Devina, Winda Nam, Dongho Hwang, Jieun Chandra, Christian Chang, Wonyoung Kim, Jaehoon 2024-01-19T19:02:00Z 2024-01-19T19:02:00Z 2021-09-04 2019-10-20 0013-4686 https://pubs.kist.re.kr/handle/201004/119435 Hierarchically porous anatase TiO2 microparticles are synthesized in supercritical methanol (scMeOH) in the presence of organic surface modifiers such as oleylamine, oleic acid, and poly(ethylene glycol)methyl ether/citric acid (PEGME/CA) mixture. Primary TiO2 nanoparticles (5-9 nm) that loosely aggregate to form secondary micron-sized particles (0.2-1.5 mu m) are obtained in the presence of PEGME/CA. The surface modifier aids the effective suppression of undesirable crystal growth because their molecules cap the surfaces of growing particles in scMeOH. An ultrathin, conformal and uniform carbon layer with 1-2 nm thickness is then formed on the surface of the TiO2 particles by heat treatment. The carbon-coated TiO2 particles delivers 231 mAh g(-1) at 0.1 C after 50 cycles and 85 mAh g(-1) at 10 C in a lithium-ion battery cell, 275 mAh g(-1) at 0.1 C after 50 cycles, 40 mAh g(-1) at 10 C, and high capacity retention of 94% after 450 cycles in a sodium-ion battery cell. The excellent electrochemical performance of the TiO2 particles is attributed to the small crystallite size, continuous electronic network formed by the close contact of individual carbon-coated primary TiO2 particles, and the effective penetration of the mesopores by the electrolytes. (C) 2019 Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD SOLID-ELECTROLYTE INTERPHASE HIGH-RATE PERFORMANCE EXPOSED 001 FACETS ANATASE TIO2 SUPERCRITICAL METHANOL OXIDE NANOPARTICLES HIGH-CAPACITY METHYL ESTERIFICATION CEO2 NANOCRYSTALS FACILE SYNTHESIS Carbon-coated, hierarchically mesoporous TiO2 microparticles as an anode material for lithium and sodium ion batteries Article 10.1016/j.electacta.2019.134639 1 ELECTROCHIMICA ACTA, v.321 ELECTROCHIMICA ACTA 321 scie scopus 000485837700006 2-s2.0-85070668251 Electrochemistry Electrochemistry Article SOLID-ELECTROLYTE INTERPHASE HIGH-RATE PERFORMANCE EXPOSED 001 FACETS ANATASE TIO2 SUPERCRITICAL METHANOL OXIDE NANOPARTICLES HIGH-CAPACITY METHYL ESTERIFICATION CEO2 NANOCRYSTALS FACILE SYNTHESIS Supercritical methanol Anatase TiO2 Surface modifiers Li-ion batteries Na-ion batteries