高首效长寿命硅碳复合材料的制备及其电化学性能

Preparation and electrochemical performance of high initial coulombic efficiency and long life Si/C composite material

本工作以氧化亚硅(SiO)、沥青、硝酸铝和氢化锂为主要原料,通过层-层包覆和一系列化学反应,制备了SiO@C@Al2O3和Li-Si-O@C@LiAlO2的三明治结构的硅碳复合材料。采用SEM、TEM、XRD和激光粒度分析仪等对制备样品进行了微观形貌表征和物相结构分析,采用CR2032扣电评估不同材料的可逆比容量、首效和循环性能,结果表明,相比于普通SiO@C,改性后的SiO@C@Al2O3和Li-Si-O@C@LiAlO2复合材料在首效和循环性能上提升明显,呈现出优异的电化学性能。本工作制备方法操作简单、成本低,适合工业化生产。

Through layer-layer coating and series chemical reaction, the sandwich structure of SiO@C@Al2O3 and Li-Si-O@C@LiAlO2 was prepared by using SiO, pitch, aluminum nitrate and LiH as the main raw materials. The morphology and the phase structure of the samples were characterized by SEM, TEM, XRD and laser particle size analyzer. It was adopted by CR2032 cell to evaluate the reversible capacity, initial coulombic efficiency and capacity retention of different products. The results showed that compared with the common SiO@C, the modified SiO@C@Al2O3 and Li-SiO@C@LiAlO2 composites had excellent electrochemical performance in initial Coulombic efficiency and capacity retention. This preparation was simple operation, low cost and suitable for industrial production.