Tuning the Chemistry of Organonitrogen Compounds for Promoting All‐Organic Anionic Rechargeable Batteries

Abstract

The ever‐increasing demand for rechargeable batteries induces significant pressure on the worldwide metal supply, depleting resources and increasing costs and environmental concerns. In this context, developing the chemistry of anion‐inserting electrode organic materials could promote the fabrication of molecular (metal‐free) rechargeable batteries. However, few examples have been reported because little effort has been made to develop such anionic‐ion batteries. Here we show the design of two anionic host electrode materials based on the N‐substituted salts of azaaromatics (zwitterions). A combination of NMR, EDS, FTIR spectroscopies coupled with thermal analyses and single‐crystal XRD allowed a thorough structural and chemical characterization of the compounds. Thanks to a reversible electrochemical activity located at an average potential of 2.2 V vs. Li+/Li, the coupling with dilithium 2,5‐(dianilino)terephthalate (Li2DAnT) as the positive electrode enabled the fabrication of the first all‐organic anionic rechargeable batteries based on crystallized host electrode materials capable of delivering a specific capacity of ≈27 mAh/gelectrodes with a stable cycling over dozens of cycles (≈24 Wh/kgelectrodes).

Pairing Cross‐Linked Polyviologen with Aromatic Amine Host Structure for Anion Shuttle Rechargeable Batteries

“…The negative electrode was also slightly oversized compared with the capacity of Li 2 DAnT (1.1 as balancing ratio), based this time on its one‐electron reaction (half of the theoretical capacity) in this second‐generation full cell. As shown in Figure c, d, a first discharge of 62 mAh per gram of Li 2 DAnT was obtained (stabilized at 50 mAh per gram after 15 cycles) with an average output voltage of 0.7 V. Although the stability upon cycling of such cells is lower compared to our former study using a zwitterionic form of viologen ((Li) 2 [diacetate‐V](ClO 4 ) 2 ) as the negative electrode, this new example of full‐cell batteries demonstrates that an operating anionic rocking‐chair cell configurations can be assembled thanks to the organic compounds used.…”

“…Nevertheless, such electrode materials (including organic robust radicals such as nitroxide derivatives) have been mainly electrochemically tested and assembled in dual‐ion cell configurations . In this context, we have been investigating for a few years the chemistry of anion‐inserting organic electrode materials in nonaqueous media and recently succeeded in elaborating an all‐organic anionic rechargeable battery based on two crystallized host electrode materials, namely dilithium 2,5‐(dianilino)terephthalate (Li 2 DAnT) for the positive electrode paired with an original zwitterionic form of viologen ((Li) 2 [diacetate‐V](ClO 4 ) 2 ) for the negative electrode capable of delivering a specific capacity of ≈27 mAh g electrodes −1 …”

“…Second, a poorly soluble cross‐linked polyviologen was synthesized for the negative electrode application. The underlying idea was also to compare its respective electrochemical response with that of the zwitterionic form of viologen ((Li) 2 [diacetate‐V](ClO 4 ) 2 ) previously studied . Note that our interest in the DAnT ligand was motivated by efforts of Clariant Ltd. (Switzerland), a leading company in the chemical industry, to make sustainability a core element of their business strategy.…”

Phosphaviologen‐Based Pyrene‐Carbon Nanotube Composites for Stable Battery Electrodes

“…Viologens and viologen derivatives have been used as electron acceptors in organic electrode materials thanks to their highly reversible reductions . Often only the first reduction is used, however, viologens can act as two‐electron acceptors when both reductions are reversible . Phosphaviologens exhibit the stable and reversible redox behavior of viologens, while the electron‐withdrawing phosphoryl unit lowers the LUMO allowing them to operate at higher voltages vs .…”

Reversible Anion Insertion in Molecular Phenothiazine‐Based Redox‐Active Positive Material for Organic Ion Batteries

“…Additionally,p -type organic cathodes can be implemented in anionic "rocking-chair" organic batteries, leading to the development of molecular-ionrechargeable batteries as recently demonstrated by one of us. [20,21] Interested in the development of new anion organic host structures operating at high potentials vs. Li + /Lia nd inspiredb yr ecent resultso n phenazine materials, [22,23] we got interested in the development of phenothiazine derivatives. The phenothiazine core is The increasing demandf or rechargeable batteries induces the development of greener and better devices.S ignificant advances have been made in the last decade together with ar enewed interest in organic electrode materials.T hus, stable electron-donating organic materialsa re candidates for "greener" molecular batteries (metal-free).…”