Vertical-cavity surface-emitting laser (VCSEL)-based ultrafast photonic sintering of solid oxide fuel cells (SOFCs): prospects for time-efficient/two-dimensional scalability to large-sized SOFCs

Abstract

Solid oxide fuel cells (SOFCs) are potential future energy conversion devices. Here, we report infrared vertical-cavity surface-emitting lasers (VCSELs) for the ultrafast fabrication of SOFCs. VCSELs eliminate the organic additives and densify the laminated multilayered SOFC NiO–YSZ|NiO–ScCeSZ|ScCeSZ|GDC (where YSZ, ScCeSZ, and GDC denote Zr_0.92Y_0.08O_2−δ, Zr_0.89Sc_0.1Ce_0.01O_2−δ, and Ce_0.9Gd_0.1O_2−δ, respectively) in just 2.42 h compared to >100 h needed for the conventional thermal sintering process. The process benefits from a VCSEL-based infrared light-material coupling effect, which allows a rapid and uniform thermal heating profile. LSC (La_0.6Sr_0.4CoO_3−δ)–GDC composite cathodes and GDC scaffolds for LSC infiltration are also fabricated using VCSEL-based sintering. SOFCs fabricated using VCSELs alone and in combination with infiltrated LSC generated 1.86 and 2.24 W cm⁻² at 750 °C, respectively, and performed more robustly compared to the 1.69 W cm⁻² and degradative performance of the SOFC fabricated using conventional sintering. VCSELs offer excellent processing compatibility and show great potential for accelerated fabrication of high-performance SOFCs.