A high performance lithium-ion sulfur battery based on a Li2S cathode using a dual-phase electrolyte

Abstract

Lithium–sulfur (Li–S) batteries are receiving intense interest because their promise for low-cost and high-energy electrochemical storage exceeds that of Li-ion batteries. Fully-lithiated lithium sulfide (Li₂S) is more desirable than sulfur as a high capacity cathode material because it allows the use of a variety of lithium-free anode materials. Widespread application of Li₂S is hindered by severe drawbacks associated with the solubility of the intermediate charge products, and the insulating nature of Li₂S. Here, we report the feasibility of utilizing Li₂S with a dual-phase electrolyte separated by a lithium super ionic conductor (LISICON). With this cell architecture that enables an efficient utilization of micro-sized Li₂S, the Li–S battery yields high specific capacity, Coulombic efficiency, cycling stability, and no self-discharge. A Li-ion sulfur battery with an aluminium or graphite anode is demonstrated as well in our initial proof-of-concept study.