Shaping triple-conducting semiconductor BaCo0.4Fe0.4Zr0.1Y0.1O3-δ into an electrolyte for low-temperature solid oxide fuel cells

Abstract

Interest in low-temperature operation of solid oxide fuel cells is growing. Recent advances in perovskite phases have resulted in an efficient H + /O 2- /e - triple-conducting electrode BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ for low-temperature fuel cells. Here, we further develop BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ for electrolyte applications by taking advantage of its high ionic conduction while suppressing its electronic conduction through constructing a BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ -ZnO p-n heterostructure. With this approach, it has been demonstrated that BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ can be applied in a fuel cell with good electrolyte functionality, achieving attractive ionic conductivity and cell performance. Further investigation confirms the hybrid H + /O 2- conducting capability of BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ -ZnO. An energy band alignment mechanism based on a p-n heterojunction is proposed to explain the suppression of electronic conductivity and promotion of ionic conductivity in the heterostructure. Our findings demonstrate that BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ is not only a good electrode but also a highly promising electrolyte. The approach reveals insight for developing advanced low-temperature solid oxide fuel cell electrolytes.

Improving Grain Boundary Conductivity of Ce0.9Gd0.1O2 − δ Electrolyte through Compositing with Carbonate or Semiconductor

“…However, for the GDC-NBSCu electrolyte, the build-in field between GDC and NBSCu particle can prohibit the electron from transport to avoid shorting circuit issue, and this work mechanism had been reported in our previous work. [41] From macroscopic perspective, the electrolyte can be divided into P region and N region. More than that, the flow direction of electrons in the electrolyte can be explained by the band energy alignment.…”

Complex Impedance Analyses of Li doped ZnO Electrolyte Materials

“…The ionic conductivity performance of oxide semiconductors as an electrolyte material in a Na 2 CO 3 (Sodium Carbonate) matrix is widely interested subject in SOFCs 10 to decrease the working temperature of fuel cells with high ionic conductivity performances. The other studies also show that p-n heterojunction composite electrolytes create low-temperature operation of solid oxide fuel cells with good enough ionic conductivity values [11][12][13] . For example, ZnO based composite electrolytes such as ZnO-LCP (La/Pr doped CeO 2 ) and BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ -ZnO with ionic conductivity values of 0.156 Scm −1 (at 550 o C) and 0.098 Scm −1 (at 500 °C), respectively [11][12][13] .…”

“…The effects of grain boundary size change were also investigated for oxide semiconductors in previous study 9 . As well as boundary size, the boundary environments were also investigated subject [10][11][12][13] . The ionic conductivity performance of oxide semiconductors as an electrolyte material in a Na 2 CO 3 (Sodium Carbonate) matrix is widely interested subject in SOFCs 10 to decrease the working temperature of fuel cells with high ionic conductivity performances.…”

A New High‐Performance Proton‐Conducting Electrolyte for Next‐Generation Solid Oxide Fuel Cells

“…At intermediate temperatures (400–700 °C), several perovskite electrolytes (general formula, ABO 3 ) exhibit good electrochemical properties in terms of proton conductivity. [ 4–8 ] Enhanced proton conduction is a promising method to improve the performance in operation. Higher efficiency can be achieved in proton‐conducting SOFCs (SOFC‐H + ) than in oxide ion‐conducting SOFCs (SOFC‐O 2− ), although the maximum voltage and power density are still lower.…”