Advances in Electrolytes for High Capacity Rechargeable Lithium-Sulphur Batteries

Abstract

Reliable energy storage is a censorious need for an extensive range of requisite such as portable electronic devices, transportation, medical devices, spacecraft and elsewhere. Among the known storage devices, the lithium ion (Li<sup>+</sup>) batteries have enticed attention because of higher theoretical energy density. Nevertheless, the state-of-the-art electrolyte in lithium batteries utilizing a Li<sup>+</sup> salt dissolved in organic-type solvents poses severe safety concerns like flammability arising from dendrite formation. Next generation (beyond Li<sup>+</sup>) battery systems such as lithium sulphur (Li-S) batteries have gained interest in recent times. This battery system has been extensively revisited in an attempt to develop high energy batteries and is now considered as the technology of choice for hybrid vehicle electrification and grid storage. Higher theoretical capacity and higher theoretical energy density, environmental friendliness and low cost of active material make the Li-S batteries an ideal candidate to meet increasing energy requirements. This review looks at various advanced electrolytic systems with much emphasis on solid state electrolytic systems for Li-S batteries because of their striking properties. The technical issues of the sulphur cathode are also summarized and the strategies followed in recent years are highlighted in this review to address these issues. It is anticipated that Li-S batteries with efficient solid electrolytic system may replace the conventional insertion-type low energy density Li<sup>+</sup> batteries in the near future.