Ouyang Cheng, Zheng Hongpeng, Chen Qiwen, Liu Hezhou, Duan Huanan
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
ACS Appl Mater Interfaces. 2023 Nov 8;15(44):51179-51190. doi: 10.1021/acsami.3c11748. Epub 2023 Oct 28.
Solid-state lithium batteries hold great promise for next-generation energy storage systems. However, the formation of lithium filaments within the solid electrolyte remains a critical challenge. In this study, we investigate the crucial role of morphology in determining the resistance of garnet-type electrolytes to lithium filaments. By proposing a new test method, namely, cyclic linear sweep voltammetry, we can effectively evaluate the electrolyte resistance against lithium filaments. Our findings reveal a strong correlation between the microscopic morphology of the solid electrolyte and its resistance to lithium filaments. Samples with reduced pores and multiple grain boundaries demonstrate remarkable performance, achieving a critical current density of up to 3.2 mA cm and excellent long-term cycling stability. Kelvin probe force microscopy and finite element method simulation results shed light on the impact of grain boundaries and electrolyte pores on lithium-ion transport and filament propagation. To inhibit lithium penetration, minimizing pores and achieving a uniform morphology with small grains and plenty of grain boundaries are essential.
固态锂电池在下一代储能系统中极具前景。然而，固体电解质中锂丝的形成仍然是一个关键挑战。在本研究中，我们探究了微观结构在决定石榴石型电解质对锂丝电阻方面的关键作用。通过提出一种新的测试方法，即循环线性扫描伏安法，我们能够有效评估电解质对锂丝的电阻。我们的研究结果揭示了固体电解质的微观结构与其对锂丝电阻之间的强相关性。具有较少孔隙和多个晶界的样品表现出卓越性能，临界电流密度高达3.2 mA/cm ，并具有出色的长期循环稳定性。开尔文探针力显微镜和有限元方法模拟结果揭示了晶界和电解质孔隙对锂离子传输和锂丝传播的影响。为抑制锂渗透，使孔隙最小化并实现具有小晶粒和大量晶界的均匀微观结构至关重要。
