High-performance novel anode-supported microtubular protonic ceramic fuel cells via highly efficient and simplified extrusion technology

Protonic ceramic fuel cells (PCFCs) are regarded as efficient energy conversion devices for addressing the challenges of carbon neutrality, which can directly convert the chemical fuel energy into electricity at reduced operating temperatures below 700 °C. However, the insufficient strength and immature preparation processes of PCFCs limit their practical application. In this work, the novel anode-supported microtubular PCFCs with a tube diameter of less than 5 mm were successfully prepared by extrusion technology combined with a dip-coating method. The newly developed BaZr_0.4Ce_0.4Y_0.1Gd_0.1O_3-δ (BZCYG4411) proton-conducting electrolyte was synthesized using an extremely simple and efficient one-step solid-state reaction method, showing comparable electrical conductivity with BaZr_0.4Ce_0.4Y_0.1Yb_0.1O_3-δ (BZCYYb4411) and BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ (BZCYYb1711) electrolytes, as well as excellent chemical stability. The single cell with Ba₂Sc_0.1Nb_0.1Co_1.5Fe_0.3O_6-δ (BSNCF) cathode exhibited a high peak power density of 906.86 mW cm^-2 at 700 °C. Additionally, this microtubular PCFC demonstrated excellent stability after about 103 h durability test at a constant current of 0.5 A cm^-2 at 650 °C. This study provides a highly efficient and simplified technology for fabricating high-performance and durable anode-supported microtubular PCFCs.