High‐Performance Natural Graphite Anode for Lithium‐Ion Batteries: Using TiO2 as an Additive

Abstract

AbstractIn this study, an attempt has been made to improve the performance of natural graphite anode using TiO2 nanoparticles additive. In this method, high‐performance electrodes have been achieved by addition of TiO2 nanoparticles to base graphite active material, which is able to offer supplementary effects. TiO2 emulsions with different concentrations of 10 %, 20 %, and 100 % are applied to prepare the binder solvent. The graphite anode made with 10 % concentration of TiO2 emulsion (NG−T10) shows the best performance in comparison with other samples. The Nano‐scale images of the scanning electron microscope (SEM) affirm the existence of a uniform coating on the surface of the natural graphite particles for the NG−T10 electrode. Energy‐dispersive X‐ray (EDX) spectroscopy on the NG−T10 sample clearly indicates the Ti element signal. According to atomic force microscopy (AFM) images, an increment in surface roughness can provide a more effective surface and improve wettability, resulting in better electrochemical performance of NG−T10. The charge‐discharge test of the NG−T10 half‐cell represents an excellent cycle performance without any capacity degradation during 100 cycles at 0.5 C. However, the value of capacity retention for bare natural graphite (BNG) is 90.7 % in the same conditions. The electrochemical impedance spectroscopy (EIS) results indicate that the existence of TiO2 nanoparticles in NG−T10 improves the resistance of solid electrolyte interface (SEI) film and charge‐transfer resistance. The NG−T10 also enhances the pouch cell capacity at various current densities up to 4 C.