Organic Zinc‐Ion Battery: Planar, π‐Conjugated Quinone‐Based Polymer Endows Ultrafast Ion Diffusion Kinetics

Abstract

A novel poly(phenazine‐alt‐pyromellitic anhydride) (PPPA) has been successfully designed and synthesized via a condensation polymerization strategy as promising cathode material in organic zinc‐ion batteries. Electrochemical quartz crystal microbalance (EQCM), FTIR and XPS characterizations verify a reversible Zn2+‐coordination mechanism in our PPPA cathode. Intriguingly, an ultrahigh Zn2+ diffusion coefficient of 1.2×10−7 cm2 s−1 was found in this large π‐conjugated system, which is the highest one among all organic cathode materials for zinc‐ion batteries. Theoretical calculations reveal the extended π‐conjugated plane in our PPPA sample results in a significant reduction on energy gap, effectively accelerating intramolecular electron transfer during charge/discharge process. Our finding provides insights to achieve high zinc‐ion transport kinetics by a design strategy on planar polymer system.

Proton‐Conductive Supramolecular Hydrogen‐Bonded Organic Superstructures for High‐Performance Zinc‐Organic Batteries

“…The charge storage kinetics of Zn//HBOS cell was further studied by CV curves. [35] CV profiles with sweep rates ranging from 1 to 10 mV s À 1 exhibit two pairs of redox signals (Figure S41, denoted as P R1 , P R2 , P O1 and P O2 ), indicative of a two-step electrochemistry. The peak shape is almost the same with the scan rate increasing, substantiating the superb electrochemical reversibility and ion diffusion kinetics.…”

A long-range planar polymer with efficient π-electron delocalization for superior proton storage

“…1b displays the solid-state 13 C NMR spectrum of the PPHZ polymer, whereby a peak at 146 ppm is related to the carbon atoms from C=N bonds (red color) 27,28 and two peaks at 125-130 and 136 ppm belong to the carbon atoms from C=C bonds (blue color). Note that the overlapped peaks are mainly due to the rigid π-conjugated molecular structure, which broadens the NMR characteristic peaks 29 . Besides, some peaks at 29, 137, 112, 94 and 154 ppm correspond to the carbon atoms from C-C bonds (cyan color).…”

Building better aqueous Zn-organic batteries

“…87 Recently, the highest average Zn 2+ ion transport coefficient of 1.2 Â 10 À7 for aqueous ZIBs among all reported organic cathode materials was obtained in a novel poly(phenazine-alt-pyromellitic anhydride) (PPPA) electrode. 88 The ion diffusion coefficient based on GITT could be calculated with the following equation:…”

“…For example, a poly-(phenazine-alt-pyromellitic anhydride) (PPPA) electrode material was obtained through a one-step polycondensation reaction between the electroactive monomers of phenazine and pyromellitic anhydride (PMDA) based on this Friedel-Crafts reaction mechanism. 88 In addition, polymer electrode materials can also be synthesized based on an addition polymerization reaction (Fig. 9e), which is commonly be used to link different organic compound monomers containing unsaturated bonds, such as CQC, CRC or CRN.…”