Multilayer Co-casting method for enhanced performance anode-supported reversible solid oxide cells: Fabrication and effect of anode functional layer thickness on electrochemical performance

Abstract

Reversible solid oxide cells (RSOCs) represent an innovative and sustainable energy solution by integrating the functionalities of solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). This dual capability allows RSOCs to efficiently convert various fuel sources into electricity and store energy via chemical production. Despite their potential, the relatively high manufacturing costs of RSOCs pose a significant barrier to widespread commercialization. This study presents an optimized multilayer co-casting method for fabricating RSOCs, offering a simplified and potentially more cost-effective manufacturing approach. Optimization involved adjusting slurry parameters via the fabrication and microstructural comparison of multiple half-cells. This optimized co-casting method yielded a thin YSZ electrolyte layer (∼3 μm), significantly thinner than the conventional thickness achieved via conventional tape-casting processes. Performance evaluations of anode-supported RSOCs demonstrated substantial improvements, with peak power density (PPD) enhancements of up to 24 % in fuel cell mode—rising from 2.03 W cm⁻² at 800 °C for conventionally coated cells to 2.52 W cm⁻² for co-casted cells. In electrolysis cell mode, current density improved nearly threefold, increasing from 0.81 A cm⁻² at 1.3 V for conventionally coated cells to 2.48 A cm⁻² for co-casted cells. Furthermore, investigations into the impact of functional layer thickness revealed that cells with a 17-μm anode functional layer achieved the highest PPD of 2.9 W cm⁻² at 800 °C in fuel cell mode. In comparison, those with an 11-μm layer excelled in the electrolysis mode, reaching a current density of 2.48 A cm⁻² at 1.3 V.