Impact‐Tolerant Batteries Enabled by High‐Conductivity Shear Thickening Electrolytes

ABSTRACT The application of shear thickening electrolytes (STEs) in batteries is hindered by the conventional trade‐off, in which enhanced impact resistance comes at the cost of reduced ionic conductivity. Here, we overcome this barrier by introducing lithium sulfonate‐functionalized mesoporous silica (M‐SiO 2 ‐SO 3 Li) as a multifunctional filler. Unlike conventional fillers that impede ion transport, M‐SiO 2 ‐SO 3 Li simultaneously induces shear thickening and enhances conductivity. At 15 wt.% loading, the electrolyte achieves a remarkable ionic conductivity of 10.73 mS cm −1 , higher than that of filler‐free traditional electrolytes (TE), by anchoring anions via the ‐SO 3 Li groups to increase the Li + transference number. This synergy enables exceptional battery performance: Li||LFP cells demonstrate 97.0% capacity retention after 500 cycles, and LFP||Gr pouch full cells maintain 83.8% capacity after 200 cycles at 0.5 C. In impact tests, the robustness of this design is evident as the M‐SiO 2 ‐SO 3 Li‐based pouch cell withstands hammer drops that cause immediate failure in standard TE cells. Thus, this design strategy overcomes the performance trade‐off, integrating high conductivity, long cycling life, and impact resistance, and provides a pathway for application across the liquid‐based electrolyte family.