That near-mythical 10X (of current lithium cells’ energy density) battery hangs out there on the distant horizon, promising automobiles that can exceed 1,000 miles range, or light aircraft that can carry four at Cessna-like distances. Right now, we have two-place trainers good for an hour’s laps around the circuit, and the hope for improvements soon. OXIS Energy, a UK-based company, has achieved 425 Watt-hours per kilogram at the cell level, and looks to go higher in the near future. Lithium-Sulfur – A Worthy Alternative? Promoters of lithium-sulfur batteries suggest their products have several desirable characteristics and performance boosts that may transcend the limits of lithium-ion cells. Sion Power, for instance, claims availability of their Licerion battery with an even better 500 Watt-hours per kilogram and 1,000 Watt-hours per liter. On the same track, OXIS Energy has announced they have a demonstrated 425 Wh/kg cell, expected to rise to 450 Wh/kg by the end of the year and to 500 by …