Dynamic behaviour of an electrolyser with a two phase solid-liquid electrolyte Part II: Investigation of elementary phenomena and electrode modelling

The dynamic behaviour of an electrolyser with a two phase solid-liquid electrolyte was investigated. In a previous paper some results were obtained with high particle concentrations by means of spectral analysis of the electrolyte resistance fluctuations and of the potential fluctuations. Here low bead concentrations were used. This allows potential and electrolyte resistance transients to be well separated and to be studied in the time domain. This analysis gives a detailed view of the approach and residence of the beads near the collector, and a quantitative estimation of the ohmic drop effect for insulating and conductive beads. Ohmic drop fluctuations account for the potential fluctuations for insulating glass beads. Zinc beads behave as insulating particles in the low frequency range and generate a similar ohmic drop effect. They behave as conducting particles in the high frequency range and the fast charge exchange induces depolarizing pulses which favour the formation of compact zinc deposits on the current collector. From the analysis of both transients and PSDs of the electrolyte resistance and potential fluctuations, the mean percentage of the particles colliding with the collector has been estimated even for high bead concentrations.