Hierarchically porous MXene decorated carbon coated LiFePO4 as cathode material for high-performance lithium-ion batteries

Abstract

As a promising cathode material for high-power lithium-ion batteries, LiFePO4 (LFP) suffers from low lithium-ion diffusivity and poor electronic conductivity. In this work, hierarchically porous Ti3C2Tx MXene decorated LFP@C (LFP@C/MXene) composite was successfully synthesized by a facile and efficient electrostatic self-assemble method at room temperature with the help of CTAB to regulate charge state. The introduction of MXene sheets realized the formation of hierarchically porous structure and “dot-to-surface” conductive network, enabling the fast ion and electrons transfer for redox reactions, meanwhile, MXene will be partially oxidized into TiO2 and carbon during cycling, which further improved the diffusion of lithium-ion. Together with the optimized structure of LFP@C nanoplates, the resulting LFP@C/MXene exhibits robust high-rate capability (139 mAh·g−1 at 20 C) as well as a long-life cycling stability (156.6 mAh·g−1 at 1 C with superior capacity retention of 94.8% for 500 cycles). This ingenious design highlights the great potential of 2D MXene for facilely constructing multifunctional electrode materials for application in high-rate Li-ion batteries.