The Growth And Electrochemical Properties Of LiNi_0.45M_0.10Mn_1.45O₄ Thin-film

Nowadays,The lithium ion batteries develop rapidly at home and aboard,with the widely use in a variety of fields from miniature electric vehicles,such as mobile phone,digital camera,laptop computer and other equipments to communication technology and mobile storage fields,people put forward higher requirements for lithium ion batteries.The performance of the battery is more or less determined by the cathode material,so the development of cathode material with stable performance,high operating voltage,and high energy density has become the focus of attention.Besides the advantages mentioned above,the spinel LiNi_0.5Mn_1.5O₄?LNMO?material also has a low cost price and is friendly to the environment,it's a kind of cathode material full of great scientific research value and application prospect.Doping modification is a method to improve the material capacity retention and the high rate discharge ability.In this paper,First,we successfully prepare the spinel LiNi_0.45Fe_0.10Mn_1.45O₄?LNFMO?target by doping Fe³⁺based on the LNMO material through high temperature solid phase sintering method,and the target structure characteristics are analyzed by TG/DTA,XRD and EDAX test,the conclusion shows that the LNFMO target has pure phase.Secondly,the abtained LNFMO target was used for depositing LNFMO films by pulsed laser deposition?PLD?.We study the effects of different parameters on the crystalline properties and electrochemical properties by changing the deposition temperature,oxygen pressure and deposition time,the XRD and FSEM test results of the film show that the film can get the best crystallinity at the deposition temperature of 750°C,the deposition time of 3h.Then we carry out the corresponding test of charge-discharge performance and discharge test with different rate,which shows that LNFMO thin film electrode materials can be obtained at the laser energy density of 2J/cm²,coating temperature of 750°C,oxygen pressure of 31Pa and depositing time of 3h,it can also get cycle performance and rate characteristics stability.Finally,through the same method,we prepare the LiNi_0.45Co_0.10Mn_1.45O₄?LNCMO?thin films by doping Co³⁺,The charge-discharge cycle performance and high rate discharge characteristics of LNFMO and LNCMO thin films were compared and analyzed,The test results show that the LNCMO thin films doped with cobalt can obtain a higher reversible capacity under the condition of constant current charging and discharging;The LNFMO thin films doped with iron are easier to gain high rate discharge capacity.Compared with undoped LNMO thin films,the doping modification of M³⁺?M=Fe/Co?can improve the reversible capacity and high current discharge capacity.