Improving rate capability of lithium-ion batteries using holey graphene as the anode material

Despite the benefit of high specific capacity offered by graphene when used as the anode material in lithium-ion batteries (LIBs), its large aspect ratio could lead to long transport paths for Li ions, thereby limiting the rate capability. We demonstrate that holey graphene (HGE) prepared by a simple and lowcost method can effectively improve the rate capability of LIBs by providing shortcuts for Li-ion diffusion through the holes in fast charge/discharge processes. HGE showed a high reversible capacity of 742 mAh/g at a current density of 0.1 A/g after 80 cycles, which was 2.3 times as much as that of non-holey graphene (GE). Moreover, at a high current density of 10 A/g, HGE still possessed a reversible capacity of 141 mAh/g, while GE retained only 27 mAh/g. In addition, both the charge transfer resistance and the interfacial resistance of HGE were lower than those of GE. We believe that HGE have high potential in applications of high-power electrochemical storage devices such as plug-in hybrid electric vehicles. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.