Delaying the onset of coulombic efficiency loss by adjusting the composite cathode processing parameters

Coulombic efficiency (CE) should be recognized as a key battery parameter since values lower than 98% are indicative of a significant loss in battery performance. CE is directly impacted by the production process in terms of speed and duration. Thus, this work reveals that regardless of the initial CE of the cell, the slurry mixing time of the PEO-based composite cathodes correlates directly to the loss of the coulombic efficiency during the cycling stability. In PEO-based catholytes, these variations are primarly related to the viscosity of the slurry and the molecular weight of the polymer. Each must be adjusted to obtain composite electrodes with optimal architectures and minimal interfacial resistances. Shorter or longer wet-mixing times result in a loss of cycling stability performance that can be reversed by adjusting the dry-mixing speed. These results are significant in determining the relationship between the quality of the electrodes and the operating parameters based on scientific evidence.