Sn-doped cobalt containing perovskite as the air electrode for highly active and durable reversible protonic ceramic electrochemical cells
Min Fu, Wenjing Hu, Hua Tong, Xin Ling, Linggui Tan, Fanglin Chen, Zetian Tao
Abstract
One potential solution to the problems of energy storage and conversion is the use of reversible protonic ceramic electrochemical cells (R-PCEC), which is based on the solid oxide fuel cell (SOFC) technology and offers a flexible route to the generation of renewable fuels. However, the R-PCEC development faces a range of significant challenges, including slow oxygen reaction kinetics, inadequate durability, and poor round-trip efficiency resulted from the inadequacy of the air electrode. To address these issues, we report a novel B-sites doped Pr<sub>0.5</sub>Ba<sub>0.5</sub>Co<sub>0.7</sub>Fe<sub>0.3</sub>O<sub>3-δ</sub> (PBCF) with varying amounts of Sn as the air electrode for R-PCEC to further enhance the electrochemical performance at lower temperatures. At 600 °C, the R-PCEC with an air electrode consisting of Pr<sub>0.5</sub>Ba<sub>0.5</sub>Co<sub>0.7</sub>Fe<sub>0.25</sub>Sn<sub>0.05</sub>O<sub>3+δ</sub> has achieved a peak power density of 1.12 W cm <sup>-2</sup> in the fuel cell mode and a current density of 1.79 A cm <sup>-2</sup> in the electrolysis mode at a voltage of 1.3 V. Moreover, the R-PCECs have shown good stability in the electrolysis mode of 100 hours. This study presents a practical method for developing durable high-performance air electrodes for R-PCECs.