LiMn₂O₄-Norit at Low Temperature and in Comparison with LiMn₂O₄-M Multi-Walled Carbon Nanotubes and LiMn₂O₄-Graphite EUZ-M in Prototype Li-Battery

CZU 541.136

DOI  https://doi.org/10.5281/zenodo.3747839

The reasons for the fall of the discharge capacity of the Norit LiMn2O4 spinel composition with a carbon filler in the redox reaction with lithium at a temperature of 271 K were analyzed using cyclic voltammetry and impedance spectroscopy. A comparison is made of the electrochemical behavior of LiMn₂O₄-Norit compositions, LiMn₂O₄-carbon nanotubes compositions, and LiMn₂O₄-natural EUZ-M graphite to identify the key factors responsible for the efficient transformation of the thin-film composite electrodes under study in the prototype lithium battery. Used in the work, the fillers differed in the parameters of the initial particles: nanometer Norit and multi-walled carbon nanotubes (MWCNT) and micrometer EUZ-M, as well as the surface area of the particles varying in the series Norit > MWHT > EUZ-M (1). The nature and parameters of the particles determine the parameters of the particular processes of the investigated deintercalation of electrode process. The resistance of diffusion-migration transport in the surface film of a SEI on a composite varies with the pattern as indicated in series (1). The maximum resistance to charge transfer across the interface of the SEI/composite film varies in the opposite direction as indicated in series (1). A distinctive feature of the LiMn2O4-Norit composition with a developed surface is the presence of a SEI surface film, in which 40% of the total ohmic electrode resistance can be reached. It is assumed that a decrease in the discharge capacity of the composites in the process of long cycling at a low temperature is significantly promoted by the degradation of the carbon filler.

Keywords: LiMn₂O₄ spinel, Norit fillers, multi-walled carbon nanotubes, graphite EUZ-M, low temperature, lithium battery, impedance, cyclic voltammetry.