Preparation And Properties Of Perovskite Anode Materials For Lithium Ion Batteries

Perovskite oxide?ABO3?conforms the requirements for the development of anode materials for lithium ion batteries in the future due to the advantage of high theoretical capacity,high ionic conductivity,abundant resource reserves and good stability.However,the research on perovskite-type oxides as electrode materials for lithium ion batteries is still insufficient,and some shortcomings similar to transition metal oxides as electrode materials have not been improved.Therefore,two different types of perovskite oxides were prepared as anode materials for lithium ion batteries.The main contents are as follows:?The perovskite type oxide Ca_1-xLi_xMnO_3-??x=0,0.02,0.05,0.1,0.2?was prepared by citric acid assisted sol-gel method.The result shows up to 10%calcium element in the lattice can be replaced by lithium without the obvious corruption of lattice symmetry or the appearance of the secondary phase.Conpared with CaMnO₃,the introduction of lithium element,Ca_0.95Li_0.05MnO_3-?in particular,has greatly improved the electrochemical performance.The specific capacity of Ca_0.95Li_0.05MnO_3-?within the initial 10 cycles were maintained at ca.480 mAh?g^-1,and after 50cycles of rate capability testing it was estimated to be around 250 mAh?g^-1 with the voltage range was 0³V and the current density was 100 mA?g^-1.The rate capability was also improved significantly.The discharge capacity at the beginning of every 10 charge/discharge cycles was498.3,301.5,210.5,180.5 and 359.0 mAh?g^-1,respectively,at thecurrent density of 100,200,300,400 and back to 100 mA?g^-1.In addition,Li doping CaMnO₃ not only reduced the particle size and improved the size distribution,but also caused two different lithium ion transport paths for ion vacancies and oxygen vacancies in the crystal lattice.The result further led to a decrease in the charge transfer resistance of the material and a significant increase in lithium ion diffusion.?we successfully synthesized the Li_0.2375La_0.5875TiO₃ pure phase by high temperature solid phase method.Compared with the previous LLTO series materials,it shows more excellent electrochemical performance.In the voltage range of 0-3V,the sample showed a discharge capacity of 552.3 mAh?g^-1 at a current density of 100 mA?g^-1 and retained 258.2 mAh?g^-1 after50 cycles.In addition,the sample exhibits excellent rate performance.The charge capacity of Li_0.2375La_0.5875TiO₃ delivers a capacity of ca.241.3,186.8,165.2,145.2 and 246.4 mAh?g^-1,respectively,at the end of each 10 cycles at the current density of 100,500,1000,2000 and back to100 mA?g^-1,The capacity has not attenuated after charging/discharging at the high current density.