A5068576543- Fuel Cells and Related Materials
- Electrocatalysts for Energy Conversion
- Advancements in Solid Oxide Fuel Cells
- Conducting polymers and applications
- Advanced battery technologies research
- Advanced Battery Technologies Research
- Electric and Hybrid Vehicle Technologies
University of California, Irvine
2019-2023
Irvine University
2022-2023
Abstract For proton exchange membrane fuel cells to be cost‐competitive in light‐ and heavy‐duty vehicle applications, their Pt content the catalyst layers needs lowered. However, lowering results voltage losses due high local oxygen transport resistances at ionomer–Pt interface. It is therefore crucial use ionomers that have higher permeability than Nafion. In this work, novel (HOPIs) are presented, with up five times Nafion, synthesized by copolymerization of...
Optimizing electrode morphology with a more uniform ionomer distribution is key to reducing ohmic losses and increasing electrocatalyst utilization in polymer electrolyte fuel cells (PEFCs). Inherent conductivity, volume fraction tortuosity determine effective ionic conductivity. We use hydrogen pump (HP) method measure conductivity of pseudo catalyst layer (PCL) comprised Vulcan XC-72 carbon black 3M 825 EW (I/C) ratios 0.6, 1 1.4 relative humidity (RH) range 50 120%. These direct current...
A cathode catalyst layer containing optimally distributed ionomer is critical to reduce the platinum loading and increase its utilization in polymer electrolyte fuel cells. Here, electrochemical impedance spectroscopy (EIS) was used measure effective ionic conductivity of pseudo layers (PCLs) at a relative humidity (RH) range 50%–120%. These results are compared previous work using hydrogen pump (HP) method. EIS reported here higher than those from HP because set-up pathways must be...
A well-designed cathode catalyst layer with optimal ionomer distribution is critical to minimizing amount of Platinum (Pt) content in polymer electrolyte fuel cells (PEFCs). The impact Pt loading, and carbon support types on the catalyst/ionomer interface were also investigated at dry wet conditions. Higher loadings resulted higher double capacity (C dl ) similar electrochemical surface area (ECSA) due well dispersed ionic phase material. conductivity but showed <?CDATA...
An optimal cathode catalyst layer with uniform ionomer distribution is critical to reduce the platinum loading and increase utilization in polymer electrolyte fuel cells (PEFCs). Having well distributed low carbon (I/C) ratio desirable, as it will also minimize local oxygen transport resistance. In this work, we used electrochemical impedance spectroscopy (EIS) method transmission line model (TLM) measure evaluate ionic conductivity of pseudo layers (PCLs) comprised Vulcan XC72 black 3M 825...
A mechanistic understanding of carbon corrosion in polymer electrolyte fuel cells (PEFCs) is required to design catalyst layers that are durable. Electrochemical oxidation occurs during uncontrolled startup and shutdown events PEFCs leading multitude degradation events, including loss electrochemical surface area (ECSA), pore structure collapse, Pt detachment, ionomer others. To understand physics resulting mechanisms a detailed characterization needed probe interfaces between Pt-ionomer,...
Optimizing ionomer content in polymer electrolyte fuel cells (PEFCs) catalyst layers is critical to achieve sufficient coverage of electrocatalyst and provide low-resistance proton transport pathways. This has resulted a need for advanced diagnostic techniques understand delineation resistance from the other contact, Ohmic electric resistances within layer. Electrochemical impedance spectroscopy (EIS) method H 2 /O or /N experiments along with transmission lime models been used measuring...
Despite the current readiness level and market availability of polymer electrolyte fuel cells (PEFCs) durability is still a technical challenge that technology, has to resolve become competitive with internal combustion engines (ICE). In automotive sector, ICE typically reach lifetimes more than decade. nearest future PEFCs can in medium heavy-duty vehicles where space constraints power density requirements are relaxed, but cell lifetime becomes critical importance for such vehicles, drive...
In a proton exchange membrane (PEM) fuel cell, the local oxygen transport across ionomer film in catalyst layer has significant impact on electrode performance especially at high current density. 1 It is therefore crucial to use ionomers that have higher permeability than baseline Nafion. this work, novel with increased been synthesized by copolymerization of perfluoro-2,2-dimethyl-1,3-dioxole (PDD) perfluoro(4-methyl-3,6-dioxaoct-7-ene) sulfonyl fluoride (PFSVE) and ter-monomer. PDD main...