Tubular Solid Oxide Fuel Cells

燃料电池是无声的，模块化的，是一种有效的电力来源（50 - 60%）。它们可用于远程供电、家庭供暖、发电厂以及医院和制造厂的备用电源。当可逆使用时，它们可以为可再生能源提供负载均衡。当多余的电力可用时，它们可以在电解模式下使用，以通过燃料提供能量存储。将甲烷干重整与燃料电池相结合，可以消除二氧化碳，同时产生电力和一氧化碳，一氧化碳是一种有价值的工业原料。 高温固体氧化物燃料电池（SOFC）与低温燃料电池相比有两个主要优点：可以避免使用昂贵的催化剂，并且可以容纳各种燃料。与平面结构相比，管状结构具有一些显著的优点，包括低温密封、上级机械性能、快速启动和如果使用小直径管则具有更高的体积功率密度。主要缺点是较低的功率输出，主要是由于内电极的长电流路径，以及对于平面设计，氧化还原循环（当空气进入阳极室时发生）导致结构损坏。 为了克服这些缺点，通过使用煅烧粉末、成孔剂和粉浆浇铸的组合，我们已经制造了具有优异的氧化还原循环抗性的坚固的管状燃料电池。它已经渗透到纳米结构的电极中，从而大大提高了功率输出。 阳极微观结构的性质（相分布、孔隙率、孔径分布）将与电池性能相关，正如我们最近对阴极所做的那样。这样的研究可能有助于理解可逆电池（在燃料电池和电解模式之间交替）中发生的微观结构变化。然后可以确定最佳的微观结构。 限制商业化的主要问题是电极渗透效率低，电流收集和退化（随着时间的推移逐渐失去动力）不可接受。每一个都将被研究。溶液成分、浆料和快速加热可以导致更好和更快的渗透。将对集电器的导电性、机械性能、形式（溶液、糊剂、金属丝、网状物等）进行评估。与稳定降解的主要原因是纳米结构的粗化、集流体的分层和扩散，这将与操作温度、电流密度和气体流速（燃料利用率）相关。 将同时考虑包括作为燃料的能量存储和二氧化碳消除在内的应用。在我们最近成功克服氧化还原循环和提高功率输出的基础上，这项研究应该提高对SOFC行为的理解，并使管状电池更接近商业化。无论是传统的发电还是独特的用途，加拿大都将作为化石燃料的主要供应国和二氧化碳的主要排放国而受益。

Fuel cells are silent, modular and an efficient source of electricity (50-60%). They could be used for remote power, home heating, power plants and backup power for hospitals and manufacturing plants. When used reversibly, they can provide load leveling for renewable energy. When excess power is available, they can be used in electrolysis mode to provide energy storage via fuel. Combining dry reforming of methane with a fuel cell can eliminate CO2 while producing both electricity and CO, a valuable industrial raw material. High temperature solid oxide fuel cells (SOFCs) offer two main advantages over the low temperature versions: expensive catalysts can be avoided and a variety of fuels can be accommodated. The tubular design has some significant advantages over the planar configuration including low temperature sealing, superior mechanical properties, rapid start-up and higher volumetric power density if small diameter tubes are used. The main drawbacks are lower power output mainly due to the long current path for the inner electrode and, as for the planar design, redox cycling (occurs when air enters the anode chamber) causes structural damage. In an effort to overcome these drawbacks, by using a combination of calcined powders, pore formers and slip casting, we have fabricated a robust tubular fuel cell with exceptional redox cycling resistance. It has infiltrated nanostructured electrodes which lead to greatly improved power output. The nature of anode microstructure (phase distribution, porosity, pore size distribution) will be related to cell performance as we have carried out recently for the cathode. Such a study might help understand the microstructural changes occurring in reversible cells (alternate between fuel cell and electrolysis modes). Optimum microstructures could then be identified. The main problems restricting commercialization are inefficient electrode infiltration, unacceptable current collection and degradation (gradual loss of power with time). Each will be studied. Solution composition, slurries and rapid heating could lead to better and faster infiltration. Current collectors will be evaluated as to conductivity, mechanical properties, form (solution, paste, wire, mesh, etc.) and stability. The main causes of degradation which are coarsening of nanostructures, delamination of current collectors and diffusion will be correlated with operating temperature, current density and gas flow rates (fuel utilization). Applications including energy storage as fuel and CO2 elimination will be concurrently considered. Building on our recent success overcoming redox cycling and improving power output, this research should improve understanding of SOFC behaviour and move tubular cells closer to commercialization. Whether for traditional power generation or unique uses, Canada will benefit as both a major supplier of fossil fuels and a large CO2 emitter.