Solid-state batteries (SSBs) have attracted many attentions due to its higher energy density and improved safety. As one of the most promising solid electrolytes, garnet Li₇La₃Zr₂O₁₂ (LLZO) has achieved significant advances in its cell performance, however, its application in Li-metal batteries is still hindered by lithium dendrite growth at voids or grain boundaries inside the solid electrolyte. Herein, a novel grain-boundary enhancement strategy was demonstrated by introducing Li₆Zr₂O₇ (LZO), which can be decomposed into Li₂O in situ, into Ta-doped LLZO (LLZT). The Li₂O provides a sufficient inner Li₂O atmosphere, achieving none mother powder sintering. The Li₂ZrO₃ stays at garnet grain boundaries or fills up the pores, which have been shown to effectively suppress the lithium dendrite growth. More importantly, the critical current density (CCD) of the Li | LLZT-LZO | Li symmetric cell achieved as high as 1.4 mA cm⁻² at 25 °C and 2.0 mA cm⁻² at 60 °C, and the long-term lithium cycling remained stable over 2000 h at 0.3 mA cm⁻². Moreover, the Li-S battery maintained high discharge capacity of 816 mAh g⁻¹ after 200 cycles at 0.5C. Therefore, our work provides a facile and effective strategy to prepare a safety-enhanced electrolyte for future applications of SSBs.

固态电池（SSB）由于具有更高的能量密度和更高的安全性而备受关注。石榴石Li ₇ La ₃ Zr ₂ O ₁₂（LLZO）作为最有前途的固体电解质之一，在电池性能方面取得了显着进步，但是，其在锂金属电池中的应用仍然受到锂枝晶在空隙或晶粒上生长的阻碍。固体电解质内部的边界。本文中，通过将可原位分解为Li ₂ O的Li ₆ Zr ₂ O ₇（LZO）引入掺Ta的LLZO（LLZT）中，证明了一种新颖的晶界增强策略。Li ₂ O提供足够的内部Li_在2 O气氛中，没有母粉烧结。Li ₂ ZrO ₃停留在石榴石晶界或填满孔，这已显示可有效抑制锂枝晶的生长。更重要的是，锂电池的临界电流密度（CCD）LLZT-LZO | Li对称电池在25°C时达到1.4 mA cm ^-2，在60°C时达到2.0 mA cm ^-2，并且长期锂循环在0.3 mA cm ^{-2的条件下}在2000 h内保持稳定。此外，Li-S电池在0.5C下200次循环后维持了816mAh g ^-1的高放电容量。因此，我们的工作提供了一种简便而有效的策略来制备安全增强型电解液，以供SSB的未来应用。