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Flexible and Mechanically Durable Asymmetric Supercapacitor Based on NiCo‐Layered Double Hydroxide and Nitrogen‐Doped Graphene Using a Simple Fabrication Method
Author(s) -
Mehrabimatin Bahareh,
Gilshteyn Evgenia P.,
Melandsø Buan Marthe Emelie,
Sorsa Olli,
Jiang Hua,
Iraji zad Azam,
Shahrokhian Saeed,
Nasibulin Albert G.,
Kallio Tanja
Publication year - 2019
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201801002
Subject(s) - supercapacitor , materials science , capacitance , electrode , graphene , composite number , fabrication , hydroxide , current density , composite material , energy storage , chemical engineering , nanotechnology , chemistry , medicine , power (physics) , alternative medicine , physics , pathology , quantum mechanics , engineering
A high‐performing, lightweight, and flexible asymmetric supercapacitor (ASC) using NiCo‐layered double hydroxide (NiCo LDH) supported on 3D nitrogen‐doped graphene (NG) as a positive electrode and NG as a negative electrode is demonstrated. Highly conductive NG provides fast electron transfer and facilitates (dis)charging of NiCo LDH deposited on it. The composite electrode of NiCo LDH@NG exhibits a high specific capacitance of 1421 F g −1 at 2 A g −1 . Moreover, the as‐obtained hybrid electrode shows an excellent rate capability with a specific capacitance of 1397 F g −1 at a high current density of 10 A g −1 , which is about 98% of the capacitance obtained at 2 A g −1 . The flexible ASC device shows a specific capacitance of 109 F g −1 at 0.5 A g −1 and a maximum energy density of 49 W h kg −1 , which is comparable with or superior to previously reported electrodes based on nickel‐cobalt hydroxides. Furthermore, an excellent mechanical stability is obtained. Under repeated mechanical bendings, the ASC demonstrates high bending stability up to 450 bending cycles at a 90° angle. Hence, this flexible NiCo LDH@NG electrode that is free of binders and conductive agents shows superior performance and stability, and is a promising candidate for the future wearable energy storage devices.