Hierarchical design of Cu-Ni(OH)₂/Cu-Mn_xO_y core/shell nanosheet arrays for ultra-high performance of asymmetric supercapacitor

Saeed, Ghuzanfar,Kumar, Sachin,Bandyopadhyay, Parthasarathi,Hoon Kim, Nam,Lee, Joong Hee Elsevier 2019 Chemical engineering journal Vol.369 No.-

<P><B>Abstract</B></P> <P>Supercapacitors lack high energy density and long term stability, so a new class of hybrid material with hierarchical structure is desirable. Herein, for the first time we are reporting a rational design of hierarchical Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> core/shell nanosheet arrays. The Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> nanosheet arrays were synthesized by a two-step hydrothermal reaction. The as-synthesized Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> hybrid structure exhibits ultrahigh areal and specific capacitances of 10.14 F cm<SUP>−2</SUP> and 2535 F g<SUP>−1</SUP>, respectively at 3 mA cm<SUP>−2</SUP>. The electrode exhibits high rate-capability (59.37%) and excellent capacitance retention of 93.09% after 10 000 cycles. In Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> core/shell hybrid structure, highly conductive and electroactive Cu-Ni(OH)<SUB>2</SUB> core and Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> shell components played a vital role to develop a high-performance and stable electrode material. Furthermore, the unique porous structure of Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> also provides enough space and short-diffusion lengths for Faradaic reaction. The asymmetric supercapacitors assembled of Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> as positive electrode and GR/CNTs as negative electrode delivers a high specific capacitance of 267.15 F g<SUP>−1</SUP> at a current density of 1 A g<SUP>−1</SUP> with high-rate capability of 60.30%. Moreover, the as-assembled ASC device also shows an ultra-high energy density of 94.98 W h kg<SUP>−1</SUP> at a power density of 759.89 W kg<SUP>−1</SUP> and a maximum power density of 15 173.5 W kg<SUP>−1</SUP> at an energy density of 57.28 W h kg<SUP>−1</SUP> with capacitance retention of 89.79% after 10 000 cycles. These outstanding results suggest that Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> hybrid structure can be considered as a cathode material for asymmetric supercapacitor in future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Unique Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> core-shell nanosheet arrays were grown on the Ni foam by two-step hydrothermal method. </LI> <LI> Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB> core-shell nanosheet arrays exhibits an excellent areal capacitance and cycling performance. </LI> <LI> The Cu-Ni(OH)<SUB>2</SUB>/Cu-Mn<SUB>x</SUB>O<SUB>y</SUB>//GR/CNTs asymmetric supercacitor device shows a high energy density of 94.98 Wh kg<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fabrication of 3D graphene-CNTs/α-MoO₃ hybrid film as an advance electrode material for asymmetric supercapacitor with excellent energy density and cycling life

Saeed, Ghuzanfar,Kumar, Sachin,Kim, Nam Hoon,Lee, Joong Hee Elsevier 2018 Chemical Engineering Journal Vol.352 No.-

<P><B>Abstract</B></P> <P>Recently, three-dimensional (3D) architectures of graphene-carbon nanotubes (CNTs) have attracted a lot of attention due to their multifunctional properties. In this study, we have reported a novel 3D graphene-CNTs/MoO<SUB>3</SUB> hybrid film as a binder free electrode material with unique morphology and outstanding electrochemical performance. The optimized 3D graphene-carbon nanotubes (GF-CNTs) framework was fabricated by a chemical vapor deposition (CVD) process on Ni foam skeleton. Further, controlled loading of MoO<SUB>3</SUB> nanoplates were grown on the GF-CNTs framework as a hybrid film, using an easy and low cost hydrothermal method. The as-fabricated hybrid electrode exhibits remarkable specific capacitance of 1503 F g<SUP>−1</SUP> at 1 A g<SUP>−1</SUP> and 798.93 F g<SUP>−1</SUP> at a current density of 10 A g<SUP>−1</SUP>, as well as exceptional capacitance retention of 96.5% after 10,000 cycles. The excellent electrochemical performance of the electrode material can be attributed to the combination of pseudocapacitance and electric double layer capacitance contributed by the MoO<SUB>3</SUB> nanoplates and graphene foam/CNTs in the hybrid system, respectively. The asymmetric supercapacitor (ASCs), assembled from GF-CNTs/MoO<SUB>3</SUB> and GF-CNTs as positive and negative electrode, respectively, delivers excellent specific capacitance of 211.71 F g<SUP>−1</SUP> at current density of 1 A g<SUP>−1</SUP>. The ASCs device also exhibits a maximum energy density of 75.27 W h kg<SUP>−1</SUP> at a power density of 816.67 W kg<SUP>−1</SUP> with excellent cycling ability of 94.2% of the initial capacitance after 10,000 cycles. These results suggest that the as-fabricated GF-CNTs/MoO<SUB>3</SUB> hybrid architecture can be used as a promising electrode material for the next generation supercacitor devices<B>.</B> </P> <P><B>Highlights</B></P> <P> <UL> <LI> Unique 3D graphene-CNTs framework was fabricated by CVD method. </LI> <LI> MoO<SUB>3</SUB> nanoplates were grown on the GF-CNTs framework using hydrothermal method. </LI> <LI> GF-CNTs/MoO<SUB>3</SUB> exhibits excellent specific capacitance and high cyclic stability. </LI> <LI> The GF-CNTs/MoO<SUB>3</SUB>//GF-CNTs device exhibits a high energy density of 75.27 W h kg<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

슈퍼커패시터 장치용 전극 재료로서 2차원 MXene 시트 위에 장식된 0차원 Sn-Co-S 나노 입자의 전기화학적 특성

김민창,Ghuzanfar Saeed,Sanjay Mathur,김광호 한국표면공학회 2023 한국표면공학회 학술발표회 초록집 Vol.2023 No.5

Hierarchical nanohoneycomb-like CoMoO₄-MnO₂ core-shell and Fe₂O₃ nanosheet arrays on 3D graphene foam with excellent supercapacitive performance

Kumar, Sachin,Saeed, Ghuzanfar,Kim, Nam Hoon,Lee, Joong Hee The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.16

<P>Recently, graphene-based three-dimensional (3D) architectures have attracted a lot of attention because of their multifunctional properties. In this paper, we report on hierarchical nanohoneycomb-like CoMoO4-MnO2 core-shell and Fe2O3 nanosheet arrays on 3D graphene foam (GF) and explore their use as a binder-free electrode in supercapacitor applications. The GF was prepared by solution casting on a Ni foam scaffold. The nanohoneycomb-like CoMoO4-MnO2 core-shell nanosheet arrays were prepared by a hydrothermal method under optimized conditions. The unique core-shell network provides efficient space and a short diffusion length for faradaic reactions. The as-synthesized CoMoO4-MnO2@GF hybrid electrode exhibits excellent areal and specific capacitances of 8.01 F cm<SUP>−2</SUP> and 2666.7 F g<SUP>−1</SUP>, respectively, at a current density of 3 mA cm<SUP>−2</SUP>. In addition, Fe2O3@GF was also prepared using a hydrothermal process followed by hydrogen treatment. Under optimized conditions Fe2O3@GF exhibits a high areal capacitance of 1.26 (572.7 F g<SUP>−1</SUP>) F cm<SUP>−2</SUP>. The asymmetric supercapacitor (ASC) assembled from CoMoO4-MnO2@GF as the positive electrode and Fe2O3@GF as the negative electrode delivers an excellent specific capacitance of 237 F g<SUP>−1</SUP> and a high rate capability of 61%. Moreover, the as-fabricated ASC also exhibits an ultra-high energy density of 84.4 W h kg<SUP>−1</SUP> and an outstanding power density of 16 122 W kg<SUP>−1</SUP> as well as an exceptional capacitance retention of 92.1% after 10 000 cycles.</P>

Ultrafine nanoparticles of tin-cobalt-sulfide decorated over 2D MXene sheets as a cathode material for high-performance asymmetric supercapacitor

Min Chang Kim,Ghuzanfar Saeed,Asrar Alam,Youngjoong Choi,Liguo Zhang,Damin Lee,Se-Hun Kwon,산제이 마튜,Kwang Ho Kim 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

The design of electrode materials for improved electrochemical properties and stable geometric configurationis known as effective research in developing the electrochemical capability of supercapacitors(SCs). However, there is a difficulty in designing innovative composite material with excellent electricalconductivity and superior specific capacity by way of low cost and easy synthesis process. Herein, for thefirst time, a stable Sn-Co-S/MXene hybrid material is fabricated through the electrochemical assembly bycombining positively charged ultrafine Sn-Co-S nanoparticles (NPs) and negatively charged 2D Ti3C2Tx(MXene) sheets due to electrostatic interaction. The Sn-Co-S/MXene hybrid material has displayed excellentelectrochemical performance with an ultrahigh specific capacity of 305.71 mA h gm1 at 1 A g1 andcapacity retention of 94.8% after 10, 000 charge–discharge cycles. The Sn-Co-S/MXene hybrid material ofhigh electrochemical performance has improved charge transfer kinetics during the charge–dischargeprocess, due to the synergistic coupling effect between ultrafine Sn-Co-S nanoparticles and MXenesheets. Furthermore, the Sn-Co-S/MXene//activated carbon (AC) asymmetric supercapacitor (ASC) devicehas been configured with the assistance of Sn-Co-S/MXene as cathode and AC as anode materials. The Sn-Co-S/MXene//AC ASC device exhibits a stable potential window of 1.7 V, a high specific capacitance of108.50F g1 at 1 A g1, and an energy density of 43.55Wh kg1 at a power density of 0.83 kW kg1. This study validates the design and application of highly electroactive Sn-Co-S/MXene hybrid electrodematerial for ultrastable asymmetric supercapacitors.