Understanding the Effect of Dispersant Rheology and Binder Decomposition on 3D Printing of a Solid Oxide Fuel Cell

Abstract

Solid oxide fuel cells (SOFCs) are a green energy technology that offers a cleaner and more efficient alternative to fossil fuels. The efficiency and utility of SOFCs can be enhanced by fabricating miniaturized component structures within the fuel cell footprint. In this research work, the parallel-connected inter-digitized design of micro-single-chamber SOFCs (µ-SC-SOFCs) was fabricated by a direct-write microfabrication technique. To understand and optimize the direct-write process, the cathode electrode slurry was investigated. Initially, the effects of dispersant Triton X-100 on LSCF (La0.6Sr0.2Fe0.8Co0.2O3-δ) slurry rheology was investigated. The effect of binder decomposition on the cathode electrode lines was evaluated, and further, the optimum sintering profile was determined. Results illustrate that the optimum concentration of Triton X-100 for different slurries was around 0.2–0.4% of the LSCF solid loading. A total of 60% of solid loading slurries had high viscosities and attained stability after 300 s. In addition, 40–50% solid loading slurries had relatively lower viscosity and attainted stability after 200 s. Solid loading and binder affected not only the slurry’s viscosity but also its rheology behavior. Based on the findings of this research, a slurry with 50% solid loading, 12% binder, and 0.2% dispersant was determined to be the optimal value for the fabricating of SOFCs using the direct-write method. This research work establishes guidelines for fabricating the micro-single-chamber solid oxide fuel cells by optimizing the direct-write slurry deposition process with high accuracy.

Three-Dimensional-Printed Composite Structures: The Effect of LSCF Slurry Solid Loading, Binder, and Direct-Write Process Parameters

“…The 40% solid loading slurry observed 2.66-fold increase in viscosity, whereas a 50% solid loading slurry observed 2.44-fold increase in viscosity. This can be attributed to the higher particle/particle interactions of higher binder concentrations, which tends to increase the effective rheological resistance [ 51 , 53 ].…”

“…The cathode slurry was formulated by blending the LSCF particles with the organic solvent terpineol, the binder PVB, and the dispersion Triton X-100. Based on the prior reported experimentation, the binder concentrations of 12% and 15% resulted in porous lines without cracks [ 51 ]. A slurry with 60% solid loading has a higher viscosity than those with 40% and 50% solid loading.…”

“…Substrates with constant surface preparation were prepared. The optimal values for the solid loading, binder, and dispersant were chosen based on the prior and this research work [ 48 , 51 , 52 , 53 , 54 ]. The factorial experimental design is illustrated in Table 2 , which includes three components and two levels each.…”

“…The 40% solid loading slurry observed 2.66-fold increase in viscosity, whereas a 50% solid loading slurry observed 2.44-fold increase in viscosity. This can be attributed to the higher particle/particle interactions of higher binder concentrations, which tends to increase the effective rheological resistance [51,53]. The surface plot of viscosity vs. solid loading and binder concentrations was illustrated in Figure 4 to estimate trend patterns.…”