(DE19514164-A1)      A self-supporting connection element, in planar high temp. fuel cells or high temp. electrolysis cells has the compsn. (I)    Li1+dMgxAlyCr1-x-yO3+/ -e (I)    d = 0 to 0.1, pref. 0.03, x = 0.02 to 0.1, pref. 0.05, y = 0.1 to 0.2, pref. 0.17 and e = 0 to 0.1.    ADVANTAGE -   The lanthanum chromite-based material has a thermal expansion coefficient (20-1000 deg.C) of 9.7 -10.4 x 10 power K power 1, a linear swelling (at 1000 deg.C and p(02)-10 power 18 bar wrt. air) of max. 0.06%, an electrical conductivity of at least 5 S/cm. in air at 1000 deg.C and at least 1 S/cm. in fuel gas with p(02)-10 power 16 bar at 1000 deg.C, long term resistance to hydrolytic decomposition, dense sinter ability at max. 1650 deg.C, increased sintering activity and reduced toxicity.    (US5747184-A)      A self-supporting connection element, in planar high temp. fuel cells or high temp. electrolysis cells has the compsn. (I)    Li1+dMgxAlyCr1-x-yO3+/ -e (I)    d = 0 to 0.1, pref. 0.03, x = 0.02 to 0.1, pref. 0.05, y = 0.1 to 0.2, pref. 0.17 and e = 0 to 0.1.    ADVANTAGE -   The lanthanum chromite-based material has a thermal expansion coefficient (20-1000 deg.C) of 9.7 -10.4 x 10 power K power 1, a linear swelling (at 1000 deg.C and p(02)-10 power 18 bar wrt. air) of max. 0.06%, an electrical conductivity of at least 5 S/cm. in air at 1000 deg.C and at least 1 S/cm. in fuel gas with p(02)-10 power 16 bar at 1000 deg.C, long term resistance to hydrolytic decomposition, dense sinter ability at max. 1650 deg.C, increased sintering activity and reduced toxicity.    (DE19514164-C2)      A self-supporting connection element, in planar high temp. fuel cells or high temp. electrolysis cells has the compsn. (I)    Li1+dMgxAlyCr1-x-yO3+/ -e (I)    d = 0 to 0.1, pref. 0.03, x = 0.02 to 0.1, pref. 0.05, y = 0.1 to 0.2, pref. 0.17 and e = 0 to 0.1.    ADVANTAGE -   The lanthanum chromite-based material has a thermal expansion coefficient (20-1000 deg.C) of 9.7 -10.4 x 10 power K power 1, a linear swelling (at 1000 deg.C and p(02)-10 power 18 bar wrt. air) of max. 0.06%, an electrical conductivity of at least 5 S/cm. in air at 1000 deg.C and at least 1 S/cm. in fuel gas with p(02)-10 power 16 bar at 1000 deg.C, long term resistance to hydrolytic decomposition, dense sinter ability at max. 1650 deg.C, increased sintering activity and reduced toxicity.