https://scholar.dgist.ac.kr/handle/20.500.11750/10195 Sat, 04 Apr 2026 20:26:14 GMT 2026-04-04T20:26:14Z https://scholar.dgist.ac.kr/handle/20.500.11750/60117 Title: Digital Twin-Driven Mechanical Degradation Diagnostics: Unraveling Microstructure Evolution of Silicon-based Lithium-Ion Battery Anodes Author(s): Lim, Jaejin; Choi, Junhyeok; Kim, Kyung-Geun; Song, Jihun; Lee, Hyobin; Lee, Yong Min Abstract: Silicon is a promising anode material due to its high theoretical capacity, but its extreme volume change (>300%) during cycling leads to contact loss, electrode delamination, and crack propagation, ultimately compromising mechanical integrity. While operando imaging captures morphological evolution, it remains insufficient to resolve the coupled electrochemical, mechanical, and microstructural dynamics that govern degradation. Here, a microstructure-resolved digital twin model of SiOx/graphite composite electrodes is presented to diagnose electrochemo-mechanical behavior. A 3D structure reconstructed from high-resolution FIB-SEM tomography is integrated into a coupled simulation framework that captures Li+ diffusion, interfacial electrochemical reactions, and concentration-dependent mechanical strain. Simulations reveal that volumetric expansion distorts internal conduction pathways-enhancing electronic conduction via broadened solid-solid interfaces while impeding ion transport through increased tortuosity. Moreover, charge-rate-dependent analysis shows that the charging rate governs the balance between the state of charge (SoC) and local stress. Increasing the rate from 0.5C to 4C reduces stress by limiting the SoC level, thereby mitigating mechanical degradation and enhancing cycling stability. This digital twin framework enables quantitative diagnostics of stress-driven failure and offers design guidelines for the development of mechanically robust, high-performance silicon-based anodes. Wed, 31 Dec 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/60117 2025-12-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58265 Title: Scalable carbon-patterned layer enhances low-temperature performance of large-format lithium-ion batteries Author(s): Lim, Jaejin; Park, Siyoung; Lee, Hyobin; Choi, Seungyeop; Nam, Gwonsik; Kim, Kyung-Geun; Choi, Jaecheol; Lee, Young-Gi; Lee, Yong Min Abstract: With electric vehicles (EVs) emerging as a primary mode of transportation, ensuring their reliable operation in harsh environments is crucial. However, lithium-ion batteries (LIBs) suffer from severe polarization at low temperatures, limiting their operation in cold climates. In addition, difficulties in discovering new battery materials have highlighted a growing demand for innovative electrode designs that achieve high performance, even at low temperatures. To address this issue, we prepared a thin, resistive, and patterned carbon interlayer on the anode current collector. This carbon-patterned layer (CPL) serves as a self-heating layer to efficiently elevate the entire cell temperature, thus improving the rate capability and cyclability at low temperatures while maintaining the performance at room temperature. Furthermore, we validated the versatile applicability of CPLs to large-format LIB cells through experimental studies and electrochemo-thermal multiphysics modeling and simulations, with the results confirming 11% capacity enhancement in 21,700 cylindrical cells at a 0.5C-rate and -24 degrees C. We expect this electrode design to offer reliable power delivery in harsh climates, thereby potentially expanding the applications of LIBs. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies. Sat, 31 May 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/58265 2025-05-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58212 Title: Validating the Virtual Calendering Process With 3D-Reconstructed Composite Electrode: An Optimization Framework for Electrode Design Author(s): Lim, Jaejin; Song, Jihun; Kim, Kyung-Geun; Koo, Jin Kyo; Lee, Hyobin; Kang, Dongyoon; Kim, Young-Jun; Park, Joonam; Lee, Yong Min Abstract: Calendering is an essential fabrication step for lithium-ion battery electrodes, aimed at achieving the target density through mechanical compression. During this process, the electrode's microstructure significantly deforms, affecting its electrochemical performance. Therefore, it is important to understand how the microstructure evolves during calendering and correlate these changes with electrochemical behavior. Despite tremendous experimental efforts, there are limitations in obtaining sufficient outcomes. In this regard, simulations offer valuable information; however, the highest priority is to develop a reliable modeling framework that reflects actual microstructural changes and establish a robust validating methodology. Without such a framework, computational predictions may not align with experimental results. This study develops a virtual calendering framework based on high-resolution FIB-SEM tomography images of a bimodal LiNi0.6Co0.2Mn0.2O2 cathode with a mass loading of 19.8 mg cm-2 and 96 wt.% active material. The framework is rigorously validated through systematically designed experiments across various electrode densities (2.3-4.0 g cm-3) and further analysis of hidden microstructural features, such as ionic tortuosity, contact area, and crack structure through additional tomography analysis. The virtual calendering framework successfully predicts microstructural changes and electrochemical performance, offering a reliable pathway for identifying optimal design parameters in a time- and cost-effective manner. Mon, 30 Jun 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/58212 2025-06-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/56852 Title: Surface Adaptive Dual-Layer Protection of Li-metal Anode for Extending Cycle-Life of Li-Sulfur Batteries with Lean Electrolyte Author(s): Choi, Bokyung; Kim, Kyung-Geun; Lim, Minhong; Kim, Beomjun; Seo, Jiyeon; Lee, Jiwon; Park, Sanghyeon; Kim, Ki-Hyun; Lee, Yong Min; Lee, Hongkyung Abstract: Building a lithium–sulfur (Li–S) battery with lean electrolytes is essential to far exceed the energy density of today's Li-ion. However, earlier electrolyte depletion triggered by Li-metal anodes (LMAs) causes sluggish Li–S redox kinetics and poor S utilization, resulting in a short cycle lifespan. To retard the electrolyte loss effectively, sustainable protection of LMAs is necessary against the dynamic interfacial evolution between LMA and protective layers (PLs). This study elucidates two critical parameters in securing the interfacial adaptivity of PLs upon local Li pitting: surface free energy (SFE) and Young's modulus through solid-mechanic simulations and experiments using three different PL models. To alleviate the PL delamination at the early stage, a dual-layer structured, adaptive protective layer (APL) is introduced to adapt the Li pitting-driven structural evolution of the PL|LMA interfaces. The APL consists of a high- SFE polymer as an inner layer, reducing the interfacial energy in contact with LMA surface, and a highly stretchable polymer for outer shield, serving as a physical barrier for the electrolyte and Li polysulfides. APL-coated LMA demonstrates stable cycling of Li–S cells, achieving a twofold extension of cycle-life compared to unprotected LMA, even superior to other single-layer PLs. © 2024 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH. Sun, 30 Jun 2024 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/56852 2024-06-30T15:00:00Z