Nano film Pr2Ni0.8Cu0.2O4+δ decorated La0.6Sr0.4Co0.2Fe0.8O3-δ oxygen electrode for highly efficient and stable reversible solid oxide cells

Abstract

Reversible solid oxide cell as an emerging star has attracted lots of attention because of its great potential in energy conversion and storage as well as reducing CO2 emissions. However, the traditional oxygen electrode (La0.6Sr0.4Co0.2Fe0.8O3-δ, LSCF) still faces insufficient activity for oxygen reduction and oxygen evolution reaction as well as instability due to Sr segregation. Herein, a simple strategy is adopted to improve the catalytic activity and stability by coating Pr2Ni0.8Cu0.2O4+δ (PNCO) layer onto LSCF oxygen electrode (PNCO-LSCF). The cell with PNCO-LSCF oxygen electrode achieves a maximum power density of 1.358 W/cm2 at 750°C, exhibiting a significant performance promotion compared with bare LSCF oxygen electrode (0.907 W/cm2) in fuel cell mode. The cell also presents a high electrolysis current density of 1.953 A/cm2 at 1.5 V with 50% H2O at 750°C, leads to a reduction of Rp from 0.141 Ω·cm2 to 0.105 Ω·cm2 after coating in electrolysis cell mode. Furthermore, PNCO-LSCF single cell exhibits long-term stability of 160 h under reversible operation mode without noticeable degradation. Therefore, coating LSCF with PNCO has been proven to be an effective method to achieve high performance. It also opens a door for the modification of the electrode in other fields such as metal air battery, water splitting etc.