Reversible Sodium Storage Behavior Of Aromatic Diimide Disodium Carboxylates

The synthesis, characterization and electrochemical sodiation/desodiation performance of two novel disodium diimide carboxylates, disodium salt of N, N'-bis (glycinyl) pyromellitic diimide (Na-2-BPDI) and disodium salt of N, N'-bis (glycinyl) naphthalene diimide (Na-2-BNDI) were reported for the first time. The Na-2-BNDI electrode material delivers a reversible capacity of 122 mAh g(-1) in the first cycle and retains a reasonable capacity of 92 mAh g(-1) after 50 cycles at a current density of 50 mA g(-1), whereas a rapid capacity fading is observed in the case of Na-2-BPDI electrode material in subsequent cycles. Ex-situ NMR and FT-IR studies confirmed that the decomposition of Na-2-BPDI electrode material upon continuous electrochemical sodiation/desodiation process. These results demonstrate that the importance of extended conjugation, as in Na-2-BNDI, for efficient electrochemical sodium storage in the redox active aromatic compound. (C) The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. All rights reserved.