Shear thickening electrolytes (STE) are materials that exhibit a sudden increase in viscosity with increasing shear rate. They can enhance the safety of lithium batteries by forming a solid-like barrier upon strong impacts, such as car accidents, preventing electrode short circuits and potential hazards like explosions or fires. When no shear forces are applied, these electrolytes remain liquid, providing higher ionic conductivity than typical solid electrolytes, which is crucial for maintaining battery performance under normal operating conditions.
In this study, we developed STEs comprising silica nanoparticles, lithium salt, and a matrix free of hydroxyl groups. The use of these matrices enabled the fabrication of stable composite electrolytes exhibiting the characteristic viscosity jump of shear thickening fluids, with values exceeding 20000 Pa·s. This significant increase in viscosity under shear stress ensures enhanced mechanical stability, which is particularly beneficial for high-performance energy storage systems. By replacing hydroxyl groups, these electrolytes become compatible with lithium metal anodes, improving their cycling stability and safety, making them promising candidates for next-generation battery technologies.