Despite all of the advances in battery technology over the past century, they remain woefully inefficient methods of storing energy compared to many other systems.
The best batteries in use today hold about 250 Watt-hours per kg. When someone claims they have a viable method to hold 400 watt-hours per kg, you have to take a look. By way of comparison, a gallon of gasoline has about 11,400 watt-hours per kg
Fortunately for +General Motors they paid very close attention to what Envia was doing before investing too much in the technology. ?
The mysterious story of the battery startup that promised GM a 200-mile electric car
At the end of November 2012, Atul Kapadia and Sujeet Kumar hosted the staff of their startup company for a holiday lunch of Mexican food at a Palo Alto, California restaurant. For days, the pair—the CEO and CTO, respectively, of a lithium-ion battery company called Envia Systems—had awaited an email from General Motors. It was…