Preparation And Properties Of LiCoO₂ Target

With the miniaturization of electronic devices,research on all solid state thin film lithium ion battery was increasingly attentioned.The performance of lithium ion battery mostly depends on the structure and performance of its internal materials,and the properties of the anode materials is the key factor for LIBs to further improve its performance.Up to now,lithium cobalt oxides,LiCoO₂,as the most common cathode material,has been widely studied,especially on its material synthesis and deposited films,however,there are few research on the preparation of LiCoO₂ target.Considering the properties of target also decides the quality of deposited film,it is necessary to have a detailed study.This paper has detailedly discussed the influence of ball-to-powder weight ratio,milling time,sintering temperature and holding time of sintering process on the properties of LiCoO₂ ceramic target.In addition,the suitable concentration of Al₂O₃ for Li(Al_xCo_1-x)O₂ target was also discussed.The main conclusions are as follows:1.By the method of dry pressing molding combined with atmospheric pressure sintering,we have successfully prepared the LiCoO₂ target with a relative density of 94.71%,bending strength of 140 MPa and the Li(Al_xCo_1-x)O₂ target with a relative density of 93.61%,bending strength of 192 MPa.2.As the ball-to-powder weight ratio was 5:1 and milling time was 96 h,ball grinding effect was evident with low ball consumption rate and better powder purity,the powder particle size can be reduced to an average of 615 nm when the LiCoO₂ raw material average size is 4.800 um.Through the powder particle size can be smaller?512 nm?when the ball-to-powder weight ratio was 8:1,the ball consumption rate was close to 0.1%,which was inadvisable.3.By comparing five sintering temperature of 900°C,950°C,1000°C,1050°C and 1100°C,LiCoO₂ target can reach an optimal performance under 1050°C,including the sample shrinkage rate of 17.28%,the weightlessness rate of 0.63%,the relative density of 94.71%,the best strength of 140 MPa,and high purity with no Co₃O₄ phase.Moreover,holding time of 3 h is more suitable for the sintering of LiCo O2 target considering the loss of lithium as well as the basic performance of the object.4.The preparation of Al₂O₃ doped lithium cobalt oxide target in 1050°C?3 h?reveals that all sample with a Al₂O₃ doping amount no more than 3 wt% can reach high purity with no Co₃O₄ peak,and all the sample weightlessness rate is around 0.62% basically identical with pure lithium cobalt oxide,the relative density is around 93.00-94.00% slightly lower than pure sample,but all the bending strength is obviously improved,the sample under 3 wt% doping amount can reach the relative density of 93.61% and the optimal bending strength of 192 MPa.