储能科学与技术 ›› 2022, Vol. 11 ›› Issue (9): 2847-2865.doi: 10.19799/j.cnki.2095-4239.2022.0097

• 创刊十周年专刊 • 上一篇    下一篇

锂镧锆氧(LLZO)基固态锂电池界面关键问题研究进展

翟朋博1(), 常冬梅2, 毕志杰1, 赵宁1, 郭向欣1()   

  1. 1.青岛大学物理科学学院,山东 青岛 266071
    2.山东理工职业学院,山东 济宁 272067
  • 收稿日期:2022-02-24 修回日期:2022-04-12 出版日期:2022-09-05 发布日期:2022-08-30
  • 通讯作者: 郭向欣 E-mail:woshizpb@qdu.edu.cn;xxguo@qdu.edu.cn
  • 作者简介:翟朋博(1993—),男,博士,副教授,主要研究方向高性能锂金属电池构筑,E-mail: woshizpb@qdu.edu.cn
  • 基金资助:
    国家自然科学基金项目(U1932205);山东省重点研发计划重大科技创新工程项目(2021CXGC010401);山东省泰山学者(ts201712035);青岛市创业创新领军人才项目

Research progress on key interfacial issues in lithium lanthanum zirconium oxide-based solid-state

Pengbo ZHAI1(), Dongmei CHANG2, Zhijie BI1, Ning ZHAO1, Xiangxin GUO1()   

  1. 1.College of physics, Qingdao University, Qingdao 266071, Shandong, China
    2.Shandong Polytechnic College, Jining 272067, Shandong, China
  • Received:2022-02-24 Revised:2022-04-12 Online:2022-09-05 Published:2022-08-30
  • Contact: Xiangxin GUO E-mail:woshizpb@qdu.edu.cn;xxguo@qdu.edu.cn

摘要:

与目前采用有机电解液的商业化锂离子电池相比,引入固体电解质的固态锂电池在同时提升电池能量密度和安全性方面具有巨大潜力,成为开发下一代锂电池的重点。在众多固体电解质材料中,石榴石型的锂镧锆氧(Li7La3Zr2O12,LLZO)凭借高锂离子电导率、优异的对锂稳定性和宽电化学窗口等优点受到广泛关注。然而,LLZO的引入带来诸多界面之间的突出问题,例如固固界面的物理接触、应力应变、电荷重新排布以及电化学稳定性等。这些问题不仅是影响电池性能的关键因素,而且带来了很多新的物理化学现象需要深入研究。因此,本文从LLZO基固体电解质与电极之间的外部界面和固体电解质及复合电极内部界面两个角度入手,依据本课题组多年的研究积累,结合领域内最新研究动态,详细讨论了:①LLZO基固体电解质粉体材料表面碳酸锂(Li2CO3)的形成原因、对电化学性能的影响以及克服这一问题的手段;②LLZO基固体电解质层内部界面调控对锂离子电导率及电池电化学性能的影响;③LLZO/Li界面特性及Li在LLZO基陶瓷电解质中贯穿生长,深入探讨了诱导Li析出和生长的电场、电荷、应力应变等作用机制;④复合正极内部界面问题及其与电解质层外部接触界面的一体化构筑方法。希望通过本文对LLZO固态锂电池界面问题的关键科学和技术的分析总结,为构筑高导通高稳定界面,推动高性能固态锂电池发展提供思路。

关键词: 石榴石型固体电解质, 固-固界面, 电荷传输, 界面调控, 固态锂电池

Abstract:

Compared with the current commercial lithium-ion batteries based on organic liquid electrolytes, solid-state lithium (Li) batteries using solid-state electrolytes hold great potential in improving safety and energy density, making them one of the important development directions for next-generation Li batteries. Among many solid-state electrolyte materials, Li7La3Zr2O12 (LLZO), a typical garnet-type solid electrolyte, has attracted extensive attention due to its high Li-ion conductivity and excellent chemical stability against lithium and wide electrochemical windows.However, the introduction of solid lithium lanthanum zirconium oxide (LLZO) causes many interfacial problems, such as noncontinuous physical contact, stress-strain, charge redistribution, and electrochemical instability. These problems affect the electrochemical performance of batteries and induce many new physical and chemical phenomena that require extensive exploration. In this review, from two perspectives of the external interface between the LLZO-based solid electrolyte and the electrode and the intrinsic interface inside the solid electrolyte and the composite electrode, the following topics are extensively discussed based on the research progress in our group and the frontier theoretical viewpoints in this field: First, the formation mechanism of lithium carbonate (Li2CO3) on the LLZO powder surface, its influence on electrochemical properties and the strategies to overcome this problem. Second, the effects of the internal interface regulation of LLZO-based electrolyte layers on the Li-ion conductivity and the electrochemical performance of the battery. Third, the characteristics of the LLZO/Li interface and the penetration growth of Li metal in LLZO-based ceramic electrolytes. The mechanism of Li infiltration and dendritic growth induced by the electric field, charge transfer, and stress-strain is also explicitly discussed. Fourth, existing problems of intrinsic interface inside the composite cathode and its integrated construction with the external interface against the solid electrolyte layer. By analyzing and summarizing the key science and technology of LLZO interfacial problems, this review inspires new insights into solving the critical problems of the garnet-type solid electrolyte/electrode interface and promoting the development of high-performance solid-state lithium batteries.

Key words: garnet electrolytes, solid-solid interface, charge transfer, interface manipulation, solid-state lithium batteries

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