Abstract
Solid oxide fuel cell (SOFC) is an electrochemical power source that meets the technical expectations for no or low emission and high energy efficiency in future hydrogen economy or renewable energy economy. The high fuel flexibility of SOFC permits the SOFC technology to establish and expand its market niche and to serve as a primary power generation technology in a long transition period. SOFC technology is expected to play an important role in this transition period in circumventing the problems of energy shortage and energy consumption related emissions when the capacity of the renewable energy production is still small. SOFC technology would play an essential role in facilitating the transition from current nonrenewable energy technologies to hydrogen energy technologies that harness unlimited renewable energy sources.
Current commercialization of miniaturized or micro-SOFC is targeted the markets for auxiliary power units (APU), uninterrupted power sources (UPS), and combined heat and power (CHP) for small-scale and mediumscale power generation. However, miniaturization of conventional large SOFC systems is facing significant technical barriers. One of them is the trend that enhancement of specific power or power density will result in a reduction of energy efficiency of the systems. For example, state-of-the-art SOFC systems that have comparable power density to that of IC engine based APUs and CHPs are as efficient as these IC engine based power sources. If this trend can’t be reversed, it would be difficult for the SOFC technology to maintain and expand its market niches, which is crucial for the development of the renewable energy technologies. This paper will review literature and identify the current technical limitations that hinder the advancement of the micro-SOFC technology and reflect recent developments that will lead to solutions. This review will include accounts on system, device, component, and material levels.