锂离子电池负极材料多孔硅/硅铁合金的制备及性能

摘要

为改善锂离子电池硅负极材料的电化学性能,利用镁热还原法制备了不同铁掺杂量的多孔硅/硅铁合金复合材料,并对其结构以及在锂离子电池中的充放电性能进行了研究.材料均呈现多孔结构,硅铁合金均匀分布在孔道内部.多孔硅/硅铁合金复合材料具有较好的循环稳定性,在0.1C倍率下循环100圈后可逆容量为1 133.5 mA·h/g,容量保持率为66％;在1C倍率下可逆容量仍可以达到776.9 mA· h/g.%In order to modify the electrochemical properties of Si anode for lithium ion batteries,a series of porous Si/Si-Fe alloy composites with different amounts of Fe doping were prepared by magnesium reduction process.The morphology and microstructure of the as-prepared composites were investigated.The electrochemical performance of the composites as anode materials for lithium-ion batteries were evaluated by galvanostatical charge-discharge testing.The composites show a porous structure with the uniform distribution of Si-Fe alloy inside the pores and possess remarkable cycle stability with a capacity of 1 133.5 mA·h/g at 0.1C after 100 cycles,a capacity retention ratio of 66％ and a reversible capacity of 776.9 mA· h/g at 1C.