High rate capability and long cycle stability of Fe2O3/MgFe2O4 anode material synthesized by gel-cast processing

In this paper, coralloid Fe2O3/MgFe2O4 composite was synthesized as anode material for lithium ion batteries via a simple gel-cast method. The Fe2O3/MgFe2O4 composite exhibits much better electrochemical performance than pure Fe2O3 and MgFe2O4. Capacity of the Fe2O3/MgFe2O4 composite maintains an anomalous increase to 1800 mAh g(-1) (at about the 300th cycle), and stabilizes at 1700 mAh g(-1), until 500 cycles at a current density of 1 A g(-1). Even cycled at a current density of 20 A g(-1), a capacity of 760 mAh g(-1) can still be achieved. The excellent performances may be attributed to the enlarged crystal lattice and the relatively lower bonding energy of Fe-O bond. Furthermore, capacity rise phenomenon of the Fe2O3/MgFe2O4 composite was studied. Results show that both interfacial lithium storage and the polymeric/gel-like layer contribute to that. (C) 2016 Elsevier B.V. All rights reserved.