A Novel Solid Oxide Electrolysis Cell with Micro‐/Nano Channel Anode for Electrolysis at Ultra‐High Current Density over 5 A cm⁻²

Abstract

Solid oxide electrolysis cells (SOECs) are regarded as promising candidates for the next generation of energy conversion device due to their extremely high conversion efficiency. However, the electrolysis current density should be further increased to meet the demands of large‐scale industrial application in the future. Here, a novel anode configuration for SOEC is reported that achieves an ultra‐high current density of 5.73 A cm−2 for at least 4 h. To the best of the authors’ knowledge, such current density surpasses the record of present state‐of‐the‐art research. The unique stability under such high current density is attributed to the novel SOEC constructed with a La0.6Sr0.4CoO3−δ anode catalyst nano‐layer to promote oxygen generation, vertically aligned micro channel anode scaffold to accelerate oxygen release, and integrated anode–electrolyte interface to improve the interfacial strength. The novel SOEC successfully demonstrates stable steam electrolysis under an ultra‐high current density of 5.96 A cm−2 at 800 °C under the constant operating voltage of 1.3 V, corresponding to a hydrogen production rate of 2.5 L h−1 cm−2.

Water Electrolysis toward Elevated Temperature: Advances, Challenges and Frontiers

“…In particular, the best reported performance of 5960 mA•cm −2 at 1.3 V and 800 °C was achieved by a SOEC with an innovative anode configuration of micro/nanochannels. 441 Among various related factors, working temperature is one of the most predominant parameters, and SOECs operating at a comparatively elevated temperature typically exhibit greatly improved performance for enhanced thermodynamics and kinetics as well as facilitated ion conduction in electrolyte materials. When the working temperature was increased from 800 to 900 °C, an improvement of the current density from 218 mA•cm −2 to 493 mA•cm −2 at 1.2 V was ascribed to the reduction of the ASR from ∼1.35 Ω•cm 2 to ∼0.75 Ω•cm 2 .…”

“…Novel (a) micro/nano channel (Reproduced with permission from ref , Copyright 2022 Wiley) and (b) bimodal (Reproduced with permission from ref , Copyright 2019 Springer under CC BY 4.0 ) structure of a SOEC oxygen electrode.…”

“…Although many novel materials, such as ScSZ and LSGM, have been developed as SOEC electrolytes with higher ionic conductivities, YSZ has practical advantages, including an enhanced stability and a relatively low cost while maintaining adequate performance. Indeed, a YSZ-based SOEC revealed ultrahigh current densities of 5960 mA·cm –2 and 4080 mA·cm –2 at 1.3 V and 800 °C, with the former surpassing the performance record.…”

Promoting High-Temperature Oxygen Evolution Reaction via Infiltration of PrCoO3−δ Nanoparticles

“…Perovskite oxide is the most common anode material in SOEC due to its high ionic and electronic conductivity, good chemical stability, and compatible coefficient of thermal expansion with the electrolyte. , However, its insufficient catalytic activity calls for efficient strategies to increase the ionic and electronic conductivity or enlarge the TPBs at the anode to enhance the OER activity. , Extensive studies have shown that constructing active anode interfaces by the infiltration method could boost the charge transfer process and expand TPBs, thus increasing the OER activity of SOEC. − Wu et al loaded La 0.6 Sr 0.4 CoO 3±δ (LSC) nanoparticles on the honeycomb yttria-stabilized zirconia (YSZ) scaffold by infiltration to facilitate OER kinetics and achieved twice current density compared with the conventional LSC electrode . Ai et al reported that the infiltration of Er 0.4 Bi 1.6 O 3 nanoparticles could substantially enhance the OER activity of the La 0.76 Sr 0.19 MnO 3+δ electrode by increasing the ionic conductivity of the anode and extending the reaction sites from the electrode/electrolyte interface to the whole surface of the electrode .…”

Non-perovskite Structural CaFe2O4 with Matched Thermal Expansion Coefficients Exhibiting High Performance for CO2 Electroreduction

“…Converting CO 2 into value-added chemicals in solid oxide electrolysis cells (SOECs) is one of the effective strategies. Electricity from clean energies, such as wind power and solar power, can be utilized to electroreduce CO 2 into CO. − …”