Tubular Solid Oxide Fuel Cells

燃料电池是无声的、模块化的，是一种高效的电力来源(50%-60%)。它们可以用于远程供电、家庭供暖、发电厂以及医院和制造厂的备用电力。当可逆使用时，它们可以为可再生能源提供负载均衡。当有多余的电力可用时，它们可以在电解模式下使用，通过燃料提供能量存储。将甲烷干法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，这是一种宝贵的工业原材料。 与低温燃料电池相比，高温固体氧化物燃料电池(SOFC)具有两个主要优势：可以避免昂贵的催化剂，并且可以容纳各种燃料。与平面结构相比，管状结构具有密封温度低、机械性能好、启动速度快、体积功率密度高等显著优点。主要缺点是输出功率较低，这主要是由于内电极的电流路径较长，而对于平面设计，氧化还原循环(当空气进入阳极室时发生)会导致结构损坏。 为了克服这些缺点，通过使用焙烧粉末、造孔器和注浆浇注的组合，我们制造了一种具有出色的氧化还原循环抗力的坚固的管状燃料电池。它已经渗透到纳米结构的电极中，从而极大地提高了功率输出。 阳极微结构的性质(相分布、孔隙率、孔径分布)将与电池性能有关，就像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(燃料电池和电解模式之间的交替)中发生的微观结构变化。然后就可以确定最佳的微观结构。 制约商业化的主要问题是低效率的电极渗透、不可接受的电流收集和降解(随着时间的推移逐渐失去电力)。每一项都将被研究。溶液成分、浆料和快速加热可导致更好和更快的渗透。将评估集电体的导电性、机械性能、形状(溶液、浆料、金属丝、网状物等)。和稳定性。降解的主要原因是纳米结构的粗化、集电体的分层和扩散，这与工作温度、电流密度和气体流量(燃料利用率)有关。 将同时考虑能源储存作为燃料和消除二氧化碳的应用。在我们最近成功克服氧化还原循环和改善功率输出的基础上，这项研究应该会提高对SOFC行为的理解，并使管状细胞更接近商业化。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排放大国而受益。

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.