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.

Automated summary

Thick NMC-LMO blend positive electrodes were made using dry-powder electrostatic spray deposition (ESD) to eliminate the need for solvents. The effects of two dry powder mixing processes prior to ESD on the electrodes were investigated using peel tests, electrochemical techniques, and microscopic analysis. Electrodes made using high-speed mixing had a dense carbon black/binder layer, limiting their contact area with the electrolyte and reducing ionic conductivity. On the other hand, electrodes made using ball mill mixing exhibited a porous structure, allowing for more contact between the active material and electrolyte, thereby improving ionic conductivity and reducing charge transfer resistance.