A ΔE = 0.63 V Bifunctional Oxygen Electrocatalyst Enables High‐Rate and Long‐Cycling Zinc–Air Batteries

• Published in: Advanced materials (Weinheim) Vol. 33; no. 15; pp. e2008606 - n/a
• Main Authors: Zhao, Chang‐Xin, Liu, Jia‐Ning, Wang, Juan, Ren, Ding, Yu, Jia, Chen, Xiao, Li, Bo‐Quan, Zhang, Qiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-04-2021
• Subjects: Benchmarks; bifunctional electrocatalysts; Chemical evolution; Current density; Cycles; electrocatalysis; Electrocatalysts; Energy storage; Hydroxides; Iridium; Iron compounds; Life span; Materials science; Metal air batteries; Nickel compounds; oxygen evolution reaction; oxygen reduction reaction; Rechargeable batteries; rechargeable zinc–air batteries; Storage batteries; Zinc; Zinc-oxygen batteries; oxygen evolution reaction; bifunctional electrocatalysts; rechargeable zinc-air batteries; oxygen reduction reaction; electrocatalysis
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202008606

Rechargeable zinc–air batteries constitute promising next‐generation energy storage devices due to their intrinsic safety, low cost, and feasibility to realize high cycling current density and long cycling lifespan. Nevertheless, their cathodic reactions involving oxygen reduction and oxygen evolution are highly sluggish in kinetics, requiring high‐performance noble‐metal‐free bifunctional electrocatalysts that exceed the current noble‐metal‐based benchmarks. Herein, a noble‐metal‐free bifunctional electrocatalyst is fabricated, which demonstrates ultrahigh bifunctional activity and renders excellent performance in rechargeable zinc–air batteries. Concretely, atomic Co–N–C and NiFe layered double hydroxides (LDHs) are respectively selected as oxygen reduction and evolution active sites and are further rationally integrated to afford the resultant CoNC@LDH composite electrocatalyst. The CoNC@LDH electrocatalyst exhibits remarkable bifunctional activity delivering an indicator ΔE of 0.63 V, far exceeding the noble‐metal‐based Pt/C+Ir/C benchmark (ΔE = 0.77 V) and most reported electrocatalysts. Correspondingly, ultralong lifespan (over 3600 cycles at 10 mA cm−2) and excellent rate performances (cycling current density at 100 mA cm−2) are achieved in rechargeable zinc–air batteries. This work highlights the current advances of bifunctional oxygen electrocatalysis and endows high‐rate and long‐cycling rechargeable zinc–air batteries for efficient sustainable energy storage.
Ultrahigh bifunctional electrocatalytic activity for oxygen reduction and evolution is achieved with the indicator ΔE = 0.63 V, far exceeding the noble‐metal‐based benchmark and most reported electrocatalysts. Corresponding rechargeable zinc–air batteries afford ultralong lifespan over 3600 cycles at 10 mA cm−2 and ultrahigh cycling current density of 100 mA cm−2.