New & Reneable Energy from Electrochemical Conversion
Each kind of new and renewable energy (NRE) has its own mechanism in production, but our lab has a great interest in NRE production via electrochemical conversion. The system covers the conversion of fuel or energy by electrochemical method, and is represented by fuel cell, secondary battery, and various forms of electrolytic cells. By doing so, an integrated production and utilization of NRE shall be accomplished.
The research extends from (1) the synthesis of electrocatalysts, (2) and their electrochemical and physico-chemical characterization, (3) the fabrication of electrode to (4) the measurement of energy generated from the devices or performance optimization.
Fuel cells have received a great attention due to its potential as a power source of various applications, such as portable electronics, a transportation, and a distributed power generation. In this sense, current research on fuel cell covers various fields which extends from the highly-advanced materials to the new concepts of fabrication, aiming for the further enhancement of present performance to cutting-edge level.
Electrocatalyst for Fuel Cells
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Oxygen Reduction Reaction (ORR) &
Hydrogen Oxidation Reaction (HOR) for
Polymer Electrolyte Membrane Fuel Cells (PEMFCs)
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Methanol Oxidation Reaction for
Direct Methanol Fuel Cells (DMFC)
Micro Fuel Cell Processor
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Micro-reformer
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Micro-reactor for preferential oxidation
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Micro-fuel cell
Selected Paper: I. Choi et al., Appl. Catal. B:Environ. 102, 608-613 (2011)
I. Choi et al., Appl. Catal. B:Environ. 168-169, 220-227 (2015)
I. Choi, Y-H. Cho, Y-E. Sung et al., Appl. Catal. B:Environ. 268, #118450 (2020)
H2 production via water electrolysis is the most promising way to realize H2-economy in the future. Unlike carbon-based H2 production, water splitting is inherently environment-friendly, and enables zero-carbon emission when associated with renewable energy sources, such as solar, wind, ocean energy. Despite of the effort, it still has large barriers to overcome; i.e. low energy efficiency, high production cost.
Electrocatalyst for PEM/AEM Water Electrolyzer
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Oxygen Evolution Reaction (OER) &
Hydrogen Evolution Reaction (HER)
Electrocatalyst for CO2 Electrolyzer
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CO2 onversion to CO, HCOOH, CH4
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Syngas (CO/H2) production
MEA-based Electrolyzer
Selected Paper: S. Ahn, I. Choi et al., Chem. Commun. 49, 9323-9325 (2013)
S. Ahn, I. Choi et al., Appl. Catal. B-environ. 154-155, 197-205 (2014)
I. Choi, S-K. Kim et al., ACS Sustain. Chem. & Eng. 7(9), 8265-8273 (2019)
LiBs have been considered as efficient energy storage devices, and they have a wide range of applications in portable electronics, electric vehicles, and so forth. In accordance with the world's future energy outlook, the effort to explore the electrode materials with high energy- and power density having been made. The research scope for positive electrode lies on developing modest transition metal oxide with high operating voltage and high reversible capacity. Meanwhile, non-graphite negative materials with distinguished cycleability is being searched.
Negative Electrodes for LiBs
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Si-based negative material
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Metal oxide negative materials
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Analyais on SEI &Failure mechanism of electrode
Positive Electrodes for LiBs
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Li-metal oxide positive electrode
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Thermal-resistant additive for high voltage LiBs
Selected Paper: I. Choi et al., Electrochim Acta 85, 369-376 (2012)
S. Kim, I. Choi et al., J. Power Source, 336, 316-324 (2016)
M. Kim, I. Choi et al., Appl. Surf. Sci. 479, 225-233 (2019)
The energy can be drawn from the change in Gibbs free energy when the solutions with different salinity, such as river and sea water, are mixed. This energy, called salinity gradient power (SGP), is completely renewable, eco-friendly, and more importantly sustainable. RED (reverse electro-dialysis) is one of the SGP techniques and is realized by placing ion-selective membrane. Due to its simple syste, RED is expected to be more promising and commercially available amongst SGP. The researchers have mainly focused on developing or modifying RED components, such as membrane, spacer, flow channel, and electrode configuration to enhance RED performance. Besides, the effect of engineering parameter on RED performance is being investigated by simulation.
Electrodes for Efficient RED System
Optimization & Power Enhancement
Selected Paper: I. Choi et al., Bull. Kor. Chem. Soc. 37, 1010-1019 (2016)
Selected Paper: J. Jeong, H. Song, I. Choi, Korean J. Chem. Eng. 38(1), 170-178 (2021)