Carbon Coating on Silicon for High-Performance Anode in Lithium-Ion Batteries

Abstract

Silicon has attracted tremendous research interest as the next-generation anode material for lithium-ion batteries (LIBs) due to its approximately 10-fold higher capacity comparing to the graphite anode that is currently dominating the LIB market. Nevertheless, a critical drawback of silicon material is the dramatic volume change (>300%) during the lithiation and delithiation processes, which is a devastating destabilization factor for the silicon anode in battery cycling. Carbon coatings can serve as rigid framework to accommodate the volume change of silicon, to increase the conductivity of the silicon materials, and to protect the silicon surface from undesired side reactions. Here, we report two types of conductive carbon coatings on silicon materials through i) graphitization of a π-π stacking precursor poly(1-pyrenemethylmethacrylate) on SiO surface to encapsulate the SiO at a mild temperature, and ii) pyrolysis of polyvinylidene chloride precursor on silicon nanoparticle surface with stoichiometric ratio of sacrificial H and Cl elements that facilitate complete carbonization of the precursor. In addition, extended two‐phase transformation of carbon‐coated Si nanoparticles during electrochemical processes is examined.