It is here that electrode materials are mixed and pressed onto aluminum sheets along with active materials, conducting aids and binders. The cells have different properties depending on the types and proportions of materials used. Nissan is working with lithium manganate as a positive electrode material as well as iron formulations. The challenge for battery makers is slightly different depending upon the application. For hybrids, scientists need the battery to be able to put out a lot of power, while for an all-electric vehicle, the amount of energy density is more important. They seem to be making some solid gains too. Nissan claims a power density of 2,500W/kg (English translation; lots of power) for a hybrid vehicle battery while its energy densities for an all-electric car battery have reached 140Wh/kg. That's not as good as the Tesla Roadster's numbers, but it is longer lasting with better thermal stability. As more advancements in batteries are made, we expect car companies to really start bragging about their products using increasingly technical language. If you want to understand what they are talking about, brush up on the science of modern batteries by clicking here.