锂离子电池硅炭负极材料的制备与电化学性能研究  

Synthesis and electrochemical properties of nano-Si/C composite anodes for lithium-ion batteries

作　　者：袁立业 吕春祥[1,2] 吕晓轩[1,2] 袁淑霞[1,2] 张甍 曹莉娟[1,2] 杨禹[1,2] YUAN Li-ye;LU Chun-xiang;LU Xiao-xuan;YUAN Shu-xia;ZHANG Meng;CAO Li-juan;YANG Yu(National Engineering Laboratory for Carbon Fiber Technology,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;CAS Key Laboratory of Carbon Materials,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院山西煤炭化学研究所,碳纤维制备技术国家工程实验室,山西太原030001 [2]中国科学院山西煤炭化学研究所,中科院炭材料重点实验室,山西太原030001 [3]中国科学院大学,北京100049

出　　处：《新型炭材料（中英文）》2023年第5期964-975,共12页New Carbon Materials

基　　金：funded by “Supported by Fundamental Research Program of Shanxi Province(20210302124312)”

摘　　要：利用微胶囊技术将酚醛树脂包覆于纳米硅表面,然后在氩气保护下高温炭化,制得硅炭复合负极材料。首先采用4种不同质量比的酚醛树脂与纳米硅制备了硅碳复合材料,得到了不同炭质厚度的硅碳复合材料。通过对其循环性能和倍率性能的比较,发现酚醛树脂与纳米硅的质量比为1∶4,即碳层厚度为4.5 nm时,电化学性能最佳。随后对该种硅碳复合材料的综合电化学性能进行了测试,该材料作为负极制备的锂离子电池具有良好的电化学性能,在电流密度为100 mA g^(-1)的条件下,其首次放电比容量为2382 mAh g^(-1),首次充电比容量为1667 mAh g^(-1),首次库伦效率为70%。经200次充放电循环后放电比容量为835.6 mAh g^(-1),库伦效率为99.2%。此外,其倍率性能非常优异,在100、200、500、1000、2000及100 mA g^(-1)电流密度下,其平均放电比容量分别为1716.4、1231.6、911.7、676.1、339.8及1326.4 mAh g^(-1)。Phenolic resin was coated on the surface of nano-Si by a microencapsulation technique,and then carbonized under Ar protection to prepare a nano-Si/C composite.The composites were first prepared using 4 different mass ratios(1∶2,1∶4,1∶6,1∶8)of phenolic resin to nano-Si.The obtained average thicknesses of amorphous carbon coating were 7,4.5,3.7,2.8 nm,respectively.By comparing the cycling and rate capability,the best electrochemical performance was obtained when this ratio was 1∶4,with a 4.5 nm amorphous carbon coating.The electrochemical properties of this material were then comprehensively evaluated,showing excellent electrochemical performance as an anode material for Li-ion batteries.At a current density of 100 mAg^(-1),the material had a first specific discharge capacity of 2382 mAhg−1,a first charge specific capacity of 1667 mAhg^(-1),and an initial coulombic efficiency of 70%.A discharge specific capacity of 835.6 mAhg−1 was retained after 200 cycles with a high coulombic efficiency of 99.2%.In addition,the nano-Si/C composite demonstrated superior rate performance.Under current densities of 100,200,500,1000 and 2000 mAg^(-1),the average specific discharge capacities were 1716.4,1231.6,911.7,676.1 and 339.8 mAh g^(-1),respectively.When the current density returned to 100 mA g^(-1),the specific capacity returned to 1326.4 mAh g−1.

关 键 词：微胶囊技术 锂离子电池 硅负极 高容量 低成本 

分 类 号：TM912[电气工程—电力电子与电力传动] TB332[一般工业技术—材料科学与工程]