Oriented wrinkle textures of free-standing graphene nanosheets: application as a high-performance lithium-ion battery anode

Morphology control of a graphene nanosheet (GNS) is important for graphene-based battery electrodes to exhibit the increased practical surface area and the enhanced ion diffusion into the nanosheets. Nevertheless, it is very difficult to minutely control the shape of graphene nanosheets based on the conventional GNS suspension methods. In this work, we fabricated wrinkle textures of free-standing GNS for large area using Langmuir–Schaefer technique. The wrinkles are oriented vertically to the direction of the monolayer compression. The textured structure of GNS was obtained by cross-deposition of each layer with controlling the orientation of the wrinkle direction. These wrinkles can cause Li-ion to diffuse into the voids created by them and raise the specific surface area between the GNSs. Consequently, as a prospective anode for Li-ion battery, the wrinkled GNS multilayer, exhibits the high specific capacity of ~ 740 mAh g−1 at 100 mA g−1 and the great power capability with ~ 404 mAh g−1 being delivered even at 2 A g−1. Furthermore, outstanding cycle performance of the wrinkled GNS multilayer is achieved over 200 cycles at 300 mA g−1 with high Coulombic efficiency of ~ 96%.