Hee Tak Kim

The increasing demands for emerging high-energy-density applications, such as electric vehicles, have prompted considerable efforts to design a new type of innovative, sustainable battery. Li–O 2 batteries can deliver much higher energy densities than current Li-ion batteries and have thus attracted much attention; however, their poor cyclic stability remains a major obstacle to their use in high-energy-density applications. The carbon-based cathode materials (CCMs) used for Li–O 2 batteries are

Li metal is considered as one of optimal candidates for high-energy anode material because it has the highest theoretical specific capacity (3,860 mAh g -1 ) and the lowest redox potential (−3.04 V vs. standard hydrogen electrode). However, safety concerns and low coulombic efficiency issues, which are caused by the inhomogeneous Li deposition/dissolution and continuous corrosion by electrolytes during battery cycling, have prohibited the use of metallic Li as anode in practical Li metal batteri

Anion exchange membrane fuel cell (AEMFC) is attractive energy conversion device that is an alternative to proton exchange membrane fuel cell (PEMFC) which required expensive materials, including platinum-based catalysts and perfluorosulfonic acid (PFSA) ionomers. Operating under the alkaline environment, enables the use of various types of low cost platinum-free-catalysts and the inexpensive metal stack hardware, allowing the system to be configured at a much lower cost. Over the past several y

In pursuing cost-effective green hydrogen production via proton exchange membrane water electrolysis (PEMWE), the high expense of the iridium (Ir)-based oxygen evolution reaction (OER) catalysts poses a significant challenge. To overcome this issue, researchers have focused on developing active OER catalysts and catalyst layers (CLs) with minimum uses of Ir. However, they frequently encountered performance problems at the single-cell level that originate not only from the kinetic polarization bu

Green hydrogen production through renewable energy-based water electrolysis is the most efficient technology for decarbonization, and demand has recently been rapidly increasing. Addressing this surge in demand requires the rapid development of reliable large-scale manufacturing methods for PEMWE membrane-electrode assemblies (MEAs). For reliable large-scale manufacturing, it is necessary to optimize electrode components, including catalysts, binders, solvents, and additives, as well as their di

Today’s lithium ion batteries, which have more than twice energy of those first released 25 years ago, power most of mobile electronic devices. However, their energy density is not high enough to provide electric vehicles and drones with mobility freedom. To make electric vehicles and drones more affordable, one needs batteries that can offer a longer cruise range with a lower cost. In this regard, lithium–sulfur (Li–S) battery is now considered a promising candidate to succeed lithium-ion batte

With the recent development of highly alkaline stable anion exchange membranes (AEMs) and ionomers (AEIs), anion exchange membrane water electrolyzer (AEMWE) has garnered attention due to its ability to achieve high hydrogen production rate at a low cost. The performance of AEMWE is determined by the anode catalyst layer, which can be made up of either a mixture of metal nanoparticles and polymer binders or a single metal. Although the integral metal has high mechanical properties, its performan

Because of the growing needs for secondary batteries with greater energy density in various applications including electric vehicle, rechargeable non-aqueous lithium–oxygen (Li-O 2 ) battery is receiving a great attention owing to its high theoretical energy density of 3505 Wh kg -1 which far exceeds that of conventional lithium ion battery (LIB) [1, 2]. However, due to the insulating nature of main discharge product, lithium peroxide (Li 2 O 2 ) the oxygen-evolving reaction (OER) during charge

Polymer electrolyte fuel cells (PEMFCs) have been spotlighted as one of the promising eco-friendly energy technologies for stationary and automotive applications owing to zero CO 2 emission, high energy density and moderate operation conditions. In this technology sector, polymer electrolyte membrane, one of the key components of PEMFC, has been intensely studied for several decades. Conventionally,perfluorinated sulfonic acid (PFSA) membranes like Nafion are used due to their high proton conduc

Interface between catalyst and ionomer in the catalyst layer of polymer electrolyte membrane fuel cells (PEMFCs) has been a subject of keen interest, but its effect to the durability has not been fully understood due to the complexity of catalyst layer structure. Herein, we suggest Pt nanoparticle (NP) array electrode fabricated using block copolymers as a platform for a focused investigation of Nafion/Pt interface. The interfacial evolution between Pt NP and Nafion thin layer during holding wit