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Anionic Redox Activity in a Newly Zn‐Doped Sodium Layered Oxide P2‐Na 2/3 Mn 1− y Zn y O 2 (0 < y < 0.23)
Author(s) -
Bai Xue,
Sathiya Mariyappan,
MendozaSánchez Beatriz,
Iadecola Antonella,
Vergnet Jean,
Dedryvère Rémi,
Saubanère Matthieu,
Abakumov Artem M.,
Rozier Patrick,
Tarascon JeanMarie
Publication year - 2018
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201802379
Subject(s) - redox , cationic polymerization , materials science , phase (matter) , alkali metal , oxidation state , inorganic chemistry , ion , sodium , density functional theory , doping , crystallography , chemistry , metal , polymer chemistry , organic chemistry , computational chemistry , optoelectronics , metallurgy
The revival of the Na‐ion battery concept has prompted intense research activities toward new sustainable Na‐based insertion compounds and their implementation in full Na‐ion cells. Efforts are parted between Na‐based polyanionic and layered compounds. For the latter, there has been a specific focus on Na‐deficient layered phases that show cationic and anionic redox activity similar to a Na 0.67 Mn 0.72 Mg 0.28 O 2 phase. Herein, a new alkali‐deficient P2‐Na 2/3 Mn 7/9 Zn 2/9 O 2 phase using a more electronegative element (Zn) than Mg is reported. Like its Mg counterpart, this phase shows anionic redox activity and no O 2 release despite evidence of cationic migration. Density functional theory (DFT) calculations show that it is the presence of an oxygen nonbonding state that triggers the anionic redox activity in this material. The phase delivers a reversible capacity of 200 mAh g −1 in Na‐half cells with such a value be reduced to 140 mAh g −1 in full Na‐ion cells which additionally shows capacity decay upon cycling. These findings establish Na‐deficient layered oxides as a promising platform to further explore the underlying science behind O 2 release in insertion compounds based on anionic redox activity.