−1, stably running for 1000 cycles. In full cells with the Li-intercalated graphite (LiC6) as the anode, PAQB@C can deliver the peak discharge capacity of 187 mAh g−1cathode and peak energy density of 374 Wh kg−1cathode. And the full cells can show the long lifespan for over 2500 cycles. To the best of our knowledge, the comprehensive performance of PAQB@C is one of the best organic cathodes reported in Li-ion batteries.