A recent study by Dutch researcher Robin Gremaud has shown that metal hydride hydrogen tanks are actually 40 to 60-percent lighter than a battery pack on an electric vehicle. The study proposed using light metal alloys comprised on magnesium, titanium and nickel for the hydrogen tanks.
By using the technique of hydrogenography, Gremaud was able to simultaneous measure the absorption rates for hydrogen of thousands of metals. The three metals listed were tested in varying ratios to measure absorption to find the ideal composition.
According to the study, “The battery, the competing form of storage for electrical energy, comes off even worse. Driving four hundred kilometres with an electric car, with performances comparable to those of the Toyota Prius, would require the car to carry 317 kilos of modern lithium batteries for its journey. With Gremaud’s light metal alloy this same distance would require a hydrogen tank of ‘only’ two hundred kilos.”
In the WTS 2008 Policy Seminar, Jaycie Chitwood of Toyota Motor Sales pointed out that under current conditions driving a Plug-in Toyota Prius 36 miles on all battery power alone would require 12 times the battery capacity of the current Prius or in other words enough batteries to fill the entire trunk.
There is no doubt that all electric and plug-in electric vehicles will have their place in the future of transportation. But, in its current state, battery technology has many miles to travel before they will have the edge on weight, range and refueling / recharging speed as hydrogen vehicles do right now.