A new Co-based cathode with high performance for intermediate-temperature solid oxide fuel cells

Abstract

Solid oxide fuel cells (SOFCs) as highly effective energy conversation devices have gained substantial recognition and research interest. The electrochemical properties of the traditional SOFCs are restricted by the sluggish reaction kinetics for the cathode material when lowering the operation temperature to below 600°C. In addition, the stability of the cathode at reduced temperatures is also a big challenge for the widely popularization of SOFC technology. Achieving high activities and stable ORR in the cathode is crucial for the development of SOFCs. The doping active metal method has been demonstrated as an effective approach to optimize the phase structure and improve the ORR activity of the cathode. Herein, we successfully develop an Ir-doped SrCoO_3 − δ (SrCo_0.98Ir_0.02O_3 − δ, SCI) cathode for SOFCs. SCI exhibits a low area-specific resistance (ASR) of 0.057 Ω cm² at 650°C, ~ 44% lower than 0.102 Ω cm² of Ir-free SrCoO_3 − δ. The Ni–Sm_0.2Ce_0.8O_1.90 (SDC) anode-supported fuel cell with SDC electrolyte and SCI cathode obtains an excellent output performance (e.g., 1,128 mW cm⁻² at 650°C). The desired results underscore the feasibility of the Ir-doping strategy as an optimized method for the exploitation of advancing cathode in SOFCs.