화학공학소재연구정보센터
Journal of Power Sources, Vol.354, 179-188, 2017
Defect-rich TiO2-delta nanocrystals confined in a mooncake-shaped porous carbon matrix as an advanced Na ion battery anode
Inferior electronic conductivity and sluggish sodium ion diffusion are still two big challenges for TiO2 anode material for Na ion batteries (SIBs). Herein, we synthesize TiO2/C composites by the pyrolysis of MIL-125(Ti) precursor and successfully introduce defects to TiO2/C composite by a simple magnesium reduction. The as-prepared defect rich TiO2 delta/C composite shows mooncake-shaped morphology consisting of TiO2-delta, nanocrystals with an average particle size of 5 nm well dispersed in the carbon matrix. When used as a SIBs anode, the defect rich TiO2 delta/C composite exhibits a high reversible capacity of 330.2 mAh g(-1) at 50 mA g(1) at the voltage range of 0.001-3.0 V and long-term cycling stability with negligible decay after 5000 cycles. Compared with other four TiO2/C samples, the electrochemical performance of defect rich TiO2 delta/C is highly improved, which may benefit from the enhanced electronic/ionic conductivities owing to the defect rich features, high surface area rendering shortened electronic and ionic diffusion path, and the suppress of the TiO2 crystal aggregation during sodiation and desodiation process by the carbon matrix. (C) 2017 Elsevier B.V. All rights reserved.