abstract
Non-aqueous sol-gel routes involving the reaction of metal oxide precursors in organic solvents (e.g., benzyl alcohol) at moderate temperature and pressure, offer advantages such as high purity, high reproducibility and the ability to control the crystal growth without the need of using additional ligands. In this paper, a study carried out on a series of iron oxide/reduced graphene oxide composites is presented to elucidate a structure-properties relationship leading to an improved electrochemical performance of such composites. Moreover, it is demonstrated that the easy production of the composites in a variety of temperature and composition ranges, allows a fine control over the final particles size, density and distribution. The materials obtained are remarkable in terms of the particle's size homogeneity and dispersion onto the reduced graphene oxide surface. Moreover, the synthesis method used to obtain the graphene oxide clearly affects the performances of the final composites through the control of the restacking of the reduced graphene oxide sheets. It is shown that a homogeneous and less defective reduced graphene oxide enables good electrochemical performances even at high current densities (over 500 mAh/g delivered at current densities as high as 1600 mA/g). The electrochemical properties of improved samples reach the best compromise between specific capacity, rate capability and cycle stability reported so far.
keywords
X-RAY-DIFFRACTION; PERFORMANCE ANODE MATERIAL; ABSORPTION FINE-STRUCTURE; LITHIUM STORAGE; NONAQUEOUS SYNTHESIS; REVERSIBLE CAPACITY; POWDER DIFFRACTION; FE3O4-GRAPHENE NANOCOMPOSITES; ELECTROCHEMICAL PERFORMANCE; SIZE DISTRIBUTION
subject category
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
authors
Yu, SH; Conte, DE; Baek, S; Lee, DC; Park, SK; Lee, KJ; Piao, Y; Sung, YE; Pinna, N
our authors
Nicola Pinna
ResearcherGroups
acknowledgements
This work was partially supported by the WCU (World Class University) program through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (R31-10013) and FCT project PTDC/CTM-NAN/110776/2009. Y.-E. Sung acknowledges financial support by Korea Ministry of Education, Science, and Technology through the Institute of Basic Science (IBS) program. Dr. Patricia Russo from the University of Aveiro is acknowledged for critical reading of the manuscript and fruitful discussion.