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

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.

Recent Advances and Perspectives of Zn‐Metal Free “Rocking‐Chair”‐Type Zn‐Ion Batteries

“…Most of the reported data are based on low discharge depth and inefficient Zn metal utilization (<5%). [ 4,15 ] As the volume/mass energy density of battery is calculated based on the volume/mass of electrode materials, the excessive Zn metal will decrease the practical energy density. [ 4,16 ]…”

“…[ 47 ] Recently, organic electrodes have attracted increased attention in aqueous Zn‐ion batteries. [ 15,18,47c,48 ] Schubert's group [ 49 ] reported 9,10‐di(1,3‐dithiol‐2‐ylidene)‐9,10‐dihydroanthracene (exTTF) as an organic cathode for Zn‐ion batteries, presenting a long lifespan of over 10 000 cycles. Various organic electrodes have been developed for Zn‐ion batteries, such as diquinoxalino[2,3‐ a :2′,3′‐ c ] phenazine (HATN) based on proton insertion, [ 50 ] polyaniline based on Zn 2+ insertion/extraction and dual‐ion mechanisms, [ 51 ] pyrene‐4,5,9,10‐tetraone electrode with supercapacitor‐like power behavior, [ 52 ] phenanthrenequinone macrocyclic trimer, [ 53 ] etc.…”

“…Liu et al. [ 15 ] recently reported that perylene‐3,4,9,10‐tetracarboxylic diimide (PTCDI) polymerized on the surface of reduced graphene oxide (PTCDI/rGO; Figure 8 b) can serve as a dendrite‐free Zn‐metal free anode for aqueous “rocking‐chair” Zn‐ion batteries (Figure 8a–f). Theoretical calculations were utilized to predict the feasibility of PTCDI as anode in advance.…”

“…Liu et al. [ 15 ] fabricated a PTCDI/rGO||Zn‐PB “rocking‐chair” Zn‐ion batteries. The Zn‐PB cathode was fabricated by preintercalating Zn in PB.…”

“…Metallic Zn has an operation voltage (−0.76 V vs SHE) lower than that of Zn‐metal free anode. [ 4,15 ] Compared to metallic Zn anode, Zn‐metal free anodes may possess better chemical and electrochemical stability toward electrolyte, which can avoid the issues associated with Zn dendrites. [ 4,15,18 ]…”