A Novel Method to Improve the Electrochemical Performance of LiMn_2O_4 Cathode Active Material by CaCO_3 Surface Coating  

作　　者：Halil Sahan Hüseyin Gktepe Saban Patat 

机构地区：[1]Deparment of Chemistry,Science of Faculty,University of Erciyes

出　　处：《Journal of Materials Science & Technology》2011年第5期415-420,共6页材料科学技术（英文版）

基　　金：supported by the Erciyes University Research Found under the code of FBA-08-439

摘　　要：Spinel LiMn204 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature （25℃） and 55℃. The uncoated and CaCO3-coated LiMn204 materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical tests. XRD and SEM results indicated that CaCO3 particles encapsulated the surface of the LiMn204 without causing any structural change. The charge-discharge tests showed that the specific discharge capacity fade of pristine electrode at 25 and 55℃ were 25.5% and 52%, respectively. However, surface modified cathode shows 7.4% and 29.5% loss compared to initial specific discharge capacity at 70th cycle for 25 and 55~C, respectively. The improvement of electrochemical performance is attributed to suppression of Mn2＋ dissolution into electrolyte via CaCO3 layer.Spinel LiMn204 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature （25℃） and 55℃. The uncoated and CaCO3-coated LiMn204 materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical tests. XRD and SEM results indicated that CaCO3 particles encapsulated the surface of the LiMn204 without causing any structural change. The charge-discharge tests showed that the specific discharge capacity fade of pristine electrode at 25 and 55℃ were 25.5% and 52%, respectively. However, surface modified cathode shows 7.4% and 29.5% loss compared to initial specific discharge capacity at 70th cycle for 25 and 55~C, respectively. The improvement of electrochemical performance is attributed to suppression of Mn2＋ dissolution into electrolyte via CaCO3 layer.

关 键 词：LIMN204 CaC03 surface coating Cathode material Capacity fade CYCLEABILITY Lithium ion battery 

分 类 号：TG174.4[金属学及工艺—金属表面处理]