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 (Li₂ DAnT) 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/g_electrodes with a stable cycling over dozens of cycles (≈24 Wh/kg_electrodes ).

Keywords: batteries; organic batteries; redox chemistry; zwitterions.