Refine your search�ソスF     
Report No.

Degradation mechanism against hydrogenation cycles in Mg$$_{2-x}$$Pr$$_x$$Ni$$_4$$ ($$x$$ = 0.6 and 1.0)

Sakaki, Koji*; Terashita, Naoyoshi*; Kim, H.*; Majzoub, E. H.*; Machida, Akihiko; Watanuki, Tetsu; Tsunokake, Shigeru*; Nakamura, Yumiko*; Akiba, Etsuo*

We present an investigation of the degradation mechanism against hydrogenation cycles in Mg$$_{2-x}$$Pr$$_x$$Ni$$_4$$ ($$x$$ = 0.6 and 1.0). Mg$$_{1.0}$$Pr$$_{1.0}$$Ni$$_{4}$$ shows significant degradation and loss of capacity after only a few cycles, while Mg$$_{1.4}$$Pr$$_{0.6}$$Ni$$_{4}$$ did not show any reduction of hydrogen storage capacity until 100 cycles. The peak broadening of X-ray diffraction patterns and accumulation of lattice strain were observed concomitantly with an increase of hydrogenation cycles only in Mg$$_{1.0}$$Pr$$_{1.0}$$Ni$$_{4}$$. These changes were not observed in Mg$$_{1.4}$$Pr$$_{0.6}$$Ni$$_{4}$$. In pair distribution function patterns, $$r$$-dependent peak broadening was observed and it became significant with an increasing number of cycles in Mg$$_{1.0}$$Pr$$_{1.0}$$Ni$$_{4}$$, suggesting an increase of the dislocation density. Mg$$_{1.4}$$Pr$$_{0.6}$$Ni$$_{4}$$ showed higher hardness and more pulverization upon hydrogenation than Mg$$_{1.0}$$Pr$$_{1.0}$$Ni$$_{4}$$.



- Accesses




Category:Chemistry, Physical



[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.