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

GAO Bo; XIE Yongxin; JIA Fei; YANG Weiqiao; MENG Weibo; LIU Yongzhi; TANG Ligang; XING Baolin

doi:10.13226/j.issn.1006-6772.24091003

Abstract：The coal-based humic acid-based graphitized carbon(HAGC)was prepared from coal humic acid using carbonization-high temperature graphitization process.The study focuses on the effect of graphitization temperature on the microstructure of humic acid-based graphitized carbon and explored its electrochemical energy storage properties as an anode material for lithium-ion batteries(LIBs).The results demonstrated that the coal-based humic acid-based graphitized carbon coexisting graphite microcrystalline structure and amorphous structure can be prepared from coal-based humic with different graphitization temperatures(2 200-2 800℃).The graphitization temperature is an important factor affecting the microstructural features such as graphitization degree,microcrystalline lamellae,nanopores and structural defects of coal-based humic acid-based graphitized carbon.When the graphitization temperature was 2 800℃,the graphitization degree of coal-based humic acid-based graphitized carbon HAGC-2800 reaches 78.6%,with long-range ordered graphite microcrystalline lamellar structure and abundant amorphous carbon such as nanopore,structural defects,etc.,and both of them are tightly combined with each other and overlap and coexist.The coal humic acid-based graphitized carbon showed excellent lithium storage performance when used as anode materials for LIBs,with a reversible capacity of 352 mAh/g at a current density of 50 mA/g,a reversible capacity of 175 mAh/g at a high current density of 2 000 mA/g,and a capacity retention of up to 116%after 400 cycles,which shows good multiplicative performance and excellent cycle stability,making it an ideal anode material for LIBs.The excellent lithium storage properties of coal-based humic acid-based graphitized carbon HAGC-2800 are closely related to its microstructure,which is rich in amorphous carbon such as graphite microcrystalline lamellae with nanopores and structural defects.