Surface engineering enables highly reversible lithium-ion storage and durable structure for advanced silicon anode

Silicon has been regarded as one of the most promising anodes for lithium-ion batteries (LIBs). However, state-of-the-art silicon-based material suffers from huge volume changes and poor conductivity. Here, we develop a surface engineering strategy to address the intrinsic defects. A dual-binder formed by cross-linking sodium alginate and chitosan is investigated and proposed. Moreover, a 3,4,9,10-perylenetetracarboxylic diimide (PDI) shell is introduced into the Si@SiOx surface. Density functional theory (DFT) calculations reveal that π-π stacking PDI with Li-ion trapping properties is compatible with an SA/CS complex (SC) binder through strong adsorption. These factors buffer the interface tension of Si@SiOx and facilitate Li-ion diffusion. The fabricated electrode shows highly reversible lithium-ion storage and long-term stability. Furthermore, a full-cell configuration with lithium nickel cobalt manganate (NCM) as the cathode demonstrates superior electrochemical properties and potential applications. Such surface engineering creates an opportunity for the fabrication of advanced silicon anodes.