Inhibition of hydrogen evolution and corrosion protection of negative electrode of lead-acid battery by natural polysaccharide composite: Experimental and surface analysis

Abstract

The investigated research illustrates the synthesis of composite polymer (GG-VA) using natural polysaccharide (Guar Gum/GG) and vinyl acetate (VA) and screening their inhibitive performance for the hydrogen gas evolution and corrosion inhibition of lead-acid battery negative electrode, i.e., Pb in 5.0 M H2SO4. The developed inhibitor is an environmentally friendly biological molecule and has been used for lead acid batteries for the first time as an additive. The methodology used to evaluate GG-VA inhibitive performance included hydrogen evolution and electrochemical methods, i.e., EIS and PDP. The corrosion inhibition performance of GG-VA is 88.57 %. The Pb surface was screened for GG-VA adsorption via SEM and AFM. The experimental data confirmed the reduction in hydrogen gas evolution with the addition of GG-VA. The EIS result supports the increasing Rct values with the rising GG-VA amount corresponding to the GG-VA adsorption. PDP data reveals the mixed inhibition action and reduction in icorr values with the addition of GG-VA. The increasing temperature causes a decrease in GG-VA performance. GG-V adsorption over the Pb surface was best described by Langmuir isotherm. The Ea data reveals the increase in the energy barrier for corrosion reaction and H2 gas evolution in the presence of GG-VA. The SEM and AFM support the adsorbed layer of GG-VA formation at the Pb surface.