摘要
氧化亚硅(SiO)的导电性较差且首次库仑效率较低。采用水热法,以葡萄糖为碳源,制备具有核-壳结构的SiO@C@碳微球(CMSs)前驱体;分别以聚乙二醇(PEG4000)、柠檬酸、葡萄糖及沥青为碳源,进行二次包覆,并与人造石墨复合,得到SiO@CMSs@C复合负极材料。二次包覆热解碳层进一步限制了嵌脱锂过程中SiO的体积膨胀,将活性物质颗粒与人造石墨紧密结合,利用石墨良好的导电性,提升复合材料的电导率。SiO@CMSs@沥青样品的性能最好:在0.01~1.50 V循环,电流为0.05 A/g时的首次脱锂比容量为672.1 mAh/g;以0.20 A/g的电流循环80次,容量保持率为92.78%;电流为1.50 A/g时,仍有约430 mAh/g的可逆比容量。
Silicon monoxide(SiO)had poor conductivity and low initial Coulombic efficiency.Precursor SiO@C@carbon micros-pheres(CMSs)with core-shell structure was prepared by hydrothermal method using glucose as carbon source.Polyethylene glycol(PEG4000),citric acid,glucose and pitch were used as carbon source to twice coat and composite with artificial graphite to obtain SiO@CMSs@C composite anode material,respectively.The secondary coated pyrolytic carbon layer further limited volume expansion of SiO during lithiation/delithiation,tightly combined active material particles with artificial graphite to improve the conductivity of composite by utilizing the good conductivity of graphite.SiO@CMSs@pitch had the best performance:when cycled in 0.01-1.50 V,the initial delithiation specific capacity was 672.1 mAh/g at a current of 0.05 A/g,the capacity retention rate was 92.78%after 80 cycles at a current of 0.20 A/g,it still had a reversible specific capacity of about 430 mAh/g at a current of 1.50 A/g.
作者
侯春平
孟令桐
侯佼
龚波林
HOU Chun-ping;MENG Ling-tong;HOU Jiao;GONG Bo-lin(College of Materials Science and Engineering,North Minzu University,Yinchuan,Ningxia 750021,China;College of Chemistry and Chemical Engineering,North Minzu University,Yinchuan,Ningxia 750021,China)
出处
《电池》
CAS
北大核心
2022年第6期675-679,共5页
Battery Bimonthly
基金
宁夏自然科学基金(2020AAC03199)
北方民族大学引进人员科研启动项目(2019KYQD17)。
