Lithium-sulfur batteries have been off-stage hopefuls, waiting for their chance to strut their stuff – and that time may have arrived, at least in trial performances. Researchers at the Department of WCU Energy Engineering, Hanyang University in South Korea and the Department of Chemistry at the University of Rome, Italy have “demonstrated a highly reliable lithium–sulfur battery showing cycle performance comparable to that of commercially available lithium-ion batteries while offering more than double the energy density.” The team, led by a group from Hanyang University, designed a lithium-sulfur cell using “a highly reversible dual-type sulfur cathode (solid sulfur electrode and polysulfide catholyte) and a lithiated Si/SiOx nanosphere anode.” Their paper in the ACS journal Nano Letters reported that their cell showed “superior battery performance in terms of high specific capacity, excellent charge–discharge efficiency, and remarkable cycle life,” The cell delivered ∼750 mAh g–1 over 500 cycles (85-percent of the initial capacity). Researchers suggested these “behaviors” may result from “a synergistic effect of the …