Electrochemical energy storage beyond Li-ion technology: Optimization of cathode and anode in Li-S batteries

Lithium-sulfur batteries have attracted worldwide attention due to its potential for achieving higher energy density than lithium ion battery technology. Sulfur, as a cathode has an excellent theoretical gravimetric discharge capacity of 1672 mAh g^-1. However, Li-S battery technology suffers from poor cyclability caused by poor- electrical conductivity of sulfur and low durability due to dissolution of polysulfides into the electrolyte. Further, use of metal lithium for the anode in Li-S batteries raises safety problems.

Herein, we investigate a novel and facile technique to fabricate the sulfur cathode for Li-S batteries with better cyclability and higher stable gravimetric capacity. In this study we have experimented the use of mesoporous TiO₂ coating to prevent polysulfide dissolution into the electrolyte. For the anode, experiments are being conducted on pre-lithiation of MoO₃ in place of lithium metal. Sulfur cathode and pre-lithiated anode are finally assembled to fabricate a high capacity and durable Li-S full cell. The full cell fabrication requires careful consideration of the irreversible capacity loss of each electrode and appropriate mass compensation.