External Current Dependence of Polarization Resistances for Reversible Solid Oxide and Protonic Ceramic Cells with Current Leakage
External Current Dependence of Polarization Resistances for Reversible Solid Oxide and Protonic Ceramic Cells with Current Leakage
复制标题
DOI：
10.1021/acsaem.2c03733
复制
发表时间：
2023-01-31
影响因子：
6.4
通讯作者：
Okuyama, Yuji
中科院分区：
文献类型：
--
作者：
Sumi, Hirofumi;Shimada, Hiroyuki;Okuyama, Yuji
本文采用掺杂gd的铈（GDC）和掺杂yb的锆酸钡（BZYb）分别作为中温固体氧化物电池（soc）和质子陶瓷电池（PCCs）的电解质。然而，GDC在低氧分压下的电子导电性和BZYb在高氧分压下的空穴导电性会导致电流泄漏，从而降低开路电压和转换效率。本文通过对GDC电解液可逆SOC和BZYb电解液可逆PCC的电化学阻抗谱（EIS）弛豫时间分布（DRT）分析，研究极化电阻对漏电流的影响。在电解模式和燃料电池模式下，氧化锆稳定电池的极化电阻分别随电流密度的增大而增大和减小。相比之下，由于漏电流的影响，使用GDC电解液的SOC的极化电阻呈现相反的趋势。对于使用BZYb电解质的PCC，根据空气电极反应过程的极化电阻在燃料电池模式下显示最大值。空穴电导率对极化电阻的影响表明PCC电极的基本速率决定过程。
Gd-doped ceria (GDC) and Yb-doped barium zirconate (BZYb) are used as electrolytes for intermediate-temperature solid oxide cells (SOCs) and protonic ceramic cells (PCCs), respectively. However, the electron conductivity of GDC under low oxygen partial pressure and the hole conductivity of BZYb under high oxygen partial pressure result in current leakage, which decreases the open circuit voltage and conversion efficiency. In the present work, the effect of polarization resistances on current leakage is investigated through the distribution of relaxation times (DRT) analysis of electrochemical impedance spectra (EIS) for a reversible SOC with GDC electrolyte and PCC with BZYb electrolyte. The polarization resistances increase and decrease with increasing current density in the electrolysis and fuel cell modes, respectively, for the conventional SOC with scandia-stabilized zirconia (ScSZ). In contrast, the polarization resistances exhibit the opposite tendency for the SOC with the GDC electrolyte owing to current leakage. For the PCC with the BZYb electrolyte, the polarization resistances according to air electrode reaction processes indicate maximum values in the fuel cell mode. The effect of hole conductivity on the polarization resistance suggests elementary rate-determining processes of the PCC electrodes.