Nanocomposite electrodes for high current density over 3 A cm^-2 in solid oxide electrolysis cells.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Conversion

Background:

• Solid oxide electrolysis cells (SOECs) offer high energy-conversion efficiency for hydrogen production.
• Current density limitations hinder the widespread application of SOECs.
• Increasing hydrogen production rate is crucial for SOEC technology.

Purpose of the Study:

• To develop a novel structure technology for SOECs to achieve significantly higher current densities.
• To improve the hydrogen production rate of SOECs for practical applications.
• To demonstrate the performance of SOECs with advanced electrode structures.

Main Methods:

• Fabrication of bimodal-structured nanocomposite oxygen electrodes using spray pyrolysis.
• Incorporation of nanometer-scale Sm_0.5Sr_0.5CoO_3-δ and Ce_0.8Sm_0.2O_1.9.
• Creation of conductive networks with broad pore channels using submicrometer-scale particles.

Main Results:

• Achieved a current density exceeding 3 A cm^-2, surpassing state-of-the-art electrolyzers.
• Demonstrated high current densities of 3.13 A cm^-2 at 750°C and 4.08 A cm^-2 at 800°C.
• Attained hydrogen production rates of 1.31 L h^-1 cm^-2 at 750°C and 1.71 L h^-1 cm^-2 at 800°C.

Conclusions:

• The developed bimodal-structured nanocomposite electrodes significantly enhance SOEC performance.
• This structure technology enables high current densities and efficient hydrogen production.
• The findings pave the way for the widespread application of SOECs in hydrogen generation.