Molten carbonate fuel cells: a technological perspective and review

Molten carbonate fuel cells (MCFCs) are high-temperature fuel cells that operate with a variety of fuels with high efficiency that, in addition to power generation, can be used for capturing and concentrating CO₂. In the present review, the advances in the last 20 years of the key components of MCFCs are discussed: anode, cathode, support electrolytes, and electrolyte composition. The current state of the technology is such that it is routinely used for power generation in stationary power plant systems. The success of the technology is due to the high temperature of operation. The operating temperature is so high that it allows hydrocarbon fuel to be used without any external reforming system. MCFCs have several other important advantageous characteristics: can attain high-energy efficiencies, almost 60% in some cases, also when applied in a cogeneration context, and overall fuel efficiencies, accounting for electrical and thermal products, can exceed 80%. Despite significant progress in the past, some issues like component range of operating temperatures and power density needs to be overcome to meet the full expectations. Thus, a significant opportunity exists for new materials in this area. Some alternative materials and strategies to mitigate the issues are discussed.