Electrochemical performances of Mg45M5Co50 (M=Pd, Zr) ternary hydrogen storage electrodes
(1. School of Materials Science and Engineering, Southeast University, Nanjing 211189, China;
2. College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China;
3. School of Electronics Science and Engineering, Southeast University, Nanjing 210096, China;
4. Dalian Environmental Monitoring Center, Dalian 116023, China)
2. College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China;
3. School of Electronics Science and Engineering, Southeast University, Nanjing 210096, China;
4. Dalian Environmental Monitoring Center, Dalian 116023, China)
Abstract: In order to improve the discharge capacity and cyclic life of Mg-Co-based alloy, ternary Mg45M5Co50 (M=Pd, Zr) alloys were synthesized via mechanical alloying. TEM analysis demonstrates that these alloys all possess body-centered cubic (BCC) phase in nano-crystalline. Electrochemical experiments show that Mg45Zr5Co50 electrode exhibits the highest capacity (425 mA·h/g) among the Mg45M5Co50 (M=Mg, Pd, Zr) alloys. And Mg45Pd5Co50 electrode lifts not only the initial discharge capacity (379 mA·h/g), but also the discharge kinetics, e.g., exchange current density and hydrogen diffusion ability from that of Mg50Co50. It could be concluded that the electrochemical performances were enhanced by substituting Zr and Pd for Mg in Mg-Co-based alloy.
Key words: Mg-based electrode alloy; hydrogen storage; mechanical alloying; body-centered cubic structure; electrochemical performance; elemental substitution