Tailored Heterojunction Active Sites for Oxygen Electrocatalyst Promotion in Zinc‐Air Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 19; no. 10; pp. e2206341 - n/a
• Main Authors: Go, Hyun Wook, Nguyen, Thanh Tuan, Ngo, Quynh Phuong, Chu, Rongrong, Kim, Nam Hoon, Lee, Joong Hee
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-03-2023
• Subjects: Carbon nanotubes; Chemical reduction; Circuits; cobalt oxide; cobalt phosphide; Electric potential; electrocatalyst; Electrocatalysts; Electronic devices; Energy storage; Heterojunctions; heterostructures; Metal air batteries; Nanotechnology; Oxygen evolution reactions; Oxygen reduction reactions; Rechargeable batteries; Stability; Storage systems; Synergistic effect; Voltage; Zinc-oxygen batteries; zinc‐air batteries; electrocatalyst; cobalt phosphide; heterostructures; cobalt oxide; zinc-air batteries
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202206341

Rechargeable zinc‐air batteries (ZABs) are promising energy storage systems due to their low‐cost and safety. However, the working principle of ZABs is based on oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), which display sluggish kinetic and low stability. Herein, this work proposes a novel method to design a heterogeneous CoP/CoO electrocatalyst on mesopore nanobox carbon/carbon nanotube (CoP/CoO@MNC‐CNT) that enriched active sites and synergistic effect. Moreover, the well‐defined heterointerfaces could lower the energy barrier for intermediate species adsorption and promote OER and ORR electrochemical performances. The CoP/CoO@MNC‐CNT electrocatalyst presents a high half‐wave potential of 0.838 V for ORR and a small overpotential of 270 mV for OER. The ZABs‐based CoP/CoO@MNC‐CNT air‐cathode shows an open‐circuit voltage of 1.409 V, the long‐term cycle life of 500 h with a small voltage difference change of 7.7%. Additionally, the flexible ZABs exhibit highly mechanical stability, demonstrating their application potential in wearable electronic devices.
The heterogeneous cobalt phosphide/cobalt oxide electrocatalyst on mesopore nanobox carbon/carbon nanotube is prepared. The bifunctional catalyst exhibits an outstanding performance for oxygen reduction reaction and oxygen evolution reaction. When it serves as an air‐cathode for zinc‐air batteries, the device displays a high open‐circuit voltage of 1.409 V, with exceptional cycle life of 500 h.