"Japanese company Sumitomo Electric Industries have developed a new material that they believe can significantly improve the capacity of EV batteries. The material is a form of porous aluminum called 'Aluminum-Celmet.' 'The positive electrode current collector in a conventional lithium-ion secondary battery is made from aluminum foil, while the negative electrode current collector is made from copper foil. Replacing the aluminum foil with Aluminum-Celmet increases the amount of positive active material per unit area. Sumitomo Electric’s trial calculations indicate that in the case of automotive onboard battery packs, such replacement will increase battery capacity 1.5 to 3 times. Alternatively, with no change in capacity, battery volume can be reduced to one-third to two-thirds. These changes afford such benefits as reduced footprint of home-use storage batteries for power generated by solar and other natural sources, as well as by fuel cells." - SlashDot