Cu(N₂)-Li Battery for Ammonia Synthesis

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• The cathodic mechanism of Li-N₂ batteries mirrors lithium-mediated N₂ reduction (LiNR).
• Existing LiNR studies often employ inert platinum anodes, limiting efficiency and stability.
• Ammonia synthesis is crucial for agriculture and chemical industries, demanding sustainable methods.

Purpose of the Study:

• To amalgamate Li-N₂ batteries, LiNR, and Cu-Li batteries into a unified milliliter-scale Cu(N₂)-Li system.
• To investigate the role of a lithium anode with lithium oxidation reaction (LiOR) in enhancing N₂ reduction.
• To explore ammonia accumulation as an indicator of reaction intermediates and optimize the system for ammonia synthesis.

Main Methods:

• Integration of Li-N₂, LiNR, and Cu-Li battery concepts into a single Cu(N₂)-Li system.
• Utilizing a lithium anode to provide a continuous supply of lithium ions via LiOR.
• Employing low-current charging to mitigate polarization during lithium regeneration and improve cycling.

Main Results:

• The lithium anode, through LiOR, ensures a steady supply of lithium ions for N₂ reduction and improves electrolyte stability.
• Voltage reduction was observed compared to systems using platinum anodes.
• Ammonia accumulation was detected in the anode chamber, confirming the presence of reaction intermediates.

Conclusions:

• The integrated Cu(N₂)-Li system demonstrates the potential of Li-N₂ batteries for efficient and sustainable ammonia synthesis.
• The lithium anode offers significant advantages over platinum anodes in LiNR systems.
• Further optimization through low-current charging can enhance the cycling performance of the system.