You must be talking about the flow version of lithium-sulfur. The ones with (presumably) graphite and cobalt oxide electrodes are going into e-scooters in China

You must be talking about the flow version of lithium-sulfur. The ones with (presumably) graphite and cobalt oxide electrodes are going into e-scooters in China now [0]. However, they are yet far from the theoretical 2x in volumetric density of lithium-ion. For a very good survey on the state of the art in lithium-sulfur look up this recent study [1]. [0] https://twitter.com/openbatt/status/766641735229464576 https://twitter.com/openbatt/status/766641735229464576 [1] http://doi.org/10.1039/C5CS00410A http://doi.org/10.1039/C5CS00410A