The Synthesis And Properties Study Of Ferrite-Based Anode Materials For Lithium Ion Battery

In recent years,with the rapid development of new energy automotive industry,more and more high-performance electrode materials are applied to the storage devices.Due to the inherent shortcomings of the pure ferrites electrode materials,it is difficult to meet the requirements of future energy storage systems,which need higher energy density and power density.Developing new composite electrode materials is becoming the focus of battery research and development.The multi-component materials could take advantage of various benefits of each material and make the best use of the synergies between them,which could enhance the performance of electrode materials.In this paper,a series of ferrite-based nanocomposites,as lithium ion battery anode materials,were designed and fabricated,and the lithium-storage properties and mechanism were investigated.1.The synthesis and litnium storage performance study of ferrites-nitrogen doped graphene?MFe₂O₄-NG?nanocomposites.MFe₂O₄-NG nanocomposites were prepared by a one-step hydrothermal reaction,and the ferrites nanoparticles were uniformly loaded on the surface of nitrogen doped graphene sheets.As anode materials for lithium ion batteries,the MFe₂O₄-NG nanocomposites delivered superior performance because of the optimization of electronic properties of nitrogen doped graphene,which could induce more defects and disordered surface morphology as the lithium ion storage active sites.The structure and morphology of MFe₂O₄-NG nanocomposites were systematically characterized by XRD,Raman spectroscopy,XPS,BET and TEM,and the lithium storage perfomance was tested by electrochemical workstation.The results show that the MFe₂O₄-NG nanocomposites exhibit excellent cycle performance,columbic efficiency and rate performance as anode materials for lithium ion batteries.2.The synthesis and litnium storage performance study of ferrites-orderly intercalated graphene?MFe₂O₄-PG?nanocomposites.MFe₂O₄-PG nanocomposites were prepared by two-step reactions,lithium storage performance was studied as anode materials for lithium ion batteries.Due to the large specific surface area,the ferrites nanoparticles could be uniformly dispersed on the surface of orderly intercalated graphene.The intercalated graphene could alleviate the volumetric shrinkage and expansion during the process of lithium insertion and extraction,resulting in the excellent cyclic stability.Meanwhile,the improvement of conductivity and orderly arrangement of MFe₂O₄-NG nanocomposites could facilitate the lithium ion diffusion and the transfer of charge,which were beneficial to the lithium storage performance at high current density.Moreover,the synergistic effects between each component play an important role in the optimization of electrode materials.3.The synthesis and lithium storage performance study of nickel ferrite nanorods-graphene nanocomposites.The precursor of nickel ferrite nanorods was derived by metal organic framework,and the as-obtained products were applied to anode materials after being calcined in different atmosphere.The results showed that the product exhibit better cycling stability and rate performance calcined in N₂ than that in air.This is may be attributed to the carbon skeleton can be retained in N₂ atmosphere.On the one hand,it can enhance the conductivity,which is conducive to charge transfer.On the other hand,the cycling stability was improved through preventing the powder cracking and aggregating in the process of charge and discharge.The lithium storage performance of electrode materials were further optimized and improved via combining with graphene,which could utilize the excellent electrochemical properties of graphene effectively,such as good electrical conductivity,mechanical strength and huge specific surface area of graphene nanosheets.