Silicon (Si) has been regarded as an alternative anode material to traditional graphite owing to its higher theoretical capacity (4200 vs. 372 mAh g-1). However, Si anodes suffer from the inherent volume expansion and unstable solid electrolyte interphase, thus experiencing fast capacity decay, which hinders their commercial application. To address this, herein, an endotenon sheath-inspired water-soluble double-network binder (DNB) is presented for resolving the bottleneck of Si anodes. The as-developed binder shows excellent adhesion, high mechanical properties, and a considerable self-healing capability mainly benefited by its supramolecular hybrid network. Apart from these advantages, this binder also induces a Li3N/LiF-rich solid electrolyte interface layer, contributing to a superior cycle stability of Si electrodes. As expected, the DNB can achieve mechanically more stable Si electrodes than traditional polyacrylic acid and pectin binders. As a result, DNB delivers superior electrochemical performance of Si/Li half cells and LiNi0.8Co0.1Mn0.1O2/Si full cells, even with a high loading of Si electrode, to traditional polyacrylic acid and pectin binders. The bioinspired binder design provides a promising route to achieve long-life Si anode-assembled lithium batteries.
Keywords: Double-network binder; Efficiency; Lithium battery; Silicon electrodes.
© 2022. The Author(s).