scholarly journals Electrochemical performance of La2NiO4+δ-Ce0.55La0.45O2−δ as a promising bifunctional oxygen electrode for reversible solid oxide cells

Author(s):  
Pengzhang Li ◽  
Wei Yang ◽  
Chuanjin Tian ◽  
Wenyan Zhao ◽  
Zhe Lü ◽  
...  

AbstractIn this work, La2NiO4+δ-xCe0.55La0.45O2−δ (denoted as LNO-xLDC) with various LDC contents (x = 0, 10, 20, 30, and 40 wt%) were prepared and evaluated as bifunctional oxygen electrodes for reversible solid oxide cells (RSOCs). Compared with the pure LNO, the optimum composition of LNO-30LDC exhibited the lowest polarization resistance (Rp) of 0.53 and 0.12 Ω·cm2 in air at 650 and 750 °C, respectively. The enhanced electrochemical performance of LNO-30LDC oxygen electrode was mainly attributed to the extended triple phase boundary and more oxygen ionic transfer channels. The hydrogen electrode supported single cell with LNO-30LDC oxygen electrode displayed peak power densities of 276, 401, and 521 mW·cm−2 at 700, 750, and 800 °C, respectively. Moreover, the electrolysis current density of the single cell demonstrated 526.39 mA·cm−2 under 1.5 V at 800 °C, and the corresponding hydrogen production rate was 220.03 mL·cm−2·h−1. The encouraging results indicated that LNO-30LDC was a promising bifunctional oxygen electrode material for RSOCs.

2020 ◽  
Author(s):  
Pengzhang Li ◽  
Wei Yang ◽  
Chuanjin Tian ◽  
Wenyan Zhao ◽  
Zhe Lü ◽  
...  

Abstract In this work, La2NiO4+δ-xCe0.55La0.45O2-δ (denoted as LNO-xLDC) with various LDC contents (x = 0, 10, 20, 30 and 40, wt %) were prepared and evaluated as bifunctional oxygen electrodes for reversible solid oxide cells (RSOCs). Compared with the pure LNO, the optimum composition of LNO-30LDC exhibited the lowest polarization resistance (Rp) of 0.53 and 0.12 Ω·cm2 in air at 650 and 750 oC, respectively. The enhanced electrochemical performance of LNO-30LDC oxygen electrode was mainly attributed to the extended triple phase boundary and more oxygen ionic transfer channels. The hydrogen electrode supported single cell with LNO-30LDC oxygen electrode displayed peak power densities of 276, 401 and 521 mW·cm-2 at 700, 750 and 800 oC, respectively. Moreover, the electrolysis current density of the single cell demonstrated 526.39 mA·cm-2 under 1.5 V at 800 oC, and the corresponding hydrogen production rate was 220.03 ml·cm-2·h-1. The encouraging results indicated that LNO-30LDC was a promising bifunctional oxygen electrode material for RSOCs.


2020 ◽  
Author(s):  
Pengzhang Li ◽  
Wei Yang ◽  
Chuanjin Tian ◽  
Wenyan Zhao ◽  
Zhe Lü ◽  
...  

Abstract In this work, La2NiO4+δ-xCe0.55La0.45O2-δ (denoted as LNO-xLDC) with various LDC contents (x = 0, 10, 20, 30 and 40, wt %) were prepared and evaluated as bifunctional oxygen electrodes for reversible solid oxide cells (RSOCs). Compared with the pure LNO, the optimum composition of LNO-30LDC exhibited the lowest polarization resistance (Rp) of 0.53 and 0.12 Ω·cm2 in air at 650 and 750 oC, respectively. The enhanced electrochemical performance of LNO-30LDC oxygen electrode was mainly attributed to the extended triple phase boundary and more oxygen ionic transfer channels. The hydrogen electrode supported single cell with LNO-30LDC oxygen electrode displayed peak power densities of 276, 401 and 521 mW·cm-2 at 700, 750 and 800 oC, respectively. Moreover, the electrolysis current density of the single cell demonstrated 526.39 mA·cm-2 under 1.5 V at 800 oC, and the corresponding hydrogen production rate was 220.03 ml·cm-2·h-1. The encouraging results indicated that LNO-30LDC was a promising bifunctional oxygen electrode material for RSOCs.


Author(s):  
P. Kim-Lohsoontorn ◽  
H.-B. Yim ◽  
J.-M. Bae

The electrochemical performance of solid oxide electrolysis cells (SOECs) having nickel – yttria stabilized zirconia (Ni-YSZ) hydrogen electrode and a composite lanthanum strontium manganite – YSZ (La0.8Sr0.2MnO3−δ – YSZ) oxygen electrodes has been studied over a range of operating conditions temperature (700 to 900°C). Increasing temperature significantly increased electrochemical performance and hydrogen generation efficiency. Durability studies of the cell in electrolysis mode were made over 200 h periods (0.1 A/cm2, 800°C, and H2O/H2 = 70/30). The cell significantly degraded over the time (2.5 mV/h). Overpotentials of various SOEC electrodes were evaluated. Ni-YSZ as a hydrogen electrode exhibited higher activity in SOFC mode than SOEC mode while Ni/Ru-GDC presented symmetrical behavior between fuel cell and electrolysis mode and gave lower losses when compared to the Ni-YSZ electrode. All the oxygen electrodes gave higher activity for the cathodic reaction than the anodic reaction. Among the oxygen electrodes in this study, LSM-YSZ exhibited nearest to symmetrical behavior between cathodic and anodic reaction. Durability studies of the electrodes in electrolysis mode were made over 20–70 h periods. Performance degradations of the oxygen electrodes were observed (3.4, 12.6 and 17.6 mV/h for LSM-YSZ, LSCF and LSF, respectively). The Ni-YSZ hydrogen electrode exhibited rather stable performance while the performance of Ni/Ru-GDC decreased (3.4 mV/h) over the time. This was likely a result of the reduction of ceria component at high operating voltage.


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