Carbon-coated rutile titanium dioxide derived from titanium-metal organic framework with enhanced sodium storage behavior

Carbon-coated rutile titanium dioxide (CRT) was fabricated through an in-situ pyrolysis of titanium based metal organic framework (Ti8O8(OH)(4)[O2CC6H4CO2](6)) crystals. Benefiting from the Ti-O-C skeleton structure of titanium-based metal organic framework, the CRT possesses abundant channels and micro/mesopores with the diameters ranging from 1.06 to 4.14 nm, shows larger specific surface area (245 m(2) g(-1)) and better electronic conductivity compared with pure titanium dioxide (12.8 m(2) g(-1)). When applied as anode material for sodium-ion batteries, the CRT electrode exhibits a high cycling performance with a reversible capacity of similar to 175 mAh g(-1) at 0.5 C-rate after 200 cycles, and obtains an excellent rate capability of similar to 70 mAh g(-1) after 2000 cycles even at a specific current of 3360 mA g(-1)(20 C-rate). The outstanding rate capability can be attributed to the carbon-coated structure, which may effectively prevent aggregation of the titanium dioxide nanoparticles, accelerate the mass transfer of Na+ and speed up the charge transfer rate. Considering these advantages of this particular framework structure, the CRT can serve as an alternative anode material for the industrial application of SIBs. (C) 2016 Elsevier B.V. All rights reserved.