Investigating discharge performance and Mg interphase properties of an Ionic Liquid electrolyte based Mg-air battery
Artikel i vetenskaplig tidskrift, 2017

The performance of a primary Mg-air cell was evaluated at room temperature using a 72 mol% ethylene glycol/trihexyl(tetradecyl) phosphonium chloride ([P-6,P-6,P-6,P-14][Cl]) ionic liquid (IL) electrolyte. The cell was cycling in ambient air as well as in the presence of pure oxygen, and interestingly the cell presented much higher discharge capacity in air than in oxygen, which was attributed to the effect of water in the ambient air. When operated in ambient air, the cell showed promising discharge behaviour with a maximum rate of 0.2 mA cm(-2) and a discharge capacity of around 4.8 mAh cm(-2). When operated at a low rate 0.0075 mA cm(-2), the cell lasted for over 260 h, 10 days, at a potential above 1.3 V. Thus, the main focus of this study is the analysis of the mechanism of discharge capacity loss in this electrolyte, which revealed that, both the polarization due to the presence of a resistive Mg interphase on the anode surface and, concentration polarization due to the quick accumulation of Mg2+ ions in the IL based electrolyte are responsible. In-depth surface characterization suggested the discharge products accumulated on the Mg surface with a proposed formula [P6,6,6,14].Cl.Mg(OH)(2).9[Mg(OCH2CH2OH)Cl]. 40H(2)O most likely had a highly-crosslinked chemical structure, which were responsible for the limited ionic conductivity of the Mg interphase.

Trihexyl(tetradecyl)phosphonium chloride

Surface Characterisation

Primary Mg-air

Ionic Liquid

Författare

Yajing Yan

Chalmers, Fysik, Kondenserade materiens fysik

D. Gunzelmann

Deakin University

C. Pozo-Gonzalo

Deakin University

A. F. Hollenkamp

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

Deakin University

P. C. Howlett

Deakin University

D. R. MacFarlane

Monash University

M Forsyth

Deakin University

Electrochimica Acta

0013-4686 (ISSN)

Vol. 235 270-279

Ämneskategorier

Elektroteknik och elektronik

Den kondenserade materiens fysik

DOI

10.1016/j.electacta.2017.03.067