High-Branched Natural Polysaccharide Flaxseed Gum Binder for Silicon-Based Lithium-Ion Batteries with High Capacity.

Silicon-based anodes heavily depend on the binder to preserve the unbroken electrode structure. In the present work, natural flaxseed gum (FG) is used as a binder of silicon nanoparticles (SiNPs) anode for the first time. Owing to a large number of polar groups and a rich branched structure, this material not only anchors tightly to the surface of SiNPs through bonding interactions but also formed a hydrogen bonding network structure among molecules. As a result, the FG binder can endow the silicon electrode with stable interfacial adhesion and outstanding mechanical properties. In addition, FG with a high viscosity facilitates the homogeneous dispersion of the electrode components. When FG is used as a binder, the cycling performance of the Si anode is greatly improved. After one hundred cycles at an applied current density of 1 A g-1 , the electrode continues to display remarkable electrochemical properties with a significant cyclic capacity (2213 mA h g-1 ) and initial Coulombic efficiency (ICE) of 89.7%.