Investigation of the temperature effect on electrochemical behaviors of TiO2 for gel type valve regulated lead-acid batteries

In this study, the effect of temperature on the electrochemical behaviors of gel electrolyte systems was investigated for valve regulated lead-acid battery at 0≤ T ≤50 o C. Fumed silica and mixture of fumed silica and TiO 2 were used as gel electrolytes. TiO 2 has a good combination with fumed silica. They were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and battery tests. The anodic peak currents and redox capacities of the gel electrolytes increased with increasing of temperature. The highest anodic peak current and redox capacity were observed at 30 o C in fumed silica and at 40 o C in fumed silica:TiO 2 based gel systems. The solution and charge transfer resistance values decreased in fumed silica:TiO 2 gel system by increasing temperature. In battery tests, discharge curves were obtained for each gel system at 0, 25 and 50 o C. The discharge time of mixture gel electrolyte system was higher than that of fumed silica based gel electrolyte at low (0 o C) and high (50 o C) temperatures. The best performance was obtained in fumed silica based gel electrolyte at 25 o C.