Paradigm-shifting catalyst layer design for high performance and low cost polymer electrolyte fuel cells

聚合物电解质燃料电池(PEFC)处于技术解决方案的前沿，旨在应对开发高效、具有成本竞争力的能源转换系统的全球挑战，同时又具有低环境足迹。PEFC在其“催化层”(CLS)中高效地将氢的化学能清洁地转化为电能，同时只产生纯净水和热能作为副产品。PEFC技术将占全球燃料电池市场的近25%，预计到2022年将超过400亿美元。我们的行业合作伙伴，位于伯纳比的Ballard Power Systems在PEFC技术方面排名全球第一，因此有望在未来获得巨大的经济效益。为了保持竞争力并增加市场份额，Ballard的PEFC系统必须降低成本并提高其性能。出现这些问题的部分原因是，目前的PEFC CLS是使用一种墨水制造的，在这种墨水中，支撑昂贵的铂(铂)纳米颗粒的碳粉颗粒随机与无序的聚合物粘结剂混合。这会导致干燥油墨或CL中的铂使用率较低(增加了成本)或毛孔不易接近(导致性能较差)。 我们将克服这些挑战，使用我们最近开发的有序、高度多孔(泡沫状)而又灵活的碳“脚手架”，结合沉积厚度可控的离聚体薄膜的能力，作为新一代CLS的基础，以取代目前不可靠的基于油墨的制造方法。这一潜在的变革性新技术将通过更高的铂催化剂利用率、通过有序的多孔结构提高性能以及由于灵活的薄膜状结构而易于电池组装来降低成本。这项研究将涉及10+名学生和PDF的培训，还将创建一个全新的关于PEFC中电子、质子、氧气和水传输的基础科学知识体系。PEFC技术的广泛采用将带来收入和新的就业机会，减少温室气体排放，并降低医疗成本，因为PEFC不会排放有害颗粒物或SOx/NOx物种。

Polymer electrolyte fuel cells (PEFCs) are at the forefront of technological solutions that are aimed at meeting the global challenge of developing highly efficient, cost competitive energy conversion systems that also have a low environmental footprint. PEFCs cleanly convert the chemical energy of hydrogen to electricity at high efficiency in their 'catalyst layers" (CLs), while generating only purewater and heat as by-products. PEFC technology will constitute nearly 25% of the global fuel cell market, projected to exceed $40B by 2022. Our industry partner, Ballard Power Systems in Burnaby, ranked #1 globally in PEFC technology, is thus poised to reap tremendous economic benefits in the future. To remain competitive and increase their market share, the cost of Ballard's PEFC system must be reduced and its performance enhanced. These issues arise partly because current PEFC CLs are made using an ink in which carbon powder particles that support expensive platinum (Pt) nanoparticles are mixed randomly with a disordered polymer binder. This results in poorly used Pt (adding to cost) or poorly accessible pores (resulting in poor performance) in the dried ink or CL. We will overcome these challenges by using our recently developed ordered, highly porous (foam-like), and yet flexible carbon 'scaffolding', combined with the ability to deposit ionomer films of controlled thickness, as the basis of a new generation of CLs to replace the current unreliable ink-based fabrication methods. This potentially transformative new technology will lead to reduced costs through higher Pt catalyst utilization, higher performance through its ordered porous structure, and ease of cell assembly owing to the flexible film-like architecture. This research, which will involve the training of 10+ students and PDFs, will also create a completely new body of fundamental scientific knowledge about electron, proton, oxygen, and water transport in PEFCs. The widespread adoption of PEFC technology will result in revenue generation and new job creation, reduce greenhouse gas emissions, and lower health care costs, as PEFCs do not emit harmful particulates or SOx/NOx species.