Highly stable lithium batteries enabled by composite solid electrolyte with synergistically enhanced in-built ion-conductive framework

The solid-state electrolytes (SSEs) are considered as a decent solution to rationally supersede the liquid one for the sake of dependable operation security and higher energy density when it comes to the next-generation lithium (Li) metal batteries. Herein, a sort of composite solid electrolyte with in-built ion-conductive 3D framework is designed to enable the stable performances of Li-metal batteries. The framework comprised of the Li+-conducting garnet components (Li6.75La3Zr1.75Nb0.25O12, LLZN) and polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) provides the vulnerable part with mechanical support and well-behaved electrochemical stability. Stemmed from this embedded framework, the whole electrolyte exhibits high Li+ conductivity (4.6×10−4 S cm−1), improved high-voltage endurance (4.4 V versus Li/Li+), better Li-anode compatibility and high-temperature feasibility. Additionally, the synergistic enhancements between LLZN and PVDF-HFP potentially facilitate the homogeneous ionic flux, thereby resulting in the persistence of a sound solid-electrolyte interphase. The solid-state batteries assembling composite solid electrolyte also deliver the preferable battery performance, featuring high-capacity output with stable cyclability. Application of this electrolyte in a pouch cell further demonstrates its feasibility and flexibility. This design concept is anticipated to give the way of exploring brand new solid electrolytes and boosting their overall electrochemical performances toward practicality.