Developing cuprospinel CuFe2O4-ZnO semiconductor heterostructure as a proton conducting electrolyte for advanced fuel cells

The interfacial properties of electrolyte materials have a crucial impact on the ionic conductivity of solid batteries and solid oxide fuel cells. Here we construct cuprospinel CuFe2O4 (CFO)-ZnO composite as a functional electrolyte for fuel cell device. In an optimal composition of 0.3CFO-0.7ZnO electrolyte fuel cell, the maximum power output of 675 mW cm(-2) is obtained at 550 degrees C. The electrical properties and electrochemical performance are strongly dependent on the ratios between CFO and ZnO in CFO-ZnO composite. Notably, surprising fuel cell performance with high ionic conductivity is attained by constructing this p-type CFO composited with n-type ZnO. Proton conduction was further verified experimentally. The interfacial ionic conduction pathway between the two constituent phases plays a vital role to enhance the proton conductivity, and the bulk p-n heterojunction can block internal electronic pass. An excellent current and power densities of CFO-ZnO composite are observed along with a high conductivity of 0.35 S.cm(-1) at 550 degrees C. This work opens a new perspective for the semiconductor materials that can widely be developed for electrolytes, based on their tunable band structure. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The interfacial properties of CuFe2O4 (CFO)-ZnO composite electrolyte have a crucial impact on the ionic conductivity of solid batteries and solid oxide fuel cells. Optimizing the ratio between CFO and ZnO can enhance the proton conductivity, leading to surprising fuel cell performance. This work opens a new perspective for semiconductor materials to be developed as electrolytes based on their tunable band structure.