Phase- and interlayer spacing-controlled cobalt hydroxides for high performance asymmetric supercapacitor applications

Milan Jana; Periyasamy Sivakumar; Manikantan Kota; Min Gyu Jung; Ho Seok Park

doi:10.1016/j.jpowsour.2019.03.019

Phase- and interlayer spacing-controlled cobalt hydroxides for high performance asymmetric supercapacitor applications

Milan Jana
, Periyasamy Sivakumar
, Manikantan Kota
, Min Gyu Jung
, Ho Seok Park

Department of Chemistry

Sungkyunkwan University

Research output: Contribution to journal › Article › peer-review

73 Scopus citations

Abstract

A facile and selective hydrothermal synthesis is performed to control the crystalline phases of cobalt hydroxides into α-Co(OH)₂ and β-Co(OH)₂: α-Co(OH)₂, consisting of both octahedral and tetrahedral Co sites, is produced without ionic liquids, whereas β-Co(OH)₂, containing octahedral Co sites, is synthesized in the presence of ionic liquids. The ionic liquids play significant role as co-solvent and template to tune the morphology of Co(OH)₂. α-Co(OH)₂ reveals flake-like structure, whereas β-Co(OH)₂ exhibits nanorod-like network structure. The interlayer spacing of α-Co(OH)₂ is 8.24 Å, which is larger than 4.63 Å of β-Co(OH)₂ due to the expansion of interlayer by the precursor Cl^─ anions. The presence of Cl^─ anions hinders the insertion of hydroxide ion into α-Co(OH)₂ interlayers, which shows the specific capacitance of 613 F g^─1 less than 1066 F g^─1 of β-Co(OH)₂ at 2 A g^─1. When the current density increases up to 20 A g^─1, the capacitance retention of β-Co(OH)₂ is 80%, greater than 70% of α-Co(OH)₂. Configuring β-Co(OH)₂ and reduced graphene oxide as positive and negative electrodes, asymmetric supercapacitor delivers the maximum energy and power densities of 20.05 W h kg^─1 and 13.40 kW kg^─1 with the capacitance retention of 93% over 10,000 cycles.

Original language	English
Pages (from-to)	9-17
Number of pages	9
Journal	Journal of Power Sources
Volume	422
DOIs	https://doi.org/10.1016/j.jpowsour.2019.03.019
State	Published - 15 May 2019

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Keywords

Asymmetric device
Cobalt hydroxide
Hybrid supercapacitors
Ionic liquid
Nanostructure
Redox capacitor

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10.1016/j.jpowsour.2019.03.019

Cite this

@article{eefd7425c6db4cbea197708b64eb77fa,

title = "Phase- and interlayer spacing-controlled cobalt hydroxides for high performance asymmetric supercapacitor applications",

abstract = "A facile and selective hydrothermal synthesis is performed to control the crystalline phases of cobalt hydroxides into α-Co(OH)2 and β-Co(OH)2: α-Co(OH)2, consisting of both octahedral and tetrahedral Co sites, is produced without ionic liquids, whereas β-Co(OH)2, containing octahedral Co sites, is synthesized in the presence of ionic liquids. The ionic liquids play significant role as co-solvent and template to tune the morphology of Co(OH)2. α-Co(OH)2 reveals flake-like structure, whereas β-Co(OH)2 exhibits nanorod-like network structure. The interlayer spacing of α-Co(OH)2 is 8.24 {\AA}, which is larger than 4.63 {\AA} of β-Co(OH)2 due to the expansion of interlayer by the precursor Cl─ anions. The presence of Cl─ anions hinders the insertion of hydroxide ion into α-Co(OH)2 interlayers, which shows the specific capacitance of 613 F g─1 less than 1066 F g─1 of β-Co(OH)2 at 2 A g─1. When the current density increases up to 20 A g─1, the capacitance retention of β-Co(OH)2 is 80\%, greater than 70\% of α-Co(OH)2. Configuring β-Co(OH)2 and reduced graphene oxide as positive and negative electrodes, asymmetric supercapacitor delivers the maximum energy and power densities of 20.05 W h kg─1 and 13.40 kW kg─1 with the capacitance retention of 93\% over 10,000 cycles.",

keywords = "Asymmetric device, Cobalt hydroxide, Hybrid supercapacitors, Ionic liquid, Nanostructure, Redox capacitor",

author = "Milan Jana and Periyasamy Sivakumar and Manikantan Kota and Jung, \{Min Gyu\} and Park, \{Ho Seok\}",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2019",

month = may,

day = "15",

doi = "10.1016/j.jpowsour.2019.03.019",

language = "English",

volume = "422",

pages = "9--17",

journal = "Journal of Power Sources",

issn = "0378-7753",

publisher = "Elsevier B.V.",

}

TY - JOUR

T1 - Phase- and interlayer spacing-controlled cobalt hydroxides for high performance asymmetric supercapacitor applications

AU - Jana, Milan

AU - Sivakumar, Periyasamy

AU - Kota, Manikantan

AU - Jung, Min Gyu

AU - Park, Ho Seok

PY - 2019/5/15

Y1 - 2019/5/15

N2 - A facile and selective hydrothermal synthesis is performed to control the crystalline phases of cobalt hydroxides into α-Co(OH)2 and β-Co(OH)2: α-Co(OH)2, consisting of both octahedral and tetrahedral Co sites, is produced without ionic liquids, whereas β-Co(OH)2, containing octahedral Co sites, is synthesized in the presence of ionic liquids. The ionic liquids play significant role as co-solvent and template to tune the morphology of Co(OH)2. α-Co(OH)2 reveals flake-like structure, whereas β-Co(OH)2 exhibits nanorod-like network structure. The interlayer spacing of α-Co(OH)2 is 8.24 Å, which is larger than 4.63 Å of β-Co(OH)2 due to the expansion of interlayer by the precursor Cl─ anions. The presence of Cl─ anions hinders the insertion of hydroxide ion into α-Co(OH)2 interlayers, which shows the specific capacitance of 613 F g─1 less than 1066 F g─1 of β-Co(OH)2 at 2 A g─1. When the current density increases up to 20 A g─1, the capacitance retention of β-Co(OH)2 is 80%, greater than 70% of α-Co(OH)2. Configuring β-Co(OH)2 and reduced graphene oxide as positive and negative electrodes, asymmetric supercapacitor delivers the maximum energy and power densities of 20.05 W h kg─1 and 13.40 kW kg─1 with the capacitance retention of 93% over 10,000 cycles.

AB - A facile and selective hydrothermal synthesis is performed to control the crystalline phases of cobalt hydroxides into α-Co(OH)2 and β-Co(OH)2: α-Co(OH)2, consisting of both octahedral and tetrahedral Co sites, is produced without ionic liquids, whereas β-Co(OH)2, containing octahedral Co sites, is synthesized in the presence of ionic liquids. The ionic liquids play significant role as co-solvent and template to tune the morphology of Co(OH)2. α-Co(OH)2 reveals flake-like structure, whereas β-Co(OH)2 exhibits nanorod-like network structure. The interlayer spacing of α-Co(OH)2 is 8.24 Å, which is larger than 4.63 Å of β-Co(OH)2 due to the expansion of interlayer by the precursor Cl─ anions. The presence of Cl─ anions hinders the insertion of hydroxide ion into α-Co(OH)2 interlayers, which shows the specific capacitance of 613 F g─1 less than 1066 F g─1 of β-Co(OH)2 at 2 A g─1. When the current density increases up to 20 A g─1, the capacitance retention of β-Co(OH)2 is 80%, greater than 70% of α-Co(OH)2. Configuring β-Co(OH)2 and reduced graphene oxide as positive and negative electrodes, asymmetric supercapacitor delivers the maximum energy and power densities of 20.05 W h kg─1 and 13.40 kW kg─1 with the capacitance retention of 93% over 10,000 cycles.

KW - Asymmetric device

KW - Cobalt hydroxide

KW - Hybrid supercapacitors

KW - Ionic liquid

KW - Nanostructure

KW - Redox capacitor

UR - https://www.scopus.com/pages/publications/85062859054

U2 - 10.1016/j.jpowsour.2019.03.019

DO - 10.1016/j.jpowsour.2019.03.019

M3 - Article

AN - SCOPUS:85062859054

SN - 0378-7753

VL - 422

SP - 9

EP - 17

JO - Journal of Power Sources

JF - Journal of Power Sources

ER -

Phase- and interlayer spacing-controlled cobalt hydroxides for high performance asymmetric supercapacitor applications

Abstract

UN SDGs

Keywords

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