Development of cross-linked dextrin as aqueous binders for silicon based anodes

In this work; cross-linked dextrin as a low-cost and aqueous binder has been prepared for silicon (Si) based anodes in Li-ion batteries. A 3D network is achieved by the aldolization between the hydroxyl groups in dextrin and the aldehyde groups in glutaraldehyde. This inter-waving structure demonstrates good mechanical property and can mitigate the volume variation of Si anodes during cycling, resulting in a better electrochemical performance than that with PVDF, CMC and pristine dextrin binders. The initial capacity is 3276 mAh g(-1) with Coulombic efficiency (CE) of 88.79% and only drops to above 1000 mAh g(-1) after 150 cycles under 0.1C. Adding 20 wt% FEC in the electrolyte, the cycling performance is further improved to about 1700 mAh g(-1) after 150 cycles under 0.1C, and over 1000 mAh g(-1) after 150 cycles under 0.5C. Therefore, the cross-linked dextrin is considered to be a promising binder for Si based electrodes, with potential for other anodes as well.