Activation behavior of an AB(2) type metal hydride alloy for NiMH batteries
Number of Authors: 5
2016 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 23, 9948-9953 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2016. Vol. 41, no 23, 9948-9953 p.
Metal hydride, Laves phase, NiMH batteries, Activation, Particle size, Hot alkaline treatment
Chemical Sciences Environmental Engineering
IdentifiersURN: urn:nbn:se:su:diva-132398DOI: 10.1016/j.ijhydene.2016.03.196ISI: 000378359400031OAI: oai:DiVA.org:su-132398DiVA: diva2:952575
1st International Symposium on Materials for Energy Storage and Conversion (ESC-IS), Middle Eeast Technical University, Ankara, Turkey, September 07-09, 2015