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

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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.