Won Bo Lee

Abstract Commercialized lithium‐ion batteries (LIBs) with a liquid electrolyte have a high potential for combustion or explosion. The use of solid electrolytes in LIBs is a promising way to overcome the drawbacks of conventional liquid electrolyte‐based systems, but they generally have a lower ionic conductivity and lithium ion mobility. Here, a UV‐crosslinked composite polymer‐clay electrolyte (U‐CPCE) that is composed of a durable semi‐interpenetrating polymer network (semi‐IPN) ion transporti

Because of the salient impact on the performance of oxygen evolution reaction (OER), the surface dynamics of precatalysts accompanying the surface oxidation and dissolution of catalytic components demands immense research attention. Accordingly, the change in the structural integrity under high current density generally results in inconsistent OER performances. To address this challenge, here, we present the intricate design of precatalysts, strategically followed by reconstruction treatment in

Density fluctuations and the Widom line are of great importance in understanding the critical phenomena and the behaviors of supercritical fluids (SCFs). We report on the direct classification of liquid-like and gas-like molecules coexisting in the SCF, identified by machine learning analysis on simulation data. The deltoid coexistence region encloses the Widom line and may therefore be termed the Widom delta. Number fractions of gas-like and liquid-like particles are found to undergo continuous

Abstract Searching for an optimal component and composition of multi‐metallic alloy catalysts, comprising two or more elements, is one of the key issues in catalysis research. Due to the exhaustive data requirement of conventional machine‐learning (ML) models and the high cost of experimental trials, current approaches rely mainly on the combination of density functional theory and ML techniques. In this study, a significant step is taken toward overcoming limitations by the interplay of experim

Discovering new materials better suited to specific purposes is an important issue in improving the quality of human life. Here, a neural network that creates molecules that meet some desired multiple target conditions based on a deep understanding of chemical language is proposed (generative chemical Transformer, GCT). The attention mechanism in GCT allows a deeper understanding of molecular structures beyond the limitations of chemical language itself which cause semantic discontinuity by payi

Small-molecule acceptor (SMA)-based organic solar cells (OSCs) have achieved high power conversion efficiencies (PCEs), while their long-term stabilities remain to be improved to meet the requirements for real applications. Herein, we demonstrate the use of donor-acceptor alternating copolymer-type compatibilizers (DACCs) in high-performance SMA-based OSCs, enhancing their PCE, thermal stability, and mechanical robustness simultaneously. Detailed experimental and computational studies reveal tha

Abstract Design of bifunctional multimetallic alloy catalysts, which are one of the most promising candidates for water splitting, is a significant issue for the efficient production of renewable energy. Owing to large dimensions of the components and composition of multimetallic alloys, as well as the trade‐off behavior in terms of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) overpotentials for bifunctional catalysts, it is difficult to search for high‐performance b

We examined the packing structure of polystyrene-coated gold nanoparticles (Au@PS) as a function of grafting density. A series of Au@PS nanoparticles with grafting densities in the range of 0.51–1.94 chains nm–2 were prepared by a ligand exchange process using thiol-terminated PS and then self-assembled at a liquid–air interface. We observed a transition from disordered to body-centered cubic (bcc) to face-centered cubic (fcc) arrangements with increasing grafting density, even though the ligand

In this study, we developed a novel strategy to control the orientation of microdomains in block copolymer thin films by introducing either selective or neutral gold nanoparticles (Au NPs) that were thermally stable. The Au NPs were modified with thiol-terminated polymeric ligands, poly[(methyl methacrylate- r -styrene)- b -azidostyrene] (P[(MMA- r -S)- b -S-N 3 ]-SH), having different compositions of methyl methacrylate (MMA) and styrene in P(MMA- r -S) block to precisely tune the interfacial i

We present a coarse-grained model in order to describe the unusual sequence of mesophases observed in aqueous solutions of nonionic lipids, such as monoolein. The lipid molecules are modeled as a rigid head and a flexible Gaussian tail, and water is treated explicitly. A key component of the model is thermally reversible hydrogen bonding between the lipid head and water resulting in changes in both head volume and the interactions of the hydrated head with its surroundings. Phase diagrams obtain

Stress autocorrelation functions (SAF) of entangled polymer melts are calculated by coarse-grained molecular dynamics (MD) simulations. We show that time-averaged stresses reduce the strong noise in SAFs while still capturing most relevant relaxations of the chains. Plateau values of the SAF compare well with plateau values predicted from the entanglement length evaluated via primitive path analysis (PPA) and from experiment (where available). Three types of polymer models are studied: a flexibl

Thermoreversible, supramolecular self-assembly in multiblock copolymer melts is investigated with two microscopic approaches. We consider a blend consisting of two chemically distinct, but reactive homopolymers. One homopolymer has a single reactive end group at one of its ends, while the second has functional end groups at both ends. Reversible bonding is constrained to occur between dissimilar blocks so that this mixture is capable of forming diblocks and triblocks but no other copolymers. All

Abstract Unit‐cell‐thick MoS 2 is a promising electrocatalyst for the hydrogen evolution reaction (HER) owing to its tunable catalytic activity, which is determined based on the energetics and molecular interactions of different types of HER active sites. Kinetic responses of MoS 2 active sites, including the reaction onset, diffusion of the electrolyte and H 2 bubbles, and continuation of these processes, are important factors affecting the catalytic activity of MoS 2 . Investigating these fact