In Situ Electrochemical Coating Mechanism of NASICON-Structured AgTi2(PO4)3 for Sodium-Ion Batteries

Zhixuan Wei; Zhongyu Zhang; Nan Chen; Gang Chen; Chunzhong Wang; Fei Du

doi:10.1021/acsami.9b20539

In Situ Electrochemical Coating Mechanism of NASICON-Structured AgTi₂(PO₄)₃ for Sodium-Ion Batteries

ACS Appl Mater Interfaces. 2020 Feb 5;12(5):5932-5938. doi: 10.1021/acsami.9b20539. Epub 2020 Jan 22.

Authors

Zhixuan Wei¹, Zhongyu Zhang¹, Nan Chen¹, Gang Chen¹, Chunzhong Wang¹, Fei Du¹

Affiliation

¹ Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), State Key Laboratory of Superhard Materials, College of Physics , Jilin University , Changchun 130012 , China.

PMID: 31916741
DOI: 10.1021/acsami.9b20539

Abstract

The development of high-performance electrode materials is of great significance for the next-generation room-temperature sodium-ion batteries. In this work, a new Na super-ionic conductor (NASICON) negative electrode, AgTi₂(PO₄)₃, is prepared by a facile solid-state reaction and employed as a sodium storage material for the first time. In situ X-ray diffraction during battery operation reveals an electrochemically Ag nanoparticle coating mechanism upon sodiation, facilitating the electron transfer in the complex. In addition, two steps of highly reversible biphasic transformation are observed. As a result, a reversible capacity of 214.9 mA h g^-1 can be achieved, corresponding to the insertion/extraction of nearly four sodium ions. The AgTi₂(PO₄)₃ electrode also demonstrates better kinetic properties than the bare NaTi₂(PO₄)₃ material. Such an "in situ" decorating method can open up a new direction for the design of NASICON-structured materials.

Keywords: NASICON-type structure; in situ XRD; negative electrode; sodium-ion battery; “in situ” electrochemical decoration.