Investigation of Poly(3,6-Dioxa-1,8-Octane-Dithiol)-Based Organosulfur Polymer as the Positive Electrode Material in Rechargeable Li-S Battery

The Li-S batteries are considered as one of the most promising new generation Li-ion battery systems. However, there are recognized hurdles such as electronic insulating nature of sulphur, polysulfide shuttle issue, volume expansion and self-discharge, which impede the widespread commercialization of Li–S batteries (LISB). To address the insulating nature of the sulphur, carbon-based host materials were utilised. However, increasing the amount of carbon content in the cathode matrix reduces the specific capacity, gravimetric energy density. To address the above-mentioned issues, we believe that developing or utilising the sulphur confining materials favourably macromolecules so-called organosulfur polymers, as a suitable candidate and potential solution. Hence, we developed sulfur rich organosulfur based polymer, Sulfur- poly(3,6-dioxa-1,8-octane-dithiol) [PSDODT] via an inverse vulcanization reaction as well as by changing the feed composition, the sulfur content of the polymer. Then the developed PSDODT used as an alternate to elemental sulfur as well as loaded to carbon host materials such as carbon black (CB) and reduced graphene oxide (rGO) in a different weight ratio of sulfur and DODT (30:70, 40:60, and 50:50) with CB and rGO as well as evaluated its electrochemical performances as the cathode materials for the Li-Sulfur Batteries. Among the developed cathode materials, the 40S:60DODT-rGO showed enhanced specific capacity with good cyclic performances than the 30S:70DODT-CB. In addition to that, it has been identified from the results that organosulfur based polymer PSDODT can be utilised as an alternate to conventional elemental sulfur and opens up some new research possibilities to the scientific communities pursuing in LISB.