THE CHEMICAL AND ELECTROCHEMICAL LITHIATION OF CUO - AN ANALYTICAL, ELECTRON-MICROSCOPY INVESTIGATION

The products formed by the slow discharge of a CuO cathode in contact with a LiBF4/propylene carbonate electrolyte and by the chemical reaction between n-butyllithium and CuO have been examined by X-ray diffraction and electron microscopy. The products, which were largely amorphous to X-rays, gave characteristic electron-diffraction patterns. The principal product of both galvanostatic and fixed applied potential discharges in the range 0-0.7 F/mol CuO was a new, cubic, copper containing phase with a ∼4.1 Å. Other conditions of discharge led to the formation of Cu2O, Cu, Li2O and LiCuO (as a minor product). The new cubic phase was absent from the products of the chemical reaction, where LiCuO, Cu2O, Cu and Li2O were identified by electron diffraction. After heating at 300-400°C, the products of chemical lithiation (at Li: CuO∼1) gave the characteristic X-ray patterns of LiCuO and Cu2O. A structural mechanism is suggested to account for the course of the reactions. © 1990.