Architecting Obliquitous and Rich Ion Transport Bridges in Polymer Electrolytes for Room Temperature Long-Life Solid-State Batteries

Solid-state lithium-metal batteries are a viable energy storage device due to their high energy density and safety features. Solid-state electrolytes are integral to maintain safety by restricting the uncontrolled growth of lithium dendrites and hindering the side reactions. However, their practical application is hampered by low ionic conductivity, undesirable interfacial contacts, severe polarization, and unbefitting operation temperature. Herein, a composite quasi-solid-state polymer electrolyte is designed via in-situ polymerization of suspension electrolyte with fumed aluminum trioxide nanoparticles and the addition of poly (ethylene glycol) diacrylate, resulting in enrichment short polymer bridges for Li ion transferring (ionic conductivity reach to 4.1×10−4 S cm−1 at room temperature). Remarkably, the polymer electrolyte with tortuous structural properties can afford a higher lateral Li ion diffusion, which facilitates the suppression of dendrite. Additionally, the addition of aluminum trioxide can improve the electrochemical stability, indicating a strong correlation between the electrolyte's physicochemical properties and the solvation structure of the precursor. As expected, this type of electrolyte-based Li metal batteries coupled with LiNi0.8Co0.1Mn0.1O2 and LiNi0.6Co0.2Mn0.2O2 cathodes can enable stable operation for both coin and pouch cells, paving the way for exploring a series of architectures such as flexible and custom shaped batteries.