Manufacturing of LiNi0.5Mn1.5O₄Positive Composite Electrodes with Industry-Relevant Surface Capacities for Lithium Ion-Cells

Influence of the electrode formulation on the cyclability of LiNi 0.5 Mn 1.5 O 4 was studied for industry-relevant surface capacities (i.e. up to ∼3 mAh cm −2 ) with two mixing methods at the lab scale: ball milling and magnetic stirring. The inactive binder and carbon additives content were varied, as well as the type of those. A more homogeneous distribution of additives is observed in ball milled electrodes compared to stirred ones. The cycle life of the former is degraded with lower coulombic efficiency at first cycle, as a consequence of higher specific surface area of the electrodes and increased parasitic reactions. The coulombic efficiency stabilizes at 99.25% after several cycles, irrespective of the electrode formulation used. The fading of the capacity is minimized by increasing the amount of conductive additives or by substituting part of carbon black for carbon nanofibers. However, the cyclability of the electrodes with high active mass loading is severely decreased. The best result found is capacity retention of 85% after 300 cycles. The electrodes prepared in water with carboxylmethyl cellulose (CMC) exhibit poorer cyclability compared to the ones prepared in N-Methylpyrrolidone (NMP) with Polyvinylidene Fluorine (PVdF). Finally, electrodes with optimized formulation was prepared at the pilot scale and evaluated.