The high pressure tanks to be used on MDI’s vehicles will be made of carbon fiber and thermoplastic liner.
The pressure for standard use is 300b, tested at 450b, and rupture tested at pressures beyond 700b. These tanks are not dangerous in the event of a crash because they do not split up.
This technology is already massively used in vehicles running on natural gas.

When used for more ‘static’ purposes (power generating units etc…), where the tanks’ weight does not affect its operating efficiency, more economic steel tanks could be used.