Facile preparation of a zinc-based alloy composite as a novel anode material for rechargeable lithium-ion batteries

초록

We report a new Zn-based nanocomposite anode material (Zn-Ti-C) for lithium-ion batteries synthesized by thermal treatment and a high energy mechanical milling process. X-ray diffraction and high-resolution transmission electron microscopy revealed the formation of active Zn nanoparticles finely dispersed in the hybrid titanium carbide (TiC) and carbon matrix. Electrochemical analyses show that the formation of the TiC and carbon buffer matrix significantly contributed to the improved performance of the Zn-based electrode by mitigating the volume changes of the Zn nanoparticles during the charge/discharge processes. Furthermore, we optimized the stoichiometric ratio of Zn and Ti in terms of specific capacity, cycling performance, and rate capability in the presence of carbon. The material with a 2:1 atomic ratio (ZnTi( 2:1)-C) exhibited the best cycle life, with a gravimetric capacity of 363.6 mAh g(-1) and a volumetric capacity of 472.7 mAh cm(-3) after 300 charge/discharge cycles (78.1% retention). At this ratio, Zn-Ti-C consistently showed the best rate capability measurements up to 3000 mA g(-1) (85% of its capacity at 100 mAg(-1)). Therefore, our Zn-Ti-C composite is a promising alternative negative electrode material for lithium-ion batteries. (C) 2017 Elsevier B.V. All rights reserved.

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