Corey Randall

• Doctor of Philosophy
• PostDoc at National Renewable Energy Laboratory

Proton exchange membrane fuel cells (PEMFCs) are a promising means to decarbonize the global vehicle fleet, but commercialization is limited by costly Pt catalysts, among other challenges. PEMFC designs with low Pt loading typically suffer anomalous performance losses. Previous studies have agreed that poor performance with low Pt-loading is attrib...

To plan and optimize energy storage demands that account for Li-ion battery aging dynamics, techniques need to be developed to diagnose battery internal states accurately and rapidly. This study seeks to reduce the computational resources needed to determine a battery’s internal states by replacing physics-based Li-ion battery models – such as the...

Bayesian parameter inference is useful to improve Li-ion battery diagnostics and can help formulate battery aging models. However, it is computationally intensive and cannot be easily repeated for multiple cycles, multiple operating conditions, or multiple replicate cells. To reduce the computational cost of Bayesian calibration, numerical solvers...

Species transport in thin-film Nafion heavily influences proton-exchange membrane (PEMFC) performance, particularly in low-platinum-loaded cells. Literature suggests that phase-segregated nanostructures in hydrated Nafion thin films can reduce species mobility and increase transport losses in cathode catalyst layers. However, these structures have...

Proton exchange membrane fuel cells (PEMFCs) are a promising means to decarbonize the global vehicle fleet, but commercialization is limited by costly Pt catalysts, among other challenges. PEMFC designs with low Pt loading typically suffer anomalous performance losses. Previous studies have agreed that poor device performance is linked to complex p...

Low-cost, high-performance proton exchange membrane fuel cells (PEMFCs) have been difficult to develop due to limited understanding of coupled processes in the cathode catalyst layer (CCL). Low Pt loaded PEMFCs suffer losses beyond those predicted solely due to reduced catalyst area. Although consensus links these losses to thin ionomer films in th...

As the world moves away from a dependence on fossil fuels, it is crucial to develop cleaner replacement technologies for transportation, electricity production, and more. In regards to the transportation sector, fuel cell electric vehicles (FCEVs) made with proton exchange membrane fuel cells (PEMFCs) provide much promise. These FCEVs offer high en...

Due to its chemical stability in acidic environments and high ionic conductivity, Nafion has proven to be an essential material in proton exchange membrane fuel cell (PEMFC) designs. Nafion functions as both a membrane – separating the two electrodes – and as a conductive binder in each catalyst layer (CL). Nano-thin films of Nafion ionomer allow p...

The critical electrochemical reactions within proton exchange membrane fuel cells (PEMFCs) take place in the heterogeneous catalyst layer (CL). This CL is comprised of three main materials: carbon, platinum, and thin film Nafion. The CL ionomer, Nafion, is particularly important with respect to PEMFC performance and durability. Ionic and charge-neu...

This work presents a pseudo-2D polymer electrolyte membrane fuel cell (PEMFC) model incorporating Nafion ionomer structure-property relationships in the cathode catalyst layer (CL) to capture and explain losses at low Pt loading. Structural data from neutron reflectometry and Nafion membrane conductivity measurements predict variations in the oxyge...

Use of pseudo-2d simulations to understand microstructure-performance relationships in PEMFC cathode catalyst layers.Prepared and presented by Corey Randall at 235th Electrochemical Society Meeting, Dallas, TX, May 29, 2019. Funding provided by the US Department of Energy, Basic Energy Sciences Early Career Award.By estimating Nafion structure-prop...

Despite the recent entrance of proton exchange membrane fuel cells (PEMFC) into the automotive industry, performance under low platinum loading is still hampered by prohibitive and poorly understood transport losses inside the heterogeneous catalyst layer (CL). Predictive models do not yet sufficiently capture the transport of oxygen, water, and pr...