Discharge Precipitate's Impact in Li-Air Battery: Comparison of Experiment and Model Predictions

Abstract

This paper presents a fundamental study on the precipitate formation/morphology and impact of discharge precipitates in Li-air batteries and compares the voltage loss with two Li-air battery models, namely a film-resistor model and surface coverage model. Toray carbon cloth is selected as cathode, which serves as large-porosity electrodes with an approximately planar reaction surface. Imaging analysis shows film formation of precipitates is observed in all the experiments. In addition, toroidal and aggregate morphologies are present under lower currents as well. Specially, toroidal or partially toroidal deposit is observed for 0.06 A/cm 2. Aggregates, which consist of small particles with grain boundaries, are shown for 0.03 A/cm 2. We found that the film-resistor model is unable to predict the discharge voltage behaviors under the two lower currents due to the presence of the deposit morphologies other than the film formation. The coverage model's prediction shows acceptable agreement with the experimental data because the model accounts for impacts of various morphologies of precipitates.

Spatial Variations of Cathode Reaction and Discharge Precipitate in Li-Air Batteries: Analysis and Experimental Measurement

“…XRD was performed, showing that the deposit is primarily Li 2 CO 3 as observed by our previous study. 36 Figures 3 and 4 show the precipitate at the layer 1 surface, i.e. the cathode surface on the air side.…”

Capacity loss of non-aqueous Li-Air battery due to insoluble product formation: Approximate solution and experimental validation

“…Schematic of a Li-air battery and its discharge operation with Li 2 O 2 as an example of discharge product[13]. metal-insulator-metal charge transport model to investigate the electrical conductivity through Li 2 O 2 films produced during Li-air battery discharge.…”