烧结助剂Al_2O_3与Y_2O_3对固态锂离子电解质LLZO的锂离子电导率的影响  

Effects of sintering aids Al_2O_3 and Y_2O_3 on the lithium ion conductivity of solid lithium ion electrolyte LLZO

作　　者：李荐[1,2] 蒋逸雄 周宏明 LI Jian;JIANG Yixiong;ZHOU Hongming(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Zhengyuan Institute for Energy Storage Materials and Devices,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]湖南省正源储能材料与器件研究所,长沙410083

出　　处：《粉末冶金材料科学与工程》2018年第2期199-205,共7页Materials Science and Engineering of Powder Metallurgy

摘　　要：以Li_2CO_3,La_2O_3和ZrO_2为原料,分别添加Al_2O_3和Y_2O_3作为烧结助剂,制备锂离子固态电解质xAl_2O_3-Li_7La_3Zr_2O_(12)和xY_2O_3-Li_7La_3Zr_2O_(12)(分别简称为xAl_2O_3-LLZO和xY_2O_3-LLZO。x为摩尔分数,x=0,0.1,0.2,0.3,0.4和0.5),研究Al_2O_3和Y_2O_3的添加量对LLZO的结构与锂离子电导率的影响。结果表明,在1 150℃烧结15 h时,Al_2O_3和Y_2O_3这2种烧结助剂都能稳定立方相石榴石结构LLZO。当Al_2O_3过量时,产生LaAlO_3杂相,当Y_2O_3过量时,产生Li_2ZrO_3和YO_(1.458)杂相。0.2Y_2O_3-LLZO在1100~1200℃范围内能形成稳定的立方相石榴石结构LLZO,并且在1 150℃烧结27 h不发生分解反应;LLZO的致密度和锂离子电导率都随烧结助剂含量增加而先增加后减小,Al_2O_3和Y_2O_3的最佳添加量x分别为0.2和0.3,所得0.2Al_2O_3-LLZO的致密度与离子电导率分别为94%和1.78×10^(-4)S/cm,0.3Y_2O_3-Li_7La_3Zr_2O_(12)的致密度与离子电导率分别为96%和5.23×10^(-4)S/cm。The garnet-type ceramic electrolyte Li7La3Zr2O12(LLZO)with composition of xAl2O3-Li7La3Zr2O12(x=0-0.4)and xY2O3-Li7La3Zr2O12(x=0,0.1,0.2,0.3 and0.4)were synthesized by adding Al2O3 and Y2O3 as sintering aids and using Li2CO3,La2O3 and ZrO2 as raw materials.The effects of the contents of sintering aids Al2O3 and Y2O3 on the lithium ion conductivity of solid lithium ion electrolyte LLZO were studied.The results reveal that two kinds of sintering aids both can stabilize the cubic phase of garnet structure LLZO after sintered at 1 500℃for 15 h.The LaAlO3 impurity phase is produced when Al2O3 is over added.The Li2ZrO3 and YO1.458 impurity phases are produced when Y2O3 is over added.Among these samples,0.2Y2O3-LLZO can stabilize the cubic phase from 1 100℃to 1 200℃and do not decompose when sintering at 1 150℃for 27 h.The density of LLZO and the conductivity of lithium ion increase first and then decrease with increasing the content of sintering aids.The optimum additions of Al2O3 and Y2O3 are 0.2 and 0.3,respectively.The density and ionic conductivity of 0.2Al2O3-LLZO are 94%and 1.78×10-4 S/cm,respectively.The density and ionic conductivity of 0.3Y2O3-Li7La3Zr2O12 are 96%and 5.23×10-4 S/cm,respectively.

关 键 词：固态锂离子电解质 石榴石结构 Li7La3Zr2O12 AL2O3 Y2O3 

分 类 号：TM911[电气工程—电力电子与电力传动]