Discharge Rate Capability of the LiCoO2 Electrode

Abstract

is shown to be a very high rate cathode. Power densities as high as 5500 W/kg have been demonstrated for cells. Such high power was obtained with approximately 75‐μm‐thick electrodes fabricated with 5 μm or smaller diameter particles and having about 65% porosity. A 2 M solution in a mixed solvent consisting of 25 vol% propylene carbonate and 75 vol% methyl acetate was the electrolyte. The high concentration of this electrolyte, together with its room temperature conductivity of , allowed the discharge of cells at currents as high as 100 mA/cm2. The utilization at 50 mA/cm2 and higher current densities showed a strong dependence on separator porosity. Cells with a 25‐μm‐thick separator having about 55% porosity showed significantly better power output than ones containing a separator of the same thickness having 32% porosity.