PEDOT encapsulated β-FeOOH nanorods: synthesis, characterization and application for sodium-ion batteries

Sodium-ion batteries (NIBs) are receiving attention again for emerging grid-scale energy storage needs. Exploring and developing NIB anode materials with excellent electrochemical properties from Earth-abundant elements are of important scientific and practical significance. Herein, we have designed poly(3,4-ethylenedioxythiophene) (PEDOT) encapsulated β-FeOOH nanorods as NIB anodes, which can be synthesized through a two-step method including surfactant-assisted hydrothermal synthesis of β-FeOOH nanorods and encapsulation of the obtained nanorods. The β-FeOOH@PEDOT nanorodes deliver a high discharge capacity of 726 mAh g−1 and maintain the reversible capacity of 468 mAh g−1 over fifty cycles. Based on a series of detailed characterizations and comparison experiments, we analyzed the sodium storage process of β-FeOOH@PEDOT nanorodes and proposed the causation of PEDOT shells improving electrochemical properties.