A reinvestigation of Na2Fe2(C2O4)3·2H2O: an iron-based positive electrode for secondary batteries
Abstract
We have reinvestigated the polyanionic compound Na2Fe2(C2O4)3·2H2O, previously reported to be electrochemically inactive in lithium-ion batteries (LIBs), as a positive electrode for sodium-ion batteries (NIBs). The present study demonstrates that it is capable of delivering a reversible capacity close to its theoretical value (117 mAhg–1) with three redox plateaus at 2.9, 3.3 and 3.6 V vs. Na/Na+ in the potential range 1.7–4.2 V. The obtained energy density of 326 WhKg–1 is among the highest of all reported polyanionic cathodes in NIBs. The origin of the electrochemical activity can be traced back to the electronic structure of the compound and the low migration energy barrier of the alkali ion observed in first-principles density-functional theory calculations.
Citation
Yao , W , Sougrati , M-T , Hoang , K , Hui , J , Lightfoot , P & Armstrong , A R 2017 , ' A reinvestigation of Na 2 Fe 2 (C 2 O 4 ) 3· 2H 2 O: an iron-based positive electrode for secondary batteries ' , Chemistry of Materials , vol. 29 , no. 21 , pp. 9095-9101 . https://doi.org/10.1021/acs.chemmater.7b02764
Publication
Chemistry of Materials
Status
Peer reviewed
ISSN
0897-4756Type
Journal article
Description
W. Y. thanks the Royal Society for the award of a Newton International Fellowship (140881).Collections
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