Modification of aluminum current collectors with laser-scribed graphene for enhancing the performance of lithium ion batteries

In this study, the graphene-modified Al foils have been prepared to assemble lithium ion batteries (LIBs). The graphene-modified Al foils are prepared through a three-step approach comprising: (1) deposition of the polyamic acid (PAA) on the Al substrate; (2) curing the PAA to form the polyimide (PI)-coated Al foils; (3) converting the PI into porous graphene by CO2 laser irradiation. With integration of the PI derived graphene (PDG) in the LIBs, the inserted PDG layer can enhance the adhesion and interface resistance between the active layer and Al electrode. The LiNi0.5Mn1.5O4 (LNMO)// Li4Ti5O12 (LTO) full cells with PDG layer are also fabricated to evaluate the effect of the modified layer on the cell performance. Compared to the pristine Al electrode, the modified current collector can improve the rate performance and reduce the temperature rise during the charge/discharge process leading to better cycling stability.