Effects of Sn Doping on the Manufacturing, Performance and Carbon Deposition of Ni/ScSZ Cells in Solid Oxide Fuel Cells

This work demonstrates the effect of tin (Sn) doping on the manufacturing, electrochemical performance, and carbon deposition in dry biogas-fuelled solid oxide fuel cells (SOFCs). Sn doping via blending in technique alters the rheology of tape casting slurry and increases the Ni/ScSZ anode porosity. In contrast to the undoped Ni/ScSZ cells, where open-circuit voltage (OCV) drops in biogas, Sn–Ni/ScSZ SOFC OCV increases by 3%. The maximum power densities in biogas are 0.116, 0.211, 0.263, and 0.314 W/cm2 for undoped Ni/ScSZ, undoped Ni/ScSZ with 3wt% pore former, Sn–Ni/ScSZ and Sn–NiScSZ with 1wt% pore former, respectively. Sn–Ni/ScSZ reduces the effect of the drop in the maximum power densities by 26% to 36% with the fuel switch. A 1.28 to 2.24-fold higher amount of carbon is detected on the Sn–Ni/ScSZ samples despite the better electrochemical performance, which may reflect an enhanced methane decomposition reaction.