TiO₂-reduced graphene oxide nanocomposites by microwave-assisted forced hydrolysis as excellent insertion anode for Li-ion battery and capacitor

TiO₂-reduced graphene oxide (rGO) nanocomposite (TiO₂-rGO) is fabricated by microwave-assisted forced hydrolysis and examined as prospective electrode for energy storage applications, especially in Li-ion battery (LIB) and Li-ion capacitor (LIC). First, the uniformly distributed nanoscopic TiO₂ particulates (∼3 nm) over rGO nanosheets is evaluated as anode in half-cell assembly to ascertain the Li-insertion behavior and found that ∼0.68 mol Li (∼227 mAh g⁻¹) is reversible. Then, “rocking-chair” type LIB is fabricated with spinel LiMn₂O₄ cathode, and the LiMn₂O₄/TiO₂-rGO assembly exhibits high capacity (∼120 mAh g⁻¹ at 0.1 C rate), good rate capability (∼53 mAh g⁻¹ at 1 C rate), and excellent cycleability (∼90% initial reversible capacity after 1000 cycle) as well. Similarly, the LIC is also constructed with activated carbon cathode, and such configuration delivered a maximum energy density of ∼50 Wh kg⁻¹ with ∼82% retention after 4000 cycles. The synergistic effect of both rGO and anatase nanoparticles provides excellent energy efficiency and battery performance in different kind of Li-ion based energy storage devices.