Effect of Carbon Black Addition on Dry-Sprayed Graphite Electrodes Fabrication for Lithium-Ion Batteries for Electric Vehicle Applications

This study explores the optimization of graphite/PVdF electrodes for lithium-ion batteries using a dry electrostatic spray-coating method, with the addition of carbon black (CB) as a conductive additive. We investigate the effects of different mixing sequences, CB content, and mixing times on the processability, mechanical, electrical, and electrochemical properties of highly loaded electrodes. Our results show that mixing graphite and PVdF before adding CB ensures a more even distribution of PVdF and CB across the graphite particles, enabling effective electrostatic coating of high areal capacity electrodes (∼4.6 mAh cm −2 ). Extended mixing times further improve CB distribution, enhancing electrode performance. In contrast, introducing CB too early leads to the agglomeration of PVdF and CB, resulting in poor distribution on the graphite surface and making the powder unsuitable for electrostatic coating. At the specific binder content tested in this study (4.0% in weight), optimized electrodes with CB retain 95.2% of their initial capacity after 150 cycles, outperforming reference electrodes without CB, which retained only 60.2%.