Our research group has been established at 2009 and thereafter focusing on the advanced research on all sorts of energy materials including catalysts, cathode or anode materials, thermoelectric materials and so on. As the industry all over the world becomes very sophisticated, the development of novel functional materials is getting more important. I think our way to develop the functional materials based on the insight from material simulation and its advanced analyses will be a concrete solution for the future material problem. Please check out our members’ potential as the future scientist who will solve couple of material and energy issues through this homepage.

우리 연구 그룹은 2009년에 설립되었으며 이후 촉매, 양극 또는 음극 재료, 열전 재료 등 모든 종류의 에너지 재료에 대한 고급 연구에 중점을 두고 있습니다. 전 세계 산업이 매우 정교해짐에 따라 새로운 기능성 재료 개발이 더욱 중요해지고 있습니다. 재료 시뮬레이션과 고급 분석을 통해 얻은 통찰력을 바탕으로 기능성 재료를 개발하는 우리의 방식이 미래 재료 문제에 대한 구체적인 해결책이 될 것이라고 생각합니다. 이 홈페이지를 통해 미래 과학자로서 우리 구성원들의 잠재력을 확인해 보십시오.

Engineering Electronic Radial Effects for Fast Li⁺ Transport in Solid-State Electrolytes

Reoriented Interracial Water Structure around Pd Enhances Oxygen Reduction Kinetics in Zn-Methanol-Air Batteries

Bridging Anode and Cathode Interfaces: Integrated Interfacial Strategies for Aqueous Metal-Air Batteries

Preparation and electrochemical properties of SnO2 nanowires for application in lithium-ion batteries

Recent developments on and prospects for electrode materials with hierarchical structures for lithium‐ion batteries

Advances in the cathode materials for lithium rechargeable batteries

Urchin‐Like CoSe 2 as a High‐Performance Anode Material for Sodium‐Ion Batteries

Rational Design of 3D Dendritic TiO 2 Nanostructures with Favorable Architectures

Cobalt‐Doped FeS 2 Nanospheres with Complete Solid Solubility as a High‐Performance Anode Material for Sodium‐Ion Batteries

Tuning local chemistry of P2 layered-oxide cathode for high energy and long cycles of sodium-ion battery

Elaborately assembled core-shell structured metal sulfides as a bifunctional catalyst for highly efficient electrochemical overall water splitting

The Effect of Morphological Modification on the Electrochemical Properties of SnO 2 Nanomaterials

Recent developments of the lithium metal anode for rechargeable non‐aqueous batteries

Emerging Pt-based electrocatalysts with highly open nanoarchitectures for boosting oxygen reduction reaction

Large‐Scale Synthesis of MOF‐Derived Superporous Carbon Aerogels with Extraordinary Adsorption Capacity for Organic Solvents

Manganese based layered oxides with modulated electronic and thermodynamic properties for sodium ion batteries

Carbon‐coated Si nanoparticles anchored between reduced graphene oxides as an extremely reversible anode material for high energy‐density Li‐ion battery

A study on the charge–discharge mechanism of Co3O4 as an anode for the Li ion secondary battery

Spinel/Post-spinel engineering on layered oxide cathodes for sodium-ion batteries

Effects of nanosized adsorbing material on electrochemical properties of sulfur cathodes for Li/S secondary batteries

Structural and chemical synergistic effect of CoS nanoparticles and porous carbon nanorods for high-performance sodium storage

Facile Method To Synthesize Na-Enriched Na 1+ x FeFe(CN) 6 Frameworks as Cathode with Superior Electrochemical Performance for Sodium-Ion Batteries

Interlayer‐Spacing‐Regulated VOPO 4 Nanosheets with Fast Kinetics for High‐Capacity and Durable Rechargeable Magnesium Batteries

Emeritus Professor, Shi Xue Dou, PhD...

KAI ZHANG (张凯)

Shulei Chou

Hua Kun Liu

Agyemang Daniel Adjei

Junghoon Yang

Kwang Chul Roh

Jung Ho Kim

Kibum Kang

Hyunjoon Song

Geunhee Lee

Yong-Mook Kang

One-dimensional (1D) nanostructured materials have received considerable attention for advanced functional systems as well as extensive applications owing to their attractive electronic, optical, and thermal properties.[1–2] In lithium-ion-battery science, recent research has focused on nanoscale electrode materials to improve electrochemical performance. The high surface-to-volume ratio and excellent surface activities of 1D nanostructured materials have stimulated great interest in their development for the next generation of power sources.[3–4] Materials based on tin oxide have been proposed as alternative anode materials with high-energy densities and stable capacity retention in lithium-ion batteries.[5–7] Various SnO2-based materials have displayed extraordinary electrochemical behavior such that the initial irreversible capacity induced by Li2O formation and the abrupt capacity fading caused by volume variation could be effectively reduced when in nanoscale form.[8–10] From this point of view, SnO2 nanowires can also be suggested as a promising anode material because the nanowire structure is of special interest with predictions of unique electronic and structural properties. Furthermore, the nanowires can be easily synthesized by a thermal evaporation method. However, in its current form, this method of manufacture of SnO2 nanowires has several limitations: it is inappropriate for mass production as high synthesis temperatures are required and there are difficulties in the elimination of metal catalysts that could act as impurities or defects. This results in reversible capacity loss or poor cyclic performance during electrochemical …

Since their successful commercialization in 1990s, lithium‐ion batteries (LIBs) have been widely applied in portable digital products. The energy density and power density of LIBs are inadequate, however, to satisfy the continuous growth in demand. Considering the cost distribution in battery system, it is essential to explore cathode/anode materials with excellent rate capability and long cycle life. Nanometer‐sized electrode materials could quickly take up and store numerous Li + ions, afforded by short diffusion channels and large surface area. Unfortunately, low thermodynamic stability of nanoparticles results in electrochemical agglomeration and raises the risk of side reactions on electrolyte. Thus, micro/nano and hetero/hierarchical structures, characterized by ordered assembly of different sizes, phases, and/or pores, have been developed, which enable us to effectively improve the utilization, reaction kinetics …

The accelerating development of technologies requires a significant energy consumption, and consequently the demand for advanced energy storage devices is increasing at a high rate. In the last two decades, lithium‐ion batteries have been the most robust technology, supplying high energy and power density. Improving cathode materials is one of the ways to satisfy the need for even better batteries. Therefore developing new types of positive electrode materials by increasing cell voltage and capacity with stability is the best way towards the next‐generation Li rechargeable batteries. To achieve this goal, understanding the principles of the materials and recognizing the problems confronting the state‐of‐the‐art cathode materials are essential prerequisites. This Review presents various high‐energy cathode materials which can be used to build next‐generation lithium‐ion batteries. It includes nickel and lithium …

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 retention of 98.6% calculated from the 30th cycle. Even at an ultrahigh rate of 50 A g −1 , the capacity still maintains 0.097 Ah g −1 . The reaction mechanism of the as‐prepared CoSe 2 is also investigated. The results demonstrate that at discharged 1.56 V, insertion reaction occurs, while two conversion reactions take place at the second and third plateaus around 0.98 and 0.65 V. During the charge process, Co first reacts …

Controlling the morphology and size of titanium dioxide (TiO 2 ) nanostructures is crucial to obtain superior photocatalytic, photovoltaic, and electrochemical properties. However, the synthetic techniques for preparing such structures, especially those with complex configurations, still remain a challenge because of the rapid hydrolysis of Ti-containing polymer precursors in aqueous solution. Herein, we report a completely novel approachthree-dimensional (3D) TiO 2 nanostructures with favorable dendritic architecturesthrough a simple hydrothermal synthesis. The size of the 3D TiO 2 dendrites and the morphology of the constituent nano-units, in the form of nanorods, nanoribbons, and nanowires, are controlled by adjusting the precursor hydrolysis rate and the surfactant aggregation. These novel configurations of TiO 2 nanostructures possess higher surface area and superior electrochemical properties compared …

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 g −1 with compatible ether‐based electrolyte in a voltage window of 0.8–2.9 V. The Fe0.5 sample transforms to layered Na x Co 0.5 Fe 0.5 S 2 by initial activation, and the layered structure is maintained during following cycles. The redox reactions of Na x Co 0.5 Fe 0.5 S 2 are dominated by pseudocapacitive behavior, leading to fast Na + insertion/extraction and durable cycle life. A Na 3 V 2 (PO 4 ) 3 /Fe0.5 full cell was assembled, delivering an …

Layered transition-metal oxides have attracted intensive interest for cathode materials of sodium-ion batteries. However, they are hindered by the limited capacity and inferior phase transition due to the gliding of transition-metal layers upon Na + extraction and insertion in the cathode materials. Here, we report that the large-sized K + is riveted in the prismatic Na + sites of P2-Na 0.612 K 0.056 MnO 2 to enable more thermodynamically favorable Na + vacancies. The Mn-O bonds are reinforced to reduce phase transition during charge and discharge. 0.901 Na + per formula are reversibly extracted and inserted, in which only the two-phase transition of P2 ↔ P’2 occurs at low voltages. It exhibits the highest specific capacity of 240.5 mAh g −1 and energy density of 654 Wh kg −1 based on the redox of Mn 3+ /Mn 4+ , and a capacity retention of 98.2% after 100 cycles. This investigation will shed lights on the tuneable chemical …

Low efficiency, short lifetimes, and limited kinds of catalysts are still three fundamental shortcomings that have plagued electrochemical water splitting. Herein, we rationally synthesized a cost-effective Co 3 S 4 @MoS 2 hetero-structured catalyst that has proven to be a highly active and stable bifunctional catalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an alkaline environment. The heterostructure was obtained via a first hydrothermal approach to obtain hollow Co 3 S 4 nanoboxes based on the ionic exchange reaction between Fe(CN) 6 3− of Co-Fe Prussian blue analogue (PBA) and S 2− at 120 °C, and the subsequent in situ growth of MoS 2 nanosheets on the surface of Co 3 S 4 nanoboxes at an elevated temperature of 200 °C. The synergistic effects between the active and stable HER catalyst of MoS 2 and the efficient OER catalyst of Co 3 S 4 , as well as the morphological …

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 characteristics and the electrochemical properties of SnO 2 nanomaterials is discussed. The interesting electrochemical results obtained here on SnO 2 nanomaterials indicate the possibility of designing and fabricating attractive nanostructured materials for lithium‐ion batteries.

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 dendrite and improve cycling performance are summarized. It has been shown that current density, solid‐electrolyte interphase (SEI) film, Li + transference number, and shear modulus have significant impact on the growth behavior and the Coulombic efficiency. Various methods have been introduced to increase the surface area of the Li anode, enhance Li + conductivity, form stable SEI film, and improve mechanical strength of …

Developing highly efficient and stable platinum (Pt)-based electrocatalysts for oxygen reduction reaction (ORR) is the most essential step toward the commercialization of fuel cells. Highly accessible reactive surfaces play a key role in boosting ORR for superior fuel cell performance due to the adequate exposure of the active surfaces and the feasible mass transport. Herein, we begin with a brief introduction to the design principles for an effective ORR electrocatalyst, which could plausibly possess high activity and durability at the same time. Corresponding with the requirements, the recent progress of rational design based on nanoarchitecture, synthesis, and electrochemical performances of Pt-based electrocatalysts with open construction is reviewed and explained accordingly.

Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high‐performance CAs on a large scale in a simple and sustainable manner. We report an eco‐friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework‐8 (ZIF‐8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF‐8/AG‐derived nitrogen‐doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm −3 , a high specific surface area of 516 m 2 g −1 , and a large pore volume of 0.58 cm −3 g −1 . The resulting CAs …

Manganese based layered oxides have received increasing attention as cathode materials for sodium ion batteries due to their high theoretical capacities and good sodium ion conductivities. However, the Jahn–Teller distortion arising from the manganese (III) centers destabilizes the host structure and deteriorates the cycling life. Herein, we report that zinc-doped Na 0.833 [Li 0.25 Mn 0.75 ]O 2 can not only suppress the Jahn–Teller effect but also reduce the inherent phase separations. The reduction of manganese (III) amount in the zinc-doped sample, as predicted by first-principles calculations, has been confirmed by its high binding energies and the reduced octahedral structural variations. In the viewpoint of thermodynamics, the zinc-doped sample has lower formation energy, more stable ground states, and fewer spinodal decomposition regions than those of the undoped sample, all of which make it charge or …

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 nanosheets by filtration, followed by a thermal reduction. The anodic properties of this composite demonstrate the potency of the novel hybrid design based on two dimensional materials for extremely reversible energy conversion and storage. A high capacity and an extremely stable cycle life are simultaneously realized with carbon‐coated Si/rGO composite, which has a sandwich structure. The unprecedented …

Co 3 O 4 has shown acceptable electrochemical properties as the anode material of Li secondary batteries. In detail, its capacity reached about 700mAh/g, twice as high as graphite, and 93.4% of initial capacity was retained after 100 cycles. EIS (electrochemical impedance spectroscopy) analyses revealed that after the 1st cycle, the insertion or extraction of Li ions in Co 3 O 4 can occur homogeneously and reversibly (randless-like behavior, homogeneous mixture: Co+Li 2 O (in the state of Li insertion), Co 3 O 4 (in the state of Li extraction)). In fact, the coulombic efficiency of Co 3 O 4 was almost 100% except for the 1st cycle. According to P. Poizot's research on several kinds of transition metal oxides, such as Co 3 O 4 , CoO, NiO, etc., a small Li 2 O particle size and catalytic activity of the transition metal are expected to decrease the binding energy of Li 2 O tremendously. As a result, Li 2 O should be easy to decompose, and …

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 the various layered oxide cathodes, those with a spinel-like structure could play an important role in boosting electron transport because of their excellent intrinsic conductivity, including by coordinating with Na + insertion/extraction. Moreover, thanks to the inherent high stability of the spinel-like phase, it could function as a stabilizer for host cathode structures. This review summarizes recent advances in spinel engineering on …

In order to prevent polysulfide dissolution into liquid electrolytes and to promote the Li/S redox reaction nanosized which has the catalytic effect of chemical bond dissociating and is expected to have an adsorbing effect due to the effect of retaining liquid electrolyte of MgO in a Li/iron sulfide secondary battery, 16 was prepared by the sol-gel method as an electrochemically inactive additive for an elemental sulfur cathode for Li/S rechargeable batteries. The Li/S battery using an elemental sulfur cathode with a nanosized added showed the improvement of not only the discharge capacity but also cycle durability (maximum discharge capacity: 1185 mAh/g sulfur, The rate capability of the sulfur cathode was also increased with the addition of the nanosized From the results, it is confirmed that the nanosized had the polysulfide adsorbing …

Considering inherent large structural deterioration of conversion-type anode materials during repeated sodiation/desodiation process, the ingenious integration of both nanostructure engineering and chemical hybridization is highly desirable and challenging. Here, ultrafine CoS nanoparticles embedded in porous carbon nanorods (denoted as 7-CoS/C) were facilely fabricated via simultaneous in-situ carbonization and sulfidation of Co-metal organic frameworks (Co-MOF) and have been applied as anode materials for sodium-ion batteries (SIBs). Benefiting from the advantageous embedding architecture between the nanoparticles and porous nanorods, the 7-CoS/C delivers long-term cycling stability (542 mAh g −1 after 2000 cycles with a capacity retention of 91.4% at 1 A g −1 ) and excellent rate performance (discharge capacities of 510 mAh g −1 at 5 A g −1 and 356 mAh g −1 even at 40 A g −1 ), which is proved to …

Different Na-enriched Na 1+ x FeFe(CN) 6 samples can be synthesized by a facile one-step method, utilizing Na 4 Fe(CN) 6 as the precursor in a different concentration of NaCl solution. As-prepared samples were characterized by a combination of synchrotron X-ray powder diffraction (S-XRD), Mössbauer spectroscopy, Raman spectroscopy, magnetic measurements, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma analysis. The electrochemical results show that the Na 1.56 Fe[Fe(CN) 6 ]·3.1H 2 O (PB-5) sample shows a high specific capacity of more than 100 mAh g –1 and excellent capacity retention of 97% over 400 cycles. The details structural evolution during Na-ion insertion/extraction processes were also investigated via in situ synchrotron XRD. Phase transition can be observed during the initial charge and discharge process. The simple synthesis method, superior …

Owing to the low‐cost, safety, dendrite‐free formation, and two‐electron redox properties of magnesium (Mg), rechargeable Mg batteries are considered as promising next‐generation secondary batteries with high specific capacity and energy density. However, the clumsy Mg 2+ with high polarity inclines to sluggish Mg insertion/deinsertion, leading to inadequate reversible capacity and rate performance. Herein, 2D VOPO 4 nanosheets with expanded interlayer spacing (1.42 nm) are prepared and applied in rechargeable magnesium batteries for the first time. The interlayer expansion provides enough diffusion space for fast kinetics of MgCl + ion flux with low polarization. Benefiting from the structural configuration, the Mg battery exhibits a remarkable reversible capacity of 310 mAh g −1 at 50 mA g −1 , excellent rate capability, and good cycling stability (192 mAh g −1 at 100 mA g −1 even after 500 cycles). In addition …

Senior Researcher, Corporate R&D Center, Samsung SDI co. Ltd

Assistant Professor, Div. of advanced Materials Eng

Associate Professor, Department of Chemistry

Associate Professor, Department of Energy & Materials Engineering

Professor, Department of Energy & Materials Engineering

Professor, Department of Materials Science and Engineering

Director, Brain Korea Center for Smart Materials and Devices

Professor, KU-KIST Graduate School of Converging Science and Technology, Korea University

ESCML

교수님 소개

강용묵

연구실 소개

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

Engineering Electronic Radial Effects for Fast Li⁺ Transport in Solid-State Electrolytes

Reoriented Interracial Water Structure around Pd Enhances Oxygen Reduction Kinetics in Zn-Methanol-Air Batteries

Bridging Anode and Cathode Interfaces: Integrated Interfacial Strategies for Aqueous Metal-Air Batteries

연구실 보유 특허

대학별 입시끈

우리 연구실 모집

교수님 소개

강용묵

연구실 키워드

알럼나이가 간 회사

연구실 지원 방법

대우 조건

연도별 논문 인용수

저널 & 학회 논문 출판 수

연구실 논문 목록

Engineering Electronic Radial Effects for Fast Li⁺ Transport in Solid-State Electrolytes

Reoriented Interracial Water Structure around Pd Enhances Oxygen Reduction Kinetics in Zn-Methanol-Air Batteries

Bridging Anode and Cathode Interfaces: Integrated Interfacial Strategies for Aqueous Metal-Air Batteries

연구실 보유 특허

최근 3년간 연구실적 높은 연구실

대학별 입시끈

우리 연구실 모집