水热合成工艺对Zn2SnO4纳米晶形貌及电化学性能的影响

采用水热法合成了新型锂离子电池阳极材料Zn2SnO4纳米晶.研究了水热时间对材料结构、形貌及电化学性能的影响.通过X射线衍射、透射电镜和电化学法表征了产物的结构和形貌,并测试了材料的电化学特性.结果表明:水热时间将影响产物的形貌、尺寸和结晶度,从而影响其电化学性能.220 ℃水热处理28 h后,所获得的Zn2SnO4具有较小的颗粒尺寸和较高的结晶度,其初始放电比容量,在100mA/g恒电流密度和0～1.4 V电压范围内,达591.9(mA·h)/g;同样温度处理24 h后获得的Zn2SnO4其初始放电容量为502.7mA·h/g,充放电14次后仍有409.5(mA·h)/g.220 ℃水热处理获得的Zn2SnO4具有锂离子电池阳极材料应用所需的优异的电化学特性.

INFLUENCE OF HYDROTHERMAL SYNTHESIS PROCESS ON MORPHOLOGY AND ELECTROCHEMICAL PROPERTIES OF Zn2SnO4 NANOCRYSTALS SYNTHESIZED BY HYDROTHERMAL METHOD

Spherical Zn2SnO4 nanocrystals, a new possible Li-ion battery anode material, were synthesized by a hydrothermal method.The influence of hydrothermal time on the product structure and the electrode performance of the samples were studied. The microstructure, morphology and electrochemical performance of the materials were investigated by the X-ray diffraction transmission electron microscopy and electrochemical methods. The results indicate that the hydrothermal time had an effect on the size and crystallinity of the as-prepared materials, which consequently affected their electrochemical performance. The Zn2SnO4 sample prepared by hydrothermal treatment at 220 ℃ for 28 h exhibited smaller particle sizes and higher crystallinity, showing a bigger initial discharge bigger particle sizes and lower crystallinity prepared at same temperature for 24 h, exhibited better cycle stability, which retained a capacity of 409.5 mA.h/g after 14 cycles. The Zn2SnO4 sample prepared at 220 ℃ for 24 h exhibited a large discharge capacity and good cycle performance, which are necessary for use as Li-ion battery anodes.