4.8-V all-solid-state garnet-based lithium-metal batteries with stable interface

Garnet-type solid electrolytes with high chemical and electrochemical stabilities are uniquely suitable for high-voltage operation but suffer from poor wettability with electrodes, resulting in large interfacial impedance. Here, we design a highly conductive and interface-friendly garnet-based composite solid electrolyte (CSE) comprising a cubic Li 6.1 Al 0.3 La 3 Zr 2 O 12 porous framework and polyvinylidene difluoride (PVDF) with a three-dimensional continuous structure. Formation of La-N and La-F bonds between ceramic and polymer moieties promotes the dissociation of Li salt and thus leads to highly efficient transport. These coupling effects contribute to a high ionic conductivity (0.437 mS cm- 1 ) and Li transfer number t+ + (0.72) at 25 degrees C, degrees C, while simultaneously enable high electrode/electrolyte interfacial stability. The high-voltage robustness of the developed CSE is demonstrated using TiO2-coated 2-coated LiNi0.6Co0.2Mn0.2O2/ 0.6 Co 0.2 Mn 0.2 O 2 / ceramic-based CSE/Li full solid-state batteries, which are stably cycled over 200 times from 3 to 4.8 V with no signs of interfacial instabilities at nanoscale.