Engineering of aqueous binder mediated organic/inorganic artificial interfacial layers for enhancing silicon anode performance

The expansion of silicon volume significantly impacts the degradation of silicon anodes. The current binder-formed interface fails to effectively suppress this expansion due to the absence of rigid inorganic components. Therefore, we develop an aqueous binder-mediated interfacial engineering strategy to construct an organic/inorganic artificial interfacial layer in situ during the electrode preparation process. This artificial interfacial layer, consisting of an organic alginate–lithium citric acid–tannin derivative (LiACT) binder and inorganic Li 2 SiO 3 , is generated by a combination of chemical reactions and hydrogen bonding between tannic acid, citric acid, sodium alginate, silicon, and lithium hydroxide. The three-dimensional structure provides the LiACT binder with a strong binding force. The elasticity of LiACT, the high Young's modulus of Li 2 SiO 3 , and their fast ionic conductivity enable this artificial interfacial layer to exhibit robust rigidity-flexibility and excellent ionic-electronic transport properties. Therefore, the Si electrode coated with this artificial interfacial layer (Si@LiACT) exhibits high coulombic efficiency (99.2 % in the 5th cycle), excellent cycling stability (89.2 % capacity retention after 200 cycles), and superior rate performance (1044 mAh g −1  at 4C). These enhancements are attributed to the unique organic/inorganic artificial interfacial layer, which effectively inhibits silicon volume expansion, alleviates interfacial side reactions, and promotes interfacial charge transfer.