Ahn. Lab at Yonsei Chemistry
Materials for Electrochemical Energy Conversion
02-2123-2634
Future Generation Energy Storage
Lithium-Air Battery
Lithium-ion batteries (LIBs) are widely used in applications such as mobile phones and electric vehicles due to their high energy density and robust cycling stability. However, they are nearing their theoretical capacity limits, restricting further advancements. In contrast, lithium-air batteries, which use air as the cathode, offer considerable potential owing to their high theoretical current density limit. Conventional lithium-air batteries typically generate Li2O2 as the discharge product, which hampers battery performance due to its low electrical and ionic conductivity.
In our study, we have addressed this limitation by promoting the formation of LiOH as the ultimate discharge product of lithium-air batteries through the reaction between Li2O2 and water vapor. This strategy effectively enhances the discharge voltage and boosts cycling stability. Moreover, utilizing scanning electrochemical microscopy (SECM), we aim to investigate and characterize the electrochemical activity at the triple-phase interface, where lithium ions, water vapor, and electrons converge on the electrode surface. This approach lays the groundwork for optimizing the performance of lithium-air batteries.
Solid-State Proton Battery
​Solid-state proton battery (SSPB) provides an advanced approach to complement the issues of conventional LIBs. Proton, as a charge carrier, can deliver the fastest charging rate due to its rapid diffusion and ensure stability in aqueous electrolyte. Using various proton-coupled organic redox molecules such as simple hydroquinone derivatives as active materials, this system strategically loads the materials over maximum solubility to generate high specific capacity. Moreover, the use of carbon nanotube (CNT) as electrode material enables effective electron transfer and the formation of elaborate adsorption structures between the active materials and the electrode material. Finally, in the future, this platform will be expanded to a lot of proton-coupled redox materials and be adopted in various portable devices that require immediate electric power source.