Rational Design of Si@SiO₂/C Composites Using Sustainable Cellulose as a Carbon Resource for Anodes in Lithium-Ion Batteries

In this work, we propose a novel and facile route for the rational design of Si@SiO₂/C anode materials by using sustainable and environment-friendly cellulose as a carbon resource. To simultaneously obtain a SiO₂ layer and a carbon scaffold, a specially designed homogeneous cellulose solution and commercial Si nanopowder are used as the starting materials, and the cellulose/Si composite is directly assembled by an in situ regenerating method. Subsequently, Si@SiO₂/C composite is obtained after carbonization. As expected, Si@SiO₂ is homogeneously encapsulated in the cellulose-derived carbon network. The obtained Si@SiO₂/C composite shows a high reversible capacity of 1071 mA h g^-1 at a current density of 420 mA g^-1 and 70% capacity retention after 200 cycles. This novel, sustainable, and effective design is a promising approach to obtain high-performance and cost-effective composite anodes for practical applications.