In situ neutron reflectometry and GI-XRD reveal the dynamics of SEI formation and layer composition during Li-NRR with current cycling.

The electrification of chemical processes provides a means to effectively utilize rapidly expanding renewable energy resources. Nonaqueous electrochemical systems offer promising opportunities, such as steering selectivity toward N 2 reduction over the H 2 evolution reaction. However, nonaqueous environments pose challenges for reference electrodes (REs), presenting a need for their design and development. In this study, we show the utility of a Li 0.5 FePO 4 (LFP) RE for nonaqueous electrochemical systems, demonstrating various desirable characteristics: remarkable voltage stability across a variety of electrochemical environments, geometric flexibility, and minimal cation leakage concerns. We show that the LFP RE can serve as an immediate replacement for conventional REs commonly employed in nonaqueous electrochemical systems, such as Pt wire and Ag/AgCl REs.