INVESTIGATION OF ELECTROCHEMICAL LITHIUM INSERTION IN LAMELLAR TERNARY OXIDES OF THE MXMNOY-CENTER-DOT-ZH(2)O GROUP

Synthesis of various X-birnessites (X = Na, Al, Mg) was performed from the oxidation of manganese hydroxide by an aqueous permanganate solut ion, Their structural and electrochemical characteristics are investig ated. The influence of the exchanged cations and water content on the galvanostatic cycling curves has been studied. The best results are ob tained for Mg-birnessite with a specific capacity of 130 Ah kg(-1) rec overed after 20 cycles at a C/20 discharge/charge rate for Mg birnessi te. The cycling stability increased with increasing crystal lattice wa ter content of the materials. (C) 1997 Published by Elsevier Science S .A.