Lithium-ion intercalation by coupled ion-electron transfer.

Zhang, Yirui; Fraggedakis, Dimitrios; Gao, Tao; Pathak, Shakul; Zhuang, Debbie; Grosu, Cristina; Samantaray, Yash; Neto, Armando R C et al. · Science · 2025

basic_science · Level V

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Abstract

The underlying reaction mechanism in lithium-ion batteries remains poorly understood. We provide experimental and theoretical evidence that lithium intercalation occurs by coupled ion-electron transfer, where ion transfer across the electrode-electrolyte interface is facilitated by electron transfer to a neighboring redox site. Electrochemical measurements for a variety of common electrode and electrolyte materials reveal a universal dependence of the (de-)intercalation rate on Li<sup>+</sup> vacancy fraction, as well as temperature and electrolyte effects consistent with the theory, which could be used to guide the molecular design of lithium-ion battery interfaces.