Synthesis of hierarchical mesoporous nest-like Li4Ti5O12 for high-rate lithium ion batteries

Hierarchical mesoporous nest-like Li4Ti5O12 is prepared by a hydrothermal reaction, using CTAB as the surfactant, and water-soluble titanium complex [NH4+](4)[H+](2)[Ti-4(C2H2O3)(4)(C2H3O3)(2)(O-2)(4)O-2](6-) as the titanium precursor. As-prepared Li4Ti5O12 has a tiny crystallite size of 8.2 nm and a very large surface area of 219.2 m(2) g(-1). Commercial micrometer-sized Li4Ti5O12 is also tested for comparision, and up to 10 000 mA g(-1) (57 C) is applied to evaluate these two samples as the anode material for lithium ion batteries. Our products deliver much better cycling and rate performances, especially at high current densities. 135.1 mAh g(-1) is obtained after 200 cycles at 2500 mA g(-1), and 113.6 mAh g(-1) is obtained at 10 000 mA g(-1). The polarization in our products is much lower, and our products also show higher lithium diffusion coefficient and higher exchange current density, calculated from CV and EIS measurements. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.