"Yet just as safe and long-lasting as the lithium ion batteries used in consumer electronics" is not happy-making as energy density increases. The existing lithium-ion technology just barely keeps from overheating and blowing itself up, and it takes about six safety devices to prevent that. (Latest major hoverboard explosion story: [1] All those safety devices really are needed.) Lithium metal batteries (available now as non-rechargeable batteries) are even more dangerous, and are currently prohibited on US passenger-carrying aircraft. Lithium metal battery fires require a class D (flammable metal) fire extinguisher.
They're vague about the safety issue. "We're going to make the anode ultra-thin" is a concern. There are safer battery technologies, such as lithium iron phosphate. That won't run away thermally, and passes the "nail test", where a nail is driven through the battery. Less capacity than regular lithium ion, which is why it's not widely used, although you can buy such batteries commercially from A123. "Boosted" skateboards use them, because they don't blow up.
Solid Energy Systems, submit your cell for UL testing. Otherwise, lithium metal is, literally, not going fly.
Company website: [2]. Uses the common "all hype no info" template.
[1] http://wsvn.com/news/local/hoverboard-explosion-causes-house... [2] http://www.solidenergysystems.com/