Mass-transport Control on the Discharge Mechanism in Li–O_sub2sub_ Batteries Using Carbon Cathodes with Varied Porosity
Dr. Mohamed Aklalouch, Dr. Mara Olivares-Marín, Dr. Rung-Chuan Lee, Dr. Pablo Palomino, Prof. Eduardo Enciso, Dr. Dino Tonti, CHEMSUSCHEM, Volume 8, Issue 20 October 26, 2015 Pages 3465–3471, DOI: 10.1002/cssc.201500719
By comparing carbon electrodes with varying porosity in Li–O2 cells, we show that the effect of electrolyte stirring at a given current density can result in a change from 2D to 3D growth of discharged deposits. The change of morphology is evident using electron microscopy and by analyzing electrode pore size distribution with respect to discharge capacity. As a consequence, carbon electrodes with different textural properties exhibit different capacity enhancements in stirred-electrolyte cells. We demonstrate that mass transport can directly control the discharge mechanism, similar to the electrolyte composition and current density, which have already been recognized as determining factors.