Electrically well-contacted state between electrode coating layer and current collector in lithium rechargeable batteries is very important because their insufficient interfacial contact can occur degradation of electrochemical performance.[1] To enhance adhesion property between silicon electrode and copper current collector, in this work, surface-roughened Cu foil (roughness: 4-5μm) is employed as a new current collector. Its physical and electrochemical performances are compared with the commercial smooth Cu foil (roughness: 1-2 μm) for lithium rechargeable batteries. The silicon anode on the surface-roughened Cu foil showed not only higher the adhesion strength, but also improved cycle performance. We verified this issue by measuring adhesion force during the peeling test (Versatile Peel Analyzer, SUNGMOON SYSTECH Corp.) and checking capacity retention ratio during galvanic cycling with 2032 coin half-cells. In addition, scanning electron microscope (SEM) and confocal optical microscope (VertScan, SUNGMOON SYSTECH Corp.) are employed for their morphological analysis.

References

[1] J. Choi et al., JPS, 2014, 252, 138

Acknowledgements

This work was supported by the Human Resource Training Program for Regional Innovation and Creativity through the Ministry of Education and National Research Foundation of Korea (NRF-2014H1C1A1066977)