Intermediate temperature fuel cells based on doped ceria-LiCl-SrCl₂ composite electrolyte

A new type of oxide-salt composite electrolyte, gadolinium-doped ceria (GDC)-LiCl-SrCl₂, was developed and demonstrated its promising use for intermediate temperature (400-700°C) fuel cells (ITFCs). The dc electrical conductivity of this composite electrolyte (0.09-0.13Scm^-1 at 500-650°C) was 3-10 times higher than that of the pure GDC electrolyte, indicating remarkable proton or oxygen ion conduction existing in the LiCl-SrCl₂ chloride salts or at the interface between GDC and the chloride salts. Using this composite electrolyte, peak power densities of 260 and 510mWcm^-2, with current densities of 650 and 1250mAcm^-2 were achieved at 550 and 625°C, respectively. This makes the new material a good candidate electrolyte for future low-cost ITFCs.