Li4Ti5O12 Nanocrystals Synthesized by Carbon Templating from Solution Precursors Yield High Performance Thin Film Li-Ion Battery Electrodes

Nanocrystals of Li4Ti5O12 (LTO) have been prepared by processing an ethanol-toluene solution of LiOEt and Ti(OiPr)4 using a carbon black template. The mechanism of crystal growth has been tracked by SEM and TEM microscopies. The resulting nanocrystals grown using the carbon template (C-LTO) show less aggregation than materials prepared from solution without the template (S-LTO), which is reflected in higher surface area (27 m2/g) and concomitantly smaller particle size (58 nm) for C-LTO compared to 20 m2/g and 201 nm for S-LTO. Electrochemically, thin-film electrodes composed of C-LTO demonstrate reversible cycling, storing approximate to 160 mAh/g at both 1 C (175 mA/g) and 10 C current. Important is that resistance to charge transfer between the C-LTO nanocrystals and added conducting carbon is 3 times smaller than that for S-LTO. Accordingly, C-LTO shows excellent rate capability, maintaining an energy-storage capacity >150 mAh/g even at 100 C current. These characteristics solidify C-LTO a suitable replacement for carbon as a Li-ion battery anode.