Critical review of models for H2-permeation through polymers with focus on the differential pressure method

To reduce loss of hydrogen in storage vessels with high energy-to-weight-ratio, new materials, especially polymers, have to be developed as barrier materials. Very established methods for characterization of barrier materials with permeation measurements are the time-lag and flow rate method along with the differential pressure method, which resembles the nature of hydrogen vessel systems very well. Long measurement durations are necessary to gain suitable measurement data for these evaluation methods, and often restrictive conditions have to be fullfilled. For these reasons, common models for hydrogen permeation through single-layer and multi-layer membranes, as well as models for hydrogen gas properties were collected and reviewed. Using current computer power together with these models can reduce measurement time for characterization of the barrier properties of materials, while additional information about the quality of the measurement results is obtained.