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Nano Res. 2012, 5(7): 477485 ISSN 1998-0124 DOI 10.1007/s12274-012-0233-2 CN 11-5974/O4 Research Article
Nano Res. 2012, 5(7): 477485 477
One-Step Hydrothermal Synthesis of ZnFe2O4 Nano-Octahedrons as a High Capacity Anode Material for Li-ion Batteries
Zheng Xing1, Zhicheng Ju1 (), Jian Yang2 (), Huayun Xu2, and Yitai Qian1,2
1 Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China
2 School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
Received: 11 April 2012 / Revised: 20 May 2012 / Accepted: 24 May 2012 Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2012
ABSTRACT
Binary transition metal oxides are considered as promising anode materials for lithium-ion batteries (LIB), because they can effectively overcome the drawbacks of simple oxides. Here, a one-step hydrothermal method is described for the synthesis of regular ZnFe2O4 octahedrons about 200 nm in size at a low temperature without further annealing being required. The ZnFe2O4 octahedrons were characterized by powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The electrochemical performance of the ZnFe2O4 octahedrons was examined in terms of cyclic voltammetry and discharge/charge profiles. The ZnFe2O4 octahedrons exhibit a high capacity of 910 mAh/g at 60 mA/g between 0.01 and 3.0 V after 80 cycles. They also deliver a reversible specific capacity of 730 mAh/g even after 300 cycles at 1000 mA/g, a much better performance than those in previous reports. A set of reactions involved in the discharge/charge processes are proposed on the basis of ex situ high-resolution transmission electron microscopy (HRTEM) images and selected area electron diffraction (SAED) patterns of the electrode materials. The insights obtained will be of benefit in the design of future anode materials for lithium ion batteries.
KEYWORDS
Hydrothermal method, ZnFe2O4 octahedrons, Li-ion batteries, anode materials, rate performance
1. Introduction
Binary transition metal oxides have been considered as promising anode materials for lithium-ion batteries (LIB), because they can effectively overcome the drawbacks of simple oxides, and high specific capacity, good cycling stability and excellent rate performance can be achieved by the selection of a suitable combination of different metal oxides. So far, a variety of binary transition metal compounds have been investigated as anode materials for LIB, including...