TY - JOUR

T1 - Facial design and synthesis of CoS x /Ni-Co LDH nanocages with rhombic dodecahedral structure for high-performance asymmetric supercapacitors

AU - Guan, X.

AU - Huang, M.

AU - Yang, L.

AU - Wang, G.

AU - Guan, Xin

PY - 2019/9/15

Y1 - 2019/9/15

N2 - In this paper, two-component nanocages containing CoS x and nickel-cobalt layered double hydroxides (Ni-Co LDH) were facilely synthesized via a multistep transformation approach. The zeolitic imidazolate framework-67 (ZIF-67) nanocrystals were firstly synthesized, and then after partial sulfuration, the CoS x /Ni-Co LDH nanocages were achieved by adding nickel ions for etching and precipitation. The prepared CoS x /Ni-Co LDH nanocages consisted of the hollow rhombic dodecahedral morphology with many nanosheets arrays on the shell. When used as electrode materials for electrochemical capacitors, this CoS x /Ni-Co LDH nanocages deliver a specific capacitance of 1562 F g −1 at a current density of 1 A g −1 . In addition, an asymmetric supercapacitor assembled with CoS x /Ni-Co LDH as cathode and active carbon (AC) as anode shows a high energy density of 35.8 Wh kg −1 at a power density of 800 W kg −1 and has an excellent cycling performance with the retention rate of 94.56% after 10,000 cycles, suggesting their potential application in high-performance electrochemical capacitors. These exceptional electrochemical properties can be attributed to the unique structure and synergistic effects between the metal sulfide and the bimetallic hydroxide, which also indicate the potential application of CoS x /Ni-Co LDH nanocages in high-performance supercapacitors. © 2019

AB - In this paper, two-component nanocages containing CoS x and nickel-cobalt layered double hydroxides (Ni-Co LDH) were facilely synthesized via a multistep transformation approach. The zeolitic imidazolate framework-67 (ZIF-67) nanocrystals were firstly synthesized, and then after partial sulfuration, the CoS x /Ni-Co LDH nanocages were achieved by adding nickel ions for etching and precipitation. The prepared CoS x /Ni-Co LDH nanocages consisted of the hollow rhombic dodecahedral morphology with many nanosheets arrays on the shell. When used as electrode materials for electrochemical capacitors, this CoS x /Ni-Co LDH nanocages deliver a specific capacitance of 1562 F g −1 at a current density of 1 A g −1 . In addition, an asymmetric supercapacitor assembled with CoS x /Ni-Co LDH as cathode and active carbon (AC) as anode shows a high energy density of 35.8 Wh kg −1 at a power density of 800 W kg −1 and has an excellent cycling performance with the retention rate of 94.56% after 10,000 cycles, suggesting their potential application in high-performance electrochemical capacitors. These exceptional electrochemical properties can be attributed to the unique structure and synergistic effects between the metal sulfide and the bimetallic hydroxide, which also indicate the potential application of CoS x /Ni-Co LDH nanocages in high-performance supercapacitors. © 2019

KW - Asymmetric supercapacitor

KW - CoS x /Ni-Co LDH nanocages

KW - Electrochemical performance

KW - Hollow rhombic dodecahedral morphology

U2 - 10.1016/j.cej.2019.04.145

DO - 10.1016/j.cej.2019.04.145

M3 - Journal article

VL - 372

SP - 151

EP - 162

JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

SN - 1385-8947

ER -