Although fuel cells were first invented almost a century ago, manufacturing and production for commercial applications did not begin until early 2000s due to technological hurdles. Since then, the types and sizes of fuel cells have expanded considerably to meet industry demands.
In general, fuel cells follow a core system design composed of stacked cells that serve as the heart of the power system. Within each cell are two electrodes, an anode and a cathode separated by a fluid or solid electrolyte that carries particles between the two electrodes via an electro-chemical reaction.
Polymer electrolyte membrane fuel cells (PEMFC) are one type of fuel cell extensively researched and developed for their ability to deliver high power density at low operating temperatures within a small volume.
Within each cell is a membrane electrode assembly (MEA) which is composed of a membrane, catalyst layers (CL), and diffusion media. This catalyst coated membrane (CCM) is responsible for conducting protons and blocking electrons, thereby allowing specific ions to travel between the anode and cathode.
CLs, on the anode side, split hydrogen molecules into protons and electrons while, on the cathode side, CLs produce water via oxidative reduction reactions (ORR) and hydrogen oxidation reactions (HOR). These layers are composed of a catalyst ink typically comprised of platinum-supported carbon (Pt/C), ionomer, and alcohol-based fluid dispersion medium.
Fuel Cell Catalyst Manufacturing Challenges
To obtain high-quality inks, various industry approaches, such as bead mills, have been utilized with limited success.
Various traditional methods of production have created unique challenges which can hinder success and need to be addressed. These challenges include:
Long processing times requiring large number of passes to achieve the desired result thereby impacting cost and deadlines.
Lower efficiency of end-product due to inconsistency of particle sizes.
Risk of contamination due to difficulty in cleaning, resulting in poor quality and safety obstacles.
Loss of product through the process increasing the cost due to waste.
Scalability to larger volumes is extremely difficult due to the long processing time impact.
Microfluidics' Impact
Microfluidizer® processors address these factors and can achieve the desired catalyst ink characteristics that translate to improved Pt loading and mass transport through the layers compared to other technologies.
Microfluidizer® processors are able to produce dispersions with exceptional stability, which is highly desired for end-product performance and efficiency.
Although formulation can significantly impact this dispersion ability, the type of processing utilized can have a greater impact on the lasting qualities of these inks and their ability to transport more efficiently.
The ability to achieve target particle size and the appropriate dispersion characteristics allows for high-throughput production of highly efficient coatings for fuel cells. The Microfluidizer® processor is capable of improving fuel cell performance and durability through its ability to finely disperse carbon within the media, which has been proven to achieve more efficient energy transport.
Using Microfluidizer® technology, the desired uniform results can be achieved. Waste loss and contamination concerns are addressed by controlling the high shear during processing.
Scalability must be considered when moving from smaller R&D volumes to production scales. Most alternative methods are not scalable. Microfluidizer® technology offers a full product range for seamless linear scaleup.
To learn more about how Microfluidizer® Technology plays a vital role in producing high-performance energy storage systems, download our new application note.
