Three-Dimensional Porous TiNb2O7/CNT-KB Composite Microspheres as Lithium-Ion Battery Anode Material

Graphical Powerful microspheres : A spherical nano-TiNb 2 O 7 /CNT-KB composite material with a 3D hierarchical heterostructure fabricated by spray drying and solvothermal method is presented. The material is characterized as an anode for lithium-ion batteries demonstrating superior electrochemical performance in terms of reversible charge specific capacity, high rate, and long-term cycling performance compared to bare TiNb 2 O 7 . Nano-TiNb 2 O 7 /multiwalled carbon nanotube and ketjen black (TiNb 2 O 7 /CNT-KB) composite microspheres with porous three-dimensional (3D) hierarchical heterostructure are fabricated by spray drying and solvothermal method. This composite material exhibits a high reversible charge specific capacity of 327.8 mAh g −1 at the current rate of 0.1 C and 151.1 mAh g −1 at 20 C rate. When it is cycled at a high current rate of 5 C for 1000 cycles, the charge capacity is dropped from the maximum value of 220.8 mAh g −1 (6 th cycle) to the end value of 145.4 mAh g −1 , with capacity retention of 65.9 %. The TiNb 2 O 7 /CNT-KB composite material demonstrates much superior electrochemical performance over the bare TiNb 2 O 7 material, and this result should be attributed to its particular porous 3D hierarchical structure, which possesses enhanced electrical conductivity as well as the ability for accommodating volume change and preventing particle aggregation of the electrode active material during the discharge and charge cycles.