PEDOT Nanowires Connecting Exfoliated HNb₃O₈ Nanosheets as High-Rate Anode for Lithium-Ion Capacitor

The development of anode materials with fast ion and electron kinetics is of great significance for a high-performance lithium-ion capacitor. In this work, we reported the incorporation of conductive poly(3,4-ethlenedioxythiophene) (PEDOT) nanowires between the exfoliated HNb3O8 (E-HNb3O8) to prepare the E-HNb3O8-PEDOT composite electrodes for lithium-ion capacitor. The conductive PEDOT nanowires in the E-HNb3O8-PEDOT composite inhibit the restacking of E-HNb3O8 sheets, create numerous ion pathways, and significantly enhance the electrode conductivity. Benefiting from the favorable ion and electron pathways, the E-HNb3O8-PEDOT composite electrode demonstrates substantially enhanced performance, including high discharge capacity (540 mAh g(-1) at 0.1 A g(-1)), high rate capability (174 mAh g(-1) at 10 A g(-1)), and good cycling lifespan (65.4% capacity retention at 10 A g(-1) for 1000 cycles). The lithium-ion capacitor assembled with E-HNb3O8-PEDOT and activated carbon can deliver a maximum energy density of 80 Wh kg(-1). Meanwhile, it maintains about 83% capacity and almost 98% Coulombic efficiency after 1000 cycles at 1.0 A g(-1). Our results indicate that the PEDOT nanowires are promising building blocks for constructing kinetically favorable ion and electron pathways for rapid lithium-ion storage.