Lithium Sulfur batteries: SOLVED! Two new tech breakthroughs in the same week!

Lithium Sulphur (or Sulfur) batteries have been on the ‘hopeful technology’ list for over a decade now. Potentially they have 5 times the energy density of existing lithium-ion batteries. The trouble is, previous prototypes had terribly short cycle lives, so they were pretty much useless. Now, after ten years of waiting, suddenly two different solutions have been announced within a week of each other, both claiming to solve the problem. So, which one will come out on top?