Battery Storage Material

Nanostructured Energy Storage Materials

재생가능한 에너지원 (태양광, 풍력, 바이오매스 등)으로부터 전기에너지를 얻는 것은 온실가스 감축을 위해 매우 중요한 기술 중 하나입니다. 대부분의 재생가능한 에너지원은 하루 24간 1년 365일 지속적으로 전기에너지를 발생시킬 수 없기 때문에 발생이 많을 때 에너지를 저장하고, 발생이 적을 때 에너지를 사용하여 지속적인 에너지 공급을 해 줄 수 있는 대용량 에너지저장시스템 개발이 매우 중요합니다. 또한 향후 그 수요가 대폭적으로 증가할 플러그인 하이브리드 자동차 및 전기자동차에 사용될 수 있는 경제적이고 안정적이며 용량이 큰 전극소재 개발이 매우 중요합니다. 현재 소형 전자기기에 사용되고 있는 리튬 코발트 산화물 및 흑연은 낮은 용량 및 낮은 고율특성으로 대용량 전력저장용 에너지저장장치 사용에 한계가 있습니다. GEMP@SKKU에서는 대용량 전력저장분야에 사용하기 적합한 다양한 구조 및 물질의 리튬 및 나트륨 이차전지 전극소재를 연구하고 있습니다.

Current issues on global warming and crude oil depletion, mainly caused by fossil fuel-based transportations, have led to urgent need to develop a new electrode material in lithium ion batteries (LIBs) for large-scale applications including plug-in hybrid electric vehicles (PHEVs), electric vehicles (EVs) and energy storage systems (ESS). Lithium cobalt oxide and graphite, which are commercially used as active materials for portable electronic devices, often fail to meet the demand of the large-scale applications due to their low theoretical capacity and poor high-rate performance. GEMP @ SKKU develops novel nanostructured energy storage materials for next-generation battery applications.

Selected publications

1. Continuous hydrothermal synthesis of HT-LiCoO2 in supercritical water, Journal of Supercritical Fluids, 2009, 50, 25
2. Small capacity decay of lithium iron phosphate (LiFePO4) synthesized continuously in supercritical water: Comparison with solid-state method, Journal of Supercritical Fluids, 2011, 55, 1027-1037
3. Facile Synthesis of Nanosized Li4Ti5O12 in Supercritical Water, Electrochemistry Communications, 2011, 13, 650-653
4. Continuous Supercritical Hydrothermal Synthesis: Lithium Secondary Ion Battery Applications, Research on Chemical Intermediates, 2011, 37, 429-440
5. Carbon coating on lithium iron phosphate (LiFePO4): Comparison between continuous supercritical hydrothermal method and solid-state method, Chemical Engineering Journal, 2012, 198-199, 318-326
6. Synthesis of Li4Ti5O12 in Supercritical Water for Li-Ion Batteries: Reaction Mechanism and High-Rate Performance, Electrochimica Acta, 2012, 78, 623-632
7. Superior High Rate Performance of Core–shell Li4Ti5O12/Carbon Nanocomposite Synthesized by a Supercritical Alcohol Approach, RSC Advances, 2012, 2, 10805-10808
8. Continuous synthesis of lithium iron phosphate (LiFePO4) nanoparticles in supercritical water: Effect of mixing tee, Journal of Supercritical Fluids, 2013, 73, 70-79
9. Facile synthesis of hierarchical mesoporous Li4Ti5O12 microspheres in supercritical methanol, Journal of Power Sources, 2013, 244, 164-169
10. Continuous synthesis of lithium iron phosphate nanoparticles in supercritical water: Effect of process parameters, Chemical Engineering Journal, 2013, 229, 313-323
11. Template-free synthesis of hierarchical porous anatase TiO2 microspheres with carbon coating and their electrochemical properties, Chemical Engineering Journal, 2014, 241, 216-227
12. A facile supercritical alcohol route for synthesizing carbon coated hierarchically mesoporous Li4Ti5O12 microspheres, Journal of Physical Chemistry C, 2014, 118, 183-193
13. Toward uniform and ultrathin carbon layer coating on lithium iron phosphate using liquid carbon dioxide for enhanced electrochemical performance, Journal of Power Sources, 2014, 262, 219-223
14. Synthesis of hydrous ruthenium oxide nanoparticles in sub- and supercritical water and their capacitive properties, Chemical Engineering Communications, 2014, 201, 1259-1269
15. Continuous Synthesis of Li4Ti5O12 Nanoparticles in Supercritical Fluids and Their Electrochemical Performance for Anode in Li-Ion Batteries, Chemical Engineering Journal, 2014, 258, 357-366
16. Continuous synthesis of hierarchical porous ZnO microspheres in supercritical methanol and their enhanced electrochemical performance in lithium ion batteries, Chemical Engineering Journal, 2015, 266, 179-188
17. Synthesis of Li4Ti5O12 /Carbon Nanocomposite in Supercritical Methanol for Anode in Li-Ion Batteries: Effect of Surface Modifiers, Journal of Supercritical Fluids, 2015, 101, 72-80
18. One-pot route to synthesize SnO2-Reduced graphene oxide composites and their enhanced electrochemical performance as anodes in lithium-ion batteries, Journal of Power Sources, 2015, 293, 1024-1031
19. One-pot route for uniform anchoring of TiO2 nanoparticles on reduced graphene oxides and their anode performance for lithium-ion batteries, Journal of Supercritical Fluids, 2017, 125, 66-78
20. Uniform One-Pot Anchoring of Fe3O4 to Defective Reduced Graphene Oxide for Enhanced Lithium Storage, Chemical Engineering Journal, 2017, 317, 890-900
21. Conformal carbon layer coating on well-dispersed Si nanoparticles on graphene oxide and the enhanced electrochemical performance” Journal of Industrial and Engineering Chemistry, 2017, 52, 260-269
22. One-pot Synthesis of Molybdenum Disulfide–Reduced Graphene Oxide (MoS2-RGO) Composites and Their High Electrochemical Performance as an Anode in Lithium Ion Batteries” Journal of Supercritical Fluids, 2017, 127, 81-89
23. New Liquid Carbon Dioxide Based Strategy for High Energy/Power Density LiFePO4, Nano Energy, 2017, 36, 398-410
24. Carbon with expanded and well-developed graphene planes derived directly from condensed lignin as a high-performance anode for sodium-ion batteries, ACS Applied Materials & Interfaces, 2018, 10, 569−581
25. Silicon oxycarbide produced from silicone oil for high-performance anode material in sodium ion batteries, Chemical Engineering Journal, 2018, 338,126-136
26. Synthesis of MoO2/Mo2C/RGO Composite in Supercritical Fluid and its Enhanced Cycling Stability in Li-Ion Batteries, Chemical Engineering Journal, 2018, 345, 1-12
27. Enhanced Lithium Storage Capacity of A Tetralithium 1,2,4,5-Benzenetetracarboxylate (Li4C10H2O8) Salt through Crystal Structure Transformation, ACS Applied Materials & Interfaces, 2018, 10, 17183–17194

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Graphene for energy storage applications

Graphene has received tremendous interest in recent years, owing to its remarkable chemical, mechanical, and electronic properties, and its great potential in applications, including integrated circuits, active materials in lithium secondary batteries, transparent conductive electrodes for solar cells, biological and chemical sensors, and polymer composites. GEMP @ SKKU develops various methods to control graphene properties for various applications including ultra-high lithium or sodium storage electrodes and efficient energy conversion applications.

Nanomaterial Synthesis in Supercritical Fluids

Nanomaterial synthesis in supercritical water (supercritical hydrothermal synthesis) or in supercritical alcohols (supercritical solvothermal synthesis) is a very promising alternative to the conventional techniques for producing nanostructured materials. The unique physical properties of supercritical water and supercritical alcohol, including extremely low viscosity, high reactant diffusivity, zero surface tension, high reactivity, and high supersaturation ratio of reaction intermediates, make them promising media for the production of highly crystalline and nanosized particles. In addition, the supercritical route is environmentally friendly, fast, simple, and readily scalable by the employment of continuous operation. Various types of metal oxide nanoparticles have been produced by SHS, including CeO2, CuO, TiO2, Fe2O3, NiO, ZrO2, and ZnO; the morphology and size distribution of fine particles can be controlled by adjusting pH, metal salt concentration, temperature, and pressure. GEMP @ SKKU heavily focused on developing new types of metal nanoparticles, metal oxide nanoparticles and surface-modified nanoparticles for applications such as electronics, catalysis, and nanocomposites.