Fluorine-Doped NaTi2(PO4)3 Via Electronic Orbital Modulation and Bandgap Engineering for Aqueous Li/Na/K-Ion Batteries
Journal article, 2025
Sodium titanium phosphate (NaTi2(PO4)3, NTP) has emerged as a promising electrode material due to its three-dimensional open framework. This study investigates the use of NTP in aqueous dilute Li+/Na+ electrolytes and extends its application to high-concentration K+ electrolytes. X-ray photoelectron spectroscopy, X-ray absorption near-edge structure analysis, and density functional theory calculations revealed that highly electronegative fluorine partially substitutes for oxygen in the NTP lattice, resulting in the formation of Ti-F bonds. The substitution effectively modulates the electronic structure of Ti4+, alters the local coordination environment, and influences the redox dynamics. Enhanced long-term cycling stability and rate performance were demonstrated across aqueous sodium-ion, lithium-ion, and potassium-ion half-cells. Among the investigated systems, the aqueous sodium-ion system exhibited the best electrochemical performance, characterized by a single, well-defined charge–discharge plateau, stable cycling behavior with 88.7% capacity retention after 500 cycles at 1 A g−1, and an initial specific discharge capacity of 121.7 mAh g−1 at 0.2 A g−1. The results establish F-doped NTP as a promising candidate for advanced energy storage applications in aqueous alkali metal-ion batteries.
aqueous Li/Na/K-ion batteries
ionic conductivity
NASICON-type NaTi2(PO4)3 electrode
electronic structure
Author
Tong Xu
Xi'an University of Technology
Xi'an Institute of Posts and Telecommunications
Jiaojiao Yu
Xi'an Institute of Posts and Telecommunications
Junchao Ma
Xi'an Institute of Posts and Telecommunications
Hongbo Yu
Xi'an Institute of Posts and Telecommunications
Junling Che
Xi'an Institute of Posts and Telecommunications
Qixiang Yin
Xi'an Institute of Posts and Telecommunications
Yukun Xi
Xi'an University of Technology
Yanyan Cao
Xi'an University of Technology
Mangmang Shi
Chemistry and Biochemistry Phd Students and Postdocs
Shuting Wang
Xi'an Institute of Posts and Telecommunications
Wu Wan
Xi'an Institute of Posts and Telecommunications
Changxin Li
Xi'an Institute of Posts and Telecommunications
Rui Chen
Xi'an Institute of Posts and Telecommunications
Jinniu Zhang
Xi'an Institute of Posts and Telecommunications
Qiyi Zhao
Xi'an Institute of Posts and Telecommunications
Wei Ren
Xi'an Institute of Posts and Telecommunications
Mingliang Hu
Xi'an Institute of Posts and Telecommunications
Xifei Li
Xi'an University of Technology
Energy and Environmental Materials
25750348 (ISSN) 25750356 (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Materials Chemistry
DOI
10.1002/eem2.70043