Shell and shrinking core kinetics model of Mg-based hydrogen storage alloys
(1.北京市清华大学机械工程系2.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China3.Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China)
Abstract: The kinetics equation of the Mg-based hydrogen storage alloys (Mg-Ni-MO) was established by the shell and shrinking core model. The total coefficients of the kinetics equation of the hydrogen absorption and desorption process with shell diffusion as the controlling step were determined by semi-empirical and semi-theoretical methods, and the apparent activation energy of the hydrogen absorption process was obtained. The calculation results can well accord with the experimental data, and can well forecast the hydrogen storage capacity and absorption rate at different times. By using the kinetics equation, the effects of temperature and pressure on the hydrogen storage process can also be well understood. The kinetics equation is helpful for the design of the hydrogen storage container.
Key words: Mg-based alloys； hydrogen storage； shell and core shrinking model； kinetics equation