UNIST · Engineering
김영식 교수의 연구실은 리튬 이온 및 나트륨 이온 이차전지, 고체 전해질, 나노복합재료를 중심으로 한 고성능 에너지 저장 소재의 개발에 주력하고 있습니다. 특히 리어카이클링 기술, 고체 전해질 기반의 유연한 배터리, 나트륨-염수 전지 시스템 등 지속 가능한 에너지 기술의 핵심 소재를 연구하고 있습니다. 그래핀-코발트 산화물 복합재, 티오게르마늄 황화물, 니켈 인산화물 등 새로운 전극 재료의 설계 및 응용도 활발히 진행 중입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Although the interest in lithium recycling is increasing the current global lithium recycling rate is lower than 1%. For this reason, our paper aims to explain the needs, current state and future directions of lithium recycling technologies.
Ceramic-based hybrid solid electrolyte (HSE) is designed to build a flexible pouch-type Na-ion battery.
The Front Cover picture shows the novel sodium/seawater rechargeable energy storage system, which can be considered as a hybrid between a battery and a fuel cell. The system comprises a positive seawater electrode (open to air) and a sealed negative tin-carbon (Sn–C) composite electrode in contact with environmental-friendly, highly stabile ionic liquid-based anolyte. The anode compartment is separated from the cathode compartment by the NASICON solid electrolyte. Upon electrochemical discharge,
Graphene–Co<sub>3</sub>O<sub>4</sub>nanocomposite as an efficient bifunctional catalyst for lithium–air batteries.
A new thio-germanium sulfide Li2Ga2GeS6 has been synthesized for the first time and its structure was found to be isomorphous with AgGaGeS4, which is well-known as a promising infrared NLO material. The host structure is built of GaS4 tetrahedra linked by corners to GeS4 tetrahedra to create a 3D framework forming tunnels along the c-axis, in which the Li+ ions are located. The second harmonic generation (SHG) efficiency determined on powders of Li2Ga2GaS6 is ∼200 times larger than that of α-SiO
A high energy hybrid capacitor fabricated from highly porous graphitic carbon and novel electrode material Ni<sub>2</sub>P<sub>2</sub>O<sub>7</sub>delivers a maximum energy density of 65 W h kg<sup>−1</sup>at a power density of 800 W kg<sup>−1</sup>, good rate capability and cycling stability in an aqueous Na-ion based electrolyte.
Among the various Ni‐based layered oxide systems in the form of LiNi 1‐ y ‐ z Co y Al z O 2 (NCA), the compostions between y = 0.1–0.15, z = 0.05 are the most successful and commercialized cathodes used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). However, tremendous research effort has been dedicted to searching for better composition in NCA systems to overcome the limitations of these cathodes, particularly those that arise when they are used use at high discharge/charge rat
Metallic lithium (Li) and sodium (Na) anodes have received great attention as ideal anodes to meet the needs for high energy density batteries due to their highest theoretical capacities. Although many approaches have successfully improved the performances of Li or Na metal anodes, many of these methods are difficult to scale up and thus cannot be applied in the production of batteries in practice. In this work, we introduce nanocrevasses in a carbon fiber scaffold which can facilitate the penet
Sr0.95Ce0.05CoO3−δ (SCCO) particles loaded with copper nanoparticles on their surface are shown to be excellent, low-cost, and stable bifunctional catalysts for the oxygen-reduction and oxygen-evolution reactions (ORR and OER) in aqueous solution. Evidence for the presence of Ce3+ and Co2+ as well as Co4+ and Co3+ ions revealed by XPS measurements as well as XRD analysis indicates that a CeCoO2.5 brownmillerite phase may be extruded to the surface. A surface Co4+/Co3+ couple is known to be a goo
Efficient and cost‐effective bifunctional electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are of vital importance in energy conversion and storage devices. Despite the recent progress in bifunctional oxygen electrocatalysts, their unbalanced and insufficient OER and ORR activities has continued to pose challenges for the practical application of such energy devices. The design of highly integrated, high‐performance, bifunctional oxygen electrocatalysts co
Concern for safety with carbon anodes has motivated a search for an alternative anode material for high-power lithium-ion batteries. Although sulfides cannot provide the high voltages versus lithium required of a cathode material, whether they can provide the low voltages required of an anode material remains to be determined. Investigation of the displacement reaction 2Li + MS = Li2S + M for M = Ti, V, Cr, Fe, Co, Ni reveals that, with increasing atomic number, the bottom of the M 4s band falls
Abstract Herein, we explore the electrochemical mechanism of a novel rechargeable seawater battery system that uses seawater as the cathode material. Sodium is harvested from seawater while charging the battery, and the harvested sodium is discharged with oxygen dissolved in the seawater, functioning as oxidants to produce electricity. The seawater provides both anode (Na metal) and cathode (O 2 ) materials for the proposed battery. Based on the discharge voltage (∼2.9 V) with participation of O
New concepts or chemistry is an urgent requirement for rechargeable batteries to achieve a low-cost, user-friendly nature with adequate energy densities and high levels of safety.