Enhancing Ion Transport and Suppressing Electron Conduction: a Hybrid Interlayer for Stable Garnet‐Based Solid‐State Batteries

AbstractCubic doped Li7La3Zr2O12s (LLZOs) are promising solid‐state electrolytes (SSE) for solid‐state lithium batteries due to their excellent lithium‐ion conductivities and electrochemical stability. However, they face the challenge of lithium dendrite growth. Here, a hybrid interlayer–alloy phases (LiZn, Li22Sn5, Li5Sn2) and Li2O–is created by an in situ reaction between the modified layer Zn2SnO4 (ZSO) on LLZO and lithium metal anodes. Benefiting from the synergistic effect of the fast lithium‐ion conduction of the Li5Sn2 alloy, the strong affinity between the LiZn alloy and LLZO, and electronic insulator Li2O, a super‐conformal structure at the Li/ZSO‐LLZO interface is formed, effectively inhibiting the formation of lithium dendrites in ZSO‐LLZO SSE. Consequently, Li/ZSO‐LLZO/Li symmetric batteries deliver stable cycling (2500 h under 0.3 mA cm−2 at 25 °C and 6000 h under 0.5 mA cm−2 at 60 °C) performances with superhigh critical current densities of 2.5 mA cm−2 at 25 °C and 3.8 mA cm−2 at 60 °C. Moreover, the LiFePO4/ZSO‐LLZO/Li battery delivers capacities of 137.45 mAh g−1 under 1 C for 500 cycles and 111.78 mAh g−1 under a high rate of 2 C for 300 cycles. This work with a hybrid interlayer opens a boulevard for designing energy‐dense and long‐life solid‐state batteries.

In situ formation of a dual-function interlayer for enhanced cycling stability in solid state lithium battery

Constructing a three-dimensional continuous grain boundary with lithium ion conductivity and electron blocking property in LLZO to suppress lithium dendrites

Constructing electron-blocking grain boundaries in garnet to suppress lithium dendrite growth

In situ construction of a multifunctional interlayer for garnet-type electrolytes to suppress lithium dendrite formation in solid-state lithium batteries