Advanced binder with ultralow-content for high performance silicon anode

Using high-content binder (10–50 wt%) are noted as effective methods to stabilize silicon anode but usually lead to a low energy density under the same electrode loading. For the first time, we design a 3D-crosslinked binder with ultralow-content (1 wt%) that not only is endure the huge volume variation of Si anode but also enhance electrochemical performance. The 3D-crosslinked binder (LiCMC-TA) is synthesized by the partially lithiated Carboxymethyl Cellulose Sodium (LiCMC) as skeleton structure and Tannic Acid (TA) as cross-linker via multiple hydrogen bonding interaction. Besides, Li-ions are quickly transferred via partially lithiated groups of LiCMC-TA binder. And highly branched TA is introduced to construct multiple hydrogen bonds network. The binder can relieve the stress of Silicon through the multiple hydrogen bonding continuing cleavage. The Density Functional Theory simulation indicates the main hydrogen bonds energies changed from −4.11 eV (CO⋯H–O–C) to −1.997 eV (CO⋯H–O-Ph), which further verify the existence of multiple hydrogen bonds. the LiCMC-TA binder provides efficient stress dissipation, which exhibits high initial Coulombic efficiency (80.65%) and excellent reversible capacity (1701 mAh g−1 after 150 cycles at 1 A g−1), making Si anode more promising for practical applications.