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44 results on '"Roh, Youngjoon"'

13. Thin, Highly Ionic Conductive, and Mechanically Robust Frame‐Based Solid Electrolyte Membrane for All‐Solid‐State Li Batteries

Author

Kim, Dohwan, primary, Lee, Hyobin, additional, Roh, Youngjoon, additional, Lee, Jongjun, additional, Song, Jihun, additional, Dzakpasu, Cyril Bubu, additional, Kang, Seok Hun, additional, Choi, Jaecheol, additional, Kim, Dong Hyeon, additional, Hah, Hoe Jin, additional, Cho, Kuk Young, additional, Lee, Young‐Gi, additional, and Lee, Yong Min, additional

Published
2023
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16. Thin, Highly Ionic Conductive, and Mechanically Robust Frame‐Based Solid Electrolyte Membrane for All‐Solid‐State Li Batteries.

Author

Kim, Dohwan, Lee, Hyobin, Roh, Youngjoon, Lee, Jongjun, Song, Jihun, Dzakpasu, Cyril Bubu, Kang, Seok Hun, Choi, Jaecheol, Kim, Dong Hyeon, Hah, Hoe Jin, Cho, Kuk Young, Lee, Young‐Gi, and Lee, Yong Min

Subjects
SOLID state batteries, SOLID electrolytes, LITHIUM cells, MECHANICAL energy, ENERGY density, IONIC conductivity, LITHIUM-ion batteries
Abstract

A thin but robust solid electrolyte layer is crucial for realizing the theoretical energy density of all‐solid‐state batteries (ASSBs) beyond state‐of‐the‐art Li‐ion batteries (LIBs). This study proposes a simple but practical strategy for fabricating thin solid electrolyte membranes using 5‐µm perforated polyethylene separators with 35% open areas as the supporting component, which ensures mechanical robustness for commercial‐level cell assembly. The thickness of this frame‐based solid electrolyte (f‐SE) membrane can be reduced to ≈45 µm, even after coating the Li6PS5Cl (LPSCl) solid electrolyte composite. Despite a slightly lower ionic conductivity compared to that of thick LPSCl pellets, the f‐SE membranes show high conductance and low overpotential in Li||Li symmetric cells. Their incorporation into LiNi0.7Co0.15Mn0.15O2 full cells increases the reversible capacity and rate capability compared to those of cells with conventional LPSCl pellets. The f‐SE membrane cells exhibit excellent cycling stability over 250 cycles, while maintaining high‐capacity retention and Coulombic efficiency. Notably, the f‐SE membranes significantly increase the energy density of ASSBs (314 Wh kg−1), exceeding the values reported for sulfide‐based cells. These results highlight the crucial role of f‐SE membranes in improving the mechanical properties and energy density of ASSBs, thereby contributing to the development of next‐generation Li battery technologies. [ABSTRACT FROM AUTHOR]

Published
2024
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17. Alkali Metal Ion Substituted Carboxymethyl Cellulose as Anode Polymeric Binders for Rapidly Chargeable Lithium‐Ion Batteries.

Author

Byun, Seoungwoo, Liu, Zhu, Shin, Dong Ok, Kim, Kyuman, Choi, Jaecheol, Roh, Youngjoon, Jin, Dahee, Jung, Seungwon, Kim, Kyung‐Geun, Lee, Young‐Gi, Ringe, Stefan, and Lee, Yong Min

Subjects
ALKALI metal ions, CARBOXYMETHYLCELLULOSE, LITHIUM-ion batteries, ELECTRIC charge, ANODES
Abstract

The increasing demand for short charging time on electric vehicles has motivated realization of fast chargeable lithium‐ion batteries (LIBs). However, shortening the charging time of LIBs is limited by Li+ intercalation process consisting of liquid‐phase diffusion, de‐solvation, SEI crossing, and solid‐phase diffusion. Herein, we propose a new strategy to accelerate the de‐solvation step through a control of interaction between polymeric binder and solvent‐Li+ complexes. For this purpose, three alkali metal ions (Li+, Na+, and K+) substituted carboxymethyl cellulose (Li‐, Na‐, and K‐CMC) are prepared to examine the effects of metal ions on their performances. The lowest activation energy of de‐solvation and the highest chemical diffusion coefficient were observed for Li‐CMC. Specifically, Li‐CMC cell with a capacity of 3 mAh cm−2 could be charged to >95% in 10 min, while a value above >85% was observed after 150 cycles. Thus, the presented approach holds great promise for the realization of fast charging. [ABSTRACT FROM AUTHOR]

Published
2024
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19. Separator Dependency on Cycling Stability of Lithium Metal Batteries Under Practical Conditions.

Author

An, Hyeongguk, Roh, Youngjoon, Jo, Youngseong, Lee, Hyuntae, Lim, Minhong, Lee, Mingyu, Lee, Yong Min, and Lee, Hongkyung

Subjects
LITHIUM cells, CHEMICAL affinity, CHEMICAL stability, POROSITY, CERAMICS
Abstract

Development of practical lithium (Li) metal batteries (LMBs) remains challenging despite promises of Li metal anodes (LMAs), owing to Li dendrite formation and highly reactive surface nature. Polyolefin separators used in LMBs may undergo severe mechanical and chemical deterioration when contacting with LMAs. To identify the best polyolefin separator for LMBs, this study investigated the separator‐deterministic cycling stability of LMBs under practical conditions, and redefined the key influencing factors, including pore structure, mechanical stability, and chemical affinity, using 12 different commercial separators, including polyethylene (PE), polypropylene (PP), and coated separators. At extreme compression triggered by LMA swelling, isotropic stress release by balancing the machine direction and transverse direction tensile strengths was found to be crucial for mitigating cell short‐circuiting. Instead of PP separators, a PE separator that possesses a high elastic modulus and a highly connected pore structure can uniformly regulate LMA swelling. The ceramic coating reinforced short‐circuiting resistance, while the cycling efficiency degraded rapidly owing to the detrimental interactions between ceramics and LMAs. This study identified the design principle of separators for practical LMBs with respect to mechanical stability and chemical affinity toward LMAs by elucidating the impacts of separator modification on the cycling performance. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Alkali Metal Ion Substituted Carboxymethyl Cellulose as Anode Polymeric Binders for Rapidly Chargeable Lithium‐Ion Batteries

Author

Byun, Seoungwoo, primary, Liu, Zhu, additional, Shin, Dong Ok, additional, Kim, Kyuman, additional, Choi, Jaecheol, additional, Roh, Youngjoon, additional, Jin, Dahee, additional, Jung, Seungwon, additional, Kim, Kyung‐Geun, additional, Lee, Young‐Gi, additional, Ringe, Stefan, additional, and Lee, Yong Min, additional

Published
2023
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43. A microcrack propagation-based life prediction model for lithium-ion batteries with Ni-rich cathode materials

Author

Park, Sun Ho, Lee, Hyobin, Park, Joonam, Roh, Youngjoon, Byun, Seoungwoo, Lim, Jaejin, Jung, Seungwon, Kim, Nayeon, Lee, Kang Taek, and Lee, Yong Min

Abstract

The formation and growth of solid electrolyte interphase (SEI) on the anode are key parameters governing battery life prediction models of lithium-ion batteries (LiBs). However, as conventional battery life prediction models do not reflect other degradation parameters such as crack formation and propagation in Ni-rich cathode materials, their accuracy is greatly reduced as the nickel content increases in layered oxide cathode materials. Herein, we propose an advanced prediction model that includes both crack propagation and SEI growth. The reliability of this microcrack propagation-based life prediction model is verified using experimental data of over 50 commercial 18650 LiB cells, which are tested under depths of discharge and current rates, from 500 to 5000 cycles. The proposed model predicts capacity retention values with less than 5 % error, even in practical operations of energy storage systems and electric vehicles, providing a standard solution for predicting the cycle life of LiBs with Ni-rich cathode materials.

Published
2022
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