Battery Materials Characterization
Battery performance is measured at the cell level, but the origins of degradation hide at the atomic scale. We investigate the origin of capacity fade and impedance rise in next-generation energy storage materials—including all-solid-state batteries, Na/K-ion batteries, and Ni-rich cathodes. By combining advanced electron microscopy with electrochemical data, we uncover process–structure–performance relationships.
Detailed Research Topics
All-Solid-State Batteries (ASSBs)
We study the buried interfaces between solid electrolytes and electrodes — regions that are critical for battery performance but notoriously difficult to characterize. Our work addresses sulfide, halide, and oxide solid electrolytes, focusing on interphase formation, mechanical degradation, and ionic transport pathways at the SEI/CEI.
Na-ion and K-ion Batteries
We investigate alloying anodes (Sn, Si, Sb) and hard carbon anodes for Na-ion and K-ion systems, elucidating phase transformation sequences, volume expansion-induced stress, and self-limiting diffusion phenomena during charge/discharge cycling.
High-Nickel Cathode Materials
Degradation of LiNixCoyMnzO2 (NCM) cathodes involves complex interplay between cation mixing, lattice strain, intragranular cracking, and surface reconstruction. We correlate these microstructural changes with electrochemical performance to guide cathode design.
Fuel Cells and Catalysts
Beyond batteries, we extend our characterization expertise to proton exchange membrane fuel cells (PEMFC), studying Pt/C catalyst degradation, oxide support stability, and protection layer effectiveness under harsh electrochemical conditions.
Synthesis Thermodynamics
We collaborate on understanding and controlling the thermodynamic conditions for solid-state synthesis, enabling predictable formation of target phases for battery materials.
Representative Publications
- Y.-W. Byeon et al., “Conductive carbon embedded beneath cathode active material for longevity of solid-state batteries,” J. Mater. Chem. A (2024)
- Y. Zeng, Y.-W. Byeon et al., “High-entropy mechanism to boost ionic conductivity,” Science (2022)
- Y.-W. Byeon, “Review on interface and interphase issues in sulfide solid-state electrolytes for all-solid-state Li-metal batteries,” Electrochem (2021)
- Y.-W. Byeon et al., “Effects of cation and anion substitution in KVPO4F for K-ion batteries,” Energy Storage Mater. (2023)
- N. Szymanski, Y.-W. Byeon et al., “Quantifying the regime of thermodynamic control for solid-state reactions,” Science Advances (2024)