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

Abstract 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%.