Environmental issues such as global warming due to fossil fuel use are now major worldwide concerns, and interest in renewable and clean energy is growing. Of the various types of renewable energy, green hydrogen energy has recently attracted attention because of its eco-friendly and high-energy density. Electrochemical water splitting is considered a pollution-free means of producing clean hydrogen and oxygen and in large quantities. The development of non-noble electrocatalysts with low cost and high performance in water splitting has also attracted considerable attention. In this study, we successfully synthesized a NiCo2O4/NF electrode for an oxygen evolution reaction in alkaline water splitting using a hydrothermal method, which was followed by post-heat treatment. The effects of heat treatment on the electrochemical performance of the electrodes were evaluated under different heat-treatment conditions. The optimized NCO/NF-300 electrode showed an overpotential of 416 mV at a high current density of 50 mA/cm2 and a low Tafel slope (49.06 mV dec-1). It also showed excellent stability (due to the large surface area) and the lowest charge transfer resistance (12.59 Ω). The results suggested that our noble-metal free electrodes have great potential for use in developing alkaline electrolysis systems.

Anion exchange membrane (AEM) with fixed charged cationic groups can selectively transport anionic molecules such as hydroxide anions. The AEM materials have been widely used in the wide range of applications such as polymer electrolyte fuel cells, water electrolysis, and reverse electrodialysis and electrodialysis. Commercially available AEM materials show high electrochemical resistance owing to their chemical architectural features leading to less separated hydrocarbon morphologies. Very low solubility to casting solvents and weak chemical durability to alkaline atmosphere of the AEM materials also makes it difficult to make thin and tough AEM membranes. In this study, AEM materials composed of perfluorinated architectures with improved chemical durability and intrinsically well separated morphologies were developed and evaluated.

알칼라인 수전해 공정에 사용되는 복합 분리막은 고분자와 나노 세라믹 입자로 구성되며 기계적 안정성과 높은 이온 전도성을 가지는 것이 필수적이다. 나노 세라믹 입자는 알칼라인 용액 내 수산화이온(OH-)의 전도성을 높인다고 보고되어 왔으나 세라믹 입자의 비율에 따른 OH-의 관계와 효과의 이해가 미흡한 실정이다. 본 연구에서는 여러 물성 측정(버블포인트, 이온 저항 등)을 통하여 분리막 성능에 입자의 비율이 미치는 영향과 원인을 연구하였다. 입자의 비율이 증가하면 이온 저항은 감소하며, 높은 버블포인트를 유지한다. 이는 분리막 내의 OH-증가로 이온 저항이 낮아지며, 입자의 밀집한 배열이 버블포인트를 유지하는 것으로 판단된다. 따라서 비율의 증가에 따라 OH-상호 작용으로 높은 전도성과 안정성을 가져온다.

Alkaline direct liquid fuel cells (ADLFCs) employing anion-exchange membranes as a fuel barrier have attracted significant attention as promising alternative energy sources. ADLFCs are allowed to use more abundant anode catalysts which are cheaper than the catalyst used in that using hydrogen fuel. In this work, novel pore-filled anion-exchange membranes (PFAEMs) were successfully fabricated by combining a highly porous poly(tetrafluoroethylene) film and cationic polyelectrolytes with structurally stable anion-exchange sites. The results of the membrane characterizations revealed that the optimization in the crosslinking degree and hydrophilicity of membranes should be considered for the successful application of the PFAEMs to ADLFCs. (KETEP)(20153030031720) and (MOTIE) (No. 10047796).