Three-dimensional NaTi2(PO4)3@C microsphere as a high-performance anode material for advanced sodium-ion batteries

Herein, three-dimensional NaTi2(PO4)3@C microsphere (denoted as 3D-NaTi2(PO4)3@C) has been designed and fabricated for the first time by using a facile spray-drying method. The well-crystallized 3D-NaTi2(PO4)3@C composite is formed by calcination at 800 °C under Ar atmosphere. The 3D microspheres with particle size of about 4 μm are assembled from 120 nm nanosized grains. As an anode material for sodium-ion batteries, the 3D-NaTi2(PO4)3@C composite exhibits good rate capability and long-cycle life due to the small NaTi2(PO4)3 nanocrystals and conductive carbon layer. It can deliver a reversible capacity of 126.6 mAh g−1 at 0.1C and show a capacity decay rate of <8% when cycled under the high rate of 10C for 500 cycles. These results demonstrate that the as-fabricated 3D-NaTi2(PO4)3@C material is a promising anode material for high-performance sodium-ion batteries.