摘要
实验采用NH_4VO_3对富锂锰基材料Li_(1.2)Mn_(0.54)Co_(0.13)Ni_(0.13)O_2(Lirich)进行表面修饰。使用扫描电镜(SEM)、X射线衍射(XRD)以及电化学方法等手段进行了表征。TEM显示在材料表面形成10 nm左右的包覆层。XRD结果发现,包覆后的Li_(1.2)Mn_(0.54)Co_(0.13)Ni_(0.13)O_2(Lirich-V_2O_5)晶体中出现Li_3VO_4。Lirich-V_2O_5的首次充放电效率为103.1%,说明V_2O_5包覆层对Li Mn_(0.54)Co_(0.13)Ni_(0.13)O_2起到了预活化的作用。Lirich循环20圈之后的容量保持率为71.4%,而Lirich-V_2O_5的容量保持率则达到了90.4%,说明V_2O_5包覆层有效抑制材料与电解液的副反应。
NH,VO3 is used to modify the lithium-rich manganese oxides Li1.2Mn0.54Co0.l3Ni0.13O2/V2O5 （Lirich）. SEM, XRD and electrochemical measurements are used to characterize the materials. TEM shows the coating layer around the material is about 10 nm. As shown in XRD spectra, Li3VO4 is found around the surface of Li1.2Mn0.54Co0.l3Ni0.13O2（Lirich-V2O5） after the modification process. The initial charge-discharge efficiency of Lirich-2O5 is 103.1%, which shows that the coating of V2O5 pre-activates LiMn0.54Co0.13Ni0.13O2. After 20 cycles test, the capacity retention of Lirich is only 71.4 %, while it is 90.4 % for Lirich-V2O5, which indicates that the coating layer of V2O5 also inhibits the side reaction of active material and the electrolyte.
出处
《广东化工》
CAS
2017年第2期33-34,共2页
Guangdong Chemical Industry
关键词
富锂锰基材料
包覆
V2O5
首次充放电效率
lithium-rich manganese oxides： coating
V2O5
Initialcharge-dischargeefficiency
