Synergetic influence of ex-situ camphoric carbon nano-grafting on lithium titanates for lithium ion capacitors
The present study provides detailed experimental results on the synthesis and characterization of carbonized lithium titanate spinel (LTO) composites as electrode materials for lithium ion capacitor. The LTO particles were grafted with a porous carbon layer obtained from the pyrolysis of camphor. The graphitic nature of the carbon was confirmed through Raman spectroscopy. The relative contributions from the capacitive and diffusion controlled processes underlying these electrodes were mathematically modeled. Electron transport mechanism underlying these electrodes was determined by measuring the work functions (φ) of LTO and carbon grafted LTO using ultraviolet photoelectron spectroscopy. These carbon grafted LTO composites exhibited an energy density of 330 mWh·L-1 and a peak power density of 2.8 kW·L-1, when employed as electrodes in coin cells with excellent cycling stability at the end of 4000 cycles.