Molecular-Level Cleavage and Kinetics Optimization in PVDF Electrolytes for Anode-Lean Ultrastable Solid-State Sodium Batteries

Here, we propose a molecular-level design using Na₃P as a dual-function nanofiller in poly(vinylidene fluoride) (PVDF) electrolytes. The nucleophilic P^3– selectively cleaves C–F bonds, reducing polymer crystallinity and releasing F^– species, while Na₃P simultaneously serves as a built-in fast-ion conductor.

Theoretical simulations reveal that Na₃P remodels the solvation structure, lowers the desolvation barrier from 9.96 to 2.84 eV, facilitates salt dissociation and reduces F^– migration barrier from 4.23 to 3.0 eV, collectively promoting Na⁺ mobility and raising bulk conductivity to 6.93 × 10^–4 S cm^–1. The released F^– promotes in situ formation of a dense, NaF-rich solid-electrolyte interphase, enabling homogeneous Na plating.