(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.