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 the 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.