化工进展2023，Vol.42Issue(12)：6259-6269,11.DOI:10.16085/j.issn.1000-6613.2023-0121
微扩层改性对煤基石墨微观结构和储锂性能的影响
Effect of mildly-expanded modification on coal-based graphite microstructure and lithium storage performance
摘要
Abstract
The mildly-expanded coal-based graphite was prepared from coal-based graphite via liquid oxidation-thermal reduction process using concentrated H2SO4 as intercalator and KMnO4 as oxidant.The microstructures of mildly-expanded coal-based graphite were characterized by XRD、SEM、TEM、Raman、nitrogen adsorption-desorption and XPS,and their lithium ions storage performance and the effect of the degree of mildly-expanded modification on their structure were further investigated.The results demonstrated that the mildly-expanded modification not only could expand the interlayer spacing of graphite crystallites,decrease the crystallite size and increase the content of nanopores,but also could introduce oxygen-containing functional groups such as carbonyl,hydroxyl and alkoxy groups into coal-based graphite.When the amount of oxidant is 0.30 times that of coal-based graphite,the interlayer distance of the mildly-expanded coal-based graphite was 0.3374nm,and its nanopore channels mainly consisted of 1-2nm micropores and 2-6nm mesopores with a specific surface area of 24.6m2/g and was rich in oxygen-containing functional groups such as C== O,C—O—H and C—O—C.Mildly-expanded coal-based graphite as anode for lithium-ion batteries exhibited excellent electrochemical performance,in which the reversible specific capacity could reach up to 511.1mAh/g at 0.1C and 348.7mAh/g at high current density of 5C,and the specific capacity at 5C could still be maintained at 313.3mAh/g after 300 cycles with a capacity retention rate of 89.9%.Its comprehensive performance was much higher than that of coal-based graphite.The excellent electrochemical energy storage properties of mildly-expanded coal-based graphite were closely related to its microstructure,which is rich in graphite microcrystal layers,nanopores and oxygen-containing functional groups.关键词
煤基石墨/微扩层改性/微观结构/负极材料/电化学性能Key words
coal-based graphite/mildly-expanded modification/microstructure/anode material/electrochemical performance分类
化学工程引用本文复制引用
李龙,邢宝林,鲍倜傲,靳鹏,曾会会,郭晖,张越,张文豪..微扩层改性对煤基石墨微观结构和储锂性能的影响[J].化工进展,2023,42(12):6259-6269,11.基金项目
国家自然科学基金(52274261,51974110) （52274261,51974110）
国家级大学生创新创业训练计划(202110460011,S202110460065). （202110460011,S202110460065）
