A novel carbon-induced-porosity mechanism for improved cycling stability of magnesium hydride  

作　　者：Shuaijun Ding Yuqing Qiao Xuecheng Cai Hongchao Wang Xun Shen Lidong Xu Yixuan Wen Fenglong Jiang Wei Zhou Tongde Shen 

机构地区：[1]Clean Nano Energy Center,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China [2]Hebei Key Laboratory of Applied Chemistry,College of Environmental and Chemical Engineering,Yanshan University,Qinhuangdao 066004,China [3]Department of Mechanical Engineering,The University of Hong Kong,Pokfulam Road,Hong Kong,China

出　　处：《Journal of Magnesium and Alloys》2025年第3期1341-1352,共12页镁合金学报(英文)

基　　金：supported by the National Natural Science Foundation of China(Nos.22279111,51971195,and 11935004);the Natural Science Foundation of Hebei Province(No.B2020203037);Subsidy for Hebei Key Laboratory of Applied Chemistry after Operation Performance(No.22567616H).

摘　　要：MgH2 has been extensively studied as one of the most ideal solid hydrogen storage materials.Nevertheless,rapid capacity decay and sluggish hydrogen storage kinetics hamper its practical application.Herein,a Ni/C nano-catalyst doped MgH2(MgH2–Ni/C)shows an improved hydrogen absorption kinetics with largely reduced activation energy.Particularly,the MgH2–Ni/C displays remarkable cycling stability,which maintains a high capacity of 6.01 wt.%(98.8%of initial capacity)even after 50 full hydrogen ab/desorption cycles,while the undoped MgH2 counterpart retains only 85.2%of its initial capacity.Detailed microstructure characterizations clearly reveal that particle sintering/growth accounts primarily for the deterioration of cycling performance of undoped MgH2.By comparison,MgH2–Ni/C can maintain a stable particle size with a growing porous structure during long-term cycling,which effectively increases the specific surface of the particles.A novel carbon-induced-porosity stabilization mechanism is proposed,which can stabilize the proportion of rapid hydrogen absorption process,thus dominating the excellent cycling performance of MgH2–Ni/C.This study provides new insights into the cycling stability mechanism of carbon-containing Mg-based hydrogen storage materials,thus promoting their practical applications.

关 键 词：Hydrogen storage materials Magnesium hydride Cycling properties Particle stability Carbon-induced-porosity 

分 类 号：O643.36[理学—物理化学] O64[理学—化学]