Influence of Mixing Process on the Performance of Electrodes Made by a Dry Coating Method

Thick NMC-LMO blend positive electrodes were manufactured using dry-powder electrostatic spray deposition (ESD) to avoid the use of unwanted solvents. The effects of two dry powder mixing processes prior to ESD on the dry-made electrodes were investigated by peel tests, electrochemical techniques, and microscopic analyses. Electrodes made using high-speed mixing had a dense carbon black/binder layer on the active materials (AM), limiting their contact area with the electrolyte and decreasing the ionic conductivity. Electrodes made using ball mill mixing exhibited a porous structure, enabling more AM-electrolyte contact, thus improving ionic conductivity and lowering charge transfer resistance.