Effects of the Pre-Freezing Time on the Structures and Electrochemical Performances of Co-B Alloys

Abstract:

A series of Co-B alloys with uniform nanoparticles were prepared via a vacuum freeze-drying method, which the precursors of Co-B alloys were prepared by the reduction of bivalent cobalt chloride with aqueous sodium borohydride solution. The alloys were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and brunauer emmett teller (BET) surface area measurement. The electrochemical activities of Co-B samples were examined by charge-discharge test. This work studied the influence of pre-freezing time on the microstructure and electrochemical performance. The sample pre-freezing for 3 hours exhibits the best cycling performance than others, the discharge capacity increase to its maximum 438mAh/g, and it still remained 232 mAh/g after 60 cycles at a current of 50 mAh/g; while those of samples pre-freezing for 1 hour and 5 hours are 399 mAh/g and 413mAh/g, respectively.

• Periodical: Advanced Materials Research (Volumes 391-392)
• Pages: 1085-1089
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.391-392.1085
• Online since: December 2011
• Authors: Chuan Wu, Chun Hui Pang, Feng Wu, Ying Bai, Chi Chen, Yu Zhong
• Keywords: Alkaline Secondary Battery, Co-B, Dehydrogenation, Electrochemical Performance, Hydrogenation, Vacuum Freeze-Drying

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