Reversible hydriding and dehydriding properties of CaSi: Potential of metal silicides for hydrogen storage

摘要

We found that CaSi reversibly absorbs and desorbs hydrogen. First-principles calculations theoretically indicated that CaSi hydride is thermodynamically stable. The hydriding and dehydriding properties of CaSi were experimentally determined using pressure-composition (p-c) isotherms and x-ray diffraction analysis. The p-c isotherms clearly demonstrated plateau pressures in a temperature range of 473-573 K. The maximum hydrogen content was 1.9 wt % under a hydrogen pressure of 9 MPa at 473 K. The reversible hydriding and dehydriding properties of CaSi suggest the potential of metal silicides for hydrogen storage.