Co-Sn金属复合氧化物的制备及电化学性能研究

Synthesis and electrochemical performance of Co-Sn metal composite oxides

采用液相沉淀法制备Co-Sn金属复合氢氧化物前驱体,在不同温度下加热分解,得到一系列Co-Sn金属复合氧化物。对前驱物和产物进行差热和热重分析(TG/DTA)、X射线衍射(XRD)分析,结果表明,Co-Sn金属复合氢氧化物前驱体低温(350,500℃)热分解得到的是非晶态CoSnO3复合物氧化物,高温(600,700,800℃)热分解得到的是四方相CoSnO3和少量尖晶石型Co2SnO4,所得Co-Sn金属复合氧化物电化学性能依赖于分解温度和结晶度。从容量和循环寿命综合考虑,相转变温度在600℃热分解所得试样的电化学性能较差。

The structural and composition evolution of cobalt tin metal composite oxides synthesized by the decomposition of CoSn（OH）6 precursor at different temperatures were investigated by X-ray diffraction （XRD）. The precursor was also studied by thermal analysis （TG/DTA）. The electrochemical performance of zinc-tin composite oxides as anode materials for Li-ion batteries was investigated in the form of Li/Co-Sn metal composite oxides cells. The results reveal that the samples heat-treated at low temperature （350, 500 ℃） are amorphous CoSnO3, and the samples heat-treated at high temperature （600, 700, 800 ℃） are crystal CoSnO3, Co2SnO4. The charge capacity and cyclability are sensitive to the structure and composition of the electrode active materials. The samples heat-treated at phase transition temperature rage （600 ℃） exhibit relatively worse electrochemical properties.