High performance binder-free SiOx/C composite LIB electrode made of SiOx and lignin

• Published in: Journal of power sources 2017-09, Vol.362 (C), p.236-242
• Main Authors: Chen, Tao, Hu, Jiazhi, Zhang, Long, Pan, Jie, Liu, Yiyang, Cheng, Yang-Tse
• Format: Article
• Language: English
• Subjects: Lignin; Lithium-ion battery; MATERIALS SCIENCE; Renewable; SiOx/C composite electrode
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.07.049

A high performance binder-free SiOx/C composite electrode was synthesized by mixing SiOx particles and Kraft lignin in a cryo-mill followed by heat treatment at 600 °C. After the heat treatment, lignin formed a conductive matrix hosting SiOx particles, ensuring electronic conductivity, connectivity, and accommodation of volume changes during lithiation/delithiation. As the result, no conventional binder or conductive agent was necessary. When electrochemically cycled, the composite electrode delivered excellent performance, maintaining ∼900 mAh g−1 after 250 cycles at a rate of 200 mA g−1, and good rate capability. The robustness of the electrode was also examined by post-cycling SEM images, where few cracks were observed. The excellent electrochemical performance can be attributed to the comparatively small volume change of SiOx-based electrodes (160%) and the flexibility of the lignin derived carbon matrix to accommodate the volume change. This work should stimulate further interests in using bio-renewable resources in making advanced electrochemical energy storage systems. •Lignin was used as a carbon precursor for making SiOx/C composite electrodes.•Mechanically robust binder-free SiOx/C composite electrodes were demonstrated.•Stable cycling of ∼900 mAh g−1 after 250 cycles at rate of 200 mA g−1