Electrochemical Behavior of Lithium Titanium oxide/activated Carbon Composite for Electrochemical Capacitor

Abstract

The Li 4 Ti 5 O 12 /AC composite was prepared by sol-gel process with ultrasonication.The prepared composite was characterized by SEM, XRD and TG analysis, and their electrochemical behaviors were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge test in 1 M LiBF 4 /PC electrolyte.From the results, the Li 4 Ti 5 O 12 particles coated on AC surface had an average particle size of 100 nm and showed spinel-framework structure.When the potential range of the Li 4 Ti 5 O 12 /AC composite was extended from 0.1 to 2.5 V, redox peaks and electric double layer property were revealed.The initial discharge capacity of Li 4 Ti 5 O 12 /AC composite was 218 mAh g -1 at 1 C.The enhancement of discharge capacity was attributed to electric double layer of added activated carbon.