Enhancing Silicon Anodes for Lithium-Ion Batteries via Carbon-Doped MoO2 Derived from Acetylacetone Molybdenum

Abstract

Silicon-based materials are considered promising anode candidates for lithium-ion batteries; however, conventional silicon anodes always suffer from poor conductivity, severe volume expansion, and an unstable solid electrolyte interface (SEI), hindering their practical application. This study provides an original design for constructing C-doped MoO₂-coated nano Si by acetylacetone molybdenum pyrolysis. This design combines the advantages of the high ionic and electronic conductivity of C-doped MoO₂ with the robustness of inorganic oxides. More importantly, during the charging and discharging process, C-doped MoO₂ is lithiated to form a highly reversible conductive phase of Li_0.98MoO₂, promoting the formation of a stable SEI and increasing the interfacial transport of Li⁺. As a result, the 12M-Si anode demonstrates significantly stable capacity retention of 96.83% after 70 cycles at a current density of 0.25 A g^–1 and an excellent rate capability of 1551 mAh g^–1 at 1.5 A g^–1. This work provides a method for designing the surface structure of silicon-based anode materials with ionic–electronic synergistic conductivity.