Efficient Bifunctional Catalytic Electrodes with Uniformly Distributed NiN2 Active Sites and Channels for Long ‐Lasting Rechargeable Zinc–Air Batteries

A 3D hierarchical self ‐supported air electrode composed of NiN2 active sites and Ni nanoparticles encapsulated in carbon nanotubes exhibits superior oxygen reduction and oxygen evolution catalytic activities. The rechargeable zinc –air batteries based on the as‐prepared air electrode show outstanding long term stability, high power density, and specific capacity. AbstractFreestanding bifunctional electrodes with outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) properties are of great significance for zinc –air batteries, attributed to the avoided use of organic binder and strong adhesion with substrates. Herein, a strategy is developed to fabricate freestanding bifunctional electrodes from the predeposited nickel nanoparticles (Ni‐NCNT) on carbon fiber paper. The steric effect of monodispersed Si O2 nanospheres limits the configuration of carbon atoms forming 3D interconnected nanotubes with uniformly distributed NiN2 active sites. The bifunctional electrodes (Ni ‐NCNT) demonstrate ideal ORR and OER properties. The zinc–air batteries assembled with Ni‐NCNT directly exhibit extremely outstanding long term stability (2250 cycles with 10 mA cm−2 charge/discharge current density) along with high power density of 120 mV cm−2 and specific capacity of 834.1 mA h g−1. This work provides a new view to optimize the distribution of active sites and the electrode structure.

Source: Small - June 30, 2020 Category: Nanotechnology Authors: Zihe Cai, Shengxuan Lin, Jiajia Xiao, Tahir Muhmood, Yuhang Chen, Yifan Wang, Xiaobin Hu, Lirong Zheng Tags: Full Paper Source Type: research