Optimization of SOFC Composite Cathodes Based on LSM and Doped Cerias Ce_0.8Ln_0.2O_2-δ(Ln = Gd, Er, Tb and Pr)

Abstract

Composites made of La 1-x Sr x MnO 3−δ (LSM) and lanthanide doped ceria (Ce 0.8 Ln 0.2 O 2-δ , Ln=Gd, Er, Tb and Pr) have been proposed as robust and high-performing solid oxide fuel cell cathodes. The addition of small amounts of highly-dispersed CoO x into the electrode promoted the formation of bridges among LSM-ceria particles. These resulted in the reduction of the required sintering temperature due to the enhancement of the sintering and proper ionic and electronic percolation pathways. In addition, Pr as a multivalent cation dopant in ceria showed the best electrochemical results towards oxygen reduction when the electrode sintering temperature is kept at 1000 °C.

The Effects of External Magnetic Field on the Physical Properties of La_0.41Ca_0.59Mn_1-xCu_xO₃ with x = 0.06 and 0.15 in the Temperature Range of 100 – 300 K

“…The summary of the results is listed in Table 3. Based on the results listed in Table 3, for H = 0 T and for more Cu content, then the quantities in the specific heat are relatively constant only the (a) 9 -coefficient value slightly increases. However, for H = 9 T, the external magnetic field becomes very influential on the  and the δ coefficients values,…”

“…are still intensively studied. Works focusing on various physical properties of the compounds, such as magnetoresistance (MR), crystal structure change, metal-insulator transition, specific heat, large magneto-caloric effect, and high electrical conductivity have been reported [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. These rare … (T MI ) of about 243 K. In case of T>T MI , the resisitivity as a function of temperature could be described by two different models, namely the variable range hopping (VRH) model or Arhenius model and the adiabatic small polaron hopping (ASPH) model but more in line with the second model (ASPH).…”

“…At the temperature less than 184 K, the resisitivity follows the Arhenius model (ln R varies as 1/T 0.25 ) while at higher temperatures it fits the metal-semiconductor model (ln R varies as 1/T). The electronic specific heat parameter γ varies with magnetic field at x = 0.06, but not at x = 0.15. earths manganite compounds have found a wide range of application, such as a mild hyperthermia mediator [1], magnetic refrigeration technology near room temperature [5], and a fuel cell cathode [7][8][9].Until now, the results of measurements and analysis of this material still make a lot of differences. Suppose La 1-x Sr x MnO 3 will change from orthorhombic (x<0.2) to rhombohedral (x>0.2) [1], at low temperatures, La 1-x Ca x MnO 3 structure will change from cubic to rhombohedral then to orthorhombic [2], while La 0.65 Ca 0.35-x Ba x MnO 3 has a rhombohedral crystal structure for x<0.15 and a cubic for 0.15<x<0.25 [3].…”

“…At the temperature less than 184 K, the resisitivity follows the Arhenius model (ln R varies as 1/T 0.25 ) while at higher temperatures it fits the metal-semiconductor model (ln R varies as 1/T). The electronic specific heat parameter γ varies with magnetic field at x = 0.06, but not at x = 0.15. earths manganite compounds have found a wide range of application, such as a mild hyperthermia mediator [1], magnetic refrigeration technology near room temperature [5], and a fuel cell cathode [7][8][9].…”

Improvement of La0.8Sr0.2MnO3−δ Cathode Material for Solid Oxide Fuel Cells by Addition of YFe0.5Co0.5O3

“…Several composite cathodes containing LSM were examined so far [14,. The second phase was reported: (i) the electrolyte material of pure ionic conductivity such as yttria-stabilized zirconia (YSZ) [16][17][18][19][20][21], scandia-stabilized zirconia [22], gadolinia-doped ceria (GDC) [18,23] samaria-doped ceria (SDC) [24], bismuth oxide conductors [25][26][27], and lanthanum tungstate [28]; (ii) the noble metal of high catalytic activity such as silver [29][30][31] and platinum [28]; (iii) material of mixed ionic electronic conductivity such as LSCF [14,32], La 0.6 Sr 0.4 FeO 3−δ , (LSF) [31], La 2 Ni 0.5 Co 0.5 O 4 , and LaNi 0.5 Co 0.5 O 3 [33]; others such as BaO [34], CeO 2 [31], CoO x [35], Co 3 O 4 [36,37], and FeO x [38].…”