(FORTUNE Small Business) – By creating a cheaper battery for hybrid cars, T/J Technologies hopes to put more of the energy-saving vehicles on the road. The Ann Arbor, Mich., 18-person firm is working with the Army to create a lithium-ion battery that will be more efficient than existing nickel-based ones. "Because of its high cost, the battery is the obstacle to mass commercialization of hybrid electric vehicles," says CEO Maria Thompson (above). T/J has procured some $17 million in contracts from the Army, NASA, and others. The firm is about two years from its goal. —MAGGIE OVERFELT