Production of nanocomposite cathode for Li-S batteries

Nowadays, the rapid increase in energy consumption has started to raise concerns about the environment and climate change. For this reason, the need for energy-efficient and energy-intensive energy resources has increased. Lithium batteries are preferred for mobile phones, laptops, electric cars and many electronic appliances. In this respect, Li-S batteries have higher energy capacities and draw attention due to the abundance of sulfur in the nature and low cost. In this thesis, considering this issue, conductive carbon and sulfur nanocomposite cathodes were developed for Li-S batteries. To produce the cathode for Lithium-Sulfur (Li-S) battery, firstly graphene oxide (GO) and carbon nanotube (CNT) were synthesized. After this, their mixture was ultrasonicated for 2 h with sodium thiosulfate pentahydrate (Na2S2O3.5H2O) solution. Then, to obtain elemental sulfur from Na2S2O3.5H2O, HCl acid was titrated into the suspension. Final suspension was vacuum filtrated and paper was obtained. S/rGO/CNT nanocomposite paper cathodes were produced by reduction of these papers with hydrazine. After the characterizations of the produced papers, cathode materials were obtained with desired properties. Li-S batteries assembled in the form of CR2032 button cell were tested between the voltage range of 1.5 and 3.0 V and at 0.1 C rate. At the end of 100 cycles, the discharge capacity of 1050 mAh/g was reached as the highest yield.