Materials for advanced flywheel energy-storage devices

Fiber-composite materials and their relevant properties for flywheel energy-storage applications were examined. Commercially-available high-performance fibers were surveyed for specific tensile strength, fiber-to-composite strength translation, and behavior under sustained loading. The strength translation and the behavior under sustained and fatigue loads are critical to determining performance in long-term rotor applications. The choice of materials for flywheel energy-storage is bracketed by the two extremes of performance versus cost.