Cross-linked solid-liquid interfaces enable a fast proton transport in the aluminate heterostructure electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Developing solid ceramic fuel cells (SCFCs) requires highly conductive protonic electrolytes for operation below 600°C.
• Conventional SCFCs rely on bulk conduction, which can be inefficient for proton transport.

Purpose of the Study:

• To develop a fast proton conducting electrolyte for SCFCs operating at lower temperatures.
• To investigate the potential of NaAlO2/LiAlO2 (NAO-LAO) heterostructure for enhanced proton conductivity.

Main Methods:

• Fabrication of a NaAlO2/LiAlO2 (NAO-LAO) heterostructure electrolyte.
• Characterization of ionic conductivity and performance of SCFCs employing the new electrolyte.
• Analysis of proton transport mechanisms at solid-liquid interfaces.

Main Results:

• Achieved an ionic conductivity of 0.23 S cm⁻¹ in the NAO-LAO electrolyte.
• SCFCs demonstrated a maximum power density of 844 mW cm⁻² at 550°C.
• Successful operation down to 370°C with a power density of 90 mW cm⁻².

Conclusions:

• The NAO-LAO electrolyte facilitates high proton conductivity through cross-linked solid-liquid interfaces.
• This design approach enables efficient SCFC operation at lower temperatures (300-600°C).
• Reduced polarization loss contributes to improved performance in SCFCs.