AN ELECTROCHEMICAL INVESTIGATION OF LI INTERCALATION IN THE SOL-GEL LIMN2O4 SPINEL OXIDE

An alternative approach for obtaining the LiMn2O4 spinel phase is prov ided by the use of the sol-gel method in aqueous solution. The main el ectrochemical properties of the sol-gel LiMn2O4 phase are reported. In addition to chronopotentiometric and voltammetric experiments, the ki netics of the electrochemical insertion-extraction of lithium in LixMn 2O4 (0.25 < x < 1) has been investigated using ac impedance spectrosco py. 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 maxim um for x = 0.55) is critically discussed. (C) 1998 Elsevier Science B. V. All rights reserved.