(92d) Porous TiO2 Conformal Coating on Carbon Nanotubes As Energy Storage Materials
TiO2 is a promising material for lithium-ion battery (LIB) and supercapacitor (SC) due to its high specific energy density, low cost, nontoxicity, eco-friendliness, and abundant availability. However, the practical electrochemical performance of anatase TiO2 is still not optimal due to its low electronic conductivity. Hybridizing with carbon nanotubes (CNTs) or other carbon materials is one of the most facile and effective approaches. CNTs can facilitate faster electron transfer, which would increase the performance of LIB or SC. Here we report a simple sol-gel method for facile synthesis of TiO2/CNTs hybrid. The porous anatase TiO2 nanoparticles are uniformly coated on the CNTs conducting network, which leads to remarkably improved electrochemical performances such as exceptional cycling stability, good high rate durability, and reduced resistance. This hybrid exhibits a reversible capacity as high as 200 mA∙h g-1 at a current density of 0.1 A g-1 as an anode in LIB. As a SC, it shows a specific supercapacitance of 145 F g−1 in 0.5 M H2SO4 electrolyte, higher than that of the previously reported TiO2 based supercapacitors. Moreover, this hybrid also exhibits excellent durability after 1000 cycles for both LIBs and SCs. The superior performance and cycling durability demonstrate the reinforced synergistic effects between the porous TiO2 and interweaved CNTs network, indicating a great application potential for such hybrid materials in high power LIBs and SCs.