Speaker
Description
The development of high-capacity electrode materials is essential for enhancing the energy density of lithium-ion batteries. Siligraphene (SiC2), inspired by silicon’s high theoretical capacity, has emerged as a promising anode material due to its high specific capacity and low open-circuit voltage. however, its performance is limited by poor mechanical stiffness. This study examines fluorine incorporation in SiC2 by evaluating its thermodynamic stability, mechanical and electronic properties using cluster expansion and density functional theory. Fluorine incorporation at the silicon 1a site yields three thermodynamically stable structures with negative formation energies, with SiC6F2 identified as the most stable configuration. In contrast, doping at the carbon 2d site predominantly produces unstable configurations, with Si4CF7 being the only stable phase. Further analysis of the most stable structures reveals that most exhibit metallic behavior with strong valence-band contributions, while SiC6F2 displays semiconducting characteristics with a narrow direct band gap of 0.092 eV. Mechanical analysis indicates that structures doped at the 1a site are mechanically unstable and brittle, whereas those doped at the 2d site are mechanically stable but remain brittle. Overall, fluorine incorporation in SiC2 exhibits strong site-dependent effects on stability, electronic structure, and mechanical behavior. While 1a-site doping favours thermodynamic stability, it compromises mechanical integrity, whereas 2d-site doping improves stability but remains limited by brittleness. These findings provide valuable insights for the rational design of modified siligraphene anodes with improved performance for lithium-ion batteries.
| Apply for student award at which level: | MSc |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |