Enhanced electrochemical performance of a lead–acid battery by a surface modified negative grid with multiwall carbon nanotube coating

Abstract

High-performance lead–acid battery (LAB) negative grids have been prepared using a simple carbon nanotube (CNT) coating method. To assess the properties of these materials for use in LAB systems, galvanostatic charging–discharging measurements, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were performed. The morphology and chemical composition of the CNT coating on the negative grid have been investigated using scanning electron microscopy (SEM), Raman spectroscopy and energy dispersive spectrometry (EDS) characterization. The results clearly demonstrate that the CNT coating is uniform and fully covers the negative grid of the LAB, which acts as a CNT adhesion layer (CNTAL) between the current collector and the negative active materials (NAMs), and improves the electrical conductivity. Moreover, an enhanced charge acceptance, and excellent electrochemical performance and cycling stability have been observed for these CNT coated electrodes in comparison to the uncoated electrode. The obtained results reveal that the CNT coating not only reduces the charge transfer resistance but also protects the NAM from irreversible lead sulfation.