Yirui Zhang, Dimitrios Fraggedakis, Tao Gao, Shakul Pathak, Debbie Zhuang, Cristina Grosu, Yash Samantaray, Armando R.C. Neto, Sravani R. Duggirala, Botao Huang, Yun Zhu, Livia Giordano, Ryoichi Tatara, Harsh Agarwal, Ryan Stephens, Martin Z. Bazant, Yang Shao‐Horn
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 + 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.