Abstract
Lithium zirconate is a candidate material in the design of electrochemical devices and tritium breeding blankets. Here we employ an atomistic simulation based on the classical pair-wise potentials to examine the defect energetics, diffusion of Li-ions, and solution of dopants. The Li-Frenkel is the lowest defect energy process. The Li-Zr anti-site defect cluster energy is slightly higher than the Li-Frenkel. The Li-ion diffuses along the c axis with an activation energy of 0.55 eV agreeing with experimental values. The most favorable isovalent dopants on the Li and Zr sites were Na and Ti respectively. The formation of additional Li in this material can be processed by doping of Ga on the Zr site. Incorporation of Li was studied using density functional theory simulation. Li incorporation is exoergic with respect to isolated gas phase Li. Furthermore, the semiconducting nature of LZO turns metallic upon Li incorporation.
Highlights
IntroductionLithium zirconate (Li2 ZrO3 or LZO) is a material of interest for many applications including electrode or electrolyte in Li-ion batteries [1,2,3], breeder blanket in nuclear reactors [4,5,6] and sorbent capture of CO2 [7,8,9] due to its chemical and thermal stability
Lithium zirconate (Li2 ZrO3 or LZO) is a material of interest for many applications including electrode or electrolyte in Li-ion batteries [1,2,3], breeder blanket in nuclear reactors [4,5,6] and sorbent capture of CO2 [7,8,9] due to its chemical and thermal stability.For battery applications, Li-ion conductivity should be high as battery performance is partly dependent on it during the charge–discharge process
Buckingham potentials used in the classical simulation and projected augmented wave (PAW) potentials utilized in the density functional theory (DFT) simulation were validated by performing geometry optimization calculations and comparing the relaxed lattice parameters with corresponding experimental values
Summary
Lithium zirconate (Li2 ZrO3 or LZO) is a material of interest for many applications including electrode or electrolyte in Li-ion batteries [1,2,3], breeder blanket in nuclear reactors [4,5,6] and sorbent capture of CO2 [7,8,9] due to its chemical and thermal stability. Li-ion conductivity should be high as battery performance is partly dependent on it during the charge–discharge process. Experimental work based on nuclear magnetic resonance (NMR) spectroscopy shows that the Li-ion conductivity in this material is high and the activation energy is calculated to be ~0.51–0.65 eV [10]. Reported that the rate performance of LiNi0.5 Co0.2 Mn0.3 O2 can be improved by the surface coating of LZO. In a density functional theory (DFT) simulation by Ferreira et al [12], the relevance of vacancy-assisted Li-ion migration has been discussed
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