One-step solid state reaction to selectively fabricate cubic and tetragonal CuFe2O4 anode material for high power lithium ion batteries

• Published in: Electrochimica acta 2013-07, Vol.102, p.51-57
• Main Authors: Xing, Zheng, Ju, Zhicheng, Yang, Jian, Xu, Huayun, Qian, Yitai
• Format: Article
• Language: English
• Subjects: Anode materials; Copper; Cubic and tetragonal CuFe2O4; Cycles; Discharge; Li-ion batteries; Lithium-ion batteries; Materials selection; Particle size; Solid state; Solid state reaction; Spinel ferrites; Surface area
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2013.03.174

Cubic CuFe2O4 and tetragonal CuFe2O4 nanoparticles were selectively prepared and exhibit good performance for Li-ion batteries. •Pure cubic and tetragonal CuFe2O4 nanocrystals.•C- and t-CuFe2O4 exhibit similar electrode reactions except the first cycle.•C-CuFe2O4 shows superior capacity and rate capability.•FexCu1−x alloy in the discharged electrode were observed for the first time. Cubic CuFe2O4 (c-CuFe2O4) and tetragonal CuFe2O4 (t-CuFe2O4) nanoparticles were selectively prepared using a facile one-step solid state reaction route by ferrous oxalate and copper acetate as the reactants. As an anode material for Li-ion batteries, compared with c-CuFe2O4 and t-CuFe2O4 synthesized at 800°C, c-CuFe2O4 synthesized at 400°C with smaller particle size and larger surface area exhibited superior discharge capacities and better cycling performance (950mAhg−1at 100mAg−1 after 60 cycles), and higher rate capability. The influence of the two crystal phases on the electrochemical performance were only exhibited at the Li+ insertion process during the first discharge. The average particle size and the surface areas play an important role in effecting the lithium-ion storage capability and cycling ability. Through ex situ HRTEM analysis, we observed the existence of metastable FexCu1−x alloy in the discharged nanocomposition for the first time, which exhibits the interaction of metallic Cu particles with the adjacent iron ions.