Enhanced electrochemical performance via synergistic effects between graphene oxide and conjugated polyquinoline prepared by Dobner polymerization

In this study, we developed a strategy about synergistic enhancement and in-situ composite between polymer and carbon to prepare an electrode material for the high-performance supercapacitor. Specifically, Dobner polymerization was selected to synthesize a conjugated polyquinoline derivative (PQLD), and along with the simultaneous introduction of graphene oxide (GO) in the reaction system for a new in-situ electrode material (PQLD-GO). The strengthened intermolecular interactions among pyridine/carboxyl groups from PQLD and carboxyl/hydroxyl groups from GO, including π-π stacking, synergistically enhance the electron/ion transport and Faraday reactions of PQLD-GOs composites. The experimental results showed that the electrochemical performance for PQLD-GOs composites is reasonably optimized as the optimal amount of 10% GO. Far different from the specific capacitance of 20 F g⁻¹ for pure PQLD and 21 F g⁻¹ for pure GO, the specific capacitance of PQLD-GO-10% composite is as high as 320 F g⁻¹ in the three-electrode test, indicating a significant synergistic enhancing effect. In the two-electrode measurement system, the energy density of PQLD-GO-10% is 7.4 Wh kg⁻¹, and the power density is 125 W kg⁻¹. Even after 10,000 cycles at 10 mV s⁻¹, the specific capacitance of PQLD-GO-10% remained 87.9%. Furthermore, the synergistic effect between PQLD and GO was also revealed through several comparative experiments such as simple mixing, replacement of non-conjugated polyquinoline or carbon nanotube and so on.