https://scholar.dgist.ac.kr/handle/20.500.11750/219 Sat, 04 Apr 2026 16:55:57 GMT 2026-04-04T16:55:57Z https://scholar.dgist.ac.kr/handle/20.500.11750/59982 Title: Engineering Hollow-Structured Carbon Framework to Facilitate High-Sulfur-Content Encapsulation for Lithium-Sulfur Batteries Author(s): Sung, Jong Hun; Lee, Soyun; Yu, Jeong-Hoon; Lee, Jiwon; Yu, Bo; 이동현; Lee, Ha-Young; Hong, Seung-Tae; Ibnu Syafiq Imaduddin; Kang, Joonhee; Yu, Jong-Sung Abstract: Lithium-sulfur batteries (LSBs) have emerged as promising candidates for next-generation energy storage systems due to their high theoretical energy density and cost-effectiveness. However, their practical application is severely limited by the shuttle effect of lithium polysulfides (LiPSs) and the inherently low electrical conductivity of sulfur, which leads to rapid capacity fading and poor rate performance. To address these challenges, this work develops a hollow-structured graphitic nitrogen-doped porous carbon (h-GNPC) framework derived from zeolitic imidazolate framework-8 via a magnesiothermic reduction (MR) process. This method effectively tailors the pore architecture and electrical conductivity, enabling efficient sulfur encapsulation and high sulfur loading up to 90 wt.%. Compared to a carbon host treated without the MR method, the h-GNPC exhibits enhanced porosity, which can accommodate sulfur with stabilized cyclability. As a result, a coin cell with sulfur-loaded h-GNPC cathode exhibits an initial capacity of 1292.9 mAh g−1 and enhanced capacity retention of 74.9% over 500 cycles at 0.2C as well as rate performance. Notably, pouch-type cells assembled with the h-GNPC cathode demonstrate excellent scalability and cycling stability, highlighting the practical potential of this design for the commercialization of LSBs technology. Sun, 30 Nov 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59982 2025-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59367 Title: Alloy-assisted stabilization of thin Li metal anodes in pouch-type cells Author(s): Sung, Jong Hun; Lee, Un Hwan; Yeu, In Won; Maulana, Muhammad Irfansyah; Kang, Joonhee; Yu, Jong-Sung Abstract: Lithium metal batteries (LMBs) with thin lithium (Li) metal anodes deliver higher energy densities compared to traditional LMBs with thicker Li anodes. However, Li metal anodes suffer from uncontrolled dendrite formation, resulting in poor cycle life and low coulombic efficiency (CE). To address these issues, we present metal trifluoromethanesulfonates (Mx(CF3SO3)y, MTFMS, where M = Li, Zn, Cu, Ag, Mg) as electrolyte additives to suppress dendrite formation and provide better cyclability. Interestingly, the metal (M) formed from MTFMS enables stable Li deposition through its alloying reaction with Li. In addition, a stable LiF-rich solid electrolyte interphase (SEI) is derived from –CF3 functional groups, further suppressing dendrite formation. Li‖Cu cells cycled with MTFMS exhibit a higher initial CE of up to 96.6% with significantly buffered overpotential. Furthermore, Li‖Li symmetric cells composed of MTFMS show superior cyclability for over 500 h. A LiNi0.8Mn0.1Co0.1O2 (NMC811) full cell assembled with a thin Li metal anode (≤50 µm) under practically controlled N/P and E/C ratios in pouch cell mode revealed a stabilized capacity retention of up to 82.3% for 150 cycles, along with excellent rate capability, particularly with MgTFMS. The introduction of MTFMS as an additive will establish a new framework in the design of high-energy-density LMBs using thin Li metal anodes. Sun, 30 Nov 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59367 2025-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59286 Title: Magnesiothermically Synthesized TiO-Decorated 3D N-Doped Graphitized Porous Carbon as a Multifunctional Sulfur Host for Li-S Batteries Author(s): Yu, Bo; Gyan-Barimah, Caleb; Wang, Jian; Maulana, Muhammad Irfansyah; Sung, Jong Hun; Yu, Jeong-Hoon; Hong, Seung-Tae; Wang, Kunpeng; Yu, Jong-Sung Abstract: Lithium-sulfur batteries are promising next-generation energy storage platforms due to their high theoretical energy density, cost-effectiveness, and environmental benefits. However, challenges such as the lithium polysulfide (LiPS) shuttling effect, low Coulombic efficiency (CE), and poor sulfur conductivity hinder their practical application. To address these challenges, we designed a previously unreported sulfur (S) host material, titanium monoxide-decorated 3D N-doped graphitized porous carbon (TiO-NGPC), via a simple and efficient magnesium thermal reduction method. TiO nanoparticles embedded in N-doped graphitized porous carbon act as polar anchors for soluble LiPSs, accelerating redox reactions and alleviating the shuttle phenomenon. Simultaneously, the 3D graphitized carbon structure facilitates efficient electron transport. These synergistic effects collectively contribute to improved sulfur utilization. When employed as a sulfur-loaded cathode material, TiO-NGPC/S delivers an initial specific capacity of 1082.32 mAh g-1 at 1.0 C, retaining 580.68 mAh g-1 after 1000 cycles with a CE of 96.06%, demonstrating excellent cycling stability. At a high sulfur loading of 8.97 mg cm-2, it achieves a specific capacity of 1100.36 mAh g-1 and an area-specific capacity of 9.87 mAh cm-2. Furthermore, the assembled pouch cell exhibited an outstanding electrochemical performance, delivering a high specific capacity of 1158.78 mAh g-1 with a corresponding CE of 99% during the first discharge cycle. Density functional theory simulations confirm the strong adsorption of LiPSs and catalytic activity of TiO, highlighting its potential as a multifunctional host for high-performance lithium-sulfur batteries. Fri, 31 Oct 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59286 2025-10-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58967 Title: Magnetocrystalline Anisotropic Platinum-Palladium-Iron Ternary Intermetallic Alloy for Enhanced Fuel Cell Electrocatalysis Author(s): Maulana, Muhammad Irfansyah; Kim, Jungho; Lee, Ha-Young; Gyan-Barimah, Caleb; Wei, Yi; Yu, Jeong-Hoon; Sung, Jong Hun; Yu, Bo; Lee, Kug-Seung; Back, Seoin; Yu, Jong-Sung Abstract: Ordered Pt-based intermetallic alloys have emerged as promising candidates for oxygen reduction reaction (ORR) electrocatalysts in comparison to their disordered counterparts. Here, novel ferromagnetic PtPdFe ternary intermetallic alloys with structurally ordered tetragonal L10 and cubic L12 phases are presented, featuring distinctive characteristics in crystal structures and atomic alignments. Insights into the fundamental understanding of the Pt-based ternary intermetallic catalysts are provided, unveiling magnetocrystalline anisotropy as a structure-intrinsic descriptor for ORR catalysis. Electrochemical half- and single-cell assessments reveal that the L10-PtPdFe intermetallic catalysts exhibit superior ORR performance compared to their L12-type counterparts. Combined experimental and theoretical investigations indicate that the unique tetragonal structure of L10-PtPdFe, characterized by strong 5d-3d orbital interactions along the c-axis direction, induces ferromagnetic ordering and leads to increased magnetocrystalline anisotropy energy, thereby accelerating the ORR process. The fuel cell fabricated by such a cathode catalyst retains its performance after prolonged degradation test, meeting the 2025 stability goals set by the US Department of Energy under H2-O2, H2-air, and H2-N2 conditions. These new conceptual findings establish a rational framework for designing high-performance Pt-based intermetallic electrocatalysts, where magnetic anisotropy arising from ferromagnetic ordering can be harnessed to tailor catalytic performance for next-generation fuel cells. Tue, 30 Sep 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/58967 2025-09-30T15:00:00Z