Theoretical investigation on Elastic, Thermodynamic and Optical Properties of Li₃P Ionic Conductor

Abstract

The elastic, thermodynamic and optical properties of Li 3 P have been studied for the first time using the plane-wave ultrasoft pseudopotential technique which is based on the firstprinciples density functional theory (DFT) within generalized gradient approximation (GGA). The optimized lattice parameters, independent elastic constants, Young's modulus E, bulk modulus B, shear modulus G, Cauchy's pressure, Pugh's ductility index (G/B), and Poisson's ratio υ have been calculated and discussed. The temperature and pressure dependence of bulk modulus, Debye temperature, specific heats, and thermal expansion coefficient are all obtained through the quasi-harmonic Debye model with phononic effects for T = 0−1000 K and P = 0−35 GPa. The large reflectivity in the ultraviolet energy region between 7-13.4 eV indicates the material to be a good candidate as coating to avoid solar heating.

Two-Dimensional Phosphorene-Derived Protective Layers on a Lithium Metal Anode for Lithium-Oxygen Batteries

“…It is known that protective layers are easily deformed because of Li dendrite growth with a high shear modulus, indicating that a protective layer should be sufficiently strong to endure the pressure originating from Li dendrite growth. The shear modulus of Li 3 P obtained from DFT calculations is 34.47 GPa, 67 which is 10 times higher than that of Li dendrites (3.4 GPa). 53 This result indicates that even in terms of mechanical strength, Li 3 P is a promising candidate for Li protection.…”