Corrosion resistant barrier layer for a solid oxide fuel cell stack and method of making thereof

1. An interconnect for a fuel cell stack, comprising

an interconnect body having an air surface having air flow channels and ribs and a fuel surface having fuel flow channels and ribs;

an electrically conductive contact layer located on the air surface of the interconnect, the electrically conductive contact layer containing at least one of Co and Mn; and

a first layer located over the electrically conductive contact layer, the first layer comprising:

at least 45 wt. % silica (SiO 2 );

at least 5 wt. % potassium oxide (K 2 O);

at least 2 wt. % calcium oxide (CaO);

5 wt. % or less barium oxide (BaO);

greater than zero wt. % boron trioxide (B 2 O 3 );

25 wt. % or less alumina (Al 2 O 3 ); and

30 wt. % or less zirconia (ZrO 2 ) on an oxide weight basis.

2. The interconnect of claim 1 , wherein the first layer comprises a glass barrier precursor layer.

3. The interconnect of claim 1 , wherein the first layer comprises a glass ceramic barrier layer.

4. The interconnect of claim 3 , further comprising a glass or glass ceramic seal located over the first layer.

5. The interconnect of claim 4 , wherein:

the glass ceramic barrier layer comprises zirconium silicate (ZrSiO 4 ) crystals, barium aluminum silicate (BaAlSiO 4 ) crystals and potassium feldspar (KAlSi 3 O 8 ) crystals located in a glassy matrix;

the seal comprises a ring seal located over the glass ceramic barrier layer in at least one fuel riser region around a fuel riser opening through the interconnect;

the electrically conductive contact layer comprises lanthanum strontium manganite (LSM), manganese cobalt oxide spinel (MCO) or a mixture thereof;

the interconnect comprises a chromium-iron alloy interconnect; and

the glass ceramic barrier layer prevents or reduces at least one of Mn and Co diffusion from the electrically conductive contact layer to the seal.