Hybrid Cryogenic Fuel Linerless Composite Tank

uah p 17026

Docket: UAH-P-17026


Current fuel tanks for spacecraft utilize carbon fiber shells, which can be prone to micro-cracking. An aluminum liner is placed inside of these tanks to combat the leaking issues formed with micro-cracking, but the aluminum liner also increases the weight of the overall fuel tank.

Researchers at UAH have developed a new method for constructing fuel tanks known as the Hybrid Cryogenic Fuel Linerless Composite Tank. This technology utilizes Ionic Liquid Epoxy (ILE) with carbon (fiberglass and Kevlar optional) fiber. ILE is very resistant to micro-cracking, and has low permeability of moisture, oxygen, and hydrogen. By using ILE as composite matrix there is no need for an aluminum liner. ILE is used in higher percentages towards the inside of the tank where the fuel contacts the tank. As the layers of the tank go outwards, ILE matrix is replaced with a cheaper commercial epoxy such as Bisphenol-A resin for the matrix of the outer structure of the fuel tank.

This technology allows a significantly lower weight eliminating the weak and heavy liner. Current composite tank designs must be at least three times as thick as this hybrid design. In addition to reducing expensive ILE material needed by applying it only where needed, the weak bond between the aluminum liner and the overwrap is eliminated. Furthermore, this technology could be applied to any pressurized cryogenic fuel tank, like those used in hydrogen fueled automobiles, forklifts, and other vehicles.


  • Aerospace industry
  • Liquid Hydrogen storage
  • Fuel tanks


  • Strength
  • Micro-crack resistant
  • Weight savings
  • Low moisture permeability


  • State of Development: Prototype
  • Licensing Status: Available for licensing
  • Patent status: Proprietary