Porous Carbon Encapsulated Si Composites With ZnO-Induced Pores for Enhanced Lithium Storage Stability

Owing to its extraordinarily large theoretical capacity, silicon (Si) stands out as a particularly attractive anode candidate for next-generation lithium-ion energy storage systems. Nevertheless, the widespread use of silicon anodes is limited by considerable volume variation during electrochemical cycling and its naturally low conductivity, which result in electrode pulverization, active material detachment, and poor cycling stability. Herein, porous carbon-coated silicon (Si@p-C) composites are fabricated via a sol-gel process. The porous carbon coating not only accommodates the strain induced by the volumetric changes of silicon and shortens lithium-ion migration paths to improve transport efficiency, but also enhances charge transfer capability and promotes a stable solid electrolyte interphase (SEI) film to suppress excessive parasitic reactions. Owing to this optimized architecture, the Si@p-C electrode delivers 1604 mAh g^-1 when cycled at 0.2 A g^-1 over 50 cycles, representing an 87.8% retention. Moreover, after 100 cycles at 1.0 A g^-1, the electrode demonstrates a well-preserved reversible capacity of 956 mAh g^-1.