Carbon nanotube decorated NaTi2(PO4)3/C nanocomposite for a high-rate and low-temperature sodium-ion battery anode

Abstract

A sodium super-ionic conductor structure NaTi₂(PO₄)₃ has been considered as a promising anode material for sodium-ion batteries. However, the inherent poor electronic and ionic kinetics leading to inferior rate and low-temperature performance severely restricts its extensive developments. In this work, we report a carbon nanotube decorated nano-NaTi₂(PO₄)₃/C anode composite to achieve high-rate capability (116.8 mA h g⁻¹ at 1C, 113.3 mA h g⁻¹ at 10C and 103.4 mA h g⁻¹ at 50C) and stable cyclability (about 98% capacity retention at 50C of 1000 cycles) as well as impressive low-temperature performance (about 65.2 mA h g⁻¹ at 10C at a temperature of minus 20 °C). The carbon nanotube network not only improved electrolyte infiltration to decrease the internal diffusion resistance, but also provides fast transport pathways for electrons to enhance the poor electronic conductivity of the NaTi₂(PO₄)₃ anodes. In view of the advantages of the electrode architecture design, we anticipate that the nanocomposites might be promising anode materials for long-life and low-temperature rechargeable sodium-ion batteries.