Quantifying Influence of the Solid-Electrolyte Interphase in Ammonia Electrosynthesis

Eric J. McShane, Valerie A. Niemann, Peter Benedek, Xianbiao Fu, Adam C. Nielander, Ib Chorkendorff, Thomas F. Jaramillo, Matteo Cargnello*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review


The solid-electrolyte interphase (SEI) is often invoked to rationalize trends observed during lithium-mediated electrochemical ammonia synthesis (LiMEAS), but quantitative analysis of the SEI constituents is lacking. In this work, we quantified lithium alkoxide SEI species (derived from proton donor reduction) under a variety of electrolyte compositions, using ethanol as the standard proton donor along with five alternative linear and branched alcohol proton donors. With ethanol, we showed that Faradaic efficiency linearly increased from ∼10 to ∼20% as the lithium ethoxide layer thickened. When comparing different proton donors, we found that FE exhibited a “volcano plot” dependence with lithium alkoxide SEI layer thickness, such that FE increased with increasing SEI thickness up to ∼4 μm and decreased with increasing SEI thickness thereafter. We concluded the lithium alkoxide SEI layer limited proton donor and solvated Li+ transport, resulting in an optimal SEI thickness at which proton donor, solvated Li+, and N2 transport were appropriately tuned to maximize NH3 selectivity.
Original languageEnglish
JournalACS Energy Letters
Issue number10
Pages (from-to)4024-4032
Publication statusPublished - 2023


Dive into the research topics of 'Quantifying Influence of the Solid-Electrolyte Interphase in Ammonia Electrosynthesis'. Together they form a unique fingerprint.

Cite this