Activation behavior of an AB(2) type metal hydride alloy for NiMH batteries

Date

2016-06-22

Author

Tan, Semra
Shen, Yang
Sahin, Ezgi Onur
Noreus, Dag
Öztürk, Tayfur

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Activation behavior of an AB(2), namely (Ti0.36Zr0.64) (V0.15Ni0.58Mn0.20Cr0.07)(2) Laves phase alloy, was investigated with regards to; particle size, ball milling and hot alkaline treatments. Galvanostatic cycling in open cells showed that an untreated alloy initially had almost no capacity, but reached a value of 220 mAh/g after 14 cycles. Experiments with different particle sizes showed that coarse particles activate faster yielding an improved capacity. In terms of activation more pronounced effect was obtained with boiling the alloy powder in a hot KOH solution. A capacity in excess of 300 mAh/g is reached in the first cycle after a 20 min treatment. The capacity was highest after 80 min, yielding a value of 390 mAh/g well above that expected from the gas-phase storage in the alloy. This was attributed to the formation of rough surface in the powder, which may stabilize hydrogen bubbles allowing pressures above 1 atm to be reached locally in the surface. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Subject Keywords

Metal hydride, Laves phase, NiMH batteries, Activation, Particle size, Hot alkaline treatment, Electrochemical properties, Alkaline-solution, Hydrogen storage, Electrodes

URI

https://hdl.handle.net/11511/30441

Journal

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

DOI

https://doi.org/10.1016/j.ijhydene.2016.03.196

Collections

Graduate School of Natural and Applied Sciences, Article

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Citation Formats

S. Tan, Y. Shen, E. O. Sahin, D. Noreus, and T. Öztürk, “Activation behavior of an AB(2) type metal hydride alloy for NiMH batteries,” INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, pp. 9948–9953, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30441.