Preparation and characterization of ramsdellite Li2Ti3O7 as an anode material for asymmetric supercapacitors

Ramsdellite Li2Ti3O7 was first synthesized via sol-gel process with good crystallity of an average particle size of 0.175 μm. The product was thoroughly investigated as a lithium intercalation compound, and as an active anode material in asymmetric supercapacitors coupling with activated carbon as cathode. Lithium intercalation reactions were found occurring at 1.32 and 1.62 V versus Li/Li+, respectively. A reversible specific capacity of 150 mA h g−1 at 1C was obtained on Li2Ti3O7 electrode in a nonaqueous electrolyte. The charge current was found to strongly influence the anodic discharge capacity in the asymmetric cell. The capacity retention at 10C charge-discharge rate was found to be 75.9% in comparison with that at 1C.