A novel flow battery: a lead acid battery based on an electrolyte with soluble lead(II) Part VII. Further studies of the lead dioxide positive electrode
Walsh, Frank C.
© 2009 Elsevier B.V. All rights reserved. This manuscript version is available under the Creative Commons CC-BY-NC-ND 4.0 licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Extensive cycling of the soluble lead flow battery has revealed unexpected problems with the reduction of lead dioxide at the positive electrode during discharge. This has led to a more detailed study of the PbO2/Pb2+ couple in methanesulfonic acid. The variation of the phase composition (XRD) and deposit structure (SEM) have been defined as a function of current density, Pb2+ and H+ concentrations, deposition charge and temperature as well as the consequences of charge cycling. Pure α-PbO2, pure β-PbO2 and their mixtures can be deposited from methanesulfonic acid media. The α-phase deposits as a more compact, smoother layer, which is well suited to charge cycling. While the anodic deposition of thick layers of PbO2 is straightforward, their reduction is not; the complexities are explained by an increase in pH within the pores of the deposit. The results suggest that operating the battery at lead(II) concentrations <0.3 M and elevated temperatures should be avoided.
DTI Technology Programme
This is the author's manuscript version. The version of record is available via DOI: 10.1016/j.electacta.2009.03.075 Available online: 7 April 2009
Vol. 54, pp. 4688 - 4695