SAIP2026

Augmenting the mechanical properties of LiTi2(PO4)3 solid electrolyte through sulfur doping for better electrode-electrolyte contact

8 Jul 2026, 12:20

20m

Lecture Hall GH1 (University of the Western Cape)

Oral Presentation Track A - Physics of Condensed Matter and Materials Physics of Condensed Matter and Materials

Speaker

MOLATELO MATLEKE

Description

The pursuit of safe, cost-effective, high-energy-density lithium-ion batteries has intensified interest in LiTi₂(PO₄)_{3 (LTP) as a solid electrolyte. Its rigid 3D framework, excellent chemical stability, and high thermal and electrochemical stability offer a vigorous alternative to flammable organic liquids. Conversely, the practical use of LTP is often hindered by its inherent low ionic conductivity at room temperature and high interfacial resistance. The Vienna Ab Initio Simulation package (VASP) was used to calculate the structural, mechanical, vibrational, and electronic properties of pristine and sulfur-doped LTP. The electronic passivity of the LTP framework is diminished through anion substitution, with calculated band gaps decreasing from 2.617 eV (pristine) to 2.089 eV (LiTi2P3O11.83S0.17) and 1.987 eV (LiTi2P3O11.67S0.33), as shown by density of state (DoS) and band structure analysis. The bulk, shear, and Young’s moduli for the pristine structure were found to be 101.01 GPa, 60.74 GPa, and 151.78 GPa, respectively. The introduction of sulfur results in a slight reduction in mechanical stiffness, demonstrated by the decreasing values of the bulk, shear, and Young’s moduli to 83.68 GPa, 55.01 GPa, and 135.35 GPa for LiTi2P3O11.83S0.17, and further to 83.22 GPa, 54.25 GPa, and 133.69 GPa for LiTi2P3O11.67S0.33, respectively. As such, sulfur doping suggests that the material is shifting towards ductility, which will improve electrode-electrolyte contact and Li-ion conductivity at the interface. These findings suggest that sulfur doping is an effective strategy for tailoring the mechanical behaviour of LTP, providing a solid foundation for mechanically compatible, high-performance solid-state electrolytes.}