skip to main content

DOE PAGESDOE PAGES

Title: Effects of Mg doping on the remarkably enhanced electrochemical performance of Na3V2(PO4)3 cathode materials for sodium ion batteries

Na3V2-xMgx(PO4)3/C composites with different Mg2+ doping contents (x=0, 0.01, 0.03, 0.05, 0.07 and 0.1) were prepared by a facile sol-gel method. The doping effects on the crystal structure were investigated by XRD, XPS and EXAFS. The results show that low dose doping Mg2+ does not alter the structure of the material, and magnesium is successfully substituted for vanadium site. The Mg doped Na3V2-xMgx(PO4)3/C composites exhibit significant improvements on the electrochemistry performances in terms of the rate capability and cycle performance, especially for the Na3V1.95Mg0.05(PO4)3/C. For example, when the current density increased from 1 C to 30 C, the specific capacity only decreased from 112.5 mAh g-1 to 94.2 mAh g-1 showing very good rate capability. Moreover, even cycling at a high rate of 20 C, an excellent capacity retention of 81% is maintained from the initial value of 106.4 mAh g-1 to 86.2 mAh g-1 at the 50th cycle. Enhanced rate capability and cycle performance can be attributed to the optimized particle size, structural stability and enhanced ionic and electronic conductivity induced by Mg doping.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2]
  1. Beijing Inst. of Technology, Beijing (China). Key Lab. of Environmental Science and Engineering, School of Chemical Engineering and Environment
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Dept.
Publication Date:
OSTI Identifier:
1177849
Grant/Contract Number:
AC02-98CH10886; 2015CB251100; NCET-12-0047; NCET-13-0033
Type:
Accepted Manuscript
Journal Name:
Journal of Materials Chemistry. A
Additional Journal Information:
Journal Volume: 3; Journal Issue: 18; Journal ID: ISSN 2050-7488
Publisher:
Royal Society of Chemistry
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE national synchrotron light source