Based on the utilization of jarosite residue: The lithium storage performance of α-Fe2O3 materials synthesized from different iron solution systems

In this work, three kinds of iron simulation solution systems (FeCl3, FeSO4, and Fe2(SO4)3 solutions) are prepared and used as an iron source for synthesizing α-Fe2O3 electrode materials by the one-step sucrose-assisted thermal decomposition method. The microstructure and lithium storage performance of the as-prepared α-Fe2O3 materials are systematically studied by XRD, SEM, TGA, FT-IR, XPS, CV, EIS, and discharge/charge measurements. The results demonstrate that the α-Fe2O3 samples prepared from FeSO4 simulation solution or Fe2(SO4)3 simulation solution are composed of interconnected nanorods particles and contain a certain amount of undecomposed SO42−; while the α-Fe2O3 sample prepared from FeCl3 simulation shows irregular particle morphology (with the size ranging from hundreds of nanometers to several microns) and contains a small amount of Cl−. The two α-Fe2O3 samples prepared from sulfate simulation solution exhibit high lithium storage activity but experience large capacity fluctuation during cycling. In contrast, the α-Fe2O3 sample prepared from the FeCl3 simulation solution gives a lower reversible capacity but much better cycling stability. After 400 cycles at 500 mA g−1, the α-Fe2O3 samples prepared from FeSO4, Fe2(SO4)3, and FeCl3 simulation solutions deliver reversible capacities of 947, 1071, and 628 mA h g−1, respectively. The results reported in this work could provide clues for the structural design and performance modification of Fe-based oxides as anode materials for lithium-ion batteries.