Property models and theoretical analysis of novel solid oxide fuel cell with triplet nano-composite electrode

•New models for conductivity, TPB length and hydraulic radius of triplet nano-composite electrode.•Theoretical I–V curves and hydraulic radius are in good agreement with experiments.•Larger core particle and smaller nano particle are helpful for improving properties.•The required nano-particle loading is determined only by conductivity consideration.

Triplet nano-composite electrodes are actively examined experimentally, but there is a shortage of theoretical study. Theoretical models are helpful for understanding the experiments and provide guidance for design optimization of the novel electrode. Here new models for computing the electrode electronic and ionic conductivities, TPB length and hydraulic radius are presented. The novel properties determined by the models are used in a multi-physics numerical model that couples the intricate interdependency among electric conductions, electrochemical reaction and gas transport in SOFC. The theoretical I–V relations and hydraulic radius are in good agreement with the experiments, validatingtheproposed property models. The property models are then used to examine the influence of microstructure and material composition. The results show that: (i) Larger core-particle size and smaller nano-particle size are helpful for improving electrode properties; (ii) The required nano-particle loading is determined by the desired electronic conductivity instead of the desired TPB length.