Enabling High-Voltage Superconcentrated Ionogel-in-Ceramic Hybrid Electrolyte with Ultrahigh Ionic Conductivity and Single Li+-Ion Transference Number

High room-temperature ionic conductivities, large Li+-ion transference numbers, and good compatibility with both Li-metal anodes and high-voltage cathodes of the solid electrolytes are the essential requirements for practical solid-state lithium-metal batteries. Herein, a unique superconcentrated ionogel-in-ceramic (SIC) electrolyte prepared by an in situ thermally initiated radical polymerization is reported. Solid-state static Li-7 NMR and molecular dynamics simulation reveal the roles of ceramic in Li+ local environments and transport in the SIC electrolyte. The SIC electrolyte not only exhibits an ultrahigh ionic conductivity of 1.33 x 10(-3) S cm(-1) at 25 degrees C, but also a Li+-ion transference number as high as 0.89, together with a low electronic conductivity of 3.14 x 10(-10) S cm(-1) and a wide electrochemical stability window of 5.5 V versus Li/Li+. Applications of the SIC electrolyte in Li||LiNi0.5Co0.2Mn0.3O2 and Li||LiFePO4 batteries further demonstrate the high rate and long cycle life. This study, therefore, provides a promising hybrid electrolyte for safe and high-energy lithium-metal batteries.

Automated summary

This study reports a unique superconcentrated ionogel-in-ceramic (SIC) electrolyte with high ionic conductivity, large Li+-ion transference numbers, and good compatibility with both Li-metal anodes and high-voltage cathodes. The SIC electrolyte exhibits ultrahigh ionic conductivity, high Li+-ion transference number, low electronic conductivity, and wide electrochemical stability window, making it promising for safe and high-energy lithium-metal batteries.