Technology:
Our technical capabilities originated in the development of a proprietary SOFC technology at our subsidiary company, Franklin Fuel Cells (FFC). That company’s mission is to commercialize highly efficient, sulfur-tolerant and multi-fuel-capable solid oxide fuel cells using its proprietary membrane electrode assembly (MEA) designs in both planar and tubular configurations. That pursuit, which began with FFC’s incorporation in 2001, resulted in the creation of a unique team of scientists, engineers and technicians along with a unique portfolio of intellectual property and technical expertise in the areas of: ceramic tape casting; thick film paste manufacturing; planar and tubular SOFC manufacturing and testing; screen-printing; high- temperature firing and materials properties characterization, among others. These capabilities, which were originally developed to serve the singular objective of commercializing proprietary SOFC technology, are now available to our industrial, research and development, and academic customers through Franklin Advanced Materials.

PV Materials
FAM has developed proprietary formulations for screen printable silver and aluminum pastes for use in the manufacture of mono and poly crystalline solar cells. Using our expertise in thick film manufacturing and our ability to develop highly engineered inorganic materials that must meet strict product requirements but that can also be manufactured consistently and economically, we began working with solar cell manufacturers in 2009 to develop a line of metallization pastes having the ability to be screen printed at higher squeegee speeds, fired under faster profiles, and able to print at higher aspect ratios than available from the existing paste manufacturers. In other words, pastes that allow our customers to significantly lower their cost of manufacturing solar cells.

The ongoing results of this effort are a full line of metallization pastes: front side silver, back side aluminum and back side silver. These paste products are customized to meet our customers’ specific performance requirements subject to their specific manufacturing and environmental constraints. Our front side silver pastes (SunAG) are designed using premium silver powders, proprietary glass formulations and rheology modifiers to produce printed lines with lower series resistance and higher geometric aspect ratios for less shading. These features serve to increase cell efficiency and lower the cost of solar power.

Additionally, we have under development a line of front side silver pastes for double line printing. This product line consists of two paste systems. Although this process adds up-front capital costs (for the extra station required in the production line for the second print and dry process) and due to “slowing down” of production for the extra process, it is under evaluation by many solar cell manufacturers since it has the possibility of increasing efficiency up to 1.5 percentage points. The first paste uses our proprietary glass formulation to penetrate the anti-reflective layer and establish both high shunt resistance and low contact resistance. The second component allows for a high aspect ratio line to be printed, one having a narrow footprint and large print thickness for both low shading and low series resistance. And, as with our line of single print SunAG pastes, our two component double print pastes are customized to meet our customers’ requirements for manufacturing constraints such as print speed and firing profiles.

For the double print a dried thickness of almost 30 microns has been achieved with excellent registration.

SOFC Materials
Seven-plus years and many millions of dollars in development work at FFC produced a solid suite of products. These range from complete cells (in both planar and tubular form), half cells for use in electrode development, green and fired Yttria-stabilized Zirconia (YSZ) and Scandia-stabilized Zirconia (ScSZ) electrolyte supports, to anode and cathode screen-printable electrode and current collection pastes. These MEA components and materials represent both state-of-the-art conventional designs (i.e. NiO based anodes and LSM or LSCF based cathodes), as well as FFC’s proprietary-electrode intellectual property.

FFC’s Direct Oxidation SOFC
Some of the most significant challenges to the commercialization of fuel cells have included high system cost, poor reliability, and the limitation of having to operate on pure hydrogen rather than more-readily-found and easily-stored fuels such as gasoline, diesel, or bio-fuels. While conventional SOFCs are considered to be fuel flexible – which is certainly a true statement relative to the highly limited hydrogen-only capability of Polymer Electrolyte Membrane (PEM) fuel cells – this fuel flexibility only extends to sulfur-free hydrogen, methane and carbon monoxide – hardly the most convenient suite of fuels. Conventional SOFCs are further challenged by anode poisoning from sulfur in concentrations greater than about 1 part per million (ppm) and anode failure due to oxidation from exposure to air, as can happen during the fuel-starved conditions possible at start-up, shut down or refueling events.
In response to these obstacles to fuel cell commercialization, FFC developed Direct Oxidation SOFC (DOSOFC) technology that employ all-ceramic anodes which have been shown to operate directly on complex, sulfur-containing hydrocarbon fuels such as diesel and military JP-8 without fouling from carbon formation or sulfur poisoning. This all-ceramic anode is also completely reduction-oxidation (redox) tolerant, capable of high power density, and can be incorporated into both planar and tubular cell configurations. What this means to the fuel cell system developer is that: a) the de-sulfurizer component of the system may be deleted; b) the fuel reformer may be eliminated or greatly simplified; and c) system startup, shut down and refueling events can not only be simplified but also have a lessened impact on component reliability. These system benefits translate to higher fuel efficiency, lower system cost and higher product quality and reliability.