Lowering the sintering temperature of low-temperature solid oxide fuel cells with Sm3+ and Nd3+ co-doped ceria electrolyte

Low-temperature solid oxide fuel cell with co-doped ceria electrolyte is a promising high efficient and cost-effective power conversion device, which needs rapid progress. One of the main issues is high sintering temperatures (1500-1600°C), increasing difficulty and cost in the cell fabrication process. To lower the sintering temperature, Fe has been evaluated as a sintering aid for Sm
³⁺
and Nd
³⁺
co-doped ceria electrolyte. The reduction in sintering temperature between Sm
_0.1
Nd
_0.1
Ce
_0.79
Fe
_0.01
O
_2-δ
and Sm
_0.1
Nd
_0.1
Ce
_0.8
O
_2-δ
is as much as 250°. The Sm
_0.1
Nd
_0.1
Ce
_0.79
Fe
_0.01
O
_2-δ
sintered at an optimal sintering temperature of 1250 °C exhibits the highest grain-boundary conductivity and relative density, which is much higher than that of Sm
_0.1
Nd
_0.1
Ce
_0.8
O
_2-δ
. The doping of Fe increases both bulk conductivity and grain boundary conductivity of the SNDC electrolyte. An integrated single cell with Sm
_0.1
Nd
_0.1
Ce
_0.79
Fe
_0.01
O
_2-δ
electrolyte exhibits a high maximum power density of 458 mWcm
^-2
at 650°C, which is 20-30% higher than previous reports.