In this study, we report the fabrication of garnet-structure composited solid-state electrolyte with high compactness as a water-proof interlayer for multilayer water-proof protected-lithium-anode. It is revealed that with the addition of Li₃BO₃ into the sintering precursor, the cubic phase garnet Li_6.75La₃Zr_1.75Nb_0.25O₁₂ with high lithium ion conductivity and compactness can be achieved at a low temperature of 1000 °C with a “binder-like” Li₃BO₃ glassy molten phase in the grain boundary, indicating Li₃BO₃ plays an important role on the densification of grain boundary and the improvement of the relative density. 50 mol % Li_6.75La₃Zr_1.75Nb_0.25O₁₂–Li₃BO₃ pellet shows a high lithium ion conductivity of 2.08 $\times$ 10⁻⁴ S cm⁻¹ and a good chemical stability in 21 m LiTFSI “water-in-salt” electrolyte at 25 °C. Hybrid lithium ion capacitor using this garnet-ceramic electrolyte as interlayer for water-proof protected-lithium-anode, 21 m LiTFSI electrolyte and commercial activated carbon as the cathode shows a high working voltage of 4.0 V and a high energy density of 228.9 Wh (kg-carbon)⁻¹ at a power density of 1343.2 W (kg-carbon)⁻¹.

在这项研究中，我们报道了具有高致密性的石榴石结构复合固态电解质的制备，作为多层防水锂离子保护阳极的防水中间层。结果表明，在烧结前体中添加Li ₃ BO ₃，可以在1000°C的低温下以高锂离子电导率和致密性实现立方相石榴石Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂。晶界的“粘结剂状” Li ₃ BO ₃玻璃状熔融相，表明Li ₃ BO ₃在晶界致密化和相对密度的提高中起着重要作用。50 mol％Li _6.75 La ₃ Zr _1.75 Nb _0.25 O ₁₂ –Li ₃ BO ₃颗粒显示出2.08的高锂离子电导率 $\times$在25°C下的21 m LiTFSI“盐包水”电解质中，具有 10 ^-4  S cm ^-1和良好的化学稳定性。使用该石榴石-陶瓷电解质作为防水保护锂阳极夹层，21 m LiTFSI电解质和市售活性炭作为阴极的混合锂离子电容器显示出4.0 V的高工作电压和228.9 Wh（千克碳）^-1在1343.2 W（千克-碳）的功率密度^-1。