Microstructure regulation of coal humate-based graphitized carbon and their lithium storage properties

LI Jie; SUN Mingfu; YU Jitu; LI Long; MENG Weibo; LIANG Hao; XING Baolin

doi:10.13226/j.issn.1006-6772.XX24110501

Abstract：Phosphorus-doped coal-based carbon fibers were prepared by electrostatic spinning method using lignite,coal humic acid and coal pitch as raw materials,polyacrylonitrile as spinning aid and triphenylphosphine as dopant,focusing on the effect of phosphorus atomic doping on the microstructure and surface properties of coal-based carbon fibers.It was shown that phosphorus-doped coal-based carbon fibers with good flexibility could be successfully prepared from lignite,coal humic acid and coal pitch by electrostatic spinning method.The prepared phosphorus-doped coal pitch-based carbon fibers P-CTP-CFs were interwoven with each other to form a three-dimensional mesh structure with an average diameter of 144.0 nm and a specific surface area of 50.3 m2/g,and also contained a large amount of amorphous carbon and heteroatomic functional groups such as C—O,C=O,O—C=O,pyridinic nitrogen,pyrrolic nitrogen,graphitic nitrogen,and P—C/P—N,P—O,P=O.When used as self-supporting anode materials for lithium-ion batteries(LIBs),P-CTP-CFs have excellent electrochemical properties,with a reversible capacity of 944.9 mAh/g at a current density of 20 mA/g,and a reversible capacity of 273.6 mAh/g at a high current density of 1 000 mA/g,and the reversible capacity can be maintained at 86.2％after 100 cycles at a current density of 100 mA/g,showing good multiplicity performance and excellent cycling stability,which is a more ideal flexible anode material for LIBs.The excellent lithium storage properties of phosphorus-doped coal pitch-based carbon fibers are closely related to their special three-dimensional mesh structure,large specific surface area and abundant heteroatomic functional groups.