Insight into the capacity decay of layered sodium nickel manganese oxide cathodes in sodium ion batteries

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

  • Xinyin Cai
  • Yanan Xu
  • Lei Meng
  • Xiujuan Wei
  • Fangyu Xiong
  • Qinyou An

Detail(s)

Original languageEnglish
Article number153093
Number of pages6
Journal / PublicationJournal of Alloys and Compounds
Volume820
Online published19 Nov 2019
Publication statusPublished - 15 Apr 2020
Externally publishedYes

Abstract

P2-type NaxNi1/3Mn2/3O2 is considered as one of the promising cathodes for sodium-ion batteries due to its low cost, low toxicity and high operating voltage. However, this material suffers the serious capacity decay and poor stability during cycling. Here, we performed the in-situ X-ray diffraction measurement to investigate the relationship among the voltage window, crystal structure evolution and capacity decay. Based on the finding that the capacity decay is mainly caused by the formation of oxygen anion group [O2]x−(0<x<4), we controlled the voltage in 2.6–3.8 V to avoid the oxygen reaction and the capacity retention of the material has been improved from ∼14% (for 100 cycles) to 94.5% (for 500 cycles).

Research Area(s)

  • Sodium-ion battery, Layered transition metal oxides, Cycling performance, Capacity decay, Structure evolution

Citation Format(s)