Today, the modern world cannot be described without considering lithium-ion batteries. Among the various energy conversion/storage systems proposed over the two last centuries, electrochemical storage and more specifically batteries seem to be very well positioned to satisfy these needs, but research to meet the application requirements is still an imperious need .
Lithium-sulfur (Li-S) batteries are regarded as one of the next-generation energy storage systems due to the extremely low-cost sulfur and their high energy density [2-4]. The price of sulfur per metric ton was as low as $160 USD in 2012 . The theoretical capacity of sulfur is 1672 mAh/g (calculated based on S0 ↔ S2-). Coupled with the average operating voltage of a Li-S cell (2.15 V vs Li+/Li0) and the theoretical capacity of a pure lithium anode (3862 mAh/g, calculated based on Li+ ↔ Li0), the energy density can be estimated as high as ~2500 Wh/kg, which is an order of magnitude higher than that of traditional Li-ion batteries. [2,6,7]
The S-LFP-MWCNTs cathode can achieve the highest initial discharge capacity of 719, 595 and 384 mAh/g-sulfur at rates of 0.2 C, 0.5 C, and 2 C, respectively. After 160 charge/discharge tests, the cathode displays a stable capacity of 561 mAh/g-sulfur at the C-rate of 0.2 C.
The objective of this work is to investigate the fundamental chemistry of sulphur composites and lithium polysulfides and develop new functional electrode materials and architectures for high energy, low cost Li-S batteries.