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 FePO4‐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 FePO4⋅H2O (FePO4⋅H2O/rGO), synthesized using a graphene oxide (GO) substrate, the resulting FePO4⋅H2O/GNs nanocomposite exhibit superior rate performance, because the GNs have a higher C/O ratio than the rGO. In addition, LiFePO4/GNs with high coulombic efficiency and energy efficiency, prepared using FePO4⋅H2O/GNs, deliver a discharge capacity of 62 mAh g−1 at 120 C rate. Furthermore, a full cell consisting of LiFePO4/GNs and Li4Ti5O12/graphene exhibits excellent rate performance up to 60 C rate. Turning up the power: Aided by urea, hydrophobic graphene nanosheets (GNs) are uniformly dispersed in an aqueous solution without functionalization, allowing fabrication of a FePO4⋅H2O/GNs nanocomposite. The LiFePO4/GNs nanocomposite prepared from the FePO4⋅H2O/GNs precursor exhibits high rate performance, and a full cell comprising LiFePO4/GNs and Li4Ti5O12/graphene electrodes shows remarkable capacity retention.