Improving the performance of Pr0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ-based single-component fuel cell and reversible single-component cells by manufacturing A-site deficiency

A-site deficiency perovskite oxides, Pr 0.35 Sr 0.6 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ , and Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ are prepared and act as the semiconductor for single-component fuel cell (SCFC) and reversible single-component cell (RSCC). After reduction, the perovskite oxides can in situ exsolve Co 3 Fe 7 alloy nanoparticles on perovskite and Ruddlesden−Popper structure oxide matrix, further facilitating the hydrogen oxidation reaction. In addition, Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ and reduced Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ have the most oxygen vacancies. Furthermore, Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ based SCFC exhibits the highest cell performance and the mximum power densities ( P max ) are 109.6, 145.2, and 211.1 mW cm −2 at 600, 650, and 700 °C, respectively. It is because Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ shows the highest catalytic activity for oxygen reduction reaction (ORR) and the reduced Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ exhibits the highest catalytic activity for hydrogen oxidation reaction (HOR). For RSCC, when 53%H 2 -47%H 2 O fuel is applied and the P max values are 105.7, 143.0, and 179.6 mW cm −2 at 700, 650, and 600 °C, respectively in solid oxide fuel cell (SOFC) mode and the current densities are −127.2, −205.8, and −265.0 mA cm −2 under 1.3 V at 600, 650, and 700 °C, respectively in solid oxide electrolysis cell (SOEC) mode, indicating that Pr 0.4 Sr 0.55 Co 0.2 Fe 0.7 Nb 0.1 O 3-δ based RSCC can generate the most hydrogen in SOEC mode.