이정태 교수

Novel nanostructured sulfur (S)-carbide derived carbon (CDC) composites with ordered mesopores and high S content are successfully prepared for lithium sulfur batteries. The tunable pore-size distribution and high pore volume of CDC allow for an excellent electrochemical performance of the composites at high current densities. A higher electrolyte molarity is found to enhance the capacity utilization dramatically and reduce S dissolution in S-CDC composite cathodes during cycling.

Nanocomposites of selenium (Se) and ordered mesoporous silicon carbide‐derived carbon (OM‐SiC‐CDC) are prepared for the first time and studied as cathodes for lithium‐selenium (Li‐Se) batteries. The higher concentration of Li salt in the electrolytes greatly improves Se utilization and cell cycle stability. Se‐CDC shows significantly better performance characteristics than Se‐activated carbon nanocomposites with similar physical properties. Se‐CDC also exhibits better rate performance and cycle

Ultrathick battery electrodes are appealing as they reduce the fraction of inactive battery parts such as current collectors and separators. However, thick electrodes are difficult to dry and tend to crack or flake during production. Moreover, the electrochemical performance of thick electrodes is constrained by ion and electron transport as well as fast capacity degradation. Here, we report a thermally induced phase separation (TIPS) process for fabricating thick Li-ion battery electrodes, whic

Enhancing the performance of rechargeable lithium (Li)–sulfur (S) batteries is one of most popular topics in a battery field because of their low cost and high specific energy. However, S experiences dissolution during its electrochemical reactions; hence, maintaining its initial capacity is challenging. Protecting the S cathode with a Li ion conducting layer that acts as a barrier for polysulfide transport is an attractive strategy, but formation of such protective layers typically involves sig

This review discusses important scientific progress, problems, and prospects of lignin-based materials in the field of rechargeable batteries. Lignin, a component of the secondary cell wall, is considered a promising source of biomass. Compared to cellulose, which is the most extensively studied biomass material, lignin has a competitive price and a variety of functional groups leading to broad utilization such as adhesive, emulsifier, pesticides, polymer composite, carbon precursor, etc. The li

Abstract The lithium–selenium (Li–Se) battery is a promising energy storage system for portable devices owing to its high energy density (2528 Wh L −1 ) and electrical conductivity (10 −3 S m −1 ). The main issue with Li–Se batteries is their poor stability originating from the dissolution of Se‐containing compounds. Hence, many studies have focused on the immobilization of Se using protective layers prepared via ex situ or in situ approaches. However, these strategies are too complicated and co

The lithium/selenium (Li/Se) rechargeable battery chemistry offers a higher energy density than traditional Li ion battery cells. However, high solubility of polyselenides in suitable electrolytes causes Se loss during electrochemical cycling, and leads to poor cycle stability. This study presents a simple technique to form a protective, solid electrolyte layer on the cathode surface. This protective layer remains permeable to Li ions, but prevents transport of polyselenides, thus dramatically e

Abstract It is proposed that the unified interplay between the chemical hardness of the Li–X (X = S, Se, and Te) bond and solid‐state conversion kinetics enables intrinsic reshaping of materials for fabricating high‐energy density lithium–sulfur batteries. This concept is evaluated using three cathode models: (i) Li 2 S, (ii) Se‐doped Li 2 S (Se‐Li 2 S), and (iii) Te‐doped Li 2 S (Te‐Li 2 S). Theoretical calculations reveal that the Li−X bond in the Se‐Li 2 S cathode shows low chemical hardness,

Abstract The room temperature sodium sulfur battery (RT‐NaS) has attracted considerable attention as a next‐generation energy storage system due to its low cost and high specific energy and the abundance of sodium and sulfur. However, the sulfur‐based cathode in RT‐NaS always undergoes dissolution of polysulfides during the cycle, which limits the utilization of active material and the stability of the RT‐NaS. In this study, the authors report an economical and simple method to suppress the diss

Li–S batteries are promising candidates for next-generation energy storage technologies owing to their high theoretical capacity and low weight and the wide availability of S. The addition of Se to S is considered a rational design principle to regulate the polarization of Li–S cells intrinsically. Moreover, the electrochemical utilization of solid-state Li2–xS (0.0 ≤ x ≤ 1.0) provides sufficiently high theoretical specific capacity (836 mA h g–1) and long-term stability. However, solid-state Se