Department of Chemistry - PhD Student Seminar - Recent Advances in Halide-Based Solid Electrolytes for Next-Generation All-Solid-State

Student: Mr. Diliyaer ROUZI

Department: Department of Chemistry, HKUST

Supervisor: Prof. Jianwei SUN

Co-supervisor: Prof. Benzhong TANG

Abstract

All-solid-state lithium batteries (ASSLBs) represent a paradigm shift in energy storage, promising unparalleled safety and exceptional energy densities that far outpace conventional liquid-electrolyte systems. Among the various solid-state candidates, halide-based solid electrolytes (HSEs) have re-emerged at the forefront of battery research. This is driven by their unique combination of high ionic conductivity, wide electrochemical oxidation windows, excellent mechanical deformability, and superior compatibility with high-voltage cathodes. In this seminar, we will systematically explore the recent breakthroughs in HSEs, beginning with a fundamental look at how their distinct crystal structures and halogen chemistry govern lithium-ion transport kinetics. We will evaluate scalable synthesis methodologies—such as mechanochemical ball-milling and liquid-phase processing—essential for transitioning from lab-scale chemistry to industrial mass production. Crucially, the talk will address the key bottlenecks currently limiting HSEs, including their severe moisture sensitivity and chemical/electrochemical instabilities at both the cathode and lithium-metal anode interfaces. We will discuss effective compositional optimization strategies, notably multi-cation/anion substitutions, designed to mitigate these interfacial vulnerabilities. Finally, the seminar will outline future engineering perspectives on integrating these advanced halides into highenergy-density solid-state pouch cells, providing a comprehensive roadmap for nextgeneration commercial battery design.