Nanohoneycomb rGO foam as a promising anode material for unprecedented ultrahigh Li storage and excellent endurance at ampere current stability

Abstract

Most rechargeable lithium-ion batteries (LIBs) exploit bulk carbon (e.g., graphite with low interlayer spacing of 0.335 nm) as an anode material despite its low theoretical capacity of 372 mAh/g because it has a high coulombic efficiency, good cycling performance, and low production costs. However, it is difficult to increase the specific capacity of graphite-based anodes without sacrificing these inherent advantages. In the present study, we developed reduced graphene oxide nanohoneycomb foam (H-rGO) as an anode material with higher surface area, porosity, and interlayer spacing for the rapid and efficient lithiation-delithiation of Li-ions. The combination of the hierarchical three-dimensional sponge-like mesoporous structure with highly efficient Li-ion conduction pathways and enlarge active surface area leads to a significantly improved specific capacity (1031 mAh/g at 0.1 A/g) and rapid charging with exceptional stability over 5,000 cycles. The H-rGO anode achieves an outstanding reversible capacity of ∼534 mAh/g over 2,500 cycles at 1.0 A/g, with a capacity retention of 87 and 84 % at high current densities of 10 and 20 A/g, respectively. Our approach is fully compatible with current LIBs technology and offer a simple and efficient strategy to significantly increase Li-storage capacity of under current graphite-based anode technology.