New Combination Battery Said to Improve Electric Car Performance A U.S. company says it has developed and patented a technology that will improve the performance of electric and hybrid vehicles by combining lithium ion batteries with a more traditional electricity storage device called a capacitor. The company, AFS Trinity, said that while lithium ion batteries store large amounts of energy, they do not deliver it quickly enough to allow rapid vehicle acceleration. By adding a capacitor — which stores far less energy but delivers it quickly to a vehicle’s power train — the new combined batteries provide ample storage and good acceleration, the company said. As a result, electric and hybrid vehicles can be made with smaller lithium ion battery packs, as the capacitor eliminates the need for the large lithium ion batteries required for good acceleration. Edward W. Furia, chief executive of AFS Trinity, said the company expected to license and sell the new technology — which has been tested in General Motors’ Saturn Vue hybrid — to numerous automakers.