Lithium-Mediated Ammonia Electrosynthesis over Orderly Arranged Dipoles Regulated Solid-Electrolyte Interphase.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The Haber-Bosch process for ammonia synthesis is energy-intensive.
• Electrocatalytic lithium-mediated nitrogen reduction reaction (Li-NRR) is a promising alternative.
• Solid electrolyte interphase (SEI) formation often hinders Li+ diffusion and N2 activation in Li-NRR.

Purpose of the Study:

• To engineer BaTiO3 nanoparticles with surface oxygen vacancies (Ov) to enhance Li-NRR.
• To investigate the role of Ov-induced ferroelectricity and ordered dipoles in SEI formation and Li-NRR performance.
• To improve ammonia yield and efficiency in the Li-NRR process.

Main Methods:

• Synthesis of Ov-enriched BaTiO3 (BTOV) nanoparticles with enhanced ferroelectricity.
• Experimental characterization and computational modeling to study SEI formation and Li+ behavior.
• Electrochemical evaluation of BTOV for Li-NRR, measuring Faradaic efficiency and NH3 yield rate.

Main Results:

• Ov-induced ordered dipoles in BTOV promote the formation of a LiF-rich SEI.
• The optimized SEI enhances Li+ transfer kinetics and uniform Li+ nucleation.
• BTOV achieved a 93.01% Faradaic efficiency and 6.94 nmol s-1 cm-2 NH3 yield rate at -0.5 V, a 45-fold improvement over BTO.

Conclusions:

• Surface oxygen vacancies and induced ferroelectricity in BTOV effectively modulate SEI chemistry.
• The engineered SEI facilitates efficient Li-NRR, overcoming limitations of traditional methods.
• This work demonstrates a novel strategy using ordered dipoles to enhance electrocatalytic N2 reduction.