Type IV Hydrogen Storage Vessels: Liner-Boss processing challenges by rotational moulding

Abstract

[Excerpt] Type IV hydrogen storage vessel is a compact and light weight structure used to store hydrogen gas under very high pressure, commonly at 700 bar, making it suitable for transport applications like fuel cell electric vehicles. It is typically constituted of a polymeric liner, which acts as a gas barrier, surrounded by a carbon fibre-reinforced polymer composite overwrap that provides mechanical strength, and a metal component, the boss, which connects the interior of the tank to the supply system. The interface between the polymeric liner and the metal boss is one of the critical points in tank design as it must ensure a complete seal to prevent hydrogen leaks. However, factors such as high fuelling pressures, liner permeability to hydrogen, and differences in the mechanical and thermal properties of polymers and metals can induce internal stresses, leading to cracks and adhesion failure. [...]