Si-Fe复合SiOx/石墨基负极材料的电化学性能

针对硅氧基负极材料的主要缺陷，在SiO_x/石墨基负极材料中巧妙地引入了Si-Fe、SnO₂合金化合物，以改善其电化学性能，并通过机械球磨、喷雾干燥和高温热解策略制备了一系列硅氧基复合负极材料。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱仪(EDS)和恒流充放电测试仪对复合材料的物相、微观形貌及电化学性能进行了表征。电化学测试结果表明，复合质量分数5% Si-Fe的目标材料充电容量高达443.4 mAh·g^-1，首次库仑效率达75.2%，循环310圈之后容量仍有369.1 mAh·g^-1，容量保持率为81.0%(相对第11圈)；同时，经Si-Fe复合之后，锂离子扩散速率得到了明显改善。

Electrochemical properties of Si-Fe incorporated SiOx/graphite base anode materials

To solve the major defects of SiO_x-based anode materials, composite materials with different Si-Fe content and SnO₂ were deliberately prepared via a tandem strategy involving mechanical ball milling, spray drying, and high-temperature pyrolysis in this paper. Furthermore, the phase structures, microscopic morphologies, and electrochemical properties of as-obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), and galvanostatic charge-discharge test system. The electrochemical results show that the composite containing a mass fraction of 5% Si-Fe possesses a relatively good comprehensive electrochemical performance with a charging capacity of 443.4 mAh·g^-1 and the first Coulombic efficiency of 75.2%. After 310 cycles, the charging capacity still retained 369.1 mAh·g^-1, and the capacity retention rate was up to 81.0%. Meanwhile, the lithium diffusion rate is remarkably improved after Si-Fe incorporation.