Electrochemical performance of Fe2(SO4)3 as a novel anode material for lithium-ion batteries

Exploring new electrode materials with high capacity, good cyclability, and low cost is of great importance for the development of lithium-ion batteries (LIBs). Herein, the lithium storage performance of Fe2(SO4)3 as an anode material for LIBs is investigated for the first time. The microstructure of the Fe2(SO4)3 sample is analyzed by XRD, SEM, TEM, and XPS measurements. The lithium storage performance of the Fe2(SO4)3 sample is characterized by discharge/charge, CV, EIS, and GITT tests. It demonstrates that the Fe2(SO4)3 has a high lithium storage capacity (delivering a stable reversible capacity of 610 mA h g−1 at 500 mA g−1), outstanding rate capability (maintaining a capacity of 400 mA h g−1 at 7000 mA g−1) and excellent cyclability (with a reversible capacity of ~540 mA h g−1 after 1000 cycles at 1000 mA g−1). The Fe2(SO4)3 electrode exhibits significant pseudocapacitive behavior during discharge/charge processes, which partially accounts for the superior high rate capability and cyclability. The lithium ions diffusion coefficient evaluated by galvanostatic intermittent titration technique (GITT) ranges from 10−11 to 10−13 cm2 s−1. The results reported in this work could provide clues for exploring novel high-performance anode materials from transition metal sulfates.