Battery-type Electrode Material Research Articles

Designing nanosheet manganese cobaltate@manganese cobaltate nanosheet arrays as a battery-type electrode material towards high-performance supercapacitors

Binder-free hierarchical nanosheet manganese cobaltate@manganese cobaltate nanosheet arrays (NS MnCo2O4@MnCo2O4 NSAs) heterostructures have been successfully deposited on nickel (Ni) foam surface using a facile two-step hydrothermal process. Scanning electron microscope characterization illustrate that the as-developed composite exhibits a growth of smaller MnCo2O4 nanosheet structures anchored on the surface of MnCo2O4 NSAs that provide abundant reactive sites and effective electronic transmission, endowing the NS MnCo2O4@MnCo2O4 NSAs an outstanding electrochemical performance. The electrochemical measurements reveal that the as-prepared NS MnCo2O4@MnCo2O4 NSAs delivers a Faradic battery-type redox behavior, which is distinct from the behaviors of carbon-based materials. As a battery-type material, NS MnCo2O4@MnCo2O4 NSAs exhibits an outstanding specific capacity (135.15 mA h g−1 at 2 A g−1) and remarkable rate capability (82.93%), which are much higher than that of bare MnCo2O4 NSAs. Moreover, NS MnCo2O4@MnCo2O4 NSAs delivers an excellent cycling stability of 88.74% over 5000 cycles. Hence, these electrochemical results suggest that the as-developed NS MnCo2O4@MnCo2O4 NSAs can serve as an advanced battery-type electrode material for supercapacitor applications.

Binder-free trimetallic phosphate nanosheets as an electrode: Theoretical and experimental investigation

Transition metal phosphides and phosphates are newly emerging electrode material candidates in energy storage devices. For the first time, we report a uniformly distributed, interconnected, and well-aligned two-dimensional nanosheets made from trimetallic Zn-Co-Ga phosphate (ZCGP) electrode materials with preserved crystal phase. It is found that the ZCGP electrode material exhibits about 2.85 and 1.66 times higher specific capacity than mono- (Co-phosphate) and bimetallic phosphate (Zn-Co phosphate) electrode materials at the same current density. The trimetallic ZCGP electrode exhibits superior conductivity, lower internal resistance (IR) drop, and high coulombic efficiency compared to mono- and bimetallic phosphate. By means of density functional theory (DFT) calculations, ZCGP shows superior metallic conductivity due to the modified exchange splitting originating from 3d-orbitals of Co atoms in the presence of Zn and Ga. Moreover, hybrid supercapacitor (ZCGP//rGO) device is engineered which delivered a high energy density of 40 W h kg −1 and a high-power density of 7745 W kg −1 , lighting 5 different colors of light emitting diodes (LEDs). These outstanding results confirm the promising battery-type electrode materials for energy storage applications. • Novel trimetallic Zn-Co-Ga phosphate (ZCGP) with nanosheets-like morphology. • Preserved crystalline phase for mono-, bi-, and trimetallic phosphates electrodes. • The charge storage mechanism for electrodes exhibit diffusion-dominated response. • The superior properties of ZCGP has been verified experimentally and theoretically. • Hybrid supercapacitor device delivered excellent energy density.

Freestanding trimetallic Fe–Co–Ni phosphide nanosheet arrays as an advanced electrode for high‐performance asymmetric supercapacitors

Transition metal phosphides hold great promise for high performance battery-type electrode materials due to their superb electrical conductivity and high theoretical capacity. Unfortunately, the electrochemical properties of single metal or bimetallic phosphides are unsatisfactory owing to their low energy density and poor cyclic stability, and one feasible approach is to introduce heteroatoms to form trimetallic phosphides. Here, novel Fe–Co–Ni–P nanosheet arrays are in situ synthesized on a flexible carbon cloth substrate via an electrodeposition method followed by a phosphorization treatment. Due to the presence of abundant redox active sites, large specific surface area with mesoporous channels, desirable electrical conductivity, modified electronic structure, and synergistic effect of Fe, Co, and Ni ions, the as-prepared Fe–Co–Ni–P electrode displays significantly enhanced electrochemical performance when compared to bimetallic phosphides Fe–Co–P and Fe–Ni–P. Remarkably, the Fe–Co–Ni–P electrode exhibits a large specific capacity of 593.0 C g−1 at 1 A g−1, exceptional rate performance (80.3% capacity retention at 20 A g−1), and good cycling stability (84.2% capacity retention after 5000cycles). Besides, an asymmetric supercapacitor device with Fe–Co–Ni–P electrode as a positive electrode and a hierarchical porous carbon as a negative electrode shows a high energy density of 57.1 Wh kg−1 at a power density of 768.5 W kg−1 as well as excellent cyclability with 88.4% of initial capacity after 10,000cycles. This work manifests that the construction of trimetallic phosphides is an effective strategy to solve the shortcomings of single or bimetallic phosphides for high-performance supercapacitors.

Hierarchical design of Ni(OH)2/MnMoO4 composite on reduced graphene oxide/Ni foam for high-performances battery-supercapacitors hybrid device

Design and synthesis advanced battery-type electrode materials with outstanding electrical conductivity and remarkable theoretical specific capacity are crucial to enhance the comprehensive performances for battery-supercapacitors (SCs). Herein, Ni(OH)2/MnMoO4 composite on reduced graphene oxide/Ni foam (rGO/NF) was successfully fabricated through the hydrothermal method and potentiostatic electrodeposition (Ni(OH)2/MnMoO4/rGO/NF). The unique honeycomb structure and the efficient synergistic effects among MnMoO4 and Ni(OH)2 of the as-prepared battery type electrode, as well as outstanding electronic conductivity of the reduced graphene oxide, were beneficial to the enhanced electrochemically active sites and increased specific capacity. Ni(OH)2/MnMoO4/rGO/NF composite employed for SCs yielded the maximum specific capacity of 1329.1 C g−1 and a superb cycle property of 86.8% during 5000 cycles. Furthermore, the battery-supercapacitor hybrid (BSH) device with the Ni(OH)2/MnMoO4/rGO/NF and active carbon (AC) as-prepared samples showed the energy density of 61.4 W h kg−1 at the power density of 428.4 W kg−1. The capacity retention of the as-fabricated hybrid device reached 96.4% over 7000 cycles. Those consequences tested that the Ni(OH)2/MnMoO4/rGO/NF composite should be the promising category of battery-type electrodes materials of the next generation energy storage devices for the high-performances SCs.

Zn induced NiCo composites modified by carbon materials as a battery-type electrode material for high-performance supercapacitors

The development of simple preparation and excellent capacity performance electrode materials is the key to energy conversion and storage for supercapacitors. Based on the growth mechanism of crystal, Zn induced NiCo nanosheets and nanoneedles composite structure deposed on Ni foam (ZNC) are successfully attained by a facile one-step method, the growth mechanism of the composite structure is further discussed. Because of its unique composites structure and additional modification of carbon, the carbon modified ZNC (ZNC@C) delivers better energy storage ability (2280 mC cm−2 at 2 mA cm−2) compare to ZNC. An asymmetric supercapacitor (ASC) is assembled by ZNC@C as the positive electrode and carbonized popcorn as the negative electrode. The ASC exhibits good energy storage performance. Zn also positively affects the adsorption energy to enhance the capacitance property based on Density Functional theory calculation. The simple method for the composite structure by tuning the kinetics behaver of the crystal can provide a new strategy in synthesizing the materials, and the material with a unique structure and high performance will have potential applications in the field of energy storage.

Facile synthesis of three-dimensional Ni3Sn2S2 as a novel battery-type electrode material for high-performance supercapacitors

Binary system sulfides hold tremendous potential for the manufacture of high-performance supercapacitors because of their rich transition states. Herein, three-dimensional Ni3Sn2S2 flower-like materials on Ni foam are ingeniously created via a simple one-pot hydrothermal and ion corrosion for employing as the electrode material in supercapacitors for the first time. According to the morphology in different reaction time, the growth mechanism of the flower-like Ni3Sn2S2 is further proposed. The morphology of as-prepared optimal sample indicates that the space of material is fully utilized to form a favorable compound structure with interconnected and uniformly branched nanosheets on the surface of polyhedrons. Electrochemical measurement reveals that Ni3Sn2S2 has a high area-specific capacitance of 0.67 mAh cm−2 at a current density of 2 mA cm−2. Impressively, the hybrid supercapacitor assembled with Ni3Sn2S2/Ni foam cathode and commercial activated carbon anode delivers a maximum energy density of 4.65 mWh cm−3 at a power density of 29.64 mW cm−3. Two devices in series can lit up 22 blue Light-Emitting Diodes more than 130 min. On the strength of outstanding electrochemical performances, Ni3Sn2S2 is a novel and promising electrode material for supercapacitor.

Shell-strengthened hollow architecture of NiCo2S4 carved through an in-situ reaction Ostwald Ripening mechanism with significantly enhanced electrochemical performance

For Faraday supercapacitors, some battery-type electrode materials such as nickel-based materials attract intensive attention by virtue of their high theoretical capacity. However, it is quite difficult for these materials to achieve the satisfied high-rate performance and cycling life concurrently due to the contradiction of their individual requirements to the microscopic structure of materials. In this work, we build a hollow architecture of NiCo2S4 at hydrothermal condition following an in-situ reaction Ostwald Ripening mechanism. The as-prepared NiCo2S4 presents a shell-strengthened hollow structure, satisfying the as-mentioned two requirements: (1) the rich pores in shell and hollow structure plus structural cobalt ions lead to the excellent high-rate performance of NiCo2S4; (2) the dense particulate layer in shell with additional mechanical strength prolongs the cycling life of NiCo2S4. Consequently, the asymmetrical supercapacitors assembled with NiCo2S4 as positive electrode material show both high energy and power densities, and excellent cycling stability.

Ternary synergistic transition metal oxalate 2D porous thin sheets assembled by 3D nanoflake array with high performance for supercapattery

Tailoring the composition and nanostructure of transition metal compounds is critical for electrochemical energy storage materials. Transition metal oxalates, which are formed by oxalic acid (OA) with transition metals, have been regarded as potential battery-type electrode material for high-performance supercapatteries due to their excellent electrochemical stability, low cost, and adjustable pore sizes, yet still limited by their low conductivity. Herein, we report a facile way for fabricating trimetal oxalates with three-dimensional (3D) architecture assembled by interwoven nanosheets by a succinct-operated hydrothermal method. Benefiting from both unique 3D porous structures and the synergistic interactions of trimetal oxalates, the developed Mn0.4Ni0.1Co-OA shows a considerably high specific capacity (1141.6 C g−1) and ultralong cyclic life (85% capacity retention over 10,000 cycles). Additionally, the supercapattery assembled with the Mn0.4Ni0.1Co-OA electrode and the activated carbon (AC) electrode displays a maximum energy density of 32.2 Wh kg−1 at the power density of 770.2 W kg−1 and outstanding cycle life (retention rate of 88.1% after 15,000 cycles). The results presented in this work that the rational design of the composition and structure of oxalates can provide a new idea for the preparation of high-performance energy storage materials.

Size-Dependent Synthesis of Hollow Co3O4 Nanocubes Derived from Co-Fe PBA as Battery-Type Electrode Materials for Hybrid Supercapacitors

Hollow nanostructures with enlarged surface areas are highly attractive electrode materials for supercapacitors. In this work, the size-dependent synthesis of hollow Co3O4 nanocubes via a facile ionic exchange reaction between Co-Fe Prussian blue analogues (PBAs) and alkali solution is reported. By adjusting the concentration of sodium citrate to control the reaction kinetics during nucleation and growth, four different sizes of Co-Fe PBAs were synthesized. It was also found that a Co-Fe PBA of about 140 nm can be easily converted into a well-defined internal hollow structure, while Co-Fe PBAs with smaller or larger sizes are challenged in generating a hollow structure. Benefitting from the inner voids and thin shell architecture, the derived hollow Co3O4 nanocubes exhibit a high specific capacity of 296.6C cm−2 at 2 mA cm−2, and a rate capability of 64.5% when the current density is increased to 60 mA cm−2. Furthermore, a hybrid supercapacitor (HSC) was fabricated with hollow Co3O4 nanocubes as the cathode and activated carbon as the anode, respectively. The HSC provided a maximum energy density of 14.1 Wh kg−1 at 464.7 W kg−1. Moreover, it retained the excellent cycling stability of 85.7% of the original capacity over 5000 continuous charging and discharging processes.

Preparation and characterization of novel 2D/3D NiSe2/MnSe grown on rGO/Ni foam for high-performance battery-supercapacitor hybrid devices

Reasonable choice of electrode materials and rational design of structures are two effective means to improve the electrochemical properties of supercapacitors. Herein, a series of NiSe2/MnSe (NMSe) battery-type electrode materials with different morphologies are attached to reduced graphene oxide (rGO)-coated Ni foam (NF) through controlling the selenization reaction temperature (NMSe/rGO). Benefiting from the unique 2D/3D architecture with 2D nanosheets and 3D nanospheres, the synergistic effects between the composites as well as the high electrical conductivity of rGO, the obtained electrode delivers the optimum electrochemical performance after selenization at 140 °C (NMSe/rGO-140). As a result, the NMSe/rGO-140 composite displays ultrahigh specific capacity of 1450.7 C g−1 at 1 A g−1 along with the advantageous long cycle stability of 87% at 10 A g−1 over 8000 cycles. Moreover, a battery-supercapacitor hybrid (BSH) device prepared using NMSe/rGO-140 (positive) and active carbon (negative) exhibits a maximum energy density of 51.4 W h kg−1 at 800.7 W kg−1 combined with outstanding capacity retention of 100% through 8000 cycles. With such prominent electrochemical behaviors, the NMSe/rGO-140//AC BSH possesses great potential utilization for high-energy storage devices.

High-performance hybrid supercapacitor based on the porous copper cobaltite/cupric oxide nanosheets as a battery-type positive electrode material

In this work, CuCo2O4/CuO nanosheets (NSs) and CuCo2O4 oblique prisms (OPs) were synthesized at 130 °C with different amounts of hexamethyltetramine (HMTA) and reaction time through a hydrothermal method, and followed by an annealing treatment of precursors in air. The CuCo2O4/CuO NSs with 40 nm in thickness possessed a large specific surface area of 43.34 m2 g−1 and a mean pore size of 18.14 nm. The electrochemical tests revealed that the CuCo2O4/CuO NSs were belonged to the battery-type electrode material and exhibited a specific capacity of 395.55 C g−1 at the current density of 1 A g−1, higher than 258.16 C g−1 for CuCo2O4 OPs. A hybrid supercapacitor (HSC) was assembled with activated carbon (AC) as negative electrode and CuCo2O4-based materials as positive electrode. The CuCo2O4/CuO NSs//AC HSC exhibited a high energy density of 30.18 Wh kg−1 at a power density of 869.62 W kg−1, and showed a fantastic cycling performance with 105.22% capacity retention over 5000 cycles. In contrast, the CuCo2O4 OPs//AC HSC delivered an energy density 26.27 Wh kg−1 at 916.74 W kg−1. These impressive electrochemical properties indicate that CuCo2O4/CuO NSs may serve as a promising electrode material for the highly capable hybrid supercapacitors in the near future.

Designing FeCoP@NiCoP heterostructured nanosheets with superior electrochemical performance for hybrid supercapacitors

The precise preparation of transition metal phosphides-based battery-type electrode materials with well-defined morphology and nanostructure have shown great potential in supercapacitors, due to their high electrical conductivity and superior redox activity. Herein, a smart nanoarchitecture comprised of a FeCoP@NiCoP core-shell hybrid is designed via a two-step electrodeposition strategy together with a phosphorization treatment. The 3D FeCoP@NiCoP nanosheet arrays grown on a flexible carbon cloth substrate can provide an efficient nanoporous framework, facilitate the electron/ion transport, and generate the effective synergy of good conductivity from FeCoP and superior redox activity from NiCoP. As a result, the as-prepared FeCoP@NiCoP electrode exhibits a high specific capacity of 973.0 C g−1 at a low current density of 1 A g−1 and excellent rate capacibity with 84.3% retention at 20 A g−1, superior to those of bare FeCoP and NiCoP electrodes. Additionally, a hybrid supercapacitor is assembled with FeCoP@NiCoP as a cathode and a barley-derived hierarchical porous carbon BPC-800 as an anode, showing a high energy density of 75.9 Wh kg−1 at a power density of 827.8 W kg−1 and outstanding cycling stability of 89.7% retention of the initial capacitance after 10000 cycles.

Controlled preparation of Ni(OH)2/NiS nanosheet heterostructure as hybrid supercapacitor electrodes for high electrochemical performance

As a battery-type electrode material, Ni(OH)2 has been widely concerned for its ultra-high theoretical specific capacity, however, its poor conductivity and lack of effective active sites hinder its application. It is a great challenge to develop Ni(OH)2 based supercapacitors. It is critical to improve the electrical conductivity and effective active sites to make full use of the energy storage of Ni(OH)2-based materials. Therefore, Ni(OH)2/NiS composites are designed and prepared by controllable low temperature chemical deposition and ion exchange method. Ni(OH)2 nanosheets with various morphology are controllably prepared by low temperature chemical deposition, and then Ni(OH)2/NiS composites are controllably prepared on Ni(OH)2 substrate by ion exchange. Due to the doping of NiS into Ni(OH)2 nanosheets, the conductive network structure is formed, which makes the composite exhibit excellent electrochemical properties, such as high specific capacity, large specific surface area and good electrical conductivity. The as-fabricated Ni(OH)2/NiS indicates an outstanding specific capacity of 240.5 mAh g−1 at 1 A g−1. This paper detailed studies the practical application of hybrid supercapacitors, which may inspire future researchers to design Ni(OH)2-based materials with desired applications.

Controllable Synthesis of complex nickel-vanadium selenide three dimensional flower-like structures as an attractive battery-type electrode material for high-performance hybrid supercapacitors

Binary metal selenide-based electrodes with absorbing structures are gaining wide attention in energy storage technology, ascribing to the excellent electrical conductivity, outstanding charge storage performance and a low band gap of these electrodes. Herein, a novel three dimensional (3D) flower-like Ni-V-Se composite was established by the hydrothermal method and vertically grew on reduced graphene oxide/Ni foam (rGO/NF) with tunable composition and morphologies. With the increase of selenization time, the morphology of composites is gradually incorporated from the nanosheets into nano-flowers and finally aggregates into large nanoparticles. The prepared optimal sample (NiVSe-6h) shows a palmary specific capacity of 1197.6 C g−1 at a current density of 1 A g−1, and stable long-term cycling performance (89.4% retention after 8000 successive charge-discharge cycles at 10 A g−1). The established NiVSe-6h//AC device uses NiVSe-6h and AC as the positive electrode and negative electrode, which obtains a large specific capacity of 225.1 C g−1 at 1 A g−1 and the high energy density of 53.1 Wh kg−1 at power density of 878.5 W kg−1. Meanwhile, the device exhibits notable cycle stability (94.4%) after 6000 charge discharge cycles. These superior electrochemical behaviors of NiVSe-6h composite indicate their possible utilization as electrodes for storage devices and energy conversion.

NiCo2S4/nitrogen and sulfur dual-doped three-dimensional holey-reduced graphene oxide composite architectures as high-rate battery-type cathode materials for hybrid supercapacitors

Battery-type electrode materials have recently been considered as a new class of high-capacity cathode materials for construction of hybrid supercapacitors, however, their low electrochemical kinetics prevent the practical application. Here, the NiCo2S4/nitrogen and sulfur dual-doped three-dimensional (3D) holey-reduced graphene oxide (NiCo2S4/N, S-HRGO) composite architectures were synthesized via a two-step hydrothermal approach. Thanks to the introduction of 3D interconnected and highly conductive holey-reduced graphene oxide with mesopore-rich structure providing fast electron/ion transport, the as-resulted NiCo2S4/N, S-HRGO composite achieves enhanced supercapacitive performances, especially exceptional rate capability compared to the pure NiCo2S4 and NiCo2S4/nitrogen and sulfur dual-doped reduced graphene oxide (NiCo2S4/N, S-RGO). The NiCo2S4/N, S-HRGO composite shows a specific capacity of 184.2 mAh g−1 at 1 A g−1, and still maintains a high specific capacity of 119.5 mAh g−1 even at 50 A g−1. The excellent rate capability of the composite can be illustrated by in-depth kinetic analysis based on the calculated diffusion coefficient and charge contribution ratio. Furthermore, a hybrid supercapacitor utilizing NiCo2S4/N, S-HRGO and N, S, P tri-doped holey-reduced graphene oxide (N, S, P-HHGO) respectively as the cathode and anode is further constructed, showing a satisfactory energy density (35.4 Wh kg−1), high power density (15.0 kW kg−1) and good cycle durability.

Metal organic framework derived hollow NiS@C with S-vacancies to boost high-performance supercapacitors

Transition metal sulfides (TMS) are of great interest as promising battery-type electrode materials, however, the poor conductivity and sluggish reaction kinetics seriously limit their application. Here, we designed a hollow structured precursor of Ni-based metal-organic frameworks (Ni-MOFs) via Ostwald ripening mechanism. Based on this unique precursor, a hollow carbon-coated nickel sulfide nanocrystal (H-NiS1-X/C) with sulfur vacancies was further synthesized through an ion exchange strategy and thermal annealing. By optimizing the content of sulfur source, the sample with appropriate S-vacancies (H-NiS1-X/C-50) was developed. Benefiting from its hollow structure and S-vacancies, this H-NiS1-X/C-50 displayed a high reversible specific capacity (1728 F g−1, 1 A g−1), stable cycling (72% capacity retention over 8000 cycles) and superior rate capability. After assembling the asymmetric supercapacitor, a high energy density of 36.88 Wh kg−1 was achieved. Experimental results and DFT calculations demonstrate that introducing S-vacancies builds an embedded electric field and produces lattice distortions in H-NiS1-X/C, thus enhancing the conductivity of the material. Our strategy also provides a facile way to construct high-performance TMS with unique hollow structure and S-vacancies for developing advanced energy storage devices.

Porous CuCo2O4 microtubes as a promising battery-type electrode material for high-performance hybrid supercapacitors

Hollow nanostructures of transition metal oxides (TMOs) with hollow interior, low density, large surface area and surface permeability have drawn significant interest as electrode materials for supercapacitors. However, it is still challenging to controllably prepare hollow nanostructures by a facile method. Herein, we report for the first time that CuCo2O4 microrod precursor obtained from a solvothermal method in ethanol media can be converted into porous CuCo2O4 microtubes (CuCo2O4 MTs) in the post annealing treatment. The results of electrochemical tests demonstrate that these MTs are categorized as the typical battery-grade electrode materials. They can deliver a high capacity up to 393.66 C g−1 at 1 A g−1 and still hold 305.99 C g−1 at 10 A g−1. Additionally, an assembled hybrid supercapacitor (CuCo2O4 MTs//AC HSC) exhibits 78.23 F g−1, good cycling durability and high energy density (32.49 W h kg−1 at 912.10 W kg−1). The present synthetic methodology may be further applicable to the preparation of other hollow structural TMOs with applications in high-performance energy storage and conversion devices.

Facile Synthesis of MgCo2O4@MMoO4 (M = Co, Ni) Nanosheet Arrays on Nickel Foam as an Advanced Electrode for Asymmetric Supercapacitors

Through a simple two-step solvothermal method, MgCo2O4@MMoO4 (M = Co, Ni) nanosheet arrays were grown on nickel foam. In a 1 M KOH aqueous solution, the two battery-type electrode materials showed ...

FeCoP nanosheets@Ni-Co carbonate hydroxide nanoneedles as free-standing electrode material for hybrid supercapacitors

Developing advanced battery-type electrode materials with versatile morphologies and micro-/nanostructures is crucial to realize high-performance hybrid supercapacitors with high energy density and excellent cycle life. Herein, a facile approach is proposed to design free-standing FeCoP nanosheets decorated by Ni substituted Co carbonate hydroxide (Ni-CoCH) nanoneedles on carbon cloth as a novel cathode for hybrid supercapacitor. This smart hetero-network assembled by conductive FeCoP nanosheets as a core and redox active Ni-CoCH nanoneedles as a shell exhibits increased surface area, improved availability of redox active sites, and facilitated ion/electron transport for faradaic reactions when compared to a single component. Benefiting from its unique core/shell nanostructure, multifunctionality and synergistic effect of two components, the as-prepared FeCoP@Ni-CoCH electrode acquires a high specific capacity of 795.5 C g−1 at a current density of 1 A g−1 and outstanding rate capability and good long-term cyclic stability (89.7% of the initial capacitance after 5000 cycles). Furthermore, a hybrid supercapacitor device consisting of FeCoP@Ni-CoCH as cathode and hierarchical porous carbon as anode in 2 M KOH electrolyte delivers a high energy density of 72.7 Wh kg−1 at a power density of 404.9 W kg−1 and superior cyclic stability.

Binder-free hierarchical core-shell-like CoMn2O4@MnS nanowire arrays on nickel foam as a battery-type electrode material for high-performance supercapacitors

Binder-free hierarchical core-shell-like CoMn2O4@MnS heterostructures have been successfully grown on the surface of nickel (Ni) foam using facile two-step hydrothermal deposition route. In supercapacitor applications, the as-prepared core-shell-like CoMn2O4@MnS composite electrode has been used successfully as a battery-type material. Scanning electron microscope (SEM) and transmission electron microscope characterizations reveal that the as-prepared CoMn2O4@MnS electrode delivers a dandelion-like heterostructures that contains the MnS nanoparticles grown on the surface of CoMn2O4 nanowire arrays (NWAs), resulting a core-shell-like structure. In addition to increasing electrochemical behaviour and precise surface area, the novel core-shell-like heterostructures provide superhighways for the ultra-fast transfer of electrons and ions. The probable plateaus of cyclic voltammetry and galvanostatic charge-discharge experiments suggest that Faradic battery-type redox activity is given by the as-prepared core-shell-like CoMn2O4@MnS NWAs electrode. As a battery-type material, core-shell-like CoMn2O4@MnS NWAs electrode exhibits a outstanding specific capacity of (~213.0 mA h g−1 at 2 Ag−1), remarkable rate capability (~89.91% retains even at 10 A g−1), and excellent cycling stability (~91.42% at 6 A g−1 over 5000 cycles), which are much higher than those of the bare CoMn2O4 electrode. The excellent energy storage performance corroborates that CoMn2O4@MnS NWAs can serve as an advanced battery-type electrode material for supercapacitor applications.