MCNT-Reinforced Na3Fe2(PO4)3 as Cathode Material for Sodium-Ion Batteries

Abstract

An iron-based phosphate composite (Na3Fe2(PO4)3@MCNT) has been synthesized by solid-state reaction method. As a sodium-ion battery cathode material, Na3Fe2(PO4)3@MCNT composite exhibits excellent reversible specific capacity of 101 mA h g−1 at 10 mA g−1 (0.1 C) and can reach high rate capability up to 96 mA h g−1 after 500 cycles at 100 mA g−1 (1 C). The enhanced sodium-ion storage performance of iron-based phosphate is likely attributed to the increased electronic conductivity and intercalation–deintercalation kinetic of sodium-ion with a high sodium-ion diffusion coefficient of up to 1.12 × 10−10 cm2 s−1 by incorporation of multi-walled carbon nanotube (MCNT).