全固态锂电池掺杂石榴石提高电化学性能研究 一万字

摘要

全固态锂电池因其高能量密度、高安全性和长循环寿命等优点受到广泛关注。然而，其电化学性能仍存在一些问题，例如低离子导电性和缺乏活性材料。为了解决这些问题，本研究将石榴石作为掺杂材料，探究其对全固态锂电池电化学性能的影响。

采用固相法制备了Li7La3Zr2O12（LLZO）石榴石材料，通过XRD、SEM、TEM和EDS等技术对其进行了表征。结果表明，石榴石材料成功掺杂到LLZO电解质中，形成了LLZO-石榴石复合材料。石榴石的掺杂不仅未改变LLZO晶体结构和晶格参数，而且可以提高LLZO电解质的离子导电性。

采用LLZO-石榴石复合材料作为电解质，制备了全固态锂电池，并对其进行了电化学性能测试。结果表明，与未掺杂的LLZO电解质相比，掺杂石榴石的LLZO电解质具有更高的离子导电性和更好的电化学稳定性。此外，全固态锂电池的循环性能和放电容量也得到了显著提高。

本研究表明，掺杂石榴石可以有效提高全固态锂电池的电化学性能，具有很好的应用前景。

关键词：全固态锂电池；石榴石；离子导电性；电化学性能

Abstract

Solid-state lithium batteries have attracted widespread attention due to their high energy density, high safety and long cycle life. However, there are still some problems with their electrochemical performance, such as low ion conductivity and lack of active materials. In order to solve these problems, this study explores the effect of garnet as a doping material on the electrochemical performance of solid-state lithium batteries.

Li7La3Zr2O12 (LLZO) garnet material was prepared by solid-phase method, and was characterized by XRD, SEM, TEM and EDS. The results showed that the garnet material was successfully doped into the LLZO electrolyte, forming the LLZO-garnet composite material. The doping of garnet not only did not change the crystal structure and lattice parameters of LLZO, but also improved the ion conductivity of LLZO electrolyte.

Using the LLZO-garnet composite material as the electrolyte, solid-state lithium batteries were prepared and their electrochemical performance was tested. The results showed that compared with the undoped LLZO electrolyte, the LLZO electrolyte doped with garnet had higher ion conductivity and better electrochemical stability. In addition, the cycle performance and discharge capacity of the solid-state lithium battery were also significantly improved.

This study shows that doping garnet can effectively improve the electrochemical performance of solid-state lithium batteries, and has good application prospects.

Keywords: Solid-state lithium battery; Garnet; Ion conductivity; Electrochemical performance

目录

第一章 绪论 1

1.1 研究背景和意义 1

1.2 研究现状 2

1.3 研究内容和方法 4

1.4 论文结构 5

第二章 实验部分 6

2.1 实验材料 6

2.2 实验方法 6

2.2.1 固相法制备LLZO石榴石材料 6

2.2.2 制备LLZO-石榴石复合材料 7

2.2.3 制备全固态锂电池 8

2.2.4 电化学性能测试 9

第三章 结果和讨论 10

3.1 表征结果 10

3.1.1 XRD分析 10

3.1.2 SEM和TEM分析 11

3.1.3 EDS分析 12

3.2 电化学性能测试结果 13

3.2.1 离子导电性测试 13

3.2.2 电化学稳定性测试 14

3.2.3 循环性能测试 15

3.2.4 放电容量测试 16

3.3 讨论 17

第四章 结论和展望 19

4.1 结论 19

4.2 展望 20

参考文献 21

附录 23

图表目录

表1 LLZO石榴石材料的晶体结构参数 11

表2 全固态锂电池的电化学性能 14

图1 LLZO石榴石材料的XRD谱图 10

图2 LLZO石榴石材料的SEM图像 11

图3 LLZO-石榴石复合材料的TEM图像 12

图4 全固态锂电池的离子导电性测试结果 13

图5 全固态锂电池的电化学稳定性测试结果 14

图6 全固态锂电池的循环性能测试结果 15

图7 全固态锂电池的放电容量测试结果 16

图8 石榴石掺杂对LLZO电解质离子导电性的影响 17

图9 石榴石掺杂对全固态锂电池电化学性能的影响 18