Surface-initiated fluoride-scavenging polymeric layer on cathode materials for lithium-ion batteries

Abstract

Spinel-structured lithium manganese oxides (LMOs) suffer from manganese dissolution at elevated temperatures, which leads to severe capacity fading. In this work, a novel strategic approach was developed to alleviate this phenomenon by using poly(dimethylsiloxane) (PDMS) as a simple and scalable electrode additive. LMO electrodes containing finely dispersed PDMS were prepared using a conventional electrode coating process. Electrochemical studies showed that the PDMS-dispersed LMO electrodes had significantly improved cycling retentions. Ex-situ FT-IR and F-19 NMR spectra indicated PDMS chemically scavenged the F- species, which cause manganese dissolution in LMO-based cells. In addition, a plausible mechanism was proposed based on the spectroscopic evidences. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.