Investigation of the Different Structures of Xanthan Gum on the Performance of Silicon Anodes in Lithium-ion batteries

It has been proved that bio-based binders play an important role in improving the electrochemical performance of silicon (Si) anodes in lithium-ion batteries (LIBs), so the effects by their molecular structure need further investigation. In this paper, we choose xanthan gums (XGs) with eight different structures (XG-00, XG-A0, XGAA, XG-00, XG-0P, XG-AP, XdM-A, XdM-0) as the binders of silicon anodes in LIBs, and the samples have been tested to explore that which structure of XGs is the most beneficial to the electrochemical performance of the Si anodes. Subsequently, the Si anodes with eight XGs were characterized by SEM and FT-IR. It is concluded that due to the acetylation of terminal mannose and internal mannose residues, the structure of XG can be stabilized, contributing to the material property. The XG binder with the structures of XG-A0 and XdM-A exhibits excellent cycle stability in the electrochemical performance. After cycling tests at a current density of 420 mA/g, the capacities were maintained at 1824.7 mAh/g & 1680.7 mAh/g (100 cycles), and 1294.6 mAh/g & 1364.4 mAh/g (300 cycles), respectively. Therefore, XG-A0 and XdM-A have the potential to become high-performance binders for Si anodes in LIBs.