Graphite-like structured conductive polymer anodes for high-capacity lithium storage with optimized voltage platform

Graphite is a widely used anode material in commercial lithium-ion batteries (LIBs), but its low theoretical specific capacity and extremely low redox potential limit its application in high-performance lithium-ion batteries. However, developing lithium-ion battery anode with high specific capacity and suitable working potential is still challenging. At present, conductive polymers with excellent properties and graphite-like structures are widely used in the field of electrochemistry, but their Li+ storage mech-anism and kinetics are still unclear and need to be further investigated. Therefore, we synthesized the conducting polymer Fe-3(2, 3, 6, 7, 10, 11-hexahydroxytriphenylene)(2) (Fe-CAT) by the liquid phase method, in which the d-pi conjugated structure and pores facilitate electron transfer and electrolyte infil-tration, improving the comprehensive electrochemical performance. The Fe-CAT electrode displays a high capacity of 950 mA h g(-1) at 200 mA g(-1). At the current density of 5.0 A g(-1), the electrode shows a reversible capacity of 322 mA h g(-1) after 1000 cycles. The average lithiation voltage plateau isti 0.79 V. The combination of ex-situ characterization techniques and electrochemical kinetic analysis reveals the source of the excellent electrochemical performance of Fe-CAT. During the charging/discharging process, the aromatic ring in the organic ligand is involved in the redox reaction. Such results will provide new insights for the design of next-generation high-performance electrode materials for LIBs. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Graphite is widely used in commercial lithium-ion batteries, but its low capacity and low redox potential limit its application in high-performance batteries. Conductive polymers with graphite-like structures are used in electrochemistry, but their Li+ storage mechanism and kinetics are still unclear. We synthesized the conducting polymer Fe-CAT with a conjugated structure and pores, improving its electrochemical performance.