> First you read the chart wrong the volumetric energy density of compressed hydrogen is lower, No, you read the chart wrong: Hydrogen gas at atmospheric press

> First you read the chart wrong the volumetric energy density of compressed hydrogen is lower, No, you read the chart wrong: Hydrogen gas at atmospheric pressure - as in not compressed - has worse energy density by volume. Hydrogen at 700 bar has ~5x the energy per liter than lithium ion batteries at liquid hydrogen 10x. And all of these have energy densities by mass that are 100x better than lithium ion battery or more. > New chemistry is hardly a dream there are a huge range of battery chemistries out there with many under active development that beat current lithium ion batteries. Such as? You gave the example of aluminum, but as you point out they have problems that inhibit practical use: namely corrosion of electrolytes. The point remains: lithium ion is the best battery chemistry we've yet found and even it is far, far from up to the task of powering an aircraft.