Pseudocapacitive Behavior of Nb۲O۵-TNTs Nanocomposite for Lithium-ion Micro-batteries

The present study aims to introduce Niobium pentoxide-Titanium nanotube (Nb۲O۵-TNTs) composite as a novel anode material synthesized through hydrothermal method. In this respect, Nb۲O۵ nanoparticles and TNTs are separately synthesized through sonochemical and anodizing processes, respectively. According to FESEM images, the well-oriented TNTs with inner and outer diameters of ۷۰ and ۸۸ nm, respectively, are well decorated by Nb۲O۵ nanoparticles. The Nb۲O۵-TNTs anode shows the areal charge and discharge capacities of ۰.۱۶۷ mAh/cm۲ and ۰.۱۴۶ mAh/cm۲, respectively, at ۰.۱۱۳ mA/cm۲ as well as ۶۰% capacitive storage in ۲۰ mV/s. High power Nb۲O۵-TNT anode reveals ۸۶% reversible capacity in the ۱۶th cycle with a columbic efficiency of ۸۴% for the ۱۶th cycle. In addition, the charge transfer resistance in TNTs declines from ۷۵۰ Ω to ۶۸۰ Ω after decorating by Nb۲O۵. The superior performance of Nb۲O۵-TNT composites is taken into account to derive higher charge storage from a capacitive charge storage which is dominant in the diffusion-controlled process. Therefore, Nb۲O۵-TNT composite can be applied to the next-generation pseudocapacitive anode in lithium-ion batteries.

Keywords:

Niobium pentoxide , Titanium nanotube , Pseudocapacitance , Lithium-ion battery , Micro-battery