Yong‐Mook Kang

Urchin‐like CoSe 2 assembled by nanorods has been synthesized via simple solvothermal route and has been first applied as an anode material for sodium‐ion batteries (SIBs) with ether‐based electrolytes. The CoSe 2 delivers excellent sodiation and desodiation properties when using 1 m NaCF 3 SO 3 in diethyleneglycol dimethylether as an electrolyte and cycling between 0.5 and 3.0 V. A high discharge capacity of 0.410 Ah g −1 is obtained at 1 A g −1 after 1800 cycles, corresponding to a capacity re

Considering that the high capacity, long-term cycle life, and high-rate capability of anode materials for sodium-ion batteries (SIBs) is a bottleneck currently, a series of Co-doped FeS2 solid solutions with different Co contents were prepared by a facile solvothermal method, and for the first time their Na-storage properties were investigated. The optimized Co0.5 Fe0.5 S2 (Fe0.5) has discharge capacities of 0.220 Ah g(-1) after 5000 cycles at 2 A g(-1) and 0.172 Ah g(-1) even at 20 A g(-1) with

Over the last 40 years, metallic lithium as an anode material has been of great interest owing to its high energy density. However, dendritic lithium growth causes serious safety issues. Awareness and understanding of the Li deposition and stripping processes have grown rapidly especially in recent years, and consequently, there have been many attempts to suppress the Li dendrites. Recent developments that have modified the electrolytes and the Li anode in order to inhibit the growth of Li dendr

Improving the lithium (Li) storage properties of silicon (Si)‐based anode materials is of great significance for the realization of advanced Li‐ion batteries. The major challenge is to make Si‐based anode materials maintain electronic conduction and structural integrity during cycling. Novel carbon‐coated Si nanoparticles (NPs)/reduced graphene oxides (rGO) composites are synthesized through simple solution mixing and layer‐by‐layer assembly between polydopamine‐coated Si NPs and graphene oxide

Abstract The electrochemical performances of 1D SnO 2 nanomaterials, nanotubes, nanowires, and nanopowders, are compared to define the most favorable morphology when SnO 2 nanomaterials are adopted as the electrode material for lithium‐ion batteries. Changes in the morphology of SnO 2 are closely related with its electrochemical performance. Some SnO 2 nanomaterials feature not only an increased energy density but also enhanced Li + transfer. The correlation between the morphological characteris

Abstract Considering that the high capacity, long‐term cycle life, and high‐rate capability of anode materials for sodium‐ion batteries (SIBs) is a bottleneck currently, a series of Co‐doped FeS 2 solid solutions with different Co contents were prepared by a facile solvothermal method, and for the first time their Na‐storage properties were investigated. The optimized Co 0.5 Fe 0.5 S 2 (Fe0.5) has discharge capacities of 0.220 Ah g −1 after 5000 cycles at 2 A g −1 and 0.172 Ah g −1 even at 20 A

Sodium-ion batteries (SIBs) have attracted much scientific interest for use in large-scale energy storage systems because sodium is cheaper than lithium. However, the large radius of Na+ and barriers to Na+ transport result in sluggish kinetics and complicated structural distortion, leading to unsatisfactory rate capability and poor cycling stability. It therefore is essential to develop an electrode with enhanced kinetics and a stable structure during cycling to improve SIB performance. Among t

PdCu bimetallic nanoparticles (NPs) having mixed disordered face-centered cubic (fcc) and ordered body-centered cubic (B2-type) phases enhance the kinetics of oxygen reduction/evolution reaction by significant reduction of overpotentials, which leads to the superb round-trip efficiency of ∼80%. In addition, the PdCu catalyst demonstrates a remarkable cyclic enhancement in stability and an outstanding rate capability even at a high current density of 5000 mA gcarbon−1. Our first-principles calcul

The increasing demand to efficiently store and utilize the electricity from renewable energy resources in a sustainable way has boosted the request for sodium-ion battery technology due to the high abundance of sodium sources worldwide. Na superionic conductor (NASICON) structured cathodes with a robust polyanionic framework have been intriguing because of their open 3D structure and superior thermal stability. The ever-increasing demand for higher energy densities with NASICON-structured cathod

The development of next-generation energy-storage devices with high power, high energy density, and safety is critical for the success of large-scale energy-storage systems (ESSs), such as electric vehicles. Rechargeable sodium-oxygen (Na-O₂ ) batteries offer a new and promising opportunity for low-cost, high-energy-density, and relatively efficient electrochemical systems. Although the specific energy density of the Na-O₂ battery is lower than that of the lithium-oxygen (L

The design of temperature-adaptive Zn-air batteries (ZABs) with long life spans and high energy efficiencies is challenging owing to sluggish oxygen reduction reaction (ORR) kinetics and an unstable Zn/electrolyte interface. Herein, a quasi-solid-state ZAB is designed by combining atomically dispersed Fe-N-C catalysts containing pyridinic N vacancies (FeNC-V_N) with a polarized organo-hydrogel electrolyte. First-principles calculation predicts that adjacent V_N sites effectiv

A hexagonally ordered mesoporous cobalt phosphate (CoPi) material is prepared by a facile one-pot soft-templating strategy using cetyltrimethylammonium bromide template. Because of its highly accessible surface area and crystalline framework with abundant active sites, the mesoporous CoPi shows a high catalytic activity for the oxygen evolution reaction compared to previously reported noble/transition-metal and nonmetal catalysts.

Abstract This study proposes a conformal surface coating of conducting polymer for protecting 1D nanostructured electrode material, thereby enabling a free‐standing electrode without binder for sodium ion batteries. Here, polypyrrole (PPy), which is one of the representative conducting polymers, encapsulated cobalt phosphide (CoP) nanowires (NWs) grown on carbon paper (CP), finally realizes 1D core–shell CoP@PPy NWs/CP. The CoP core is connected to the PPy shell via strong chemical bonding, whic

Redox reactions of oxygen have been considered critical in controlling the electrochemical properties of lithium-excessive layered-oxide electrodes. However, conventional electrode materials without overlithiation remain the most practical. Typically, cationic redox reactions are believed to dominate the electrochemical processes in conventional electrodes. Herein, we show unambiguous evidence of reversible anionic redox reactions in LiNi_1/3 Co_1/3 Mn_1/3 O<sub>2</