Abstract:

Iron-based anode materials for lithium ion batteries has attracted wide attentions due to its high capacity, rich resource, environmentally friendly property, etc. However, its low-conductance(comparing to carbon-based anode materials) and high-volume change during charge/discharge cycles results in a poor rate performance and serious capacity fade after long-term cycles. In this paper, flower-like iron-based anode materials(Fe₂O₃) were synthesized by sintering the iron alkoxides precursor with the same nano-structure under the atmosphere of air. The as-obtained anode materials possess high reactivity from nanosheets of iron alkoxides, which can lower the sintering temperature and allow the product to keep the morphology of its precursor. The sample obtained by heating iron alkoxides precursor under 300 ℃ shows an initial specific discharge capacity of 1360 mA·h/g at a current density of 200 mA/g. Moreover, the specific capacity of the sample is 515.6 mA·h/g after 100 charge/discharge cycles at 200 mA/g, while the samples obtained after calcining the precursor under 450 and 800 ℃ present a capacity of 247.6 and 206.7 mA·h/g, respectively, after 100 charge/discharge cycles. The as-obtained Fe₂O₃ with micro/nano-structure not only improves high reactivity due to the high special surfaces, but also inhibits its pulverization during charge/discharge process. Therefore, the as-obtained materials with hollow micro/nano-structure show both high discharge capacity and good cycle performances, which affords us another method to solve the problem of the capacity fade of Fe₂O₃ as anode material for lithium ion battery.

Key words: flower-like iron alkoxides, micro-nano structure, ferric oxide, Li-ion batteries, anode materials