Al-doped Li₂ZnTi₃O₈ as an effective anode material for lithium-ion batteries with good rate capabilities

By Tang, Haoqing; Zhu, Jiangtao; Tang, Zhiyuan & Ma, Chenxiang
Published in Journal of Electroanalytical Chemistry NULL 2014

Abstract

Al-doped Li₂ZnTi₃O₈ in the form of Li₂ZnTi₃₋ₓAlₓO₈ (0 ⩽ x ⩽ 0.2) compounds are successfully synthesized by a simple and facile high temperature solid-phase reaction. The characteristics of Li₂ZnTi₃₋ₓAlₓO₈ are examined by X-ray diffraction, scanning electronic microscopy, transmission electron microscopy and laser particle size analyzer, while the electrochemical performances including galvanostatic charge–discharge testing, cyclic voltammetry, and electrochemical impedance spectroscopy were also investigated. It is shown from the structure analysis that Li₂ZnTi₃₋ₓAlₓO₈ (x = 0, 0.05, 0.1) has the pure phase structure, but impurity peak of LiAlO₂ can be detected when x > 0.1. In the voltage range of 0.05–3.0 V, Li₂ZnTi₂.₉Al₀.₁O₈ electrode presents the largest initial discharge capacity of 223.1 mA h g⁻¹ at 0.1 A g⁻¹. Moreover, the discharge capacities of Li₂ZnTi₂.₉Al₀.₁O₈ after 100 cycles are 173.2, 136.7, 108.6, and 61.4 mA h g⁻¹ at 0.5, 1.0, 2.0, and 3.0 A g⁻¹, respectively, which obviously higher than those of un-doped sample. The electrode reaction reversibility and electronic conductivity of pure Li₂ZnTi₃O₈ are enhanced after doping Al (x = 0.1). The results revealed that doping Al should be an effective way to improve the cycling performance.

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