Professor Ryu Jae-geon's Research Team of the Department of Chemical & Biomolecular Engineering Presents Technology for Controlling High-Performance Electrode Structures via Hydride-Driven Reduction
Professor Ryu Jae-geon's research team of the Department of Chemical & Biomolecular Engineering (First author: Lee Ki-jeong, Master’s student) has proposed a novel synthesis strategy enabling precise control over the structure of germanium (Ge), a material gaining attention as an anode material for lithium-ion batteries. This study demonstrated that by utilizing a hydride-driven multi-phase reduction reaction to regulate germanium's microstructure can significantly enhance electrode performance.
Germanium exhibits superior electrical and ionic conductivity compared to silicon (Si), making it a promising next-generation high-power anode material for lithium-ion batteries. However, its large volume changes and structural instability during charging and discharging have limited its practical application in batteries. To address these issues, the research team introduced a novel approach distinct from existing synthesis methods.
The research team precisely analyzed the roles of hydrogen and metallic sodium generated during the reduction of germanium oxide (GeO₂) using sodium hydride (NaH) as a reducing agent. As a result, they demonstrated for the first time that hydrogen generated during the decomposition of NaH contributes to the formation of a porous structure, while metallic sodium plays a key role in effectively reducing the oxide. This multi-phasic reduction mechanism enabled the realization of a unique germanium structure consisting of nanocrystalline and amorphous phases (see figure).
The germanium electrode synthesized in this study demonstrated superior electrochemical performance compared to conventional commercial germanium particles. Notably, it maintained structural stability and high reversible capacity even during repeated charge-discharge cycles, and maintained stable performance under high-current conditions. This performance is attributed to the porous structure that effectively alleviates volume expansion and the hybrid nanocrystalline–amorphous structure that synergistically enhances both electronic and ionic transport.
Professor Ryu Jae-geon, the corresponding author of this study, stated, "This research systematically elucidated the reduction mechanism of metal oxides and represents the first approach to comprehensively control both the pore structure and crystallinity based on this understanding." He added, "This strategy has high potential for extension to the synthesis of various metal oxide-based high-capacity anode materials, and will mark a significant turning point for designing next-generation high-energy-density active materials."
The findings were published in the internationally renowned journal in the field of energy, Advanced Science (impact factor: 14.1, JCR Top 7.1%). This study was conducted with support from the Korea Institute of Materials Science.
▶Title: "Unraveling Hydride-Driven Multiphasic Reduction Toward Tunable Germanium Structures for Lithium-Ion Batteries" (Co-first authors: Lee Ki-jeong, Dr. Kang Ji-eun; Co-corresponding authors: Dr. Lee Jin-woo, Professor Ryu Jae-geon)
▶Paper URL: https://advanced.onlinelibrary.wiley.com/doi/10.1002/advs.74278
▶Laboratory Website: https://sites.google.com/view/jryugroup/home
[SEO 키워드]
Professor Ryu Jae-geon, lithium-ion batteries, Advanced Science
[Summary]
A research team led by Professor Ryu Jae-geon from the Department of Chemical & Biomolecular Engineering has developed a novel synthesis strategy for high-performance germanium anodes in lithium-ion batteries. Published in Advanced Science, the study introduces a hydride-driven multi-phasic reduction mechanism that precisely controls the microstructure of germanium, significantly enhancing electrode stability and power performance for next-generation energy storage.
Germanium exhibits superior electrical and ionic conductivity compared to silicon (Si), making it a promising next-generation high-power anode material for lithium-ion batteries. However, its large volume changes and structural instability during charging and discharging have limited its practical application in batteries. To address these issues, the research team introduced a novel approach distinct from existing synthesis methods.
The research team precisely analyzed the roles of hydrogen and metallic sodium generated during the reduction of germanium oxide (GeO₂) using sodium hydride (NaH) as a reducing agent. As a result, they demonstrated for the first time that hydrogen generated during the decomposition of NaH contributes to the formation of a porous structure, while metallic sodium plays a key role in effectively reducing the oxide. This multi-phasic reduction mechanism enabled the realization of a unique germanium structure consisting of nanocrystalline and amorphous phases (see figure).
The germanium electrode synthesized in this study demonstrated superior electrochemical performance compared to conventional commercial germanium particles. Notably, it maintained structural stability and high reversible capacity even during repeated charge-discharge cycles, and maintained stable performance under high-current conditions. This performance is attributed to the porous structure that effectively alleviates volume expansion and the hybrid nanocrystalline–amorphous structure that synergistically enhances both electronic and ionic transport.
Professor Ryu Jae-geon, the corresponding author of this study, stated, "This research systematically elucidated the reduction mechanism of metal oxides and represents the first approach to comprehensively control both the pore structure and crystallinity based on this understanding." He added, "This strategy has high potential for extension to the synthesis of various metal oxide-based high-capacity anode materials, and will mark a significant turning point for designing next-generation high-energy-density active materials."
The findings were published in the internationally renowned journal in the field of energy, Advanced Science (impact factor: 14.1, JCR Top 7.1%). This study was conducted with support from the Korea Institute of Materials Science.
▶Title: "Unraveling Hydride-Driven Multiphasic Reduction Toward Tunable Germanium Structures for Lithium-Ion Batteries" (Co-first authors: Lee Ki-jeong, Dr. Kang Ji-eun; Co-corresponding authors: Dr. Lee Jin-woo, Professor Ryu Jae-geon)
▶Paper URL: https://advanced.onlinelibrary.wiley.com/doi/10.1002/advs.74278
▶Laboratory Website: https://sites.google.com/view/jryugroup/home
[SEO 키워드]
Professor Ryu Jae-geon, lithium-ion batteries, Advanced Science
[Summary]
A research team led by Professor Ryu Jae-geon from the Department of Chemical & Biomolecular Engineering has developed a novel synthesis strategy for high-performance germanium anodes in lithium-ion batteries. Published in Advanced Science, the study introduces a hydride-driven multi-phasic reduction mechanism that precisely controls the microstructure of germanium, significantly enhancing electrode stability and power performance for next-generation energy storage.