A Novel Anion Receptor Additive for ‐40ºC Sodium Metal Batteries by Anion/Cation Solvation Engineering

Sodium metal batteries, known for their high theoretical specific capacity, abundant reserves, and promising low‐temperature performance, have garnered significant attention. However, the large ionic radius of Na+ and sluggish transport kinetics across the interfacial structure hinder their practical application. Previous reviews have rarely regulated electrolyte performance from the perspective of anions; as important components of the electrolyte, the regulation mechanism is not well understood. Herein, a novel anion receptor additive, 4‐aminophenylboronic acid pinalol ester (ABAPE), is proposed to weaken the coupling between anions and cations and accelerate Na+ transport kinetics. The results of theoretical calculations and X‐ray photoelectron spectroscopy with deep Ar‐ion etching demonstrate that the introduction of this additive alters the solvation structure of Na+, reduces the desolvation barrier and forms a stable and dense electrode‐electrolyte interface. Moreover, ABAPE forms hydrogen bonds (–NH···O/F) with H2O/HF, effectively preventing the hydrolysis of NaPF6 and stabilizing acidic species. Consequently, the Na||Na symmetric cell exhibits excellent long‐cycle performance of 500 h at 1 mA cm‐2 and 0.5 mAh cm‐2. The Na||Na3V2(PO4)3 (NVP) full cell with the addition of ABAPE maintains a capacity retention of 84.29% at 1 C after 1200 cycles and presents no capacity decay over 150 cycles at ‐40°C.