Could ultracapacitors be the key to hybrid cars?

One of the main concerns regarding hybrid cars for many potential customers is the life of the hybrid battery pack. Additionally, it is the hybrid battery which significantly limits or increases fuel economy, especially in urban driving. Thus, many hybrid vehicle proponents are very interested in lithium-ion technology. Such technology has caused Toyota to believe that a lithium-ion powered Prius could achieve more than 90 mpg. While lithium will be a great technology, it isn't the only technology. For example, Maxwell Technologies, is developing ultracapacitors for hybrid cars, which help manage the electrical load of batteries. Such technology not only extends the life of the hybrid battery, but results in better fuel efficiency and even lower emissions. Despite the beliefs of some geniuses, such as Robert Lutz, hybrids do make business sense - at least if you are thinking about the future.