EnerDel says tests by the DOE's Argonne National Laboratory confirm that its lithium ion batteries provide longer life and more power than today's hybrid batteries.

According to the company, a modified plug-in Prius attained more than 77 miles per gallon when the nickel metal hydride batteries were replaced by EnerDel's battery pack. The company is using lithium-titanate in its cathode to prevent over heating, which was a problem with previous iterations of lithium ion batteries.

EnerDel says the advances allow the batteries needed to power a hybrid to be reduced in size and weight by half.

Why this matters: Plug-in and extended range vehicle makers are waiting until they are confident in the battery technology before going into production. EnerDel, which has a deal to provide batteries with EV maker Think of Norway, could find many willing customers.

Read more at Edmunds' Green Car Advisor