Fabrication and Electrochemical Studies of Ncm Cathode Active Material with Nano-Grade Materials for All-Solid State Batteries

Abstract

Recently, all-solid state batteries (ASSBs) are studied using hybrid solid electrolyte and composite cathode by wet process. NCM materials is suitable for high voltage and capacity of ASSBs. However, since the ASSBs are used under high-temperature (60~80°C), the initial capacity is lower than that of the liquid type lithium ion battery, and the discharge capacity tends to decrease according to the charge/discharge cycle. In order to improve the thermal properties and the electrochemical reactivity of the NCM material, the surface was coated with nanoparticles of LFP or LMO material using liquid dispersion method. The surface of the active materials was observed by SEM and TEM analysis, and the lattice parameter was analyzed by XRD and Rietveld analysis. Furthermore, the coated NCM active materials were mixed with garnet LLZO, a polymeric binder, and a conductive material to prepare a cathode by a wet process. A 2032 coin cell was fabricated using Garnet LLZO composite solid electrolyte sheet (SE) as a solid electrolyte and Li-metal as anode to evaluate electrochemical characteristics. The characteristics of charge/discharge cycle of ASSBs will be described in more detail.