一步烧结制备锂镧钛氧直孔陶瓷及其固态电池性能研究

摘要/Abstract

摘要： 锂镧钛氧(LLTO)陶瓷电解质因具有高的离子电导率和热稳定性,成为制备固态电池的理想材料,然而传统的电解质制备方法存在界面接触差、步骤烦琐、高温烧结过程中锂损耗大等问题。针对这些问题,开发了一种用于合成具有直孔结构的LLTO陶瓷电解质的一步烧结法,深入研究了一步烧结制备的LLTO陶瓷电解质的微观形貌和电化学性能。结果表明,该方法能够一步合成和烧结具有直孔结构的LLTO陶瓷,从而有效规避了多次烧结过程中的锂损失,增强了LLTO陶瓷的致密化程度,降低了晶界阻抗。通过一步烧结法制备的LLTO陶瓷电解质在室温时表现出2.31×10^-4 S/cm的高电导率。此外,使用所制备的直孔LLTO陶瓷电解质组装的Li/Li对称电池具有良好的锂离子沉积剥离性能,在0.1 mA/cm²的电流密度下循环超过350 h。使用该电解质组装的全固态锂电池在0.2 C倍率下进行200次循环后,容量保持率为94%,证明了一步烧结所制备的直孔LLTO陶瓷具有优异的稳定性。

关键词: 锂电池, 一步烧结, 直孔固态电解质, Li_0.33La_0.56TiO₃, 离子电导率, 陶瓷

Abstract: Lithium lanthanum titanium oxide (LLTO) ceramic electrolyte possesses high ion conductivity and thermal stability, rendering it an ideal candidate for solid-state batteries. However, conventional methods of electrolyte preparation suffer from drawbacks such as poor interface contact, cumbersome procedures, and significant lithium loss during high-temperature sintering. To address these issues, a one-step sintering method to synthesize LLTO ceramic electrolytes with a straight-hole structure was developed. The micromorphology and electrochemical properties of one-step sintering prepared LLTO ceramic electrolytes were thoroughly investigated. The results reveal that this method enables the synthesis and sintering of LLTO ceramics with straight-hole structure in one step, thereby efficiently circumventing lithium loss during multiple sintering processes, enhancing the densification of LLTO ceramics, and reducing grain boundary resistance. Notably, LLTO ceramic electrolytes synthesized via one-step sintering method exhibit a high conductivity of 2.31×10^-4 S/cm at room temperature. Moreover, Li/Li symmetric batteries assembled using this electrolytes demonstrate excellent Li⁺ deposition and stripping performance, which can be stable cycling for over 350 h at a current density of 0.1 mA/cm². Furthermore, the all-solid-state lithium battery assembled with this electrolytes maintains a capacity retention rate of 94% after 200 cycles at a rate of 0.2 C, demonstrating the exceptional stability of straight-hole LLTO ceramics prepared via one-step sintering.

Key words: lithium battery, one-step sintering, straight-hole solid-state electrolyte, Li_0.33La_0.56TiO₃, ionic conductivity, ceramics

中图分类号:

TM911.3

辛文凯, 马晓君, 杨尚运, 毛东旭, 李加杰. 一步烧结制备锂镧钛氧直孔陶瓷及其固态电池性能研究[J]. 硅酸盐通报, 2024, 43(9): 3417-3423.

XIN Wenkai, MA Xiaojun, YANG Shangyun, MAO Dongxu, LI Jiajie. One-Step Sintering Preparation of Lithium Lanthanum Titanium Oxide Straight-Hole Ceramics and Solid-State Battery Performance[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(9): 3417-3423.

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