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KR-102965248-B1 - Preparation method of amphiphilic titanium porous transport layer and its use

KR102965248B1KR 102965248 B1KR102965248 B1KR 102965248B1KR-102965248-B1

Abstract

The present invention relates to a method for manufacturing an amphiphilic titanium porous transport layer and to the application thereof. More specifically, the invention relates to a method for manufacturing an amphiphilic titanium porous transport layer characterized by comprising the steps of: preparing a titanium porous transport layer; surface-treating the titanium porous transport layer with a fluorosilane; and forming a pattern on the titanium porous transport layer surface-treated with the fluorosilane. Separation of gas channels and water channels in a diffusion layer through an amphiphilic SP-F-Ti PTL manufactured according to the method of the present invention significantly improves performance in fuel cell mode while minimizing the decrease in performance in water electrolysis mode, and consequently, the efficiency of the URFC can be greatly improved.

Inventors

  • 김태호
  • 유덕만
  • 이성민
  • 장정규
  • 정환엽

Assignees

  • 한국화학연구원

Dates

Publication Date
20260513
Application Date
20230228

Claims (10)

  1. It includes an amphiphilic titanium porous transport layer, and A device capable of operating in fuel cell mode and water electrolysis mode is integrated into a single system, An integrated fuel cell characterized by a Round Trip Efficiency (RTE) of 45.6% to 33.5% defined by the following formula at 1 A cm⁻² to 2 A cm⁻² based on a low metal catalyst usage of 1.3 mg cm⁻² , In the above equation, V FC and V WE represent the cell voltages of the fuel cell mode and water electrolysis mode, respectively, at the corresponding current densities.
  2. In claim 1, The above amphiphilic titanium porous transport layer Titanium porous transport layer; A fluorosilane layer deposited on the above titanium porous transport layer; and An integrated fuel cell characterized by including a hydrophilic pattern formed in a portion of the fluorosilane layer using UV irradiation and oxygen radical gas.
  3. In claim 2, An integrated fuel cell characterized in that the above-mentioned fluorosilane is a linear perfluoroalkylsilane having 8 or more carbon atoms.
  4. In claim 2, An integrated fuel cell characterized in that the above hydrophilic pattern is one of a serpentine shape, a lattice structure, or a perforated plate shape.
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Description

Preparation method of amphiphilic titanium porous transport layer and its use The present invention relates to a method for manufacturing an amphiphilic titanium porous transport layer and to the use thereof. More specifically, the invention relates to a method for manufacturing an amphiphilic titanium porous transport layer characterized by comprising the steps of: preparing a titanium porous transport layer; surface-treating the titanium porous transport layer with a fluorosilane; and forming a pattern on the titanium porous transport layer surface-treated with the fluorosilane. Over the past few decades, as global energy demand and consumption have exploded due to population growth and industrialization, the use of fossil fuels has also risen sharply. The indiscriminate consumption of fossil fuels resulting from this process is causing serious environmental problems, such as global warming caused by greenhouse gases. While renewable energy sources such as solar, wind, geothermal, and tidal power are receiving attention to address global warming, it is virtually impossible to continuously supply energy by directly utilizing these sources due to their intermittent nature and inconsistent output. Consequently, research on energy storage devices to effectively utilize renewable energy sources is actively underway. Electrochemical energy storage systems, such as lithium-ion batteries and Unitized Regenerative Fuel Cells (URFCs), are one of the ideal approaches for storing energy from renewable sources and have the advantage of enabling the realization of zero-energy energy storage systems. While lithium-ion batteries are receiving the most attention as energy storage systems suitable for short-term energy storage, they have limitations that make them unsuitable for long-term energy storage, such as low durability during deep cycling and self-discharge over time. Furthermore, since the total amount of energy stored in lithium-ion batteries is proportional to the cell size, costs increase dramatically as energy capacity increases. In contrast, URFCs possess several advantages favorable for long-term energy storage systems based on their high theoretical energy density (3.7 kWh/kg). As a dual-function single cell capable of operating in both electrolysis mode (charging) and fuel cell mode (discharging), URFCs store energy as oxygen and hydrogen gases in separate gas tanks. This offers the advantage that the cell size does not increase proportionally with the energy storage capacity, making it possible to lower the expected cost of high-capacity energy storage devices. Additionally, URFCs have the advantage of enabling stable long-term energy storage without self-discharge because the energy storage and power generation sections are physically separated. The structure of such URFCs is basically similar to that of water electrolysis unit cells or fuel cell unit cells, except for the composition of the catalyst used. In terms of operation in water electrolysis and fuel cell modes, two types of electrode configurations are possible: 1) a constant gas configuration (CG) that supplies a constant gas to each electrode, and 2) a configuration that separates the oxidation electrode and the reduction electrode (CE). The CG configuration has the advantage of eliminating the risk of gas mixing because the lines between hydrogen and oxygen gases are separated; however, the oxygen evolution reaction (OER) occurs at a single electrode in water electrolysis mode, while the oxygen reduction reaction (ORR) occurs in fuel cell mode. However, since the commonly used Ir has low activity for the ORR reaction and Pt has low activity for OER, there is a problem that a large amount of catalyst must be used to obtain high efficiency of the URFC. In contrast, the CE configuration requires nitrogen purging to prevent mixing of hydrogen and oxygen when switching operating modes, but since the OER reaction and ORR reaction occur at different electrodes, it is possible to significantly reduce the amount of catalyst required for cell manufacturing, and the final power production cost is lower than that of the CG configuration. However, challenges remain to be overcome for URFCs to be widely utilized as energy storage systems. Unlike water electrolysis cells using hydrophilic titanium porous transport layers (Ti PTLs) and fuel cell cells using hydrophobic carbon gas diffusion layers (carbon GDLs), the diffusion layer of a URFC must be amphiphilic to transport both water and gas, and must be durable at high operating voltages of approximately 2 V. Consequently, Ti PTLs, commonly used in water electrolysis, are currently utilized; however, the surface of Ti PTLs easily forms a hydrophilic oxide layer, causing severe water flooding in fuel cell mode. On the other hand, hydrophobic carbon GDLs used in fuel cells cannot be used because they corrode easily at the operating voltages of water electrolysis. Therefore, the development of amphiphilic poro