title: Facile Fabrication of Ethoxy-Functional Polysiloxane Wrapped LiNi0.6Co0.2Mn0.2O2 Cathode with Improved Cycling Performance for Rechargeable Li-Ion Battery.
abstract: Dealing with the water molecule on the surface of LiNi0.6Co0.2Mn0.2O2 (NCM) cathode and hydrogen fluoride in the electrolyte is one of the most difficult challenges in Li-ion battery research. In this paper, the surface polymerization of tetraethyl orthosilicate (TEOS) on NCM to generate ethoxy-functional polysiloxane (EPS) wrapped NCM (E-NCM) cathode under mild conditions and without any additions is utilized to solve this intractable problem. The differential scanning calorimetry, transmission electron microscopy, and X-ray photoelectron spectroscopy results show that the formed amorphous coating can provide a protective shell to improve the NCM thermal stability, suppress the thickening of the solid electrolyte interphase (SEI) layer, and scavenge HF in the electrolyte. The E-NCM composite with 2 mol % EPS delivers a high discharge capacity retention of 84.9% after 100 cycles at a 1 C discharge rate in the 2.8-4.3 V potential range at 55 °C. Moreover, electrochemical impedance spectroscopy measurements reveal that the EPS coating could alleviate the impedance rise during cycling especially at an elevated temperature. Therefore, the fabricated E-NCM cathode with long-term cycling and thermal stability is a promising candidate for use in a high-energy Li-ion battery.
authors.affiliation: Graduate University of Chinese Academy of Sciences , Beijing 100039, P.R. China.|Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu, Sichuan 610041, P.R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Graduate University of Chinese Academy of Sciences , Beijing 100039, P.R. China.|Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu, Sichuan 610041, P.R. China.
authors.forename: Wujie
authors.initials: W
authors.lastname: Ge
authors.affiliation: Hebei Academy of Sciences , Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.affiliation: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu, Sichuan 610041, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu, Sichuan 610041, P.R. China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu, Sichuan 610041, P.R. China.
authors.forename: Mei-Zhen
authors.initials: MZ
authors.lastname: Qu
authors.affiliation: Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences , Chengdu, Sichuan 610041, P.R. China.
authors.forename: Gongchang
authors.initials: G
authors.lastname: Peng
keywords: Li-ion battery; Ni-rich layered oxide; polysiloxane; surface modification; thermal stability