Functionally Gradient Seals for Solid Oxide Fuel Cells

World energy markets have entered a period of inexpensive natural gas and fossil fuels, as hydraulic fracturing technologies offer energy independence to the U.S. This likely will extend the continued and increased fossil fuels use for the next decades. To create the greatest economic advantage from these domestic natural gas, oil and coal reserves, new energy systems are required that utilize these resources efficiently at the emerging micro-grid and conventional grid scale. Further, the cost of these systems must be comparable to current energy systems. SOFC’s are highly efficient, quiet, and environmentally clean devices for generating electricity and heat from natural gas, coal, biomass, and other fuels. They are one of the most promising technologies to meet the Nation’s future energy needs. For SOFC to realize their potential and achieve widespread commercial adoption these complex electrochemical systems must be made robust to harsh operating conditions and periodic thermal cycling. Component technologies (fuel cell membranes, gas separator plates, and balance of plant components) have been developed to meet the performance requirements but sealing has remained a persistent issue facing SOFC developers. To achieve the required U.S. DOE long-term performance target (less than 0.2 percent degradation per 1000 hours over an operating lifetime of 40,000 hours) and cost targets (stack cost of $225/kW), reliable cost-effective seals are critical. Nexceris’ GasLok sealing technology has been designed specifically to address failure mechanisms that cause seal degradation. In Phase I Nexceris successfully demonstrated technical feasibility of the sealing approach for electrolyte and anode-supported cell platforms. A 90-percent improved in sealing performance was demonstrated versus Nexceris’ incumbent sealing technology and enhanced seal durability and thermal cycling robustness were demonstrated in offline and single-cell electrochemical tests. In Phase II Nexceris’ will strengthen GasLok’s value proposition. Potential failure modes will be addressed to reduce risk and advance GasLok’s technical readiness. In parallel manufacturing improvements will be implemented to achieve a low-cost sealing solution that is amenable to high-volume production and has a clear roadmap for achieving U.S. DOE cost targets. Phase II will cumulate in stack-level demonstrations and customer evaluations to position GasLok for future commercialization.