Thermoplastic Alternatives to Thermosets in Type IV COPVs : A Review of Materials, Manufacturing, and Performance for Hydrogen Storage

ABSTRACT The rapid expansion of hydrogen‐powered technologies has developed the need for lightweight, high‐performance storage solutions. Composite overwrapped pressure vessels (COPVs), particularly Type IV designs featuring polymer liners and carbon‐fiber reinforcements, represent the most widely used means of on‐board hydrogen storage due to their exceptional strength‐to‐weight ratios and fatigue resistance. However, conventional thermosetting epoxies, while offering excellent processability, pose significant recyclability challenges amid escalating sustainability and ecology requirements. This review critically examines the state of the art in composite materials for hydrogen tanks, with a special focus on Elium liquid thermoplastic resin as an eco‐friendly alternative. The principal filament winding techniques, namely wet winding, dry winding, towpreg winding, and thermoplastic prepreg winding with in situ consolidation, are systematically reviewed and comparatively analyzed in terms of their processing characteristics, compatibility with resin systems, and resulting composite quality. Recent advancements in the optimization of filament winding process parameters, such as fiber tension, winding angle, and geometry factors, are critically examined for their direct influence on key performance indicators, including burst pressure (the maximum internal pressure a tank can withstand before catastrophic failure) and structural weight. By synthesizing recent advances in materials, processing parameters, and performance metrics, this review outlines a roadmap toward fully recyclable, high‐integrity hydrogen storage solutions.