Development of industrial-scale L-shaped dielectric barrier discharge reactor for improving capacity retention of graphite anode using plasma pretreatment
Geon Woong Eom, Min Young Hur, Hyung Cheoul Shim, Seungmin Hyun, Hye‐Mi So, Minsub Oh, Areum Kim, Yunseon Jang, Woo Seok Kang, Daewoong Kim, Hyeong‐U Kim, Sang Ho Lee, In Yong Park, Eun Su Jang, Ji-Su Ahn, Dong-hyun Yun, J. Kim, Shinjae You, Jin Young Lee · Journal of Physics D Applied Physics · 2025
Abstract Electrode slurry coatings on the current collector of a Li-ion battery suffer from high mass loading owing to the severe floating of the binder during solvent drying. Atmospheric plasma pretreatment of the Cu current collector forms a functional group on its surface, which forms a hydroxyl bond with the binder materials. However, the Cu foil transferred to a high-speed roll-to-roll machine undergoes displacement due to wrinkling. This foil displacement deteriorates the uniformity of the process results and the discharge stability. To overcome the above-mentioned limitations, in this study, we designed an L-shaped dielectric barrier discharge (DBD) reactor as a combination of the direct-type DBD reactor with high processing speed and a jet-type DBD reactor with high discharge stability for industrial-scale current collector pretreatment. Helium gas injected between a pair of L-shaped electrodes and an electrode with bipolar high-voltage power generated stable seed electrons, which led to a homogeneous discharge between the lower part of the L-shaped electrode and the high-speed moving Cu current-collector surface. The plasma-treated Cu current collector exhibited stronger solvent adhesion and improved surface tension. In addition, the graphite anode coated on the plasma-treated current collector showed high mechanical adhesion strength with the anode materials and high-capacity retention in the half-cell test.