Li4Ti5O12/AC Hybrid Supercapacitor combining High Power of Supercapacitor and High Energy of Li-ion battery

Abstract Spinel lithium titanate (Li4Ti5O12) has been synthesized by solid state route. Prepared Li4Ti5O12 powder was characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) for phase purity and particle size estimation respectively. Hybrid supercapacitor consisting of activated carbon and synthesized Li4Ti5O12 as electrodes is assembled inside the glovebox filled with argon gas. Electrochemical characteristics of hybrid supercapacitor are observed by constant current charging-discharging cyclic voltammetry. Activated carbon based electric double layer capacitor (EDLC) was also prepared and electrochemically characterized for comparison. Hybrid supercapacitor shows better discharge capacities of 12 and 10 mAhg-1 at 0.5C and 1C (1C = 100mAhg-1) compared to 9 and 3 mAhg-1of EDLC respectively. Cyclic performances are also observed for 80 cycles at 2C. The capacity retention of hybrid supercapacitor is >86% compared to 80% of EDLC.