Open AccessМоноокись кремния, карбонизированная фторуглеродом, как композитный материал для анодов литий-ионных аккумуляторов
Author(s) -
Д.А. Ложкина,
Е.В. Астрова,
А.И. Лихачев,
А.В. Парфеньева,
А.М. Румянцев,
А.Н. Смирнов,
В.П. Улин
Publication year - 2021
Publication title -
žurnal tehničeskoj fiziki
Language(s) - English
Resource type - Journals
eISSN - 1726-748X
pISSN - 0044-4642
DOI - 10.21883/jtf.2021.09.51218.83-21
Subject(s) - silicon monoxide , materials science , annealing (glass) , analytical chemistry (journal) , argon , silicon , chemical engineering , silicon carbide , disproportionation , oxygen , graphite , composite material , metallurgy , chemistry , biochemistry , organic chemistry , chromatography , engineering , catalysis
Dispersed composite materials based on silicon monoxide and carbon (SiO/C) were obtained as a result of heat treatment of a powder mixture consisting of 40 wt% SiO and 60 wt% CF0.8. Annealing was carried out in an argon atmosphere at temperatures 1000 − 1250°C. Using electron microscopy and Raman scattering, it was found that at Т>=1100°C, silicon carbide appears in the solid-phase product, including in the form of cubic nanowhiskers. Based on the data on the weight loss of the reaction mixture, the composition of the resulting products was calculated as a function of the annealing temperature. Anodes made of composites obtained at temperatures above 1100°C demonstrate a sharp drop in capacitance and Columbic efficiency. It is shown that the observed changes are caused not so much by the formation of SiC as by an increase in the oxygen content in the matrix surrounding the silicon precipitates, which were formed as a result of disproportionation of SiO. It was found that the optimal annealing temperature, which provides the highest values of capacity, the initial coulombic efficiency and the ability to operate at high speed current densities is Т =1150°С.