摘要
Silicon monoxide(SiO) has been considered as one of the most promising anode materials for next generation highenergy-density Li-ion batteries(LiBs) thanks to its high theoretical capacity. However, the poor intrinsic electronic conductivity and large volume change during lithium intercalation/de-intercalation restrict its practical applications. Fabrication of SiO/C composites is an effective way to overcome these problems. Herein, a series of micro-sized SiO@C/graphite(Si0@C/G) composite anode materials, with designed capacity of 600 mAh·g-1, are successfully prepared through a pitch pyrolysis reaction method. The electrochemical performance of SiO@C/G composite anodes with different carbon coating contents of 5 wt%, 10 wt%, 15 wt%, and 35 wt% is investigated. The results show that the SiO@C/G composite with15-wt% carbon coating content exhibits the best cycle performance, with a high capacity retention of 90.7% at 25℃ and90.1% at 45 0 C after 100 cycles in full cells with LiNi0.5Co0.2Mn0.3O2 as cathodes. The scanning electron microscope(SEM) and electrochemistry impedance spectroscopy(EIS) results suggest that a moderate carbon coating layer can promote the formation of stable SEI film, which is favorable for maintaining good interfacial conductivity and thus enhancing the cycling stability of SiO electrode.
Silicon monoxide（SiO） has been considered as one of the most promising anode materials for next generation highenergy-density Li-ion batteries（LiBs） thanks to its high theoretical capacity. However, the poor intrinsic electronic conductivity and large volume change during lithium intercalation/de-intercalation restrict its practical applications. Fabrication of SiO/C composites is an effective way to overcome these problems. Herein, a series of micro-sized SiO@C/graphite（Si0@C/G） composite anode materials, with designed capacity of 600 mAh·g-1, are successfully prepared through a pitch pyrolysis reaction method. The electrochemical performance of SiO@C/G composite anodes with different carbon coating contents of 5 wt%, 10 wt%, 15 wt%, and 35 wt% is investigated. The results show that the SiO@C/G composite with15-wt% carbon coating content exhibits the best cycle performance, with a high capacity retention of 90.7% at 25℃ and90.1% at 45 0 C after 100 cycles in full cells with LiNi0.5Co0.2Mn0.3O2 as cathodes. The scanning electron microscope（SEM） and electrochemistry impedance spectroscopy（EIS） results suggest that a moderate carbon coating layer can promote the formation of stable SEI film, which is favorable for maintaining good interfacial conductivity and thus enhancing the cycling stability of SiO electrode.
作者
Hao Lu
Junyang Wang
Bonan Liu
Geng Chu
Ge Zhou
Fei Luo
Jieyun Zheng
Xiqian Yu
Hong Li
陆浩;汪君洋;刘柏男;褚赓;周格;罗飞;郑杰允;禹习谦;李泓(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences(CAS),Beijing 100049,China;CAS Research Group on High Energy Density Lithium Batteries for EV,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China;Key Laboratory of Green Process Engineering,State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;Tianmulake Excellent Anode Materials Co.,Ltd.,Changzhou 213300,China)
基金
Project supported by the State Grid Technology Project,China(study on the mechanism and characterization of lithium dendrite growth in lithium ion batteries,Project No.DG71-17-010)
the National Key Research and Development Program of China(Grant No.2017YFB0102004)
the National Natural Science Foundation of China(Grant No.51822211)
作者简介
Corresponding author:李泓,E-mail:hli@iphy.ac.cn;Corresponding author:禹习谦,E-mail:xyu@iphy.ac.cn
