Na4Fe3(PO4)2(P2O7)@C/Ti3C2Tx Hybrid Cathode Materials with Enhanced Performances for Sodium-Ion Batteries

Developing cost-effective cathode materials is conducive to accelerating the commercialization of sodium-ion batteries. Na4Fe3(PO4)2P2O7 (NFPP) has attracted extensive attention owning to its high theoretical capacity, stable structure, and low cost of raw materials. However, its inherent low conductivity hinders its further application. Herein, carbon-coated NFPP nanospheres are anchored to crumpled MXene nanosheets by an electrostatic self-assembly; this cross-linked structure induced by CTAB not only significantly expands the contact area between particles and improves the electronic conductivity, but also effectively reduces the aggregation of NFPP nanoparticles. The as-designed Na4Fe3(PO4)2(P2O7)@C/Ti3C2Tx (NFPP@MX) cathode exhibits a high discharge capacity (106.1 mAh g−1 g at 0.2 C), good rate capability (60.4 mAh g−1 at 10 C), and a long-life cyclic stability (85.2% capacity retention after 1000 cycles at 1 C). This study provides an effective strategy for the massive production of high-performance NFPP cathodes and broadens the application of MXene in the modification of other cathode materials.