Extension of Anodic Potential Window of Ester-Based Electrolyte Solutions for High-Voltage Lithium Ion Batteries

Abstract

A stability against oxidation of ester-based electrolyte solution was highly improved by a tandem preparation method, i.e., increasing concentration of lithium salt and diluting with a miscible diluent. The resultant saturated electrolyte solution offered a wide anodic potential window and allowed a LiNi0.5Mn0.2Co0.3O2 positive electrode to deliver charge/discharge capacities over 200 mAh g-1 up to 4.6 V almost without capacity fading after 50 cycles. The solution structure was studied to clarify the stabilizing mechanism of the electrolyte solution. On the basis of the results, this study presents a viable strategy to design an electrolyte solution with a wide potential window for various electrochemical systems.