祝贺郭行等同学的文章
“调控炭化过程优化煤基硬炭负极储钠性能”
被 化工学报 接受发表！
郭行,韩纹莉,董晓玲,李文翠.调控炭化过程优化煤基硬炭负极储钠性能.化工学报, 2021,DOI:10.11949/0438-1157.20211503.
Abstract
Coal is a precious carbon-containing resource, which is widely distributed in China. With its abundant resource, low price, high carbon contents, rich aromatic ring structures, coal can be considered as a high-quality precursor for carbon-based anode materials, which is capable of increasing added value and technical content. We can prepare hard carbon anode materials for sodium ion batteries by pyrolysis and carbonization. This paper uses Xinjiang bituminous coal as the carbon source, adopts a two-step process of low-temperature pyrolysis and high-temperature carbonization, and adjusts the corresponding process conditions. The effect of the development process of bituminous coal mesophase on the structure of hard carbon and its sodium storage electrochemical behavior was studied. We have found that changing the temperature range, carrier gas flow rate, and heating rate of low-temperature pyrolysis can adjust the decomposition and depolymerization reactions in the formation stage of colloids, then adjust the degree of volatile matter generation and escape, and the degree of colloidal solidification, so as to adjust the specific surface area, graphitization degree and heteroatom content of the obtained hard carbon. The electrochemical performance test demonstrated that the carbonized anode electrode material under low-speed heating range of 350-550℃, carrier gas flow rate of 60 cc·min-1, and heating rate of 1 ℃·min-1 has the best reversible specific capacity and initial coulombic efficiency, reaching 314.3 mA·h·g-1 and 82.8% at a current density of 0.02 A·g-1, respectively. These excellent performances should be attributed to the coordination between the ordered carbon structure and the defect structure of the coal-based hard carbon material.
