Study On Modification Of Titanium Dioxide And Lithium Electrical Properties

Lithium-ion batteries?LIBs?have been a new energy storage sources due to their high energy density,long cycle life and no memory effect,which has been widely used in electric vehicles,mobile phones,laptops and other equipment.Titanium dioxide?TiO₂?is considered as an ideal anode material for LIBs because of its abundant content,small volume change and high operating voltage.Although this anode material has a high theoretical specific capacity?335 mAh/g?,its low ion diffusion capacity and electronic conductivity limit actual specific capacity,which has hindered the practical application.The results show that the electrochemical properties of TiO₂ can be improved by synthesizing some special structures.In this paper,two special structures of TiO₂ were synthesized by one-step synthesis and anodization,and their battery performance was studied.The core-shell nanostructure TiC@C-TiO₂ samples were obtained using one step synthesis method,in which titanium carbide?TiC?was adopted as raw materials under the condition of 350?,and we studied the morphology,structure and electrochemical properties of the material.The results indicate that the porous material has obvious core-shell structure,in which the shell element contains TiO₂ including carbon,and the interior part is the incomplete oxidized TiC.The specific capacity is 253.6 and 158.1mAh/g under the current density of 1 A/g and 10 A/g,respectively.Moreover,the specific capacity is arond 150 mAh/g after 400 cycles in the rae of 10 A/g,exhibiting a good rate capability and outstanding cycle stability.The nanotubes were prepared by anodizing Ti-6Al-4V-51Zr alloy under different oxidation conditions.The morphology,structure and electrochemical properties of the nanotubes were studied.Results show that the sample under the condition of voltage 30 V oxidation for four hours has the best electrochemical performance.At the rate current density of 20,50,100,200,500 and 20 uA/cm²,the discharge specific capacity are 800,494,275,160,55,471 uAh/cm²,respectively,which is far higher than that of pure titanium dioxide nanotubes,exhibiting a good stability.Moreover,we can expect this material to be a kind of functional materials for application.