A novel method to prepare Ti1.4V0.6Ni alloy covered with carbon and nanostructured Co3O4, and its good electrochemical hydrogen storage properties as negative electrode material for Ni-MH battery

摘要

We describe our recent progress on a novel method to prepare Ti1.4V0.6Ni hydrogen storage alloy covered with nanostructured Co3O4 by utilizing zelolitic imidazolate framework 67 (ZIF-67) as the template. Ti1.4V0.6Ni@C@Co3O4 composite is prepared through a dopamine self-polymerization and a facile precipitation reaction with the subsequent thermal treatment. This specific composite structure combines the high conductivity of carbon together with the promising catalytic property of nanostructured Co3O4, therefore the enhanced electrochemical activity and stability are realized. As a result, Ti1.4V0.6Ni@C@Co3O4 composite electrode possesses a capacity conservation rate of 56.1% after 300 charging/discharging cycles, remarkably larger than that of Ti1.4V0.6Ni (25.3%). Moreover, a study of the kinetics demonstrates that nanostructured Co3O4 coating accelerates the charge-transfer reaction of the electrode. These results prove that coating with carbon and nanostructured Co3O4 is a potential method for enhancing electrochemical hydrogen storage properties of hydrogen storage alloys. (C) 2016 Elsevier Ltd. All rights reserved.