CuO掺杂纳米SnO_2锂离子电池负极材料的合成与电化学性能

Preparation and Electrochemical Properties Analysis of CuO-Doped Nano-SnO_2 Powders as Anode Materials for Lithium Ion Batteries

以SnCl4.5H2O、Cu(NO3)2.3H2O和NH3.H2O为原料,采用化学共沉淀法制备了CuO掺杂的纳米SnO2粉末.运用X射线衍射、扫描电镜等手段对合成粉末进行了表征.将合成粉末作为锂离子电池负极材料,研究了其充放电容量、循环性能和交流阻抗等电化学性能.结果表明:采用化学共沉淀法可以得到平均粒度为87 nm的CuO掺杂的纳米SnO2粉末;在SnO2中掺入CuO,并没有改变SnO2的结构,但能够有效抑制SnO2粒子的长大;CuO掺杂的纳米SnO2粉末的可逆容量可以达到752 mA.g-1,经60次循环后,CuO掺杂的纳米SnO2粉末的容量保持率分别为93.6%,优于纳米SnO2(92.0%),掺杂CuO改善了纳米SnO2的循环性能.

CuO-doped nano-SnO2 powders were prepared by chemical copreeipitation method using SnCl4·5H2O,NH3· H2O,and Cu（NO3）2· 3H2O as raw materials. The powders were characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The electrochemical properties of CuO- doped nano-SnO2 powders and undoped SnO2 powders as anode materials of lithium ion batteries were investigated comparatively by charge-discharge curves, cyclability and AC impedance. Results show that SnO2-CuO nano composite powders with average particle size of 87 nm could be obtained through chemical coprecipitation method. The structure of SnOz was not changed,but the average particle size of nano- SnO2 decreased due to the introduction of CuO. CuO-doped nano-SnO2 powders show a reversible capacity of 752 mA·g^-1 and better cyclability compared with undoped nano-SnOz. The capacity retention rate of undoped nano-SnO2 and CuO-doped nano-SnO2 powders is 93.6% and 92.0% at 0.1 C rate,respectively, which suggests that introduction of CuO in SnO2 can improve the cyclability of nano-SnO2.