Barium-doped Pr_(2)Ni_(0.6)Cu_(0.4)O_(4+δ) with triple conducting characteristics as cathode for intermediate temperature proton conducting solid oxide fuel cell

摘要

Proton conducting solid oxide fuel cell(H-SOFC)is an emerging energy conversion device,with lower activation energy and higher energy utilization efficiency.However,the deficiency of highly active cathode materials still remains a major challenge for the development of H-SOFC.Therefore,in this work,K_(2)NiF_(4)-type cathode materials Pr_(2-x)Ba_(x)Ni_(0.6)Cu_(0.4)O_(4+δ)(x=0,0.1,0.2,0.3),single-phase tripleconducting(e-/O^(2-)/H^(+))oxides,are prepared for intermediate temperature H-SOFCs and exhibit good oxygen reduction reaction activity.The investigation demonstrates that doping Ba into Pr_(2-x)BaxNi_(0.6)Cu_(0.4)O_(4+δ) can increase its electrochemical performance through enhancing electrical conductivity,oxygen vacancy concentration and proton conductivity.EIS tests are carried at 750℃ and the minimum polarization impedances are obtained when x=0.2,which are 0.068 Ω·cm^(2) in air and 1.336 Ω·cm^(2) in wet argon,respectively.The peak power density of the cell with Pr_(1.8)Ba_(0.2)Ni_(0.6)Cu_(0.4)O_(4+δ) cathode is 298 mW·cm^(-2) at 750℃ in air with humidified hydrogen as fuel.Based on the above results,Ba-doped Pr_(2-x)Ba_(x)Ni_(0.6)Cu_(0.4)O_(4+δ) can be a good candidate material for SOFC cathode applications.