(Ni,Co)Se2 /NiCo-LDH Core/Shell Structural Electrode with the Cactus-Like (Ni,Co)Se2 Core for Asymmetric Supercapacitors.

Supercapacitors (SCs) have been widely studied as a class of promising energy-storage systems for powering next-generation E-vehicles and wearable electronics. Fabricating hybrid-types of electrode materials and designing smart nanoarchitectures are effective approaches to developing high-performance SCs. Herein, first, a Ni-Co selenide material (Ni,Co)Se2 with special cactus-like structure as the core, to scaffold the NiCo-layered double hydroxides (LDHs) shell, is designed and fabricated. The cactus-like structural (Ni,Co)Se2 core, as a highly conductive and robust support, promotes the electron transport as well as hinders the agglomeration of LDHs. The synergistic contributions from the two types of active materials together with the superior properties of the cactus-like nanostructure enable the (Ni,Co)Se2 /NiCo-LDH hybrid electrode to exhibit a high capacity of ≈170 mA h g-1 (≈1224 F g-1 ), good rate performance, and long durability. The as-assembled (Ni,Co)Se2 /NiCo-LDH//PC (porous carbon) asymmetric supercapacitor (ASC) with an operating voltage of 1.65 V delivers a high energy density of 39 W h kg-1 at a power density of 1650 W kg-1 . Therefore, the cactus-like core/shell structure offers an effective pathway to engineer advanced electrodes. The assembled flexible ASC is demonstrated to effectively power electronic devices.

[1]  N. Kim,et al.  Flexible Solid‐State Asymmetric Supercapacitors Based on Nitrogen‐Doped Graphene Encapsulated Ternary Metal‐Nitrides with Ultralong Cycle Life , 2018, Advanced Functional Materials.

[2]  N. Kim,et al.  Hierarchical 3D Zn–Ni–P nanosheet arrays as an advanced electrode for high-performance all-solid-state asymmetric supercapacitors , 2018 .

[3]  Haijun Wu,et al.  Cactus‐Like NiCoP/NiCo‐OH 3D Architecture with Tunable Composition for High‐Performance Electrochemical Capacitors , 2018 .

[4]  C. Li,et al.  Hierarchical Zn–Co–S Nanowires as Advanced Electrodes for All Solid State Asymmetric Supercapacitors , 2018 .

[5]  Xiaogang Zhang,et al.  A binder-free NiCo2O4 nanosheet/3D elastic N-doped hollow carbon nanotube sponge electrode with high volumetric and gravimetric capacitances for asymmetric supercapacitors. , 2017, Nanoscale.

[6]  Bing Zhang,et al.  Honeycomb-like metallic nickel selenide nanosheet arrays as binder-free electrodes for high-performance hybrid asymmetric supercapacitors , 2017 .

[7]  M. Leung,et al.  Nanohybridization of MoS2 with Layered Double Hydroxides Efficiently Synergizes the Hydrogen Evolution in Alkaline Media , 2017 .

[8]  C. Li,et al.  Hierarchical design of Cu1−xNixS nanosheets for high-performance asymmetric solid-state supercapacitors , 2017 .

[9]  John Wang,et al.  Nanoflakes of Ni-Co LDH and Bi2O3 Assembled in 3D Carbon Fiber Network for High-Performance Aqueous Rechargeable Ni/Bi Battery. , 2017, ACS applied materials & interfaces.

[10]  J. Yu,et al.  Metallic Layered Polyester Fabric Enabled Nickel Selenide Nanostructures as Highly Conductive and Binderless Electrode with Superior Energy Storage Performance , 2017 .

[11]  C. Li,et al.  One-pot synthesis of hollow NiSe–CoSe nanoparticles with improved performance for hybrid supercapacitors , 2016 .

[12]  Yanfang Gao,et al.  Ni0.9Co1.92Se4 nanostructures: binder-free electrode of coral-like bimetallic selenide for supercapacitors , 2016 .

[13]  Qiangqiang Zhang,et al.  Hierarchical Ni–Co Hydroxide Petals on Mechanically Robust Graphene Petal Foam for High‐Energy Asymmetric Supercapacitors , 2016 .

[14]  Yang Yu,et al.  Porous Nickel-Iron Selenide Nanosheets as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction. , 2016, ACS applied materials & interfaces.

[15]  Zhenxing Wang,et al.  Selenium-Enriched Nickel Selenide Nanosheets as a Robust Electrocatalyst for Hydrogen Generation. , 2016, Angewandte Chemie.

[16]  Yan Zhao,et al.  Preparation of MnCo2O4@Ni(OH)2 Core–Shell Flowers for Asymmetric Supercapacitor Materials with Ultrahigh Specific Capacitance , 2016 .

[17]  K. Kang,et al.  High‐Performance Sodium‐Ion Hybrid Supercapacitor Based on Nb2O5@Carbon Core–Shell Nanoparticles and Reduced Graphene Oxide Nanocomposites , 2016 .

[18]  Z. Han,et al.  Three-dimensional hierarchical NiCo2O4 nanowire@Ni3S2 nanosheet core/shell arrays for flexible asymmetric supercapacitors. , 2016, Nanoscale.

[19]  C. Jo,et al.  A mini review of designed mesoporous materials for energy-storage applications: from electric double-layer capacitors to hybrid supercapacitors. , 2016, Nanoscale.

[20]  Dandan Zhu,et al.  Hierarchically Porous N-doped Carbon Derived from ZIF-8 Nanocomposites for Electrochemical Applications , 2016 .

[21]  Jizhang Chen,et al.  Amorphous nanostructured FeOOH and Co–Ni double hydroxides for high-performance aqueous asymmetric supercapacitors , 2016 .

[22]  Mingfei Shao,et al.  A flexible all-solid-state micro-supercapacitor based on hierarchical CuO@layered double hydroxide core–shell nanoarrays , 2016 .

[23]  Yeong Hwan Ko,et al.  Hierarchical Ni-Co layered double hydroxide nanosheets entrapped on conductive textile fibers: a cost-effective and flexible electrode for high-performance pseudocapacitors. , 2016, Nanoscale.

[24]  Hui Peng,et al.  A novel aqueous asymmetric supercapacitor based on petal-like cobalt selenide nanosheets and nitrogen-doped porous carbon networks electrodes , 2015 .

[25]  C. Li,et al.  Bimetallic nickel cobalt selenides: a new kind of electroactive material for high-power energy storage , 2015 .

[26]  Min Wei,et al.  Layered double hydroxides toward electrochemical energy storage and conversion: design, synthesis and applications. , 2015, Chemical communications.

[27]  D. Dubal,et al.  Hybrid energy storage: the merging of battery and supercapacitor chemistries. , 2015, Chemical Society reviews.

[28]  Hua Zhang,et al.  Novel Metal@Carbon Spheres Core–Shell Arrays by Controlled Self‐Assembly of Carbon Nanospheres: A Stable and Flexible Supercapacitor Electrode , 2015 .

[29]  Weimin Du,et al.  NiS hollow spheres for high-performance supercapacitors and non-enzymatic glucose sensors. , 2015, Chemistry, an Asian journal.

[30]  D. J. Lockwood,et al.  Nickel hydroxides and related materials: a review of their structures, synthesis and properties , 2015, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[31]  Q. Qu,et al.  Core-shell structure of hierarchical quasi-hollow MoS2 microspheres encapsulated porous carbon as stable anode for Li-ion batteries. , 2014, Small.

[32]  Juan-Yu Yang,et al.  3D Architecture Materials Made of NiCoAl‐LDH Nanoplates Coupled with NiCo‐Carbonate Hydroxide Nanowires Grown on Flexible Graphite Paper for Asymmetric Supercapacitors , 2014 .

[33]  Haotian Wang,et al.  First-row transition metal dichalcogenide catalysts for hydrogen evolution reaction , 2013 .

[34]  P. Ajayan,et al.  Hybrid Nanostructures for Energy Storage Applications , 2012, Advanced materials.

[35]  T. Zhai,et al.  Core-shell structured Co3O4@NiCo2O4 electrodes grown on flexible carbon fibers with superior electrochemical properties , 2017 .

[36]  Qiu Jiang,et al.  Selenide‐Based Electrocatalysts and Scaffolds for Water Oxidation Applications , 2016, Advances in Materials.