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