Affiliation:
1. The State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 P. R. China
2. Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 China
Abstract
AbstractNASICON‐type Na+ conductors show a great potential to realize high performance and safety for solid‐state sodium metal batteries (SSSMBs) owing to their superior ionic conductivity, high chemical stability, and low cost. However, the interfacial incompatibility and sodium dendrite hazards still hinder its applications. Herein, a conversion‐alloy reaction‐induced interface ionic/electronic redistribution strategy, constructing a gradient sodiophilic and electron‐blocking interphase consisting of sodium‐tin (Na‐Sn) alloy and sodium fluoride (NaF) between NASICON ceramic electrolyte and Na anode is proposed. The NaxSny alloy‐rich layer near the side of the sodium electrode acts as a superior conductor to enhance the anodic sodium‐ion transport dynamics while the NaF‐rich layer near the side of the ceramic electrolyte serves as an electron insulator to confine the interfacial electron turning ability, achieving uniform and dendrite‐free Na deposition during the cycling. Profiting from the synergistic effect of the gradient interphase, the critical current density (CCD) of the assembled Na symmetric cell is significantly increased to 1.7 mA cm−2 and the cycling stability of that is as high as 1200 h at 0.5 mA cm−2. Moreover, quasi‐solid‐state sodium batteries with both Na3V2(PO4)3 and NaNi1/3Fe1/3Mn1/3O2 cathode display outstanding electrochemical performance.
Funder
National Natural Science Foundation of China
Subject
General Materials Science,General Chemistry