A vessel for storing pressurized gas. The storage vessel may be manufactured in a variety of predetermined shapes. Plural frame members are interconnected with each other, collectively forming a lattice frame. A network of internal supports is disposed within the interior of the lattice frame, the internal supports being made of a carbon-reinforced composite material. The storage vessel has an outer shell made up of layers of carbon-reinforced composite material sheets enveloping the exterior of the lattice frame.