Structural and Electrochemical Studies of La₂O₃ Coated LiCoO₂ Particles

Abstract

Nanocrystalline LiCoO₂ particles have been surface modified with La₂O₃ by a simple and cost effective resin coating process. The synthesized pure and La₂O₃ coated samples were characterized by thermogravimetric analysis / differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. XRD studies revealed that the presence of La₂O₃ coating over LiCoO₂ particles did not affect the original layer structure of pure LiCoO₂. Also, no extra peak was detected for La₂O₃ phase. FTIR results confirmed the structural co-ordination of the samples. Also, the shifting and broadening of IR peaks corresponding to LiCoO₂ confirmed the presence of IR peaks of La₂O₃. TEM image showed the formation of interconnected small nanoparticle subunits structure for LiCoO₂. TEM image also showed the presence of thin La₂O₃ layer over LiCoO₂ particles. The cyclic voltammetry studies revealed that the La₂O₃ coated LiCoO₂ particles exhibited reversible redox peaks with slight increase in peak intensity and peak area compared to pure LiCoO₂. It indicates an improved charge storage capacity of La₂O₃ coated LiCoO₂ sample compared to pure LiCoO₂ sample.

GRAPHICAL ABSTRACT

Keywords:

• Nanocrystalline LiCo O₂
• La₂O₃ coating
• X-ray diffraction (XRD)
• Transmission electron microscopy (TEM)
• Cyclic voltammetry (CV)