Enhancing lead-acid battery performance via strengthening a novel lead alloy (Pb97.25, Sn2.47, Ca0.17, Al0.11) against corrosion in high-temperature, considering surface morphology evolution

Twelve lead-based alloys (labels A 1 -A 12 ) were systematically fabricated by introduction of different elements including Sb, Sn, Al, Ca, Na and Ba metals (W%). Their corrosion behavior was studied using weight-loss measurements, OCP, potentiodynamic polarization, and EIS at various temperatures between 20 and 70°C. Microstructural and compositional analyses of lead alloys were performed by FE-SEM, mapping, and EDX. To investigate the effect of the surface morphological features on corrosion resistance of alloy electrodes, the surface morphological and statistical, watershed algorithm, and fractal studies were performed using FE-SEM analysis. The result show that, the distinct morphology of the label A 5 (Pb 97.25 , Al 0.11 , Ca 0.17 , Sn 2.47 ) alloy electrode provides a lower contact area at interface of electrode/electrolyte, originating from smooth surface with minimum roughness and porosity, with more well-developed and noncomplicated topography. Accordingly, among the manufactured lead alloys and in 70°C, A 5 exhibited the lowest corrosion current density (<0.02 mA cm⁻²), highest polarization resistance (>590 Ω cm²), and most coherent SnO 2 -rich passive layer, resulting in a minimal weight-loss rate. By adding the Sn element into the lead alloy, the reduction of alloy corrosion occurs by the formation of SnO 2 in A 5 alloy. Sn element in A 5 reduces slope of cathodic and anodic lines and shifts corrosion potential towards positive values resulting better corrosion resistance. Sn presence in A 5 alloy, compared to other alloys, has increased surface chemical stability, improved oxidation resistance, and reduced rate of redox reactions in 70°C. These findings demonstrate the critical synergy of Sn with minor alloying elements in enhancing high-temperature corrosion resistance in lead-acid battery applications.