一锅法快速合成核壳结构 NiO@TiO2 纳米粉末及其作为锂离子电池阳极材料的优异电化学性能。

One-pot rapid synthesis of core-shell structured NiO@TiO2 nanopowders and their excellent electrochemical properties as anode materials for lithium ion batteries.

机构信息

Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Korea.

出版信息

Nanoscale. 2013 Dec 21;5(24):12645-50. doi: 10.1039/c3nr04406h.

Abstract

Core-shell structured NiO@TiO2 nanopowders for application as anode materials for lithium ion batteries are prepared by one-pot flame spray pyrolysis from aqueous spray solution containing Ni and Ti components. A new formation mechanism of the core-shell structured nanopowders in the flame spray pyrolysis is proposed. Composite nanopowders are first formed by surface growth and coagulation from NiO and TiO2 vapors. A small amount of TiO2 in composite powders disturbs the crystallization of TiO2. Therefore, the TiO2 component moves out to the surface of the powders forming an amorphous shell during the formation of single crystalline NiO. The initial discharge and charge capacities of the NiO@TiO2 nanopowders at a current density of 300 mA g(-1) are 1302 and 937 mA h g(-1), respectively. The discharge capacities of the pure NiO and NiO@TiO2 nanopowders after 80 cycles are 542 and 970 mA h g(-1), respectively. The capacity retentions of the pure NiO and NiO@TiO2 nanopowders after 80 cycles measured after the first cycles are 75 and 108%, respectively.

摘要

用于锂离子电池阳极材料的核壳结构 NiO@TiO2 纳米粉末通过一步火焰喷雾热解法，由含有 Ni 和 Ti 成分的水性喷雾溶液制备而成。提出了在火焰喷雾热解中核壳结构纳米粉末的新形成机制。复合纳米粉末首先通过 NiO 和 TiO2 蒸气的表面生长和凝聚形成。在形成单斜晶 NiO 期间，少量 TiO2 在复合粉末中会干扰 TiO2 的结晶。因此，TiO2 成分在形成单斜晶 NiO 的过程中会迁移到粉末的表面形成非晶壳。在 300 mA g(-1) 的电流密度下，NiO@TiO2 纳米粉末的初始放电和充电容量分别为 1302 和 937 mA h g(-1)。在 80 次循环后，纯 NiO 和 NiO@TiO2 纳米粉末的放电容量分别为 542 和 970 mA h g(-1)。在经过 80 次循环后，首次循环后测量的纯 NiO 和 NiO@TiO2 纳米粉末的容量保持率分别为 75%和 108%。