Relationships between processing, morphology and discharge capacity of the composite electrode

The cycled capacity of Li1.1V3O8 based positive electrodes varies between 100 and 250 mAh g−1 (C/5 rate, 3.3–2 V) depending on the processing parameters. The initial volatile solvent concentration has a strong impact on the distribution of the electrode constituents. For a concentration below the optimal one, the mechanical energy available for mixing is insufficient to overcome viscosity forces and to reach a good dispersion of the constituents in the bulk of the electrode. Above the optimal concentration, settling of the Li1.1V3O8 and carbon black particles in the low viscosity suspensions creates a concentration gradient. In these two cases the electrochemical performance are degraded. The viscosity of the electrode slurry must be systematically adjusted since the grain size and density depend on the active material.