A low-cost and sustainable cross-linked dextrin as aqueous binder for silicon anodes in lithium-ion batteries

Silicon is a promising anode material for lithium-ion batteries (LIBs) because of its impressive theoretical capacity. However, it undergoes severe volume changes in the lithiated state thus limiting its development in LIBs. Herein, a cross-linked dextrin binder is created through in-situ thermal cross-linking of dextrin and the inorganic cross-linker sodium tetraborate decahydrate, which is a cost-effective, “greener” water-soluble binder. This binder can significantly strengthen the adhesion between Si electrode and copper current collector, which is almost three times more effective in adhesion than commercially available CMC binder. Meanwhile, the cross-linked dextrin binder also has superior mechanical properties and is able to well mitigate the huge volume changes upon cycling, consequently achieving an excellent cycling stability and superior rate capability. It is believed that this aqueous binder has the potential to utilize in silicon anodes for high-energy-density LIBs, as well as providing a new idea in the design of binders for other electrode materials which suffer from volume change during cycling.