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 m2 g−1) and better electronic conductivity compared with pure titanium dioxide (12.8 m2 g−1). When applied as anode material for sodium-ion batteries, the CRT electrode exhibits a high cycling performance with a reversible capacity of ∼175 mAh g−1 at 0.5 C-rate after 200 cycles, and obtains an excellent rate capability of ∼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.