The free energy profile of the Li + deintercalation reaction in Ultimately Li + ends in the bulk electrolyte (④ in Figure .A). ET (coupled to IT) occurs in the step ② ⇌ ③. This step is assumed to be the rate-limiting step based on previous experimental and MD studies. ET between the qO and qR states along the IT desorption profiles provides the reaction barrier for each IT coordinate (ξ), with the minimal energy path corresponding to the most likely reaction pathway (red path in Scheme 1.C).