Preparation Of Ti 3 O 5 By Carbothermal Reduction And Its Application In Lithium Ion Batteries

Ti₃O₅,as one kind of like-semiconductor conductive ceramic material,had high conductivity,good electrochemical stability and high resistance properties to acid and alkali corrosion.These excellent features drove it to have a great application prospect on conductive substrate material and electrode material additives in lead-acid batteries,fuel cell and lithium ion batteries.In this paper,Ti₃O₅'s energy structure,density and skew density were calculated and analyzed by the density function theory.The feasibility of Ti₃O₅ synthesized from anatase-TiO2 by carbothermal reduction was verified by the basic theory of thermodynamics and kinetics theory as well.Under the guidance of these theories,Ti₃O₅ was successfully synthesized from anatase-TiO2 by carbothermal reduction.The effects of carbon content and temperature on the reduced product were investigated.It was found that a relatively pure Ti₃O₅ particle with a particle size about 2?m could be obtained at the temperature of 1200?for 3 hours with the carbon content was 3.6%.The result of differential thermal analysis of Ti₃O₅ showed that Ti₃O₅ would not be oxidized below 550? in the air,which Indicated that Ti₃O₅ had good thermal stability.The results of Ti₃O₅'s electrochemical properties in strong acid and alkali solution showed that Ti₃O₅ can be used as an optional material in lead-acid batteries,fuel cells and other fields.The electrochemical properties of LiFePO4 and Li4Ti5O212 atfer adding Ti₃O₅ were researched respectively.The results showed that the Li₄Ti₅O₁₂/Ti₃O₅ battery performed good rate performance with the increase adding amount of Ti305.Especially under the strong charge-discharge rate test?lOC?,the Li₄Ti₅O₁₂/Ti₃O₅ battery's capacity was enhanced obviously after adding Ti₃O₅.After adding 6%mass fraction of Ti₃O₅,Li₄Ti₅O₁₂/Ti₃O₅ cell's capacity reached 173,9mAh/g at the rate of 0.2C,it was close to the Li₄Ti₅O₁₂'s theoretical specific capacity.And the specific capacity maintained at 148.6mAh/g under the rate of 10C.Besides,the specific capacity remained at 138.7 mAh/g after 100 cycles under 10C.At the same time,it was investigated that the effect of Ti₃O₅,as a conductive additive,on LiFePO4.The results showed that the sample cells of LiFePO4 after adding 6 wt%Ti₃O₅ showed smaller electrochemical impedance and polarization effect than the blank simple cells of LiFePO4.It illustrated that the LiFePO4 could show better electrochemical reversibility and cyclic properties after adding Ti₃O₅.