DEVELOPMENT OF GEL ELECTROLYTE IN VALVE REGULATED LEAD-ACID BATTERY USING GRAPHENE-POLYANILINE COMPOSITE

Abstract

In this work, novel additives in the gelled electrolyte of valve- regulated lead-acid (VRLA) battery were studied, including graphene (GP), graphene-polyaniline (GP-PANI), and graphene-polyvinylpyrroridone-polyaniline (GP-PVP-PANI). Gelled electrolyte was prepared by mixing fumed silica, concentrated sulfuric acid, and additives with high stirring rate of homogenizer at room temperature. The electrochemical behavior and performance of VRLA battery were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge method. The morphology of battery plates was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), and infrared spectroscopy (IR). The results were found that gelled electrolyte in the presence of GP-PANI provided the lowest charge transfer resistance comparing to GP and GP-PVP-PANI. After that, various GP-PANI concentrations between 5 and 60 ppm added into the gelled electrolyte were investigated. The lowest charge transfer resistance was obtained at 20 ppm of GP-PANI. Furthermore, gelled electrolyte in the presence of GP-PANI additives provided higher discharge capacity than the conventional gel electrolyte without GP-PANI additive. Therefore, the addition of GP-PANI additive showed the significant improvement of battery performance.