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N, S Codoped Carbon Matrix‐Encapsulated Co 9 S 8 Nanoparticles as a Highly Efficient and Durable Bifunctional Oxygen Redox Electrocatalyst for Rechargeable Zn–Air Batteries
Author(s) -
Lyu Dandan,
Yao Sixian,
Ali Asad,
Tian Zhi Qun,
Tsiakaras Panagiotis,
Shen Pei Kang
Publication year - 2021
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202101249
Subject(s) - bifunctional , overpotential , electrocatalyst , materials science , oxygen evolution , nanoparticle , catalysis , chemical engineering , battery (electricity) , oxygen , redox , carbon fibers , nanotechnology , electrode , electrochemistry , chemistry , organic chemistry , thermodynamics , composite material , power (physics) , physics , composite number , engineering , metallurgy
Herein, a N, S co‐doped carbon encapsulating Co 9 S 8 nanoparticles (Co 9 S 8 @N, S–C) catalyst is successfully synthesized by a new precursor of Co‐pyridine coordinated‐polymer consisting of 2,6‐diacetylpyridine and 4,4′‐dithiodianiline. Benefiting from the abundant pore‐structure (average pore‐size ≈25nm) and unique electronic‐properties of the Co 9 S 8 and N, S–C layer, the as‐prepared Co 9 S 8 @N, S‐C exhibits rapid oxygen reduction reaction (ORR) kinetics with high electron transfer number of ≈3.998 and demonstrates a low overpotential of 304 mV for the oxygen evolution reaction (OER). It exhibits a small potential difference of 0.647V for overall ORR/OER activity, outperforming most of the non‐precious metal‐catalysts previously reported. The rechargeable Zn–Air battery test further demonstrates its excellent activity and stability, in which the battery delivers a maximum power density output of 259 mW cm −2 , a specific capacity of 862 mAh g Zn −1 , and after continuous 110 h operation the charge‐discharge round‐trip efficiency only reduces by 4.83%. Theoretical calculation studies show that the surface N, S–C layers and Co 9 S 8 can adjust each other's Fermi levels, so that the adsorption energy of Co 9 S 8 @N, S–C on O intermediate is more favorable than using Co 9 S 8 and N, S–C alone. This study reveals the structure‐function relationship of coated‐nanostructures with multifunctional electrocatalytic properties, and provides a feasible strategy for the design of non‐noble metal‐catalysts.