QCM-D studies of polypyrrole influence on structure stabilization of beta phase of Ni(OH)(2) nanoparticles during electrochemical cycling

Pure beta badly crystallized, beta(bc)-Ni(OH)(2), and hybrid beta(bc)-Ni(OH)(2)/polypyrrole nanoparticles (NPs) were synthesized and immobilized by electrophoretic deposition. The influence of polypyrrole (Ppy) on the structural stability with cycling was evaluated by Quartz Crystal Microbalance with Dissipation. The results show that Ppy stabilizes the NP structure avoiding stress features provoked by the formation of gamma-NiOOH. Ppy remains oxidized during the entire process and, as it is doped with a big counter anion such as dodecylbenzenesulfonate (DBS-) which is not removed during cycling, avoids volumetric changes of Ni(OH)(2) leading to higher cyclability. (C) 2014 Elsevier B.V. All rights reserved.