Our group introduced a transitional layer between the La_0.75Sr_0.25Cr_0.5Mn_0.5O_3-d-Gd_0.1Ce_0.9O_1.95 cathode and the electrolyte to improve CO₂ electrochemical reduction performance by a calcining-stripping-calcining method. This work has been published in Journal of Power Sources, 2020, 451, 227743.