Robust Artificial Interlayer with High Ionic Conductivity and Mechanical Strength toward Long‐Life Na‐Metal Batteries

Abstract

Sodium metal, benefiting from its high theoretical capacity and natural abundance, is regarded as a promising anode for sodium‐metal batteries (SMBs). Unfortunately, the uncontrollable sodium dendrites formation caused from the sluggish ion‐transport kinetics and fragile solid electrolyte interphase (SEI) interlayer induces a low Coulombic efficiency and poor cycling stability. Constructing an artificial SEI interlayer with high ionic conductivity, stability, and mechanical toughness is an effective strategy for Na‐metal anode, yet it still presents major challenge for high current density and long cycling life. Herein, an artificial SEI interlayer composed of Na–Sn alloy, Sn, and Na2Te (denoted as NST) is designed via in‐situ conversion/alloying reaction of tin telluride (SnTe) with Na. Such artificial interlayer possesses rapid Na+‐transport kinetics and high Young's modulus (5.3 GPa), benefitting to even Na plating/stripping and suppressing Na dendrite growth. Owing to these merits, the symmetrical Na/NST cell presents an ultralong cycle life span over 1390 h with a small voltage hysteresis at 1 mA cm−2 with 1 mAh cm−2. And the Na3V2(PO4)3 (NVP)||Na/NST full cell exhibits a prolonged life of 1000 cycles with a high‐capacity retention of 88% at 5C. Herein, a promising strategy is provided to construct a high‐performance artificial interlayer for SMBs.

A Rooted Multifunctional Heterogeneous Interphase Layer Enabled by Surface‐Reconstruction for Highly Durable Sodium Metal Anodes

“…On the one hand, the formed tiny Na 15 Sn 4 nanoparticles are homogeneously distributed in the heterogeneous artificial SEI interlayer. [ 50,51 ] On the other hand, the Na‐based alloys derived from the spontaneous reconstruction reaction have relatively low crystallinity, thus leading to a low inimitable signal in the XRD pattern. Therefore, to gain a deeper insight into the chemical state and bonding condition of the heterogeneous components of the designed artificial SEI layer, X‐ray photoelectron spectroscopy (XPS) analysis was conducted.…”

Na metal anodes for liquid and solid-state Na batteries

“…However, the irreversible reactions continuously consume the electrolyte additives upon repeated cycling leading to poor cycling stability. 235…”

Stabilized Solid–Solid Interface for Solid-State Sodium Batteries Using Gradient Ion-Electron Conductive Phases Modified Sodium Metal Anode

“…Driven by the emerging need for large-scale energy storage, Na-ion batteries are considered the ideal battery system to replace the existing Li-ion batteries with their abundant reserves and low prices. − However, traditional Na-ion batteries using organic electrolytes present safety issues, and conventional hard carbon anodes cannot meet high energy density requirements. , High-performance solid-state sodium–metal batteries (SSSMBs) with solid-state electrolytes (SSEs) are considered the ideal new-generation Na-ion batteries because they can apply high-energy-density Na-metal anodes and high-voltage cathodes. Among various types of SSEs, including polymers, , sulfides, , halides, and oxides, − etc., the sodium superionic conductor oxide SSEs , (usually indicated as NZSP, Na 1+ x Zr 2 Si x P 3– x O 12 ) have gained extensive prominence owing to their high ionic conductivity, wide electrochemical window, and good chemical compatibility with Na metal.…”