Rheological characterization and optimization of gelled electrolyte for sealed lead–acid batteries by small amplitude dynamic oscillation measurement

Rheological and mechanical properties of silica colloids: from Newtonian liquid to brittle behaviour

“…Trompette and Meireles (2003) and Trompette and Clifton (2004) showed, by means of dynamic measurements, how the nature of the electrolyte, such as the structure-breaker ammonium counterion or the structure-maker sodium counterion, and their concentration strongly affect the kinetics of gelation (Trompette and Meireles 2003) and the strength of the gelled network (Trompette and Clifton 2004) by varying significantly the critical coagulation value. Park et al (2005) found that, despite the fact that a positively charged surface of Ludox® suspension accelerates gelation, the stabilizing sodium ions have to be removed to achieve a high gel strength. Madeline et al (2007) studied the restructuring processes when low volume fraction Ludox® suspensions are dewatered by osmotic pressure and compressed to the point where the colloid aggregates connected to each other and built a macroscopic network.…”

Concentration Optimization of Fumed Silica as Gelator in Lead-acid Batteries

“…2,[4][5][6][7][8] The increased F-SiO 2 content produced an increase in the density of silica particles in the suspension, which increased the frequency of particle collisions and consequently influenced the thixotropic behaviour of these particles, and then the electrochemical properties of the gelled electrolyte. 2,4,[9][10][11][12][13] For instance, the thixotropy of FSiO 2 enhanced when its density increased and thus the gelling time, at which the three-dimensional framework began to form, was shortened. 9,13 With increasing F-SiO 2 density, the rates of the hydrogen and oxygen reactions decreased and the intensity of both hydrogen and oxygen evolution decreased.…”

“…2,4,[9][10][11][12][13] For instance, the thixotropy of FSiO 2 enhanced when its density increased and thus the gelling time, at which the three-dimensional framework began to form, was shortened. 9,13 With increasing F-SiO 2 density, the rates of the hydrogen and oxygen reactions decreased and the intensity of both hydrogen and oxygen evolution decreased. 2 Also, gelled electrolyte was traditionally thought to have higher internal resistance to the conductance and diffusion of ions compared with conventional flooded batteries due to the formation of its three-dimensional framework.…”

“…Although knowledge of the effect of silica density is of practical significance, most investigations only examine a narrow range of silica contents, e.g., 3-5 wt%, or 6 wt%, or even narrower, 2,4,9,11,13 which may limit understanding because contrary phenomena sometimes appeared. In the present work, a systematic examination was performed over a wide range of F-SiO 2 densities from 1 wt% to 12 wt%, over which the density effects on the properties of the gelled electrolytes were investigated, including the conductivity and diffusion of ions, the redox capacity of the lead electrode, the evolution of both hydrogen and oxygen, etc.…”

Investigation and application of polysiloxane-based gel electrolyte in valve-regulated lead-acid battery

“…Compared with conventional flooded or AGM batteries, gel VRLA batteries have the following features: (i) long service life and high reliability under deepdischarge cycles; (ii) no acid stratification and installation in any orientation; (iii) no leakage of acid mist, good charge stability (resistant to thermal runway), maintenance-free operation and wide operating temperature. More attention has been paid to gel VRLA batteries since the 1990s [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The key factor that affects the performance of gel batteries is the gel electrolyte itself.…”