Decoration of Hydrophobic Graphene Nanosheets with Iron Phosphate Based Materials in an Aqueous Solution

The surfaces of hydrophobic graphene nanosheets (GNs) are successfully decorated, aided by urea, with FePO 4 ‐based materials in an aqueous solution. The hydrophobic GNs can easily disperse in the aqueous solution without functionalization in the presence of urea, leading to the formation of a GNs‐based nanocomposite with minimal sacrifice of the electrical conductivity of the GNs. Compared with reduced graphene oxide (rGO) decorated with FePO 4 ⋅H 2 O (FePO 4 ⋅H 2 O/rGO), synthesized using a graphene oxide (GO) substrate, the resulting FePO 4 ⋅H 2 O/GNs nanocomposite exhibit superior rate performance, because the GNs have a higher C/O ratio than the rGO. In addition, LiFePO 4 /GNs with high coulombic efficiency and energy efficiency, prepared using FePO 4 ⋅H 2 O/GNs, deliver a discharge capacity of 62 mAh g −1 at 120 C rate. Furthermore, a full cell consisting of LiFePO 4 /GNs and Li 4 Ti 5 O 12 /graphene exhibits excellent rate performance up to 60 C rate.