Iodine-Doped Graphene with Opportune Interlayer Spacing as Superior Anode Materials for High-Performance Lithium-Ion Batteries

In this article, the iodine doped graphene (I-RGO) materials with different interlayer spacings were prepared by a one-pot hydrothermal method, and the direct effect of the interlayer spacing on the electrochemical properties was studied as the anode materials of lithium ion batteries for the first time. The results show that the I-RGO(0.01) anode with the optimal interlayer spacing delivers a high specific capacity of 958.1 mAhg(-1) after 390 cycles at the current density of 1 Ag-1. Furthermore, at the high current density of 2 and 4 Ag-1, the high-rate capacities of 525.8 and 343.1 mAhg(-1) could still be achieved for the I-RGO(0.01) electrode after 1045 and 2000 cycles with the small capacity decay rates of 0.032% and 0.024% per cycle, respectively. The excellent electrochemical performance is mainly attributed to the expanded interlayer distance of graphene, which is capable of improving the electrode/electrolyte contact region and accelerating the difussion and surface absorption of lithium ion.