A Conjugated Coordination Polymer with Benzoquinone as Electrode Material for All Organic Symmetric Lithium-ion Batteries

Carbonyl rich conjugated polymer electrode materials for lithium-ion batteries possessed the advantages of strong molecular design ability, abundance and high theoretical capacity. In this work, a Co²⁺ coordinated conjugated polymer using 2,3,5,6-tetraamino-p-benzoquinone (TABQ) as building block was constructed and developed as electrode material for all organic symmetric lithium-ion batteries, outputting a specific capacity of over 100 mAh g^-1 after 50 cycles at 50 mA g^-1 . Performances of Co-TABQ in half cells were explored. The Co-TABQ cathode delivered a capacity of 133.3 mAh g^-1 after 150 cycles at 20 mA g^-1 . When cycled at higher current density of 500 mA g^-1 , the capacity gradually increased to 109.4 mAh g^-1 after 4000 cycles. The Co-TABQ anode displayed a stable capacity of 568.6 mAh g^-1 at 1 A g^-1 . The charge transfer within the electrode was greatly reduced due to the metallic centers in the extended conjugated skeleton, and the reversible Li⁺ storage was achieved by the active C=O and imine groups. This work showed the great potential of metal mediated conjugated polymer in Lithium-ion batteries.