2023-08-14 ロスアラモス国立研究所(LANL)
◆同軸ナノワイヤーで構成されるこの革新的電極は、水素を使用して排出ゼロの電力を供給する燃料電池の中核部であり、従来の炭素ベースの触媒支持体の腐食問題を排除しつつ、高い性能を維持できるという。この耐久性向上により、25,000時間以上の寿命が求められる重いトラックなどでの使用が期待されている。
＜関連情報＞
- https://discover.lanl.gov/news/0814-fuel-cells/
- https://onlinelibrary.wiley.com/doi/10.1002/adma.202301264
同軸ナノワイヤー電極が燃料電池の優れた耐久性を実現 Coaxial Nanowire Electrodes Enable Exceptional Fuel Cell Durability
Gaoqiang Yang, Siddharth Komini Babu, Wipula P. R. Liyanage, Ulises Martinez, Dmitri Routkevitch, Rangachary Mukundan, Rodney L. Borup, David A. Cullen, Jacob S. Spendelow
Advanced Materials Published: 19 June 2023
DOI:https://doi.org/10.1002/adma.202301264
Abstract
Polymer-electrolyte-membrane fuel cells (PEMFCs) hold great promise for applications in clean energy conversion, but cost and durability continue to limit commercialization. This work presents a new class of catalyst/electrode architecture that does not rely on Pt particles or carbon supports, eliminating the primary degradation mechanisms in conventional electrodes, and thereby enabling transformative durability improvements. The coaxial nanowire electrode (CANE) architecture consists of an array of vertically aligned nanowires, each comprising an ionomer core encapsulated by a nanoscale Pt film. This unique design eliminates the triple-phase boundary and replaces it with two double-phase boundaries, increasing Pt utilization. It also eliminates the need for carbon support and ionomer binder, enabling improved durability and faster mass transport. Fuel cell membrane electrode assemblies based on CANEs demonstrate extraordinary durability in accelerated stress tests (ASTs), with only 2% and 5% loss in performance after 5000 support AST cycles and 30000 catalysts AST cycles, respectively. The high power density and extremely high durability provided by CANEs can enable a paradigm shift from random electrodes based on unstable platinum nanoparticles dispersed on carbon to ordered electrodes based on durable Pt nanofilms, facilitating rapid deployment of fuel cells in transportation and other clean energy applications.
