Preparation Of Graphitic Carbon Materials From Anthracite Catalyzed By Cerium And Their Applications As Anode For Lithium Ion Batteries

The abundance of cerium in the earth is about 0.0046%,account for28% of all rare earth elements,and is the most abundant substance rare earth element.Cerium and its compounds have been widely used as catalysts.However,the researches on the catalytic graphitization of carboneuoce materials with cerium as catalyst has reported barely.In this work,using cerium as catalyst,the graphitization of anthracite under different temperatures,and different ratios of cerium to anthracite are investigated systematicaly.The composition,crystalline status,and morphologies of as-obtained graphtic carbon materials are characterized.The underneath mechanisms are discussed.The electrochemical properties of the graphtic carbon materials as anode for lithium ion batteries are explored.The research contents are as follows:(1)Using the mixtures with different cerium to anthracite ratios as reactants,a medium frequency induction furance(<3100 ℃)as heating setup,a series of graphite carbon materials are prepared at 1600 ℃,1900 ℃,2100 ℃,2300 ℃ and 2500 ℃.The structure,crystalline status and morphologies of as-prepared materials are systematically characterized using XRD,SEM and TEM.The results show that at the same cerium content in the reactant mixture,the graphite extent of the products increated with increasing of the reation temperature.On the other hand,an the same temperature,the graphite extent of the products increated also with increasing of the cerium content in the reactant.Comparably,the product prepared at relatively low temperature of 1900 ℃,and with the cerium to anthracite ratio of 1:1,show the highest graphite extent with also highist anthracite to graphite conversion effciency.(2)Half-cell lithium ion batteries with as-prepared graphitic carbon materials as anodes were assembled,and their electrochemical properties were studied.It was demonstrated that the lithium/delithium performance of the graphitic carbon materials depend on the graphitization conditions which can enhanced by lifting the reation temperature or lifting the cerium to anthracite ratio in the reactant.Based on the TOF-SIMS measurement,it was found that the onion rings formed within the graphitic materials may play important role in the lithium capacity performance.(3)The conversion of anthracite to graphite with cerium/iron bimetal as catalyst was also explored.At a relaticely low temperature,the as-obtainted graphitic carbon materials assume better crystallinity.And which can be increased by increasing the iron to cerium ratio.As anode for lithium ion battery,the as-obtainted graphite show also manifest electrochemical performance.