Building High Rate Capability and Ultrastable Dendrite‐Free Organic Anode for Rechargeable Aqueous Zinc Batteries

TLDR

Aqueous zinc‑ion batteries offer low cost, safety, and durability for grid storage, but their performance is limited by Zn dendrite growth and dead Zn, which cause poor cycling stability and cell shorting. The study introduces a dendrite‑free organic anode composed of perylene‑3,4,9,10‑tetracarboxylic diimide polymerized on reduced graphene oxide for use in zinc‑ion batteries. The PTCDI/rGO electrode operates via a proton‑ and zinc‑ion coparticipant phase‑transfer mechanism with high charge‑transfer capability, as confirmed by ex‑situ analyses and theoretical calculations of its low redox potential. This design delivers a high rate capability of 121 mAh g⁻¹ at 5000 mA g⁻¹ (retaining 95 % of the capacity at 50 mA g⁻¹) and retains 96 % capacity after 1500 cycles at 3000 mA g⁻¹.

Abstract

Aqueous zinc-ion batteries (ZIBs) are an alternative energy storage system for large-scale grid applications compared with lithium-ion batteries, when the low cost, safety, and durability are taken into consideration. However, the reliability of the battery systems always suffers from the serious challenge of the large Zn dendrite formation and "dead Zn," thus bringing out the inferior cycling stability, and even cell shorting. Herein, a dendrite-free organic anode, perylene-3,4,9,10-tetracarboxylic diimide (PTCDI) polymerized on the surface of reduced graphene oxide (PTCDI/rGO) utilized in ZIBs is reported. Moreover, the theoretical calculations prove the reason for the low redox potential. Due to the protons and zinc ions coparticipant phase transfer mechanism and the high charge transfer capability, the PTCDI/rGO electrode provides superior rate capability (121 mA h g-1 at 5000 mA g-1, retaining the 95% capacity of that compared with 50 mA g-1) and a long cycling life span (96% capacity retention after 1500 cycles at 3000 mA g-1). In addition, the proton coparticipation energy storage mechanism of active materials is elucidated by various ex-situ methods.