Abstract
Graphene nanosheets (G), polyaniline (PANI), nanocrystallites of V-doped Li4Ti5O12 (V-LTO), and LiMn2O4 (LMO) were synthesized to be used as electrodes in supercapacitors and hybrid BatCap. The composite electrode material (LTO-T) containing PANI was prepared through the polymerization process. Materials were characterized by XRD, XPS, FT-IR, SEM and TEM. The introduction of PANI into the composite system led to an improvement in the electrical conduction process. The electrochemical properties of the single electrodes were measured in half cells against lithium to test their potential as anode materials for Li batteries. The highest electrochemical performance is obtained for the LTO-T electrode. This is explained based on the synergistic effects of the discrete components LTO nanoparticles avoid restocking of graphene sheets in the ternary composite system and support the Faradaic processes to amplify the total electrical capacitance of the electrode. BatCap cell has been assembled using LTO-T as an anode, LiMn2O4 as a cathode, and high ionic conducting PEO: Li (with a molar ratio of PEO: LiI = 6:1) as a solid electrolyte and tested its electrochemical behavior. The device displays ultrahigh capacitance (173.4 mAh/g), and an energy density of 254 Wh/kg at a rate of 1C over a broad voltage range (1-2.5 V) The electrical capacity is slightly changed from 173 to 156 (mAh/g) after 1000 cycles.