Search

Herein, Mg/Co(OH)F precursors were constructed by a hydrothermal method using secondary water and anhydrous ethanol in a volume ratio of 3:2 as solvents, followed by sodium hypophosphite and high temperature to yield stable MgP 4 O 11 /CoP (MPO/CP) composite electrode materials. The optimized MPO/CP nano-walls exhibited more outstanding energy storage performance compared with the single MgCo 2 O 4 /MgO oxide (MCO/MO). Specifically, the fabricated MPO/CP electrodes displayed paramount specific capacitance (1870 Fg−1 formed at 1 Ag−1), high rate retention (72.2% specific capacitance maintained when the current density was ramped up from 1 to 15 Ag−1), and exceptional cycling stability (93% after 6000 charge and discharge cycles). These boosted results are ascribed to the formation of multistage honeycomb-walled MPO/CP nanosheets with optimized crossover and multivalency, which promotes MPO/CP with faster transport channels and more reactive sites. Moreover, the P element can reasonably modulate the electronic structure, reduce the internal resistance of ion or electron transport, as well as give full play to the synergistic effect, which can enhance the electrochemical function. Meanwhile, the constructed MPO/CP//AC asymmetric supercapacitor achieves an energy density of 34.3 Wh kg−1 at a power density of 707.2 W kg−1. An encouraging stability of 86.2% was obtained after 8000 cycles at 10 A g−1. Thereby, the proposed novel MPO/CP electrode material with modified electrochemical properties was developed as a prospective candidate for application in energy storage devices. [Display omitted] • MPO/CP is manufactured by hydrothermal and single-step phosphorylation processes. • Synergetic effects of Mg, Co, and P-element's electron-modulating are essential for promoting electrochemical reactivity. • The honeycomb-wall-like MPO/CP electrode displays superior supercapacitor storage performance than MCO/MO. [ABSTRACT FROM AUTHOR]

In this paper, a facile hydrothermal treatment method was employed to successfully synthesize the NiMoO 4 @Mg-Co(OH)F/NF (NM-MCF) nanocomposites by taking NiMoO 4 nanorods as cores, and assembling them with the shell of Mg-Co(OH)F nanosheets. The high conductivity of Mg-Co-F was combined with the nanosheet-assembled core-shell structure, and the multivalent states of Ni, Mg, and Co increased the number of active sites and improved the synergy, contributing greatly to excellent performance of NM-MCF. As expected, the optimized NM-MCF nanocomposite electrode exhibits superb capacitive performance, including excellent specific capacitance of 1630 F g −1 at 1 A g −1 and remarkable cycle stability with 86 % after 6000 cycles. Notably, the NM-MCF exhibits a regular rate capability of 56.5 % from 1 to 15 A g−1, superior to that of NiMoO 4 (56.4 %) and Mg-Co(OH)F (28.8 %). Employing the as-prepared NM-MCF composites as positive electrode and activated carbon as negative electrode, the hybrid supercapacitor device with spectacular capacity of maximum energy density and power density up to 28.2 Wh kg−1 and 0.7 kW kg−1 and impressive long-term stability of 73.3 % retention after 6000 cycles is assembled. [Display omitted] • The NiMoO 4 @Mg-Co(OH)F/NF composite was synthesized by a two-step hydrothermal treatment method. • The synergetic effects of Ni, Mo, Co, Mg, and F were essential for facilitating electrochemical reactivity. • The NiMoO 4 @Mg-Co(OH)F/NF-based ASC exhibited splendid energy storage property. [ABSTRACT FROM AUTHOR]

Metal sulfides with nanostructures have attracted much attention in the research of supercapacitor electrode materials due to their excellent electrochemical properties. This paper used a simple, energy-saving and rapid hydrothermal method combined with an electrochemical deposition method to prepare the Co 3 S 4 /Ni 0.96 S composite with a porous ultrathin nanosheet structure. The results show that non-stoichiometric Ni 0.96 S nanocrystals provide abundant defects and nickel vacancies. The porous nanosheet structure formed by the Co 3 S 4 /Ni 0.96 S composite provides a large specific surface area, which is more conducive to promoting ion transport. For this reason, the electrolyte can penetrate the Co 3 S 4 /Ni 0.96 S nanoscale, while also giving the entire electrode material a rich conductive path and cycle durability. In summary, the optimized Co 3 S 4 /Ni 0.96 S composite has the largest specific capacitance (1102.0 C g−1) in the three-electrode system. In addition, asymmetric supercapacitors composed of Co 3 S 4 /Ni 0.96 S have a high energy density (40.6 Wh kg−1 at 800.0 W kg−1). This work provides a simple and effective strategy for designing metal sulfide composites and applying them to energy storage devices. [Display omitted] • Ultra-thin nanosheets Co 3 S 4 /Ni 0. 96 S with nickel vacancy three-dimensional porous structure; • Co 3 S 4 /Ni 0. 96 S nanocomposites were prepared by hydrothermal electrodeposition using three-dimensional nickel foam as substrate. • Co 3 S 4 /Ni 0. 96 S electrode achieves a high specific capacity of 1102 C g−1 at a current of 1 A g−1; • The ASC device presents a remarkable energy density of 40.6 Wh∙kg −1. [ABSTRACT FROM AUTHOR]

Due to the unconventional properties of MWCNTs-GONRs (multiwalled carbon nanotubes-graphene oxide nanoribbons), we have tried to use it as a carbon resource for supercapacitors. MWCNTs-GONRs/Ni(OH) 2 electrode was obtained by hydrothermal method. Velvet α-Ni(OH) 2 was prepared above NF (nickel-foam) loaded with MWCNTs-GONRs. This layered design can effectively promote the diffusion of ions and increase the active site for MWCNTs-GONRs/Ni(OH) 2 electrode, thus enhancing the electrochemical performance. The electrode exhibits extraordinary electrochemical performances in electrochemical testing, such as supernal specific capacitance (1713.2 F g−1) and prominent working time. In addition, supercapacitors was assembled with MWCNTs-GONRs/Ni(OH) 2 and active carbon as materials. Which represents a prominent energy density (41.23 Wh kg−1), high power (6.80 kW kg−1) and prominent cycling stability property (95.18%, 3000 times). The electrode prepared in this work provides a clue to enlighten people for energy storage. [ABSTRACT FROM AUTHOR]

Here, a unique sulfurization/phosphorylation transformation method was used to create S-P-Co x Ni y , a Co-Ni bimetallic nanoparticle with S and P coordinated. The electrode had higher capacitive capabilities due to its unique structure and synergistic component. The highest performance was revealed by the as-obtained S-P-Co x Ni y with the 1:4 Co: Ni molar ratio (S-P-Co 1 Ni 4), as seen by its specific capacitance. The S-P-Co 1 Ni 4 electrode developed a 1739.3 F g−1 specific capacitance at a 1 Ag−1 current density and strong cycle stability with retention of 92.6% after 10,000 cycles. These electrochemical results were superior to parent monophosphates (Co 1 Ni 4 P, 1223.2 F g−1, 88.3%), monosulfides (Co 1 Ni 4 S, 867.9 F g−1, 79.3%) and other derived counterparts (Co 1 Ni 4 O, 674.7 F g−1, 81.8%). It is shown that the high conductivity of sulfur, high stability of phosphide, multivalent states of nickel and cobalt, and tremendous synergy all contributed significantly to the excellent performance of S-P-Co 1 Ni 4. Also, the built AC/S-P-Co 1 Ni 4 asymmetric supercapacitor provided a high energy density of 42.7 Wh kg−1 at a power density of 703.9 W kg−1 and a good specific capacitance of 156.89 F g−1 at 1 Ag−1. This is in addition to amazing stability of 90.5% after 10,000 cycles at 10 A g−1. In this case, the improved electrochemical performance of the developed electrode material indicates that it holds great promise as a material for use in energy storage devices. • S-P-Co x Ni y was produced using a coprecipitation followed by a single-step sulfurization/phosphorylations transition. • S-P-Co 1 Ni 4 electrode containing Co: Ni molar ratio equal to 1:4 exhibited the best performance. • Synergetic effects of Ni, Co, P, and S are essential for promoting electrochemical reactivity. • The S-P-Co 1 Ni 4 with more active sites shows excellent supercapacitor storage performance. [ABSTRACT FROM AUTHOR]

Flexible and portable energy storage gadgets have aroused mounting interest because of the remarkable achievement in the field of intelligent and wearable devices. In this paper, perpendicularly organized CoMoO 4 /MnO 2 (CMO/MO) heterostructures are produced in situ on the surface of Ni foam, and the porous 3D architectures and rough nanoplates outside could offer substantial active sites and decrease the ion diffusion distances. Such splendid architecture with massive electrochemically active sites exhibits greater areal capacity in contrast to CoMoO 4. Subsequently, an all-solid-state asymmetric supercapacitor (ASSC) based on the CMO/MO and PVA/KOH gel electrolyte is prepared. The ASSC could work under high voltages ranging from 0 to 1.4 V and deliver a maximum areal capacitance of 0.467 Fcm−2 (1 mAcm−2). It also exhibits a great energy density of 35.81 Wh kg−1 at a watt density of 198.22 W kg−1, and the capacity retention could keep 75% even after 8000 cycles. Collectively, this research offers enlightenment regarding the synthesis of electrode materials. [Display omitted] • The CoMoO 4 /MnO 2 composite was synthesized by the hydrothermal method and chelation-mediated aqueous processes. • The synergetic effects of Co, Mo, and Mn are essential for facilitating electrochemical reactivity. • The CoMoO 4 /MnO 2 -based all-solid-state supercapacitor exhibited splendid energy storage property. [ABSTRACT FROM AUTHOR]

Flexible and portable energy storage gadgets have aroused mounting interest because of the remarkable achievement in the field of intelligent and wearable devices. In this paper, perpendicularly organized CoMoO 4 /MnO 2 (CMO/MO) heterostructures are produced in situ on the surface of Ni foam, and the porous 3D architectures and rough nanoplates outside could offer substantial active sites and decrease the ion diffusion distances. Such splendid architecture with massive electrochemically active sites exhibits greater areal capacity in contrast to CoMoO 4. Subsequently, an all-solid-state asymmetric supercapacitor (ASSC) based on the CMO/MO and PVA/KOH gel electrolyte is prepared. The ASSC could work under high voltages ranging from 0 to 1.4 V and deliver a maximum areal capacitance of 0.467 Fcm−2 (1 mAcm−2). It also exhibits a great energy density of 35.81 Wh kg−1 at a watt density of 198.22 W kg−1, and the capacity retention could keep 75% even after 8000 cycles. Collectively, this research offers enlightenment regarding the synthesis of electrode materials. [Display omitted] • The CoMoO 4 /MnO 2 composite was synthesized by the hydrothermal method and chelation-mediated aqueous processes. • The synergetic effects of Co, Mo, and Mn are essential for facilitating electrochemical reactivity. • The CoMoO 4 /MnO 2 -based all-solid-state supercapacitor exhibited splendid energy storage property. [ABSTRACT FROM AUTHOR]

Preparation of multi-component composites is an effective strategy to obtain novel and highly efficient electrode materials. Herein, to achieve the synergistic effect of compositions and microstructures, hybrid materials made of Ni embedded carbon nanofibers/Ni-Al layered double hydroxides (Ni-Al LDH) were prepared in this work. Ni embedded carbon nanofibers were first fabricated ingeniously via the combination of electrospinning and thermal treatment, which provided a great number of active sites and increased the space for ion transportation. Subsequently, we combined Ni embedded carbon nanofibers with a nanostructured Ni-Al LDH via a hydrothermal process. It was reasoned that Ni embedded carbon nanofibers could help optimize microstructures of Ni-Al LDH, which could alleviate the aggregation problem and improve the rate performance of Ni-Al LDH. A series of composites were made and evaluated. It was found out that, the 3 % Ni embedded carbon nanofibers/ Ni-Al-LDH (3 %-Ni-CNA) electrode achieved an outstanding specific capacity of 1228.2 C g−1 at 1 A g−1, an excellent rate performance of 68.1 % of initial capacity even at 20 A g−1,and a long-cycle lifetime with 88.6 % of initial capacity retention after 10,000 cycles at 8 A g−1. In addition, an asymmetric supercapacitor device based on 3 %-Ni-CNA and AC was constructed and demonstrated a high energy density of 74.9 W h kg−1 at 800 W kg−1 It is noteworthy that the capacity of the device achieved 91.4 % retention after 10,000 cycles at 6 A g−1. Hence, the 3 %-Ni-CNA could be an ideal material for the hybrid supercapacitors and other energy storage applications. At the same time, it provides a novel mentality for improving the electrical conductivity of electrodes and constructing nanomaterials with heterostructures [Display omitted] [ABSTRACT FROM AUTHOR]

The mixed metal oxides with high conductivity and multi-metal centers could easily meet the growing needs of high performance energy-storage materials. Herein, ternary phase aluminum-nickel-cobalt oxide (AlNiCo-O) is facilely prepared by a hot-air oven-based method with a subsequent calcination. The as-obtained AlNiCo-O flower-like network makes fully use of the synergistic effects among the transition metals, and exploits more electro-active surface sites, thereby allowing to undergo the redox reactions more efficient. The AlNiCo-O electrode exhibits better charge storage performances with a remarkable specific capacity of 1008.5 C g−1 at 1 A g−1. Furthermore, the hybrid supercapacitor based on AlNiCo-O electrode exhibits a high energy density of 63.3 W h kg−1 at the power density of 881.4 W kg−1, good rate capability (41.6 W h kg−1 at 13.3 kW kg−1) and a satisfying cycling performance of 84.27% after 5000 cycles. This work proposes a feasible design of high-efficiency metal oxides for application in hybrid supercapacitors. The AlNiCo-O flower-like structure contributes to high-efficient charge storage. Image 1 • Ternary aluminum-nickel-cobalt oxide (AlNiCo-O) with ultrathin flower-like is facilely prepared. • The AlNiCo-O exhibit excellent conductivity and high-efficient charge storage. • The assembled asymmetric supercapacitor shows outstanding performance. [ABSTRACT FROM AUTHOR]

The Core-branched NiCo 2 S 4 @CoNi-LDH heterostructure contributes to high-efficient charge storage. • The Core-branched NiCo 2 S 4 @CoNi-LDH heterostructure is facilely prepared. • The Core-branched NiCo 2 S 4 @CoNi-LDH heterostructure exhibited excellent conductivity and high-efficient charge storage. • The CN-LDH NSs@NCS NSs//AC device delivered an high energy density of 93.21 Wh kg−1 at 1.045 kW kg−1. Constructing hierarchical core-branched configuration from the well-known multicomponent metal hydroxides/sulfides is a way to further tune and utilize distinctive species. Herein, we develop a novel core-branched heterostructure based on NiCo 2 S 4 nanosheets (NCS NSs) branched on CoNi-LDH nanosheets (CN-LDH NSs), which involves facile hot-air oven-based and electro-deposition methods. The CN-LDH NSs acts as the host stem and supports NCS NSs electroactive species to provide reliable electrical contact for electron transfer; whereas the highly active NCS NSs "branch" on the outside of CN-LDH NSs "core" provide sufficient access to active sites, and electron transport regions for the valence transitions of Ni2+/Ni3+ and Co2+/Co3+/Co4+ during redox process. The CN-LDH@NCS NSs electrode achieves a notable specific capacity of 1385.7 C g−1 at 1 A g−1, and good rate capability. Additionally, the as-prepared CN-LDH@NCS NSs//AC device exhibits a high energy density of 93.21 Wh kg−1 at a power density of 1.045 kW kg−1 and satisfying cycling lifespan, with nearly 81.49% capacitance retention after 7000 cycles (20 A g−1). [ABSTRACT FROM AUTHOR]