Nowadays, lowering the operating temperature of solid oxide fuel cells (SOFCs) is a major challenge towards their widespread application. This has triggered extensive material studies involving the research for new electrolytes and electrodes. Among these works, it has been shown that CeO₂ is not only a promising basis of solid oxide electrolytes, but also capable of serving as a catalytic assistant in anode. In the present work, to develop new electrolytes and electrodes for SOFCs based on these features of CeO₂, a new type of functional composite is developed by introducing semiconductor CuO into CeO₂. The prepared composites with mole ratios of 7:3 (7CeO₂–3CuO) and 3:7 (3CeO₂–7CuO) are assessed as electrolyte and anode in fuel cells, respectively. The cell based on 7CeO₂–3CuO electrolyte reaches a power outputs of 845 mW cm⁻² at 550 °C, superior to that of pure CeO₂ electrolyte fuel cell, while an Ce_0.8Sm_0.2O_2-δ electrolyte SOFC with 3CeO₂–7CuO anode achieves high power density along with open circuit voltage of 1.05 V at 550 °C. In terms of polarization curve and AC impedance analysis, our investigation manifests the developed 7CeO₂–3CuO composite has good electrolyte capability with a hybrid H⁺/O²⁻ conductivity of 0.1–0.137 S cm⁻¹ at 500–550 °C, while the 3CeO₂–7CuO composite plays a competent anode role with considerable catalytic activity, indicative of the dual-functionalities of CeO₂–CuO in fuel cell. Furthermore, a bulk heterojunction effect based on CeO₂/CuO pn junction is proposed to interpret the suppressed electrons in 7CeO₂–3CuO electrolyte. Our study thus reveals the great potential of CeO₂–CuO to develop functional materials for SOFCs to enable low-temperature operation.

如今，降低固体氧化物燃料电池（SOFC）的工作温度是对其广泛应用的主要挑战。这引发了广泛的材料研究，涉及新电解质和电极的研究。在这些工作中，已经表明CeO ₂不仅是固体氧化物电解质的有前途的基础，而且还能够充当阳极中的催化助剂。在当前的工作中，为了基于CeO _2的这些特征开发用于SOFC的新型电解质和电极，通过将半导体CuO引入CeO _2中来开发新型的功能复合材料。制备的摩尔比为7：3（7CeO ₂ –3CuO）和3：7（3CeO ₂–7CuO）被分别评估为燃料电池中的电解质和阳极。基于7CeO ₂ –3CuO电解质的电池在550°C时的功率输出达到845 mW cm ^-2，优于纯CeO ₂电解质燃料电池，而具有3CeO ₂的Ce _0.8 Sm _0.2 O2 _-δ电解质SOFC –7CuO阳极在550°C时具有高功率密度以及1.05 V的开路电压。在极化曲线和交流阻抗分析方面，我们的研究表明，开发的7CeO ₂ –3CuO复合材料具有良好的电解质性能，H ⁺ / O ²⁻杂化电导率为0.1–0.137 S cm ^-1在500–550°C的温度下，而3CeO ₂ –7CuO复合材料则发挥了称职的阳极作用，具有相当大的催化活性，表明燃料电池中CeO ₂ –CuO的双重功能。此外，提出了基于CeO ₂ / CuO pn结的体异质结效应来解释7CeO ₂ –3CuO电解质中受抑制的电子。因此，我们的研究揭示了CeO ₂ -CuO在开发SOFC的功能材料以实现低温操作方面的巨大潜力。