ELECTROCHEMICALLY ACTIVE LITHIATED NICKEL OXIDE FILMS FABRICATED BY NOVEL THERMAL SYNTHESIS USING Ni/Li/Ni FILMS

Abstract

Lithiated nickel oxide films were thermally synthesized using Ni/Li/Ni films at various temperatures between 873 K and 1123 K. Structural and electrochemical properties of the synthesized films were investigated by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and galvanostatic charge-discharge half-cell tests between 4.5 V and 2.5 V. Lithiated nickel oxide films with the composition near stoichiometric LiNiO2 could be obtained under annealing conditions (973-1073 K, 1 h). Surfaces of synthesized films consisted of some particles and became smoother with an increase in annealing temperature. Particles with the sharpest edge were formed at 1023 K. Cells with synthesized electrodes showed reversible Li ion transfer and clear voltage plateaus in charge-discharge curves that can confirm the phase transformation of LiNiO2.