| Lithium-ion batteries,as a clean energy,have the characterizations of high energy densities,long cycle numbers,few-environment pollutions and no memory effect,thus used in phones,portable computers and other potable electronic products,as well as electric vehicles,smart power grids and other emerging fields.With respect to insert type electrode materials,transition metal oxides（TMOs）based on redox reaction have merits of high specific capacity,environmental friendliness,abundant in resource,low price and so on,making it popular in lithium-ion batteries materials.However,TMOs are still far from their practical application limited by its intrinsic low conductivity and unstable structure.Focusing on above problems,the author synthesized a serious of lithium-ion batteries anode materials with high specific capacities and long cycle numbers by designing the structure and composites reasonably and the corresponding work and results are as follows. （1）Mn Cl2（2-meim）3was a precursor and Mn3O4nanoparticles with dimeter of 40 nm were obtained by hydrolysis reaction.The Mn3O4nanoparticles were calcined in C2H2/Ar atmosphere in order to enhanced conductivity and prevent agglomerating of nanoparticles.And Mn O@C nanoparticles with different carbon layer thickness were obtained by controlling calcine time.The electrochemical process was analysed by Galvanostatic charge/discharge（GCD）,Cyclic Voltammetry（CV）and Electrochemical Impedance Spectroscopy（EIS）.The results indicated that differences in carbon thickness impact on the Li+diffusion rate,electrical conductivity,polarization,and electrochemical mechanism.d Q/d V were calculated in order to examine the results that Mn O@C electrodes have more superior performance.The method could be easily scaled up by simply enlarging the amounts of raw materials,making it a candidate method for the preparation of Mn O@C nanocomposites.（2）Binary metal oxides（AxByOz）have more superior electrochemical performance than single component and element A is important for the generation of pseudocapacitance.So,we synthesized the Co3V2O8anode materials using a simple bake in salt method.By designing the Co3V2O8electrode materials in which element A has a high ratio,high energy density and power density were obtained under the pseudocapacitance effect.Co3V2O8anode materials show ultra-superior rate and cycle performance,it can achieve specific capacity of～835 m Ah g-1at current density of 4.0 A g-1for more than 500 cycles and capacity retention is close to 100%.Moreover,even if the current density increases to20 A g-1,the electrode delivers a reversible capacity of～310 m Ah g-1.The method could be easily scaled up by simply enlarging the amounts of raw materials,making it a candidate method for the preparation of Mn O@C nanocomposites.（3）As a precursor,zeolite imidazole framework（ZIF-67）structure materials were used as precursor to prepared carbon-coating V2O3@Co/Co O with complex hollow structure which was researched as lithium-ion batteries anode materials.Electrode materials with superior electrochemical performance were synthesized by controlling design of structure and composition.In detail,conductive Co particles were used as core to enhanced conductivity,at the same time,hollow structure could relieve stress during charge and discharge. |
