Open AccessS, N‐Co‐Doped Graphene‐Nickel Cobalt Sulfide Aerogel: Improved Energy Storage and Electrocatalytic Performance
Author(s) -
He Guanjie,
Qiao Mo,
Li Wenyao,
Lu Yao,
Zhao Tingting,
Zou Rujia,
Li Bo,
Darr Jawwad A.,
Hu Junqing,
Titirici MariaMagdalena,
Parkin Ivan P.
Publication year - 2017
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201600214
Subject(s) - materials science , graphene , cobalt , electrolyte , nickel sulfide , inorganic chemistry , supercapacitor , aerogel , nickel , sulfide , cobalt sulfide , battery (electricity) , electrochemistry , chemical engineering , electrode , redox , alkaline battery , catalysis , nanotechnology , chemistry , metallurgy , organic chemistry , power (physics) , physics , quantum mechanics , engineering
Metal sulfides are commonly used in energy storage and electrocatalysts due to their redox centers and active sites. Most literature reports show that their performance decreases significantly caused by oxidation in alkaline electrolyte during electrochemical testing. Herein, S and N co‐doped graphene‐based nickel cobalt sulfide aerogels are synthesized for use as rechargeable alkaline battery electrodes and oxygen reduction reaction (ORR) catalysts. Notably, this system shows improved cyclability due to the stabilization effect of the S and N co‐doped graphene aerogel (SNGA). This reduces the rate of oxidation and the decay of electronic conductivity of the metal sulfides materials in alkaline electrolyte, i.e., the capacity decrease of CoNi 2 S 4 /SNGA is 4.2% for 10 000 cycles in a three‐electrode test; the current retention of 88.6% for CoS/SNGA after 12 000 s current–time chronoamperometric response in the ORR test is higher than corresponding CoS nanoparticles and CoS/non‐doped graphene aerogels. Importantly, the results here confirm that the NiCoS ternary materials behave as an electrode for rechargeable alkaline batteries rather than supercapacitors electrodes in three‐electrode test as commonly described and accepted in the literature. Furthermore, formulas to evaluate the performance of hybrid battery devices are specified.