Strontium doped lanthanum manganite

Fig. 13.22. The monolithic SOFC concept of Argonne National Laboratory. Anode nickel-yttria-stabilized zirconia. Cathode strontium-doped lanthanum manganite. Interconnect doped lanthanum chromite, a, Interconnection b, electron-ion path c, anode d, electrolyte e, cathode. (Reprinted from K. Kordesch,...

Yasuda, I. and Hishinuma, M., Electrical conductivity and chemical diffusion coefficient of strontium-doped lanthanum manganites, Journal of the Electrochemical Society 143, 1996, 1583. 

The favoured material is modified lanthanum manganite (e.g. La0 8Sr0 2Mn03+x) which has the perovskite structure. It is a p-type semiconductor the electron transport occurring by electron-hopping (see Section 2.6.2) between the +3 and +4 states of the Mn ion. The strontium-doping enhances the conductivity. 

The anode material in SOFCs is a cermet (metal/ceramic composite material) of 30 to 40 percent nickel in zirconia, and the cathode is lanthanum manganite doped with calcium oxide or strontium oxide. Both of these materials are porous and mixed ionic/electronic conductors. The bipolar separator typically is doped lanthanum chromite, but a metal can be used in cells operating below 1073 K (1472°F). The bipolar plate materials are dense and electronically conductive. 

A. Belzner, T.M. Giir and R.A. Huggins, Oxygen chemical diffusion in strontium doped lanthanum manganites. Solid State Ionics, 57 (1992) 327-337. 

Strontium-doped lanthanum manganite synthesis for solid oxide fuel cells cathode. Journal of New Materials for Electrochemical Systems, Vol. 12, No. 2-3, (1 April 2009), pp. (109-113), ISSN 1480-2422... 

Ahlgren, E. O., andPoulsen, F. W. (1996). Thermoelectric power and electrical conductivity of strontium-doped lanthanum manganite. Solid State Ionics 86-88 1173-1178. 

Fig. 2 Schematic of SOFC operation presenting the four-step anodic. H2O formation and electron transfer were shown in the insert. LSM strontium-doped lanthanum manganite (cathode for SOFC), Vq" vacancy of oxygen...

Stochniol G, SyskaMs E, Naoumidis A (1995) Chemical cmnpatibifity between strontium-doped lanthanum manganite and yttiia-stabllized ziiconia. J Am Ctaam Soc 78 929—932... 

Lanthanum Manganite doped with strontium Oxide (LSM) (Lao.8SRo.2)o.98Mn03-6 La rare earth metal Sr as mineral Mn ore component... 

For the cathode, a mixture of strontium-doped lanthanum manganite (LSM) proved most suitable, and as the slurry spray process was not scalable to larger modules and production volumes, the screen printing process was chosen for the cathode fabrication [76]. 

To ensure good contact resistance (primarily with the cathode) and minimize evaporation of chromia, many developers use interconnect coatings of strontium-doped lanthanum cobaltite or manganite, which have proven effective for at least several thousand hours. 

Yang, C.K., Yamazaki, Y., Aydin, A., and Haile, S.M. (2014) Thermodynamic and kinetic assessments of strontium-doped lanthanum manganite perovskites for two-step thermochemical water splitting. 

Strontium-doped lanthanum manganite, La1 3.Sr3.MnO3 (LSM) is developed by doping lanthanum manganite with a small fraction (10%-20%) of strontium in order to enhance electronic conductivity of the cathode electrode. Lanthanum strontium cobalt ferrite (LSCF) is a mixture of lanthanum oxide, strontium oxide, cobalt oxide, and iron oxide with typical composition given as Lao eSro iCoo Fco sOs. 

---