An alternative approach for obtaining the LiMn2O4 spinel phase is provided by the use of the sol-gel method in aqueous solution. The main electrochemical properties of the sol-gel LiMn2O4 phase are reported. In addition to chronopotentiometric and voltammetric experiments, the kinetics of the electrochemical insertion-extraction of lithium in LixMn2O4 (0.25 < x < 1) has been investigated using ac impedance spectroscopy. The strong variation of the chemical diffusion coefficient D-Li vs x, in the range 10(-8)-10(-11) cm(2) s(-1) (D-Li is found to be maximum for x = 0.55) is critically discussed.