Publication

Abstract : Lithium ion batteries are dominating the energy storage market owing to its capability in powering portable electronics to electric vehicles. However, the power capabilities of these batteries are still relatively low limiting their applications in fast charging. In this paper, we report a strategy in elevating the rate capability of lithium titanate (Li 4 Ti 5 O 12 - LTO), one of the safest anode materials known. We demonstrate that a simple chemical method of coating titania (TiO 2 ) on lithium titanate nanoparticles followed by low temperature annealing yields a superior anode to bare-LTO. The surface coated electrode exhibits high discharge capacity of 212 mAh/g at 10C rate while the bare-LTO deliver only 138 mAh/g. Likewise, the surface engineered electrode displays excellent ultra-high rate capability (150C) and long cycling stability of 1000 cycles (at 60C rate). Impedance spectroscopy results confirm that the charge transfer resistance in surface engineered sample (CS-3) is comparatively lower than the bare-LTO electrode. Ex situ TEM investigation shows that the titania inhibits surface phase transition when cycled at elevated temperature which could be advantageous as it is a manifestation of minimal gassing in the batteries.