铝钡钇钨掺杂锆酸镧电解质性能的研究

采用高温固相法制备了Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12(0.00≤x≤0.25)和Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12(0.00≤y≤0.04)电解质,研究了不同Al含量、Ba含量分别对制得的电解质性能的影响,并运用


摘要:本文采用高温固相法制备了Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12(0.00≤x≤0.25)和Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12(0.00≤y≤0.04)电解质,研究了不同Al含量、Ba含量分别对制得的电解质的离子电导率、相对致密度和收缩率的影响,并用X射线衍射(XRD)和扫描电镜(SEM)对电解质样品进行了表征。研究结果表明,Al的较佳掺杂量x为0.20,此时制得的电解质的离子电导率、相对致密度和收缩率分别为3.30×10-4 Scm-1、90.33%和6.28%,与x=0.00时相比分别提高了38.66%、21.28%和25.10%;Ba的较佳掺杂量y为0.02,此时制得的电解质的离子电导率、相对致密度和收缩率分别为6.60×10-4 Scm-1、89.19%和8.76%,与y=0.00时相比分别提高了41.60%、11.54%和9.50%。XRD和SEM的结果表明,控制一定量Al、Ba的掺杂有助于纯的立方相石榴石结构的形成,能使固体电解质的晶粒变大,晶界变少。本文的创新点在于,目前有关于研究Al含量和Ba含量分别对Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12和Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12电解质性能影响的文献还未见报道。

关键词:固体电解质;离子电导率;相对致密度;收缩率

Study on LiLaBaZrWYAlO Electrolyte

Abstract: In this paper, Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12(0.00≤x≤0.25) and Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12(0.00≤y≤0.04) solid electrolytes were prepared by high temperature solid-state method, the effects of Al-doping and Ba-doping on the properties of prepared solid electrolytes samples were studied, and the electrolytes samples were characterized by X-Ray Diffraction(XRD) and Scanning Electron Microscopy(SEM).The results showed that for Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12 electrolytes, the optimal conductivity of 3.30×10-4 Scm-1, relative density of 90.33% and shrinkage of 6.28% is found to be achieved at x=0.20, and were increased by 38.66%, 21.28% and 25.10% respectively. For Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12 electrolytes, the optimal conductivity of 6.60×10-4 Scm-1, relative density of 89.19% and shrinkage of 8.76% is found to be achieved at y=0.02, and were increased by 41.60%, 11.54%, and 9.50% respectively. The results of XRD and SEM indicated that the doping of a certain amount of Al and Ba could contribute to the formation of a pure cubic phase garnet structure electrolyte and enlarge the crystalline size. The innovation of this paper is that current studies of the effects of Al-doping and Ba-doping on the properties of Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12 and Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12 solid electrolytes have not been reported yet.

KeyWords: Ionic conductivity; Solid-State electrolytes; Relative density; Contractibility rate

目录

1 绪论 1

1.1 选题意义 1

1.2 锂离子固体电解质 2

1.2.1 钙钛矿型(Perovskite)固体电解质 2

1.2.2 NASICON型固体电解质 3

1.2.3 LISICON型固体电解质 3

1.2.4 石榴石型(Garnet)固体电解质 3

1.3 研究内容 8

2 实验内容 9

2.1 原料、试剂以及仪器 9

2.2 LiLaBaZrWYAlO电解质的制备 9

2.2.1 高温固相法制备LiLaBaZrWYAlO电解质的工艺路线图 10

2.2.2 高温固相法制备LiLaBaZrWYAlO电解质的过程 10

2.3 掺杂剂含量的选择 11

2.3.1 Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12电解质中Al含量的选择 11

2.3.2 Li5.8+yLa3-yBayZr1.55W0.35Y0.1Al0.2O12电解质中Ba含量的选择 12

2.4 LiLaBaZrWYAlO电解质的性能测定及表征 12

2.4.1 离子电导率的测定 12

2.4.2 相对致密度的测定 12

2.4.3 收缩率的测定 13

2.4.4 晶体结构的表征 13

2.4.5 断截面形貌的表征 13

3 结果与讨论 14

3.1 Al含量对Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12电解质性能的影响及表征分析 14

3.1.1 Al含量对Li6.42-3xLa2.98Ba0.02Zr1.55W0.35Y0.1AlxO12电解质室温下离子电导率的影响 14