POSITION PAPER ON HYDROGEN ECONOMY
Meanwhile, the current LaMnO3-based cathode materials can interact with the Cr-based interconnect materials through the Cr diffusion into the cathode. This behaviour lowered the electrochemical performance of the cathode for oxygen reduction at high temperatures. Our research group has focused on reducing the operating temperature of SOFCs (< 800 °C) with the development of new and improved electrodes (Ni-Cu, Ni-Fe and Ni-Co based anodes, Co and Cr free cathodes), electrolyte (carbonated samarium doped ceria, SDCC, multi-doped ceria electrolyte) and interconnect pr26000 coating ((Cu,Mn,Co)3O4 spinel) materials. However, further investigation is necessary to ensure these materials have long term reliability and compatibility at a reduced temperature in both oxidizing (fuel) and reducing (oxidant) environments. Also, the development of new materials, improvement in the materials properties and fabrication conditions are critical to realising the operation of SOFCs at a reduced temperature with minimal cost.
3.3.2
Direct Liquid Fuel Cell (DLFC)
Direct liquid fuel cells (DLFCs) are among the most promising types of fuel cells due to their high energy density, simple structure, small fuel cartridge, instant recharging, and ease of storage and transport. Alcohols such as methanol and ethanol were the most common types of fuel used, although glycols and acids are also used. The main problem that arose in DLFCs was the high cost of the catalyst and the high catalyst loading. Other issues, such as fuel crossover, cathode flooding, the generation of various side products, fuel safety and unproven long-term durability, must also be solved to improve the performance of DLFCs. More research studies are required to increase its performance and foster its commercialisation. Currently, there are some commercial products using direct methanol fuel cells (DMFCs) and direct ethanol fuel cells (DEFCs). Non-alcohol fuels, such as formic acid, dimethyl ether, hydrazine, ammoniaborane and sodium borohydride, also can be used in DLFCs. Although DLFCs have advantages over rechargeable batteries, the current power supply systems in portable electrical devices are still mainly dominated by rechargeable lithium and nickel-based batteries. The commercialisation of DLFC, especially DMFC, has been continuously postponed since the early 2000s due to their high cost, low lifetime, and technical barriers. Thus, our research group focuses on the development of high performance DLFC including DLFC system, the material of catalyst, membrane and electrode, storage system as well as DLFC application in education, portable power supply and medical purposes.
Figure 45: Schematics of a Direct Methanol
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