Characterization Of Electrochemical Properties Of Doped Transition Metal Oxide Anode Material

Due to its many advantages such as high specific capacity,abundant resources,safety and reliability,transition metal oxides are widely used in the research of negative electrode materials for lithium ion batteries.However,as a negative electrode material of lithium-ion battery,although the transition metal oxide has a strong advantage,but the material itself has many shortcomings,such as poor conductivity,easy to happen in the process of lithium ion deintercalation their own volume Expansion resulting in structural collapse,the above shortcomings strictly limit the material in the practical application.By used doping means to improve the electrochemical properties of the material.The main contents of this thesis are as follows:First,the cobalt-doped zinc oxide anode materials were synthesized by method of acrylamide sol-gel using zinc nitrate,cobalt nitrate and citric acid as raw materials.The effects of doping amount on the electrochemical performance of zinc oxide were investigated first x,the initial charge-discharge capacity of negative material Zn_1-xCo_xO（0≤x≤0.15）first increases and then decreases.Under the optimal doping amount of 9%,the voltage range of 0-3 V,the current density of 200 mA g^-1,the first discharge capacity of 1836 mAh g^-1,the first coulombic efficiency can reach 68%,After 20 cycles the material can still maintain the capacity of more than 1000 mAh g^-1.In the second part,Cobalt-doped copper oxide was prepared by sol-gel method using cupric nitrate,cobalt nitrate,ethylene glycol and citric acid as raw materials.The XRD results showed that the structure of the cobalt-doped copper oxide changed more than 6%.The discharge capacity of Cu_0.94Co_0.06O was 1789 mAh g^-1 at a voltage range of 0.001-3.0 V and a current density of 67 mA g^-1.After 10 cycles,the specific discharge capacity was 644.1 mAh g^-1.In the last part,Potassium-doped copper oxide was prepared by sol-gel method using cupric nitrate,potassium nitrate,ethylene glycol and citric acid as raw materials.The electrochemical tests and characterization were performed on the materials doped with different contents of potassium.XRD showed that the structure of the material did not change.The initial discharge capacity of K_0.08Cu_0.92O_1-γwas 1891.7 mAh g^-1 in the voltage range of 0.001-3.0 V and the current density was67 mA g^-1.After 50 cycles,The specific discharge capacity is 594.8 mAh g^-1.