Hydrogen Storage in Small Size Hollow Microspheres

Hollow microspheres with less than 1 millimeter in diameter and several micrometers in wall thickness are attractive for hydrogen storage and transportation. The hollow microspheres can be made by drop tower technique, microencapsulation and vapor deposition methods. By immersion in high pressure hydrogen for a period of time at elevated temperature, the hollow microspheres can be filed with hydrogen gas at pressures up to one hundred MPa. The hydrogen mass fraction can be varied from 1% to 10% for hollow microspheres with different membrane hoop stress at failure.