复合溶胶–凝胶一锅法制备锂离子电池氧化亚硅/碳复合负极材料

Dual Sol–Gel One-Pot Synthesis of Silicon Suboxide/Carbon Anode for Lithium-ion Batteries

采用复合溶胶–凝胶法结合后续热处理,制备了具有包埋结构的氧化亚硅/碳(SiO_(x)/C)复合负极材料。扫描电子显微镜分析结果表明:氧化亚硅纳米颗粒嵌入在无定形碳中。电化学性能测试表明:SiO_(x)/C复合材料具有较高的比容量、优异的循环稳定性和倍率性能。材料在0.1 A/g的电流密度下100次循环后的可逆比容量为710 m A·h/g,容量几乎无衰减;在1.6 A/g的电流密度下,可逆比容量为380 m A·h/g。优异的电化学性能是由于材料的包埋结构能有效地缓冲SiO_(x)充放电过程中的体积膨胀,保证材料的结构完整性和电化学循环稳定性。

A SiO_(x)/C composite with an embedded-structure was prepared by a dual sol–gel one-pot method and subsequent heat treatment. Based on the analysis by scanning electron microscopy, SiO_(x) nanoparticles are fully embedded in an amorphous carbon matrix. The results by electrochemical test indicate that as anode material for Li-ion battery, the optimized SiO_(x)/C composite demonstrates a high specific capacity, an excellent cyclic performance and a rate capability. A reversible specific capacity of 710 m A·h/g is achieved without an obvious decline of the capacity for 100 cycles at a current density of 0.1 A/g, and a specific capacity is 380 m A·h/g at a current density of 1.6 A/g. The excellent electrochemical performance is attributed to the well-designed embedded-structure, which can effectively accommodate the volume variation of SiO_(x) during charge/discharge process and therefore ensure the structural integrity and cyclic stability of SiO_(x)/C electrode.