Doping effects on the structural and electrochemical properties of cathode materials for solid oxide fuel cells: a technical perspective

• Controlled B-site doping improves conductivity in SOFC cathode. • SOFC cathode stability is limited by CO 2 and Cr contamination effects. • Strategic doping ensures structural integrity in cobalt-free SOFC cathodes. • EIS reveals ORR kinetics and degradation in LSC cathodes at 750 °C. • Doping enhances stability by tuning redox behaviour and oxygen mobility. Solid oxide fuel cells (SOFCs) offer a promising option for efficient clean energy generation, with cathode materials playing a critical role in determining overall cell performance. Doping is an effective strategy employed by various studies to enhance the electrochemical performance of cathode materials in SOFCs. The specific choice of dopant is influenced by several factors, including cost, chemical properties, sustainability, and thermal stability at high temperatures. This review provides a technical analysis of doping effects on various series of cathode materials, including perovskite oxides such as (La,Sr)MnO 3 , (La,Sr)FeO 3 , and Ba(Zr,Ni)O 3 , among others. The present study also investigates how dopants modify lattice cell parameters, oxygen vacancy concentration, and linear thermal elongation behaviour to optimize cathode performance. Doping influence on oxygen reduction reaction (ORR) kinetics, electrical conductivity, and long-term stability is discussed. Special attention is given to cobalt-free cathode materials to meet sustainability goals. Several dopants employed in cathode materials were compared, and their effects on the electrochemical performance were highlighted. Key insights into the design of next-generation cathode materials with superior performance and durability for SOFC applications were revealed.