Preparation Of Lignin-based Carbon Microspheres And Study On Sodium Storage Properties

The demand for lithium-ion batteries as a major power source in portable electronic devices and vehicles is rapidly increasing:lithium-ion batteries are regarded as the battery of choice for powering future generations of electric vehicles and hybrid electric vehicle.Lithium resource consumption showed blowout trend,however,because lithium resources in the crust is limited storage,lithium resources will eventually be exhausted! Na-ion batteries(NIBs)represent one of the most promising alternatives due to the similar chemical and electrochemical properties between Na and Li and the vast abundance of Na resources,larger ionic radius of Na+(102 nm)than that of Li+(76 nm),Graphite,the most commonly used as anode in lithium ion cells,does not intercalated by sodium to any appreciable extent and is electrochemically irreversible.After a lot of research,hard carbon can be used as aanode material for ion sodium battery.In this paper,hard-carbon microspheres were prepared by used papermaking waste lignosulfonate as precursors through a simple carbon-spray drying method,and carbonized at 1250? as sodium ion battery anode material,to study its sodium storage properties.In order to improve the capacity of the hard carbon microspheres and the first coulombic efficiency,the phenolic resin was compounded,and the electrochemical properties of the hard carbon microspheres were also controlled.The electrochemical test showed that the pure lignosulfonate exhibits a reversible specific capacity of 249 mAh/g with an initial efficiency of 59.7%.After the composite of phenolic resin,the capacity of the composites was improved obviously,the first reversible specific capacity was 350 mAh/g with an initial efficiency of 61.41%.When the mass ratio of phenolic resin/lignin was 5/5,the reversible specific capacity was 321 mAh/g with an initial efficiency of 71.06%.At the same time,the electrode showed excellent cycle stability,and the capacity retention rate was more than 95%after 200 cycles at a constant current density of 100 mA/g.Nitrogen-rich lignin hard carbon microspheres were prepared by melamine as nitrogen source and carbonized at 700 ? as the negative electrode material of sodium ion battery.After being carbonized at 700 ?,the reversible specific capacity of lignin-based hard carbon microspheres was 122 mAh/g and 207 mAh/g,respectively.The reversible specific capacity of the lignin hard carbon microspheres after doping with nitrogen was 207 mAh/g and excellent cycle stability.