286061 Performance and Modeling of Convection Battery
The convection battery forces flow of electrolyte through the cathode, anode, and the separator between them. The goal is to increase ion fluxes (A/cm2) to realize the benefit of thicker electrodes, lower cost batteries, and reduced charge times. A pump that circulates electrolyte was turned off to create a diffusion cell that was used as a control to which the performance of the convection battery was compared.
Based on performance at <1.1 V overpotential (based on a 3.1 V open circuit) and similar capacity utilization, the convection battery provided a 5.6 fold increase in ion flux for these initial studies, increasing flux from 1.6 A/cm2 to 8-10 A/cm2. Little capacity fade was observed on the measured discharge cycles (10 cycles). These studies provided an important milestone in the research, development, and validation of a new battery design including cycling studies with lithium iron phosphate chemistry.
A model for the convection cell is presented based on porous electrode theory. The model uses a concentrated binary electrolyte. The model was applied to a convection cell without electrolyte flow electrolyte, and a convection cell with flow of electrolyte. The different models are compared and parametric studies were performed on the convection cell to determine the effect of flow rate on the cell.
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