Polyethylene Oxide (PEO) Provides Bridges to Silica Nanoparticles to Form a Shear Thickening Electrolyte for High Performance Impact Resistant Lithium‐ion Batteries

The development of shear thickening electrolytes is proving to be pivotal in the quest for impact resistant lithium‐ion batteries (LIBs). However, the high viscosity and poor stability associated with the need for high filler content has to date impeded progress. Here, this work reports a new type of polymer‐bridged shear thickening electrolyte that overcomes these shortcomings, by utilizing the interaction between polymer chains and silica nanoparticles. The incorporation of polyethylene oxide (PEO) facilitates hydrocluster formation providing impact resistance with a filler content as low as 2.2 wt%. This low viscosity electrolyte has a high ionic conductivity of ≈5.1 mS cm(−1) with excellent long‐term stability, over 30 days. The effectiveness of this electrolyte in LIBs is demonstrated by excellent electrochemical performance and high impact resistance.