https://scholar.gist.ac.kr/handle/local/8026 Wed, 13 May 2026 15:23:33 GMT 2026-05-13T15:23:33Z https://scholar.gist.ac.kr/handle/local/33569 Title: Synthesis of pompon-like ZnO microspheres as host materials and the catalytic effects of nonconductive metal oxides for lithium-sulfur batteries Author(s): Song, Hyeongi; Suh, Seokho; Park, Hyeonghun; Jang, Daeun; Kim, Jihun; Kim, Hyeong Jin Abstract: Lithium-sulfur batteries have attracted tremendous attention as promising next-generation battery systems because of their high theoretical specific capacity and cost-competitiveness. Nevertheless, the commercialization of sulfur-based cathodes has been limited by substantial problems such as the insulating property of S8/Li2S, low active material utilization, and inevitable dissolution of lithium polysulfides into organic electrolytes. Among the materials used to solve these problems, metal oxide materials have attracted attention because of their strong chemical/physical interactions with polysulfides and catalytic effect. However, most studies include strategies to add electron networks or synthesize metal oxides into nanosize because of the nonconductive properties of metal oxides. Herein, to demonstrate the intrinsic effect of metal oxides, pompon-like ZnO microspheres (p-ZnO) are employed by a hydrothermal method and subsequent calcination for a sulfur host (p-ZnO/S) for the first time. The composite of p-ZnO/S significantly enhanced the sulfur utilization and rate capability without additional efforts to improve the electrical conductivity. In addition, the decrease of reaction resistance and charge-transfer resistance was shown in electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) results. Furthermore, the catalytic effect is described by analyzing the lithium ion diffusion coefficient and verifying the chemical composition change on the cathode surface during the sulfur redox reaction. Wed, 30 Jun 2021 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/33569 2021-06-30T15:00:00Z https://scholar.gist.ac.kr/handle/local/31985 Title: Synergistic effect of electrolyte additives on the suppression of dendrite growth in a flowless membraneless Zn–Br2 battery Author(s): Park, Hyeonghun; Park, Geumyong; Kumar, Santosh; Yoon, Hocheol; Baek, Juyeon; Tamulevičius, Tomas; Tamulevičius, Sigitas; Kim, Hyeong-Jin Abstract: Aqueous ZnBr2 batteries (ZBBs), particularly in flowless and membraneless form (FLML-ZBB), offer a cost-effective and promising large-scale energy storage system. Unfortunately, these batteries suffer from unavoid-able Zn dendrite growth and inherent cross-diffusion of volatile and corrosive soluble Br3- species, which can eventually lead to a short circuit and serious self-discharge of the battery, respectively. To address these chal-lenges, a single chamber FLML-ZBB is demonstrated in which the synergic effect of various metal ions (Li+, Na+, K+, Mn2+, and Cr3+) suppresses Zn dendritic growth. In addition, the use of a bromine complexing agent (BCA), 1-ethylpyridinium bromide (1-EPBr), efficiently inhibits cross-diffusion and induces reversible complexation of Br2/Br3-. The experimental results reveal that a battery with both Mn2+ ions and 1-EPBr electrolyte additives shows stable operation and exhibits a high Coulombic efficiency of 98.5% over 700 charge/discharge cycles at a high current density of 20 mA cm-2 and a long cycle life (1600 cycles) of over 3200 h at 1 mA cm-2. Sat, 30 Sep 2023 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/31985 2023-09-30T15:00:00Z https://scholar.gist.ac.kr/handle/local/33545 Title: Precision Capsular Infarct Modeling to Produce Hand Motor Deficits in Cynomolgus Macaques Author(s): Kim, Hyung-Sun; Hwang, Jeong Ho; Han, Su-Cheol; Kang, Goo-Hwa; Park, Ji-Young; Kim, Hyoung-Ihl Abstract: Stroke research in non-human primates (NHPs) with gyrencephalic brains is a critical step in overcoming the translational barrier that limits the development of new pharmaceutical and rehabilitative strategies for stroke. White-matter stroke (WMS) has a unique pathophysiology from graymatter stroke and is not well understood because of a lack of pertinent animal models. To create a precise capsular infarct model in the cynomolgus macaque, we first used electrical stimulation to map hand movements, followed by viral tracing of the hand motor fibers (hMFs). This enabled us to identify stereotactic targets in the posterior limb of the internal capsule (PLIC). Neural tracing showed that hMFs occupy the full width of the PLIC, owing to overlap with the motor fibers for the leg. Furthermore, the hMFs were distributed in an oblique shape, requiring coronal tilting of the target probe. We used the photothrombotic infarct lesioning technique to precisely destroy the hMFs within the internal capsule. Double-point infarct lesioning that fully compromised the hMFs resulted in persistent hand motor and walking deficits whereas single-point lesioning did not. Minor deviations in targeting failed to produce persistent motor deficits. Accurate stereotactic targeting with thorough involvement of motor fibers is critical for the production of a capsular infarct model with persistent motor deficits. In conclusion, the precision capsular infarct model can be translated to the NHP system to show persistent motor deficits and may be useful to investigate the mechanism of post-stroke recovery as well as to develop new therapeutic strategies for the WMS. Thu, 30 Sep 2021 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/33545 2021-09-30T15:00:00Z https://scholar.gist.ac.kr/handle/local/31631 Title: Integrated Energy Conversion and Storage Device for Stable Fast Charging Power Systems Author(s): Kim, Jihun; Park, Hyeonghun; Jang, Junsung; Song, Hyeongi; Lee, Byeong Hoon; Lee, Dongmin; Jang, Suyoung; Kim, Jin Hyeok; Kim, Hyeong-Jin Abstract: Herein, an integrated device that comprises inorganic kesterite solar cells and Li-ion batteries (LIBs) has been proposed for application in fast photo-charging power systems. LiFePO4 and Li4Ti5O12 were selected as the battery electrode materials and six kesterite solar cells connected in series were fabricated to satisfy the charging voltage required for LIBs. Photo-charging was conducted at the rate of 1C (1.790 mAh g-1) at 2.1 V. An energy conversion and storage efficiency of 3.87% was acquired in the integrated device, and a storage efficiency of over 70% was observed in LIBs. Furthermore, by synchronizing the charging voltage of the solar cell and LIB, over 70% of the capacity was obtained at the rate of 1C, while preventing overvoltage during long-term charging. © 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. Mon, 30 Nov 2020 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/31631 2020-11-30T15:00:00Z