A highly active and durable electrode with in situ exsolved Co nanoparticles for solid oxide electrolysis cells

Exsolution on perovskite oxides: morphology and anchorage of nanoparticles

“…Nanoparticle exsolution on perovskite oxides has been a ''hot topic'' and focus of extensive research for more than a decade. Ni, 28,[31][32][33]38,39,41,45,47 Co, 80 Fe, 67,74 Ru, 90,93 Ag, [95][96][97] Au, 100 Fe-Ni, 35,[49][50][51][53][54][55][56][57][58][59]62,64 Co-Ni, 83 Co-Fe, 75,77,[79][80][81][82][83][84] Fe-Re, 49 (Pr,Ba)O x 103 Ellipsoidal 23 Ni, 29,30,32,40,46 Co, 87,88 Fe, 69,72,73 Ru,…”

Advancing Electrode Properties through Functionalization for Solid Oxide Cells Application: A Review

“…A voltage degradation of ~0.7 % and 1.22 % for constant 240 h has been obtained for cells with LSCF@CoC-GO-air electrode, while under the same condition degradation in voltage of ~1.5 % and 2.87 % is observed for the ball-milled composite of these two phases at constant load of 0.5 A.cm À 2 and 1 A.cm À 2 respectively as also depicted in the characteristic VÀ T plot in Figure18d-e. [190] During SOEC-mode of operation, air electrode should possess high partial molar free energy change so as to withstand in the high partial pressure of oxygen during oxidation of oxide ions. In this aspect, development of Ba 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3 having intrinsically high partial molar free energy change for O 2 have been synthesised and studied by Dey et al [28] A maximum C.D of 1.37 A.cm À 2 (Figure 19a) with hydrogen flux of 0.57Nl.h À 1 .cm À 2 is obtained for the cell of configuration Ni-YSZ/YSZ/GDC/BSCF-GDC/BSCF at an applied [28] ; (b) Electrolysis current as a function of %Relative Humidity (%RH); [123] (c) Symmetric cell performance with SFCM symmetric electrode [192] ; (d) Comparative SOC performance at 60%RH [123] [Figures are reproduced upon copyright permission from [28,123,192]].…”

“…[191] In-situ exsolved Co nanoparticle decorated Sr 2 Fe 1.5 Mo 0.5 O 6-δ (Sr 2 Fe 1.3 Co 0.2 Mo 0.5 O 6-δ -SFCM) has been reported by Yang et al where in the reducing atmosphere, active Co metal nano-particulates were exsolved out from the pristine lattice structure of SFM-based double perovskite. [192] They have studied the rate-limiting steps for electrolysis comprising of the surface exchange and diffusion by electrochemical impedance spectroscopy (EIS) and distributed relaxation time analysis (DRT), wherein significant decrease in the resistances reflected the higher activity and better stability of such air electrode for SOEC application. Air electrode consisting of LSC (La 0.6 Sr 0.4 CoO 3δ ) and Gd, Pr co-doped cerium oxide nanocomposite placed onto CGO scaffold have been proven to be effective as an OER catalyst with high mixed conducting nature and fast oxygen exchange rate.…”

“…On the other hand, Yang et al have demonstrated the concept of symmetric cell using SFCM double perovskite with exsolved Conanoparticulate as symmetric electrode. [192] Cells with configuration of SFCM/LSGM/SFCM has been tested with 45 %CO 2 -45 %H 2 O-10 %H 2 for co-electrolysis. At an operational temperature of 800 °C cells comes out with a much higher C.D of 2.3 A.cm À 2 at an applied voltage of 1.5 V as shown in the I-V plot in Figure 19c.…”

“…Figure19. Electrochemical performances of the single cells (a) with BSCF air electrode in the temperature range of 750-850 °C[28] ; (b) Electrolysis current as a function of %Relative Humidity (%RH);[123] (c) Symmetric cell performance with SFCM symmetric electrode[192] ; (d) Comparative SOC performance at 60%RH[123] [Figures are reproduced upon copyright permission from[28,123,192]]. …”