Feasibility Study of Perovskite Solid Electrolyte for Electrochemical Lithium-Ion Cells

To achieve a high energy density in lithium-ion batteries (LIB), replacing the graphite anode with lithium metal is essential, as it offers a theoretical capacity of 3840 mAh/g.(Q. Wang et al. 2021) However, the use of lithium metal anodes is restricted by the formation of lithium dendrites, which can cause short circuits.(Wood et al. 2016) Solid-state electrolytes present a viable alternative to conventional liquid electrolytes by potentially mitigating dendrite growth. Among these, the perovskite-type Li3/8Sr7/16Ta3/4Zr1/4O3 (LSTH) stands out due to its excellent ambient stability, although its synthesis, properties, and applications remain underexplored.(Y. Li et al. 2018) In this study, I conducted a systematic investigation into LSTH to fill these knowledge gaps. I explored the impact of various sintering conditions on LSTH’s phase purity, microstructure, and chemical composition, establishing optimal conditions for impurity-free production via solid-state and sol-gel methods. The chemical, mechanical, and electronic properties of LSTH were characterized, and its microstructure was analyzed using neutron diffraction. Lithium-ion migration in LSTH was simulated through ab initio molecular dynamics (AIMD). Despite its reactivity with lithium metal, limiting its use in lithium metal batteries, LSTH showed superior performance in direct lithium extraction from seawater. I examined the ion migration mechanism and internal resistance, and improved electrolysis cell performance through bubble management and surface modification techniques.