锂离子电池中空SiO@Void@C复合负极材料的制备与性能研究

摘要

利用商业化SiO@ C材料通过 HF刻蚀一步处理快速制备出具有中空结构的SiO@ Void@ C复合材料,通过XRD、SEM、充放电循环等方法研究了材料的物化结构及电化学性能,并讨论了冷压与否对其结构及电化学性能的影响.研究表明,在低压密情况下,具有中空结构SiO@ Void@ C复合材料具有较优的电化学性能,材料的可逆比容量高达1305m Ah/g,可稳定循环长达500圈容量保留54%,相比初始SiO@ C材料性能明显提升;但在高压密情况下,SiO@ Void@ C复合材料的中空结构受到严重破坏,材料的循环性能明显降低.因此,具有中空结构类Si基负极材料在实际商业化锂离子电池应用中仍存在较大挑战.%SiO@ Void@ C composite with a hollow structural feature was obtained through a facile HF etching process with commercial SiO @ C as a raw material.Physical and electrochemical characteristics of the composite are researched by using XRD,SEM,cycling tests and other typi-cal techniques.Influence of a calender process on the structure and cycling performance of the e-lectrodes is discussed.It is show n that in a condition of a low press density,the hollow SiO@Void@ C composite shows a superior electrochemical performance with a high reversible capacity of 1305mAh/g,a long cycling stability with a capacity retention of 54% after 500 cycles,which values are significantly better than the bare SiO@ C material.However,the hollow structure of SiO@ Void@ C composite can be severely destroyed with a high pressure,resulting in a strongly decreased cycling performance.Therefore the actual commercialization process of Si - based anode materials with the hollow structure is still suffering from big challenges.