Design And Synthesis Of Triphenylamine-based Organic Electrode Materials And Their Energy Storage Performance

Organic materials are considered to be one of the most promising active electrode materials for future energy storage systems due to their tunable structure,abundant resources and low cost.The development of organic electrode materials with high specific capacity,high operating voltage and cycling stability has become a hot topic in the field of batteries.In this article,novel bipolar organic electrode materials are designed and synthesized based on trianiline active structural units,and their energy storage mechanisms are investigated as follows:（1）Two conjugated microporous polymers were synthesized by combining the triphenylamine structure with the anthraquinone structure via the Suzuki coupling reaction and the Buchwald-Hartwig reaction which named TNAQ and TPAQ.Theoretical calculations and electrochemical performance tests show that TNAQ exhibits excellent electrochemical performance due to the introduction of a conjugated imino group（-NH-）in the molecular structure,has a narrower band gap and higher electron transport capacity than TPAQ.TNAQ was applied as a bipolar electrode to a dual-ion battery system,it demonstrated an average discharge voltage of 3.0 V and a reversible capacity of～231 m Ah g^-1.The capacity retention after 300 cycles is 81%at a current density of 200 m A g^-1.The energy storage mechanism of these electrode materials is a reversible alternating chemical association and deconjugation reaction of anions/cations with triphenylamine sites and carbonyl sites.（2）The coordination compounds BTD-Cu,BTD-Ni and BTD-Zn based on triphenylamine structure were synthesized by using BTD as organic ligands and coordination with metal ions,respectively.The molecular structure,morphology,electrochemical properties and energy storage mechanism were investigated.DFT theoretical calculations were used to compare the energy bands of BTD-M to predict their electron transport capabilities.The experimental results show that BTD-Cu exhibits superior electrochemical performance in the lithium-based half-cell system,with a discharge capacity of 133 m Ah g^-1 at 1 C and a median discharge voltage of 3.1V.When the current density is increased to 10 C,BTD-Cu still has a specific capacity of 85 m Ah g^-1.The capacity retention rate is～90% after 400 cycles at 5 C.