Facile and efficient synthesis of binary FeOOH/Fe2O3 composite as a high-performance anode material for lithium-ion batteries

Abstract

Compared with single-component electrode materials, multi-component composite materials are more capable to promote the electrochemical performance of electrode materials because of the synergistic effect of different components. In this work, a binary FeOOH/Fe2O3 composite is fabricated by a facile and low-cost hydrothermal method with FeCl3•6 H2O and CO(NH2)2 as raw materials. The microstructure and composition of the as-prepared sample is characterized by XRD, SEM, TEM, FT-IR, and XPS. The electrochemical performance of the binary FeOOH/Fe2O3 composite is investigated by CV, EIS, charge-discharge test, and GITT measurement. Compared to single-component FeOOH or Fe2O3, this binary FeOOH/Fe2O3 composite exhibits outstanding high-rate capability (645 mA h g-1 at 1 A g-1) and superior long-term cycling stability (779 mA h g-1 after 300 cycles at 0.5 A g-1) due to the synergetic effect between FeOOH and Fe2O3. EIS analysis reveals that the electrochemical reaction resistance in binary FeOOH/Fe2O3 composite is lower than that in single-component FeOOH or Fe2O3. CV analysis demonstrates that the binary FeOOH/Fe2O3 composite has a certain pseudocapacitive behavior during discharge and charge processes. The lithium ion diffusion coefficient of the binary FeOOH/Fe2O3 composite derived from GITT data ranges from 4.0 × 10-12 to 1.0 × 10-14 cm2 s-1. Ex-situ SEM observations revealed that the binary FeOOH/Fe2O3 composite has good structural integrity upon cycling, which partially accounts for the superior electrochemical performance of the electrode. The reported method could provide a facile avenue for the ingredient design of high-performance anode materials for next-generation lithium-ion batteries (LIBs).