Synthesis of $Li_2S$ -Carbon composite materials via ultrasonic spray pyrolysis and their electrochemical performance

Abstract

In light of projections over the inevitable depletion of fossil fuels, much attention has been directed towards the search for alternative sources of energy, especially in terms of storage. This has led to the advent of powerful energy storage technology, mainly in the form of rechargeable batteries such as lithium-ion batteries. Among these batteries, however, the lithium-sulfur battery has received its fair share of the spotlight due to its potential to reach beyond the current battery technology in terms of its energy density. In fact, lithium-sulfur batteries are expected to be able to provide approximately four to five times more energy density than that of conventional lithium-ion batteries. Unfortunately, several problems such as polysulfide dissolution, metal degradation, and volume expansion upon continued cycling plague the potential commercialization of this promising battery system. This work strives to circumvent these issues by proposing the synthesis of a different cathode for lithium-sulfur battery systems: $Li_2S-carbon$ composites. This material allows the use of alternative anode materials other than lithium metal, which is the limiting performance factor in most cases. $Li_2S-carbon$ composites are synthesized via ultrasonic spray pyrolysis followed by a simple heat treatment process. The as-synthesized material was not only analyzed through various techniques, but also tested as cathode materials for lithium-sulfur batteries in half cell systems with lithium metal anodes. These tests yielded satisfactory results, where approximately $450 mAh g^{-1}$ was maintained for over 60 cycles at 0.5 C.