Solid Oxide Fuel Cells for Undersea Naval Applications

SOFC Construction
Ceramic electrolyte (yttria-stabilized zirconia,
YSZ) sandwiched between two electrodes
The electrolyte’s function:
(1) acts as a diffusion barrier between
the fuel and oxidizer and
(2) serves as an ionic conductor for the
transport of oxide ions from the cathode
to the anode.
The anode is a cermet of metallic nickel
and YSZ, while the cathode is a p-type
semiconductor such as La 0.7 Sr 0.3 MnO 3 .
Cathode
Electrolyte
Anode
The interconnect is a necessary component of
the stack. It must have high electrical conductivity
while being inert in oxidizing and reducing
environments. It provides electrical connection and
gas flow channel separation between cells.
Operation below 750°C allows the use of stainless
steel interconnects, which are cost effective.
Fuel
Channel
Cathode:
O 2 + 2e - → 2O 2-
Anode:
Bipolar Plate
Interconnect
H 2 + O 2- → H 2 O + 2e -
CO + O 2- → CO 2 + 2e -
Oxidant