https://scholar.dgist.ac.kr/handle/20.500.11750/12118 2026-08-03T12:49:03Z https://scholar.dgist.ac.kr/handle/20.500.11750/60513 Title: Lithiophilic Current Collector Without Interfacial Penalty in Zero-Excess Lithium Metal Batteries Author(s): Seo, Jiyeon; Lee, Sangseob; Jeon, Seojin; Lim, Minhong; Koo, Hyegang; Hong, Seung-Tae; Jang, Woosun; Soon, Aloysius; Lee, Hongkyung Abstract: Highly reversible lithium (Li) plating/stripping in zero-excess Li metal batteries (ZE-LMBs) demands lithiophilic current collectors to suppress Li dendrite formation and Li pulverization. Although Li-alloyable metals have been recognized as lithiophilic substrates, their structural and interfacial stability over cycling are still poorly understood. Here, we present a bimetallic lithiophilic current collector through sequential coatings of platinum (Pt) and silver (Ag). Experimental and computational studies reveal that Ag facilitates uniform Li nucleation and seamless solid electrolyte interphase (SEI) formation owing to the low Li diffusion barrier and strong anion adsorption, whereas Pt maintains lithiophilicity and structural integrity. Leveraging this complementarity, the Ag-outer/Pt-inner bilayer (Ag/Pt@Cu) achieves superior cycling stability through location-specific functional decoupling: the outer Ag layer ensures uniform Li deposition and robust SEI formation, whereas the inner Pt layer supports long-term lithiophilicity, thereby outperforming the reversed configuration (Pt/Ag@Cu). Given that the structural robustness of lithiophilic coatings is essential for enhancing the cycling performance of ZE-LMBs, this study provides a versatile design framework for multi-component, multi-layer architectures, enabling the rational engineering of structurally resilient, lithiophilic current collectors. 2026-05-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60484 Title: Stepwise Activation-Guided Zn Deposition for Ultra-High Capacity in Flowless Zn-Br Batteries Author(s): Han, Jaewoong; Lee, Mingyu; Lee, Hyuntae; Shin, Youyeong; Kim, Suhwan; Shin, Kyungjae; Kim, Chanyeon; Kim, Hee-Tak; Lee, Yong Min; Lee, Hongkyung Abstract: Flowless Zn-bromine batteries (FL-ZBBs) are attracting attention as a route to overcome the inherent system-level limitations of conventional flow batteries. However, the difficulty of achieving high ZnBr2 utilization and ultra-high areal capacity jeopardize practical feasibility: Under practically relevant conditions, Zn-hosting electrodes suffer from top-plating issues and dendrite-triggered "dead" Zn accumulation, which deteriorates reversible Zn plating/stripping. This work presents a stepwise activation (SWA) electrode that guides top-plating-free, bottom-to-top sequential Zn deposition. The SWA architecture is designed by introducing insulating porous membranes physically separating stacked CF layers while electrically linking through controlled partial Zn penetration. Benefiting from SWA-guided Zn deposition, FL-ZBBs can stably retain higher Coulombic and energy efficiencies even at a high current cycling (20 mA cm-2) over 10 000 cycles. For the first time, we demonstrate a stable ultra-high capacity cycling (100 mAh cm-2) of FL-ZBB with SWA electrode by maximizing the ZnBr2 utilization (similar to 33%). This simple, scalable SWA design offers broad applicability, enabling high-capacity operation in flowless batteries and extending to other metal-deposition-limited redox systems. 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57420 Title: Sustaining Surface Lithiophilicity of Ultrathin Li-Alloy Coating Layers on Current Collector for Zero-Excess Li-Metal Batteries Author(s): Seo, Jiyeon; Lim, Jihye; Chang, Hongjun; Lee, Jiwon; Woo, Jiyun; Jung, Injun; Kim, Yechan; Kim, Beomjun; Moon, Janghyuk; Lee, Hongkyung Abstract: Zero-excess Li-metal batteries (ZE-LMBs) have emerged as the ultimate battery platform, offering an exceptionally high energy density. However, the absence of Li-hosting materials results in uncontrolled dendritic Li deposition on the Cu current collector, leading to chronic loss of Li inventory and severe electrolyte decomposition, limiting its full utilization upon cycling. This study presents the application of ultrathin (≈50nm) coatings comprising six metallic layers (Cu, Ag, Au, Pt, W, and Fe) on Cu substrates in order to provide insights into the design of Li-depositing current collectors for stable ZE-LMB operation. In contrast to non-alloy Cu, W, and Fe coatings, Ag, Au, and Pt coatings can enhance surface lithiophilicity, effectively suppressing Li dendrite growth, thereby improving Li reversibility. Considering the distinct Li-alloying behaviors, particularly solid-solution and/or intermetallic phase formation, Pt-coated Cu current collectors maintain surface lithiophilicity over repeated Li plating/stripping cycles by preserving the original coating layer, thereby attaining better cycling performance of ZE-LMBs. This highlights the importance of selecting suitable Li-alloy metals to sustain surface lithiophilicity throughout cycling to regulate dendrite-less Li plating and improve the electrochemical stability of ZE-LMBs. © 2024 Wiley-VCH GmbH. 2024-10-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57412 Title: Current-mediated suppression of hydrogen evolution reaction in determination of Zn-metal Coulombic efficiency Author(s): Lee, Mingyu; Lee, Hyuntae; Han, Jaewoong; Kim, Chanyeon; Lee, Hongkyung Abstract: Coulombic efficiency (CE) is a crucial metric in battery research, particularly for aqueous Zinc (Zn)-metal batteries. Nonetheless, the accurate determination of Zn CE is complicated due to a lack of awareness about charge loss triggered by the hydrogen evolution reaction (HER) and non-standardized testing conditions. This study reveals the governing factors affecting the Zn CE measurement under different testing conditions, such as applied current density, Zn-plating capacity, and half-cell platforms. Through literature and experimental studies, it is evident that the Zn CE inherently increases with higher current densities and capacities. When decoupling the actual potentials of HER and Zn deposition, HER-triggered parasitic reactions can be self-suppressed owing to greater overpotential for HER than for Zn-plating at higher current densities. A consistent trend was observed when using different Zn salts and current collectors. This awareness can help standardize CE measuring protocols for validating novel concepts and materials. © 2024 Elsevier B.V. 2024-09-30T15:00:00Z