▎ 摘　　要

The relatively low ionic and electronic conductivities of lithium iron phosphate (LFP) are barriers in its utilization in electric vehicles (EVs) and smart grids. In this study, a composite of N-doped carbon-coated LFP (NCL) nanoparticles attached to a reduced graphene oxide (rGO)-wrapped N-doped carbon framework was synthesized using polydopamine as the binding agent as well as the carbon coating source and was studied as the cathode material for a lithium-ion battery. The N doped carbon framework provided a high surface area for attaching the LFP particles, pore space for Li ion migration, and network for high electrical conductivity. LFP nanoparticles were densely attached to a N-doped carbon framework due to the interaction between rGO and polydopamine. The porous and active material-interconnected structure enabled rapid lithium-ion and electron transport for improved rate performance. Furthermore, the high interaction between rGO and polydopamine could help to achieve long cyclic stability of the electrode material. The as-prepared N-doped carbon framework@rGO@N-doped carbon-coated LFP (NCFG-NCL) showed excellent cycle stability with a capacity retention of 92.2% after 500 cycles at 2 C. A remarkable rate performance with a discharge capacity of 108 mAh/g even at 20 C was also achieved. This NCFG-NCL composite offers new opportunities for high-power lithium-ion batteries.