Supplementary theoretical design framework for Type IV hydrogen storage vessel liners: A minimum wall thickness addressing discharge buckling failure

The plastic liner is critical in Type IV hydrogen storage tanks due to its lightweight and hydrogen anti-embrittlement properties. However, hydrogen permeation from free volume and accumulation at the liner-composite interface can cause buckling under inappropriate rapid discharge. Existing studies focus on evaluating buckling under the assumption of its inevitability, examining parameters such as Thickness-to-diameter ratio and discharge rate, but neglect the underlying permeation-structure interaction and lack a systematic design approach for minimizing liner thickness. This work introduces a novel theoretical framework to determine the minimum wall thickness that prevents buckling under any discharge condition by coupling material permeability, structural parameters, and service pressure. The method allows early safety validation via material-level testing, reducing the need for extensive cycle type tests. Furthermore, a large-capacity hydrogen storage vessel is taken as an example, and representative experimental data are analyzed. This research provides a foundational design tool enhancing reliability, cutting development cost, and supporting standard optimization for high-pressure hydrogen vessels.