Contribution of n-TiO2 Combining with PAM/PPG/NFS Ternary Additive to Improving the Capacity of Gel Lead Acid Battery

Abstract

An additive mixture of nanoTiO2 (n-TiO2 in sol form), nano fumed SiO2 (nf-SiO2, NFS), propylene glycol (PPG) and polyacryl amide (PAM) was used for preparation of gelled electrolytes. They were characterized by some physicochemical and electrochemical methods to consider their effect on the capacity of lead acid battery during working process. The material property of samples was observed by scanning electron microscopy, thermal analysis, FTIR study, and X-ray diffraction. The resistance of electrolyte was considered by electrochemical impedance spectroscopy. The capacity of battery were observed by charge-discharge at constant current density (0.8 mA cm−2) and charge-discharge according to the international recognized standards (IEC 61056–1:2012; 2.35 V/6 h–0.25 C/1.7 V or 0.5 C/1.7 V) for anodized PbO2 cells and VRLA cells (Gel-VRLA cells, AGM Gel-VRLA cells, and AGM flooded-VRLA cells), respectively. The results showed that a suitable content of n-TiO2 should be 0.2 wt% combined with ternary additive (PAM/PPG/NFS, 0.2/0.1/0.6 wt%, respectively). The discharge capacity of the VRLA cells with 0.2 wt% n-TiO2 was higher than that without n-TiO2 at both discharge rates 0.25 and 0.5 C. In particular, their service life reaches more than 225 cycles at 0.25 C discharging thanks to the use of AGM separator, meeting the IEC 61056–1:2012 standard (200 cycles).