NaF-Rich Multifunctional Layers toward Stable All-Solid-State Sodium Batteries

Tinghu Liu; Lin Shen; Yunming Li; Kemin Jiang; Libo Song; Yuming Jin; Jing Yang; Xing Xin; Xiayin Yao

doi:10.1021/acsami.3c10128

NaF-Rich Multifunctional Layers toward Stable All-Solid-State Sodium Batteries

ACS Appl Mater Interfaces. 2023 Sep 27;15(38):45026-45034. doi: 10.1021/acsami.3c10128. Epub 2023 Sep 15.

Authors

Tinghu Liu^{1

2}, Lin Shen², Yunming Li², Kemin Jiang², Libo Song^{1

2}, Yuming Jin², Jing Yang², Xing Xin¹, Xiayin Yao²

Affiliations

¹ School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, P. R. China.
² Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, P. R. China.

PMID: 37713612
DOI: 10.1021/acsami.3c10128

Abstract

NASICON oxide solid electrolytes are considered promising candidates for all-solid-state sodium batteries due to their extremely high ionic conductivity and favorable electrochemical stability. However, the practical application of NASICON electrolytes is greatly impeded by poor electrolyte-electrode interfacial contact and continuous sodium dendrite propagation. Herein, a NaF-rich multifunctional interface layer on the surface of a Na anode (Na@NaF-rich), containing NaF, amorphous carbon, and an unreacted C-F bond species, is developed in situ by the reaction between Na and commercial poly(tetrafluoroethylene). This NaF-rich interface layer is proven to reduce the diffusion barriers at the Na/NASICON electrolyte interface and homogenize Na deposition as well as suppress Na dendrite growth, thus achieving a high critical current density of 4 mA cm^-2. The resultant Na₃V₂(PO₄)₃@C/Na@NaF-rich all-solid-state cell showed a high initial specific capacity of 117.6 mAh g^-1 at 0.1 C with a Coulombic efficiency of 94.8%. Even at 0.5 and 1 C, it still exhibited high capacity retentions of 83.3% and 80.4%, respectively, after 750 cycles.

Keywords: Na metal anode; Na3V2(PO4)3 cathode; NaF-rich interface layer; all-solid-state sodium batteries; dendrite suppression.