High-Performance Reversible Solid Oxide Cells for Powering Electric Vehicles, Long-Term Energy Storage, and CO 2 Conversion.

The rapid population growth coupled with rising global energy demand underscores the crucial importance of advancing intermittent renewable energy technologies and low-emission vehicles, which will be pivotal toward carbon neutralization. Reversible solid oxide cells (RSOCs) hold significant promise as a technology for high-efficiency power generation, long-term chemical energy storage, and CO 2 conversion. Herein, RSOCs were, for the first time, studied to power electric vehicles. Based on our experimental results, an ideal RSOC stack was established with reasonable assumptions. Subsequently, through analysis and comparison of important merits, such as power densities, energy densities, charging/refueling time, and fuel economy of RSOC-based electric vehicles (RSOCEVs), conventional internal combustor vehicles (ICEVs), and battery-based electric vehicles (BEVs), the advantages and prospects of RSOCEVs were highlighted. Our H 2 -H 2 O RSOCs exhibit high electrochemical performances in both fuel cell (peak power density = 1.6 W cm -2 at 750 °C) and electrolysis modes (current density = 2.0 A cm -2 at 1.3 V and 750 °C), along with durable reversible operation under a wide range of conditions. In CO-CO 2 , our RSOCs achieved excellent performance in fuel cell mode (peak power density = 0.68 cm -2 at 700 °C). Furthermore, a world record current density of 3.4 A cm -2 at 1.5 V and 750 °C was achieved in the CO 2 electrolysis mode. Moreover, an assessment of the CO 2 electrolysis efficiency was conducted, offering insights for establishing energy storage strategies and mitigating CO 2 emissions. Therefore, the RSOC technology has the potential to assume a central role in a future energy system with abundant renewable power generation while mitigating the CO 2 released from fossil fuels.