Experimental battery could increase electric-car driving range

MIT Technology Review : A California start-up company is developing a lithium-ion battery for electric vehicles that could double their driving range. The company, Seeo , has replaced the liquid electrolyte used in most batteries with a solid one composed of pure lithium. Unlike liquid electrolytes, the company’s DryLyte solid polymer electrolyte is nonflammable and nonvolatile, and the pure lithium allows for higher energy density. However, solid electrolytes don’t conduct electricity as well as liquids, and pure lithium tends to sprout metal filaments, called dendrites, that cause short circuits. To overcome those difficulties, the company has incorporated two polymer layers into its battery design. The result is a lithium-ion battery that is not only safer and higher energy but also lighter and more reliable than conventional ones, according to the company. Seeo is currently testing its prototype for another key design element: how many times it can be recharged.