Electrochemical performance of polyaniline electroless deposited La-Mg-Ni-based hydrogen storage alloys

Polyaniline (PANI) electroless-deposition is applied onto La-Mg-Ni-based La0.80Mg0.20Ni2.70Mn0.10Co0.55 Al-0.10 hydrogen storage alloy powders in order to improve electrochemical and kinetic properties. FE-SEM and FT-IR results reveal that coral-like PANI particles are deposited on the surface of the alloy. Owing to the PANI coating the initial discharge capacity of the alloy electrodes increases from original 174 mAh g(-1) to 226 mAh g(-1), the capacity retention rate at 200 cycles (S-200) increases from 85% to 88%, and the high rate discharge ability (HRD) is scaled up by 18% at discharge current density of 1500 mA g(-1). Linear polarization, EIS, anodic polarization and potential static step discharge measurements indicate that charge transfer resistance decreases and the hydrogen diffusion rate increases after PANI-coating. (C) 2011 Elsevier B.V. All rights reserved.