Mapping the reduction-resistant solution components: ethers confirmed, tertiary amines revealed

Abstract

Electrolyte engineering for lithium metal anodes requires reduction-resistant components compatible with lithium metal. Ethers are widely considered the primary class of such reduction-resistant molecules. Here, we show through high-throughput quantum chemical screening that, while ethers indeed dominate this space, tertiary amines represent the second-largest and previously overlooked class of reduction-resistant solution components. Experimental validation (literature electrochemistry and Li contact reflectometry) supports low interfacial reactivity of representative tertiary amines under strongly reducing conditions. These results broaden the landscape of reduction-resistant motifs and suggest tertiary amines as promising functional additives (impurity scavengers or CEI modifiers) that do not compromise reductive stability.