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On the basis of previous studies of perovskites in the quasi-ternary system LaFeO3–LaCoO3–LaNiO3, LaNi0.5Co0.5O3 (LNC) is chosen as the most promising air-electrode material in the series for solid...

Summary Solid oxide fuel cells (SOFCs) exhibit potential to become a key technology for future clean energy systems. The metal-supported SOFC exhibits decisive strengths like fast start-up capability, mechanical robustness, and acceptable cost, making it the concept of choice for mobile applications. As a promising example, SOFC-powered range extenders for electric vehicles offer fast refueling and significantly increased driving range, while lowering size, weight, and the cost of the vehicle’s battery. Here, we report the development of a metal-supported SOFC aiming at exceptionally high power density. A knowledge-based improvement of all electrochemically active cell components enables a performance increase up to a factor of 10 and demonstrates the effectiveness of target-oriented optimization of processing and microstructure. Ultimately, enhanced cells meet the industrial performance target by providing a current density of 2.8 A × cm−2 at 650°C and 0.7 V, setting a benchmark for SOFC performance.

Based on previous studies of perovskites in the quasi-ternary system LaFeO3–LaCoO3–LaNiO3, La0.97Ni0.5Co0.5O3 (LNC) is chosen as the most promising air-electrode material in the series for solid oxide cells (SOCs). The properties of the material itself have been investigated in detail. However, the evaluation of LNC97 air electrodes in practical SOCs is still at a very early stage. In the present study, SOCs were prepared based on LNC97 air electrodes. The I-U performance of the SOCs in both solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) modes, i.e. reversible SOCs (r-SOCs), was investigated systematically for different air-electrode designs, temperatures and fuel gases. In general, the performance of the r-SOCs tested in the present study is higher than the published results of other LaFeO3–LaCoO3–LaNiO3-based SOCs and is comparable to or even better than state-of-the-art La1−xSrxFe1−yCoyO3 (LSCF)-based SOCs. Mid-term operation of about 1000 h for SOCs in both SOFC and SOEC modes primarily proved the stability of LNC97-based air electrodes. Impedance spectra were systematically applied to understand the polarization processes of the SOCs.

Power-to-X concepts promise a reduction of greenhouse gas emissions simultaneously guaranteeing a safe energy supply even at high share of renewable power generation, thus becoming a cornerstone of a sustainable energy system. Power-to-syngas, that is, the electrochemical conversion of steam and carbon dioxide with the use of renewably generated electricity to syngas for the production of synfuels and high-value chemicals, offers an efficient technology to couple different energy-intense sectors, such as "traffic and transportation" and "chemical industry". Syngas produced by co-electrolysis can thus be regarded as a key-enabling step for a transition of the energy system, which offers additionally features of CO2 -valorization and closed carbon cycles. Here, we discuss advantages and current limitations of low- and high-temperature co-electrolysis. Advances in both fundamental understanding of the basic reaction schemes and stable high-performance materials are essential to further promote co-electrolysis.