Fabrication And Lithium Storage Performance Of New Anode Materials For Lithium Ion Batteries

Lithium-ion battery is a very important energy storage and conversion device with advantages of high efficiency,low pollution,and long service life.The development of anode materials with excellent lithium storage properties is one of the hot topics in the current field of lithium-ion batteries.This dissertation aims at some problems existing in lithium ion battery anode materials at present,and devotes to synthesize three different types of new lithium ion battery anode materials.The specific research contents are as follows:(1)Fe2O3 nanoparticles were synthesized by solvothermal method and calcination.The precursors is calcined by three different temperatures in NH3 atmospheres and Fe2N nanoparticles are obtained.The results of electrochemical tests show that the sample Fe2N-500 calcined at 500? have the best lithium storage properties.When the current density is 100 mA·g-1,the reversible specific capacity of Fe2N-500 can achieve 565 mAh·g-1 after 100 cycles.(2)The graphene oxide foams and Fe2O3 nanoparticles were effectively mixed.And then the graphene foams coated Fe2N nanoparticles were obtained by calcining the mixture under NH3 atmosphere.Electrochemical test results show that the lithium storage performance of the material is significantly better than that of pure Fe2N nanoparticles.At the current density of 100 mA·g-1,the reversible specific capacity can achieve 867 mAh·g-1 after 120 cycles.(3)Absorbent cotton was used as raw material and carbonized in Ar atmosphere to synthesize carbon microtubes,which was ultilized as anode material for lithium ion batteries.In order to continue to optimize the electrochemical performance of carbon microtubes,three different doping sources were attempted for heteroatom doping of carbon microtubes.Electrochemical test results show that the performance of N,S co-doped carbon microtubes prepared with thiourea as the doping source have the best lithium storage performance.The reversible specific capacity of N,S co-doped carbon microtubes can achieve 565.3 mAh·g-1 after 100 cycles.