Novel Terahertz Spectroscopy Analysis for the Electrode with Carbon Nanotubes (CNTs) in Lithium-Ion Batteries

Abstract

In this study, to use carbon nanotubes (CNTs) as a conductive material instead of carbon black in cathode electrodes, their dispersions were prepared in 1-Methyl-2-pyrrolidinone (NMP) solvent by using an ultrasonic horn, and their dispersion stability was analyzed using CNTs on the formation of the network between cathode electrode constituent materials comprised of cathode material, CNTs, and current collectors, and their correlation with electrochemical performance results were investigated using various analytical techniques. Particularly, in the analysis, terahertz time domain spectroscopy (THz-TDS), a new non-destructive analysis method, was used to analyze and compare the various optical properties of the cathode’s slurries that co-existed with CNTs and cathode material, suggesting the suitability of its analytical use in the field of materials dispersion and the slurry manufacturing process for lithium-ion batteries (LIBs). In the investigated results, the sample with the highest dispersion stability of CNTs uniformly formed the networks of CNTs and cathode material in the electrode, which results in the highest electrical conductivity among all samples, and as a result, the best performance in electrochemical evaluations.

Keywords

• carbon nanotubes
• conductive material
• dispersion stability
• terahertz spectroscopy
• lithium-ion batteries