Enhancement of the electrochemical performance of CoB amorphous alloy through the addition of A2B7-type alloy. (28th September 2016)

• Record Type: Journal Article
• Authors: Qiu, Shujun; Huang, Jianling; Shen, Feihong; Pang, Rui; Chu, Hailiang; Zou, Yongjin; Xiang, Cuilin; Yan, Erhu; Xu, Fen; Sun, Lixian; Zhou, Huaiying; Ouyang, Liuzhang; Zhu, Min
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 36(2016)
• Page Start: 16142
• Page End: 16147
• Publication Date: 2016-09-28
• Subjects: Electrochemical properties -- Composite -- A2B7-type alloy -- CoB alloy; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.04.227
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The CoB− x A2 B7 composites ( x = 0–30 wt.%) were prepared by ball milling the powdery mixture of both pristine alloys. As negative electrodes in nickel-metal hydride (Ni/MH) rechargeable batteries, the CoB− x A2 B7 composites exhibit a superior electrochemical performance. It has a maximum discharge capacity ( C max ) of up to 730 mAh/g and its high-rate dischargeability ( HRD ) is significantly increased to 82.5% for x = 30 wt.% at a discharge density of 900 mA/g. The capacity retention rate ( C 100 / C max ) is increased firstly from 37.1% ( x = 0 wt.%) to 45.6% ( x = 5 wt.%), then decreased to 42.4% ( x = 30 wt.%). The anodic polarization (AP) and potential-step measurements indicate that the diffusion ability of hydrogen atoms in the composite electrodes is distinctly improved by doping with A2 B7 -type alloy. Highlights: CoB− x A2 B7 composites ( x = 0–30 wt.%) were prepared. C max remains to be 730 mAh/g for x = 30 wt.%. HRD 900 is significantly increased to 82.5% for x = 30 wt.%.