Pairing cross-linked polyviologen with aromatic amine host structure for anion shuttle rechargeable batteries.

Electroactive organic compounds could bring new chemical opportunities to further improve existing electrochemical energy storage technologies as they can be prepared from less-limited resources and potentially at low environmental footprint. Among the current explored research fields, the anion-ion cell configuration appears poorly investigated although quite promising to promote the fabrication of molecular (metal-free) rechargeable batteries. Herein, we report the synthesis and the electrochemical behavior of both Mg/Li salts of 2,5-(dianilino)terephthalate (MgDAnT and Li2DAnT) and cross-linked polyviologen (c-PV2+) that can reversibly uptake/extract anions at different working potentials enabling the assembly of full anionic organic batteries. The reversible anion ingress in MgDAnT is however accompanied by solvent co-insertion from the electrolyte that provokes an overpotential effect during the first charge. Full anionic batteries pairing Li2DAnT with c-PV2+ were assembled giving rise to 0.7 V as output voltage with a specific capacity of 50 mAh per gram of Li2DAnT.