Highly enhanced electrical properties of lanthanum-silicate-oxide-based SOFC electrolytes with co-doped tin and bismuth in La_9.33−xBi_xSi_6−ySn_yO₂₆

Abstract

Structure modification of La9.33Si6O26 (LSO) as SOFC electrolyte via a bi-doping mechanism provides enhanced electrical properties of La7.83Bi1.5Si5.7Sn0.3O26 at 873 K (1.84 × 10−2 S cm−1) with low activation energy of 0.80 eV compared to pristine LSO (0.08 × 10−2 S cm−1).

Synthesis and Densification of Mo/Mg Co‐Doped Apatite‐type Lanthanum Silicate Electrolytes with Enhanced Ionic Conductivity

“…The comparison of total conductivity at 800 °C and Arrhenius plots of different dopants between this work and the literature are listed in Figure 13 [14–16,18–19,22–28,37] . Several works have been conducted to enhance the conductivity of LSO by aliovalent doping in La 3+ and Si 4+ , and the ionic conductivity of LSO increases with La content due to the increase in interstitial oxide ions.…”

“…[36] The comparison of total conductivity at 800 °C and Arrhenius plots of different dopants between this work and the literature are listed in Figure 13. [14][15][16][18][19][22][23][24][25][26][27][28]37] Several works have been conducted to enhance the conductivity of LSO by aliovalent doping in La 3 + and Si 4 + , and the ionic conductivity of LSO increases with La content due to the increase in interstitial oxide ions. Compared with doping in the La 3 + , Si 4 + site substitution shows to be more effective in improving the total conductivity, especially doping Cu 2 + .…”

“…The dense co‐doped Ba 2+ and W 6+ solid electrolytes La 9.4 Ba 0.6 Si 5.9 W 0.1 O 26.8 exhibited high conductivity with a value of 8.11×10 −3 S ⋅ cm −1 at 800 °C after sintering at 1550 °C for 5.5 h [25] . The addition of Bi 3+ and Sn 4+ as dopants has increased the conductivity with a high value of 1.84×10 −2 S ⋅ cm −1 at 873 K [26] . Al 3+ and In 3+ were doped in Si 4+ of LSO, which also improved the total ionic conductivity [27] .…”

“…[24] Furthermore, the codoped method can significantly improve conductivity and sintering temperature and restrain the formation of the impurity phase (La 2 SiO 5 and La 2 SiO 7 ), which are the main limitations of practical application. The dense co-doped Ba 2 + and W 6 + solid electrolytes La 9.4 Ba 0.6 Si 5.9 W 0.1 O 26.8 exhibited high conductivity with a value of 8.11 × 10 À 3 S • cm À 1 at 800 °C after sintering at 1550 °C for 5.5 h. [25] The addition of Bi 3 + and Sn 4 + as dopants has increased the conductivity with a high value of 1.84 × 10 À 2 S • cm À 1 at 873 K. [26] Al 3 + and In 3 + were doped in Si 4 + of LSO, which also improved the total ionic conductivity. [27] Codoped on the Si 4 + site with Al 3 + and different other cations (W 6 + , In 3 + , Nb 5 + or Mg 2 + ) were investigated and the La 10 Si 5 Al 0.9 W 0.1 O 26.65 exhibits the highest conductivity of 3.03 × 10 À 2 S • cm À 1 at 1073 K. [28] This work reports the preparation and characteristics of a new co-doped LSO with Mg 2 + and Mo 6 + on Si-site LSO synthesised by a straightforward co-precipitation method, which is ideal for developing SOEC and SOFC electrolytes.…”

LSCF–WO3 semiconductor composite electrolytes for low-temperature solid oxide fuel cells

“…Solid oxide fuel cell (SOFC) is a power generating device that can directly convert the chemical energy of the fuel into electricity with high efficiency due to the advantages of low noise, environment friendly nature, and no requirement of precious metal catalysts. [1][2][3][4][5][6] Conventional high-temperature SOFCs operate at about 1000 °C, which leads to several concerns, such as difficulty in material selection and sealing the fuel cell stack, slow start, and poor durability. [7][8][9] These problems could be effectively solved when their working temperature reduced to <600 °C.…”