Synthesis Of Transition Metal Oxide As Anode Materials For High-performance Lithium Ion Batteries

In recent years,the development of clean energy and energy storage systems suitable for modern society has become important on account of the depletion of energy resources and the increasingly serious environmental problems.Lithium-ion batteries(LIBs),according to their advantages of high efficiency,low cost and environmental friendliness,has become the representative of high-performance batteries and widely used as storage system of high energy consumption electronic equipment.However,traditional graphene anode materials have low theoretical specific capacity,which limits their development in large electronic devices such as electric vehicles(EVs)and hybrid electric vehicles(HEV).Hence,the development of high specific capacity,high power,safety,stable as well as long-range lithium-ion battery anode materials has become urgent problems to be solved.Nano-materials are the most dynamic fields in nano-materials science.Because of surface effect,small size effect and macroscopic quantum tunneling effect,they have a broad application prospects in high-tech fields of biology,information,energy environment.Hollow porous transition metal oxide nano-materials due to their unique size and structure,large specific surface area,small volume effect have become one research hotspots in the design and construct of the new generation of high capacity and high-performance lithium-ion battery anode materials.In this paper,transition metal oxides nano-materials as lithium-ion battery anode materials were selected for the study.Two kinds of nano-composites,that is,r GO-coated Mn2O3 nanospheres,porous N-doped C-coated Mn O nanospheres,have been synthesized.The morphology,structures and chemical compositions of the obtained electrode materials were characterized by a variety of testing methods,and studied as an anode material in LIB applications.The main work is as follows:1.Porous Mn2O3 nanospheres(Mn2O3 NSs)were prepared via calcination treatment of Mn(OAc)2-C-8 precursors,which generated from coordination reaction of manganese acetate and long chain organic ligand(referred as HL10).Served as anode material of lithium-ion battery(LIBs),the Mn2O3 NSs shows irreversible capacity decay owing to the structural unstability.2.The r GO-coated porous Mn2O3 nanospheres(Mn2O3@r GO)were fabricated from the coordination self-assembled aggregation via calcination treatment followed by a graphene-coating approach.The Mn2O3@r GO delivers superior lithium storage ability as an anode material in lithium-ion batteries(LIBs).3.Polydopamine-coated Mn2O3 nanospheres(Mn2O3@PDA)were formed through a facile solvothermal and polymerization reaction of dopamine by a high temperature carbonization treatment,the Polydopamine-coated Mn2O3 nanospheres were further transformed into porous N-doped C-coated Mn O nanospheres(Mn O@NC).The core-shell structure maintains the structural stability and improves the conductivity of anode material.Therefore,acting as an anode material for lithium-ion batteries,the Mn O@NC exhibits superior lithium storage performance.