Enhanced Performance of a Lithium-Sulfur Battery Using a Carbonate-Based Electrolyte.

The lithium-sulfur battery is regarded as one of the most promising candidates for lithium-metal batteries with high energy density. However, dendrite Li formation and low cycle efficiency of the Li anode as well as unstable sulfur based cathode still hinder its practical application. Herein a novel electrolyte (1 m LiODFB/EC-DMC-FEC) is designed not only to address the above problems of Li anode but also to match sulfur cathode perfectly, leading to extraordinary electrochemical performances. Using this electrolyte, lithium|lithium cells can cycle stably for above 2000 hours and the average Coulumbic efficiency reaches 98.8 %. Moreover, the Li-S battery delivers a reversible capacity of about 1400 mAh g(-1) sulfur with retention of 89 % for 1100 cycles at 1 C, and a capacity above 1100 mAh g(-1) sulfur at 10 C. The more advantages of this cell system are its outstanding cycle stability at 60 °C and no self-discharge phenomena.