Formation of self-limited, stable and conductive interfaces between garnet electrolytes and lithium anodes for reversible lithium cycling in solid-state batteries
Formation of self-limited, stable and conductive interfaces between garnet electrolytes and lithium anodes for reversible lithium cycling in solid-state batteries
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在石榴石电解质和锂阳极之间形成自限、稳定和导电的界面，用于固态电池中的可逆锂循环
DOI：
10.1039/c8ta02276c
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发表时间：
2018-06-28
影响因子：
11.9
通讯作者：
Guo, Xiangxin
中科院分区：
文献类型：
--
作者：
He, Minghui;Cui, Zhonghui;Guo, Xiangxin
固态电池（SSB）已经引起了人们的极大关注，因为与目前使用的具有液体电解质的锂离子电池相比，它们具有提供高能量密度和优异安全性的潜力。在SSB中使用锂阳极对于实现这些优点极其重要。从一个高导电性的立方石榴石固体电解质（Li6.375La3Zr1.375Nb0.625O12，LLZNO）的合成使用Nb作为结构稳定剂，在这项研究中，我们证明了解决石榴石电解质和锂阳极之间的界面问题和锂阳极的集成到石榴石基SSB通过修改合成的LLZNO与Sn薄膜。由于Sn改性，石榴石电解质和锂阳极之间的界面电阻降低约20倍，仅为46.6 Ω cm 2。实现了Li/Sn-LLZNO/LiFePO 4全电池在高电流密度下的快速可逆的锂镀/脱和优异的电池性能。这种改进归因于Li-Sn合金中间层的形成，其充当自限制稳定且导电的界面，桥接石榴石电解质和锂阳极，并使得能够快速且稳定地输运锂。作为一种概念验证，这种有效的表面改性方法将为研究人员克服界面问题和促进高性能SSB的发展提供启示。
Solid-state batteries (SSBs) have already attracted significant attention due to their potential to offer high energy density and excellent safety as compared to the currently used lithium-ion batteries with liquid electrolytes. The use of a lithium anode in SSBs is extremely important to realize these advantages. Starting from the synthesis of a highly conductive cubic garnet solid electrolyte (Li6.375La3Zr1.375Nb0.625O12, LLZNO) using Nb as a structure stabilizer, in this study, we demonstrated the resolution of interfacial problems between the garnet electrolyte and lithium anode and the integration of the lithium anode into garnet-based SSBs by modifying the as-synthesized LLZNO with a Sn thin film. Due to the Sn modification, the interfacial resistances between the garnet electrolyte and the lithium anode decreased approximately 20 times to only 46.6 Ω cm2. The fast and reversible lithium plating/stripping under high current densities and the excellent battery performance of Li/Sn-LLZNO/LiFePO4 full cells were achieved. This improvement is ascribed to the formation of a Li–Sn alloy interlayer, which severs as a self-limited stable and conductive interface, bridging the garnet electrolyte and the lithium anode and enabling fast and stable lithium transport. As a proof-of-concept, this effective surface modification method will offer inspirations to researchers for overcoming the interfacial problems and promoting the development of high-performance SSBs.