Design and synthesis of three-dimensional NaTi2(PO4)3@CNT microspheres as advanced anode materials for rechargeable sodium-ion batteries

NASICON-type NaTi2(PO4)(3) with a zero-stress framework has been receiving particular attention as an advanced anode material for high-performance sodium-ion batteries. In this work, the three-dimensional (3D) NaTi2(PO4)(3)@CNT microspheres were prepared by using a spray drying method with thermal calcination. In this composite, the conductive CNT was condensed into the NaTi2(PO4)(3) microspheres, leading to intimate interfacial contact between the NaTi2(PO4)(3) and CNT. As an anode for energy storage, the NaTi2(PO4)(3)@CNT exhibited a high reversible capacity and stable cycling performance due to the constructed 3D network which could greatly enhance the electronic conductivity of NaTi2(PO4)(3) material. It delivered the initial capacities of 127, 125 and 123 mA h g(-1) at 0.1, 0.2 and 0.5 C, respectively. Even at 10 C, this composite still showed a capacity of 88 mA h g(-1) with capacity retention of about 99.3% over 20 cycles.