Effect of Li2CO3 and LiOH on the ionic conductivity of BaCe0.9Y0.1O3 electrolyte in SOFCs with a lithium compound electrode.

The effects of Li 2 CO 3 and LiOH on the ionic conductivity of BaCe 0.9 Y 0.1 O 3 (BCY)-x%Li 2 CO 3 (x = 0, 5, 10 and 30) and BCY-y%LiOH (y = 0, 2, 5 and 8) composite electrolytes were investigated. Symmetrical cells with the structure of foam Ni–Ni 0.8 Co 0.15 Al 0.05 LiO 2 (NCAL)∖BCY-x%Li 2 CO 3 or y%LiOH∖foam Ni-NCAL and Pt∖BCY-x%Li 2 CO 3 or y%LiOH∖Pt were prepared with NCAL-coated foam Ni and porous Pt as symmetrical electrodes, respectively. The ionic conductivity test results of the cells with Pt as the symmetrical electrode showed that the addition of LiOH did not improve the ionic conductivity of the BCY electrolyte, while the addition of Li 2 CO 3 could significantly improve the ionic conductivity of the BCY electrolyte. The maximum power density of the cells with the structure of foam Ni-NCAL∖BCY-x%Li 2 CO 3 or y%LiOH∖foam Ni-NCAL decreases with the increase in the amount of Li 2 CO 3 or LiOH, which indicates that adding Li 2 CO 3 or LiOH to BCY via mechanical mixing did not improve the electrochemical performance of the cells with NCAL as the electrode, and the NCAL electrode has the greatest impact on the performance of the cells. The interface of Li 2 CO 3 and BCY should be a high-speed channel for ion conduction. Increasing the effective area of the interface between BCY and Li 2 CO 3 and optimizing its continuity in the electrolyte should be the main development direction for improving the ionic conductivity. • Adding Li 2 CO 3 could significantly improve the ionic conductivity of BCY electrolyte. • Adding LiOH cannot improve the ionic conductivity of BCY-LiOH composite electrolyte. • NCAL anode has the greatest impact on the performance of new structure SOFC. • Increase the effective interface area of Li 2 CO 3 /BCY is the key to enhance conductivity. [ABSTRACT FROM AUTHOR]