Study of the Failure Mechanisms of LiNi0.8Mn0.1Co0.1O2 Cathode Material for Lithium Ion Batteries
By Jing Li, L. Downie, Lin Ma, W. Qiu, J. Dahn. 2015
445 citations recorded by the source corpus.
LiNi0.8Mn0.1Co0.1O2 (NMC811) can deliver a high capacity of ∼200 mAh/g with an average discharge potential of ∼3.8 V (vs. Li+/Li), making it a promising positive electrode material for high energy density lithium ion batteries. However, electrochemical tests from half cells and full cells show poor cycling performance when charged to potentials above 4.2 V. The calendar and cycle lifetimes of cells are affected by the structural stability of the active electrode materials as well as the parasitic reactions that occur in lithium ion batteries. In order to explore the major failure mechanisms of the material, half cells (coin cells) with control electrolyte and full cells (pouch cells) with control electrolyte and with selected electrolyte additives were tested over four different potential ranges. Isothermal microcalorimetry was used to explore the parasitic reactions and their potential dependence. In-situ and ex-situ X-ray diffraction and scanning electron microscopy were used to investigate the structural and morphological degradation of the materials over cycling. It was found that the dramatic c-axis change of the active material during charge and discharge may not be the major problem for cells that are cycled to higher potentials. The parasitic reactions that arise from the interactions between the electrolyte and the highly reactive delithiated cathode surface at high potentials are suggested as the main reason for the failure of cells cycled above 4.2 V. It should be possible to further improve the performance of NMC811 at high potentials by modifying the cathode surface and/or identifying and using electrolyte blends which reduce parasitic reactions. © The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.1011507jes] All rights reserved.
Subfields: Automotive Engineering, Electrical and Electronic Engineering
View Paper: https://www.semanticscholar.org/paper/aeb178c4aba1a2a25142019a063a1f13a82cc75e
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.