Optimizing the Mg Doping Concentration of Na3V2- xMgx(PO4)2F3/C for Enhanced Sodiation/Desodiation Properties

Diah Agustina Puspitasari, Jagabandhu Patra, I. Ming Hung, Dominic Bresser, Tai Chou Lee, Jeng Kuei Chang

研究成果: Article同行評審

摘要

Na3V2(PO4)2F3 with a NASICON (Na-superionic conductor) structure is a promising cathode material for sodium-ion batteries (NIBs) due to its high-energy density and great cycling stability. However, its low conductivity leads to inferior rate capability, which impedes its practical application. Herein, we report the synthesis of carbon-coated Na3V2-xMgx(PO4)2F3 with various Mg2+ doping levels (x = 0, 0.01, 0.05, and 0.1) using a facile sol-gel method. The effects of Mg2+ doping on the material and electrochemical properties are systematically investigated. The X-ray diffraction peaks shift to higher angles, reflecting a lattice contraction with increasing Mg2+ content. Rietveld refinement reveals the Na-O, V-O, and P-O bond length values of various Na3V2-xMgx(PO4)2F3 samples. The optimal carbon-coated Na3V1.95Mg0.05(PO4)2F3 shows excellent rate capability of 80 mA h g-1 at 10 C; moreover, 88% of this capacity can be retained after 500 charge/discharge cycles with an average Coulombic efficiency of 99.9%. The superior performance can be attributed to (i) enhanced electronic conductivity, (ii) improved Na+ transport, (iii) reduced crystal and particle sizes, and (iv) increased structural stability due to Mg2+ doping.

原文English
頁(從 - 到)6962-6971
頁數10
期刊ACS Sustainable Chemistry and Engineering
9
發行號20
DOIs
出版狀態Published - 2021 五月 24

All Science Journal Classification (ASJC) codes

  • 化學 (全部)
  • 環境化學
  • 化學工程 (全部)
  • 可再生能源、永續發展與環境

指紋

深入研究「Optimizing the Mg Doping Concentration of Na<sub>3</sub>V<sub>2- x</sub>Mg<sub>x</sub>(PO<sub>4</sub>)<sub>2</sub>F<sub>3</sub>/C for Enhanced Sodiation/Desodiation Properties」主題。共同形成了獨特的指紋。

引用此