scholarly journals Hetero-architectured core–shell NiMoO4@Ni9S8/MoS2 nanorods enabling high-performance supercapacitors

Author(s):  
Lu Chen ◽  
Wenjing Deng ◽  
Zhi Chen ◽  
Xiaolei Wang

Abstract An effective technique for improving electrochemical efficiency is to rationally design hierarchical nanostructures that completely optimize the advantages of single components and establish an interfacial effect between structures. In this study, core–shell NiMoO4@Ni9S8/MoS2 hetero-structured nanorods are prepared via a facile hydrothermal process followed by a direct sulfurization. The resulting hierarchical architecture with outer Ni9S8/MoS2 nanoflakes shell on the inner NiMoO4 core offers plentiful active sites and ample charge transfer pathways in continuous heterointerfaces. Ascribing to the porous core–shell configuration and synergistic effect of bimetal sulfides, the obtained NiMoO4@Ni9S8/MoS2 as electrode material presents an unsurpassed specific capacity of 373.4 F g−1 at 10 A g−1 and remarkable cycling performance in the 6 M KOH electrolyte. This work delivers a rational method for designing highly efficient electrodes for supercapacitors, enlightening the road of exploring low-cost materials in the energy storage domain. Graphical Abstract

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2263 ◽  
Author(s):  
Xiaoning Wang ◽  
Dan Wu ◽  
Xinhui Song ◽  
Wei Du ◽  
Xiangjin Zhao ◽  
...  

Polyaniline has been widely used in high-performance pseudocapacitors, due to its low cost, easy synthesis, and high theoretical specific capacitance. However, the poor mechanical properties of polyaniline restrict its further development. Compared with polyaniline, functionalized carbon materials have excellent physical and chemical properties, such as porous structures, excellent specific surface area, good conductivity, and accessibility to active sites. However, it should not be neglected that the specific capacity of carbon materials is usually unsatisfactory. There is an effective strategy to combine carbon materials with polyaniline by a hybridization approach to achieve a positive synergistic effect. After that, the energy storage performance of carbon/polyaniline hybridization material has been significantly improved, making it a promising and important electrode material for supercapacitors. To date, significant progress has been made in the synthesis of various carbon/polyaniline binary composite electrode materials. In this review, the corresponding properties and applications of polyaniline and carbon hybrid materials in the energy storage field are briefly reviewed. According to the classification of different types of functionalized carbon materials, this article focuses on the recent progress in carbon/polyaniline hybrid materials, and further analyzes their corresponding properties to provide guidance for the design, synthesis, and component optimization for high-performance supercapacitors.


NANO ◽  
2020 ◽  
Vol 15 (02) ◽  
pp. 2050014
Author(s):  
Zhipeng Ma ◽  
Fengyang Jing ◽  
Liyin Hou ◽  
Lukai Fan ◽  
Yao Zhao ◽  
...  

Manganese-based oxides are one of the most promising high-performance supercapacitor (SC) electrode materials. In this work, a stable MnOx nanowires@MnOx nanosheets core–shell heterostructure electrode material consisting of MnOx nanosheets grown uniformly on the surface of MnOx nanowires has been prepared by a simple liquid phase method followed by thermal treatment. The electrode displays a specific capacity of 336 F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text] and exhibits a good cycling life of 83% capacitance retention after 5000 cycles. This is mainly due to the synergy effect between the one-dimensional MnOx nanowires as the backbone structure and the two-dimensional MnOx nanosheets with large specific surface area provide more active sites and the rapid transmission of electrons.


2021 ◽  
Author(s):  
Yi He ◽  
Lei Xie ◽  
Shixiang Ding ◽  
Yujia Long ◽  
Xinyi Zhou ◽  
...  

Although the zinc oxide (ZnO) with wide distribution is one of the most attractive energy storage materials, the low electronic conductivity and insufficient active sites of bulk ZnO increase the...


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Wenyan Du ◽  
Kangqi Shen ◽  
Yuruo Qi ◽  
Wei Gao ◽  
Mengli Tao ◽  
...  

AbstractRechargeable room temperature sodium–sulfur (RT Na–S) batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D “branch-leaf” biomimetic design proposed for high performance Na–S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive “branches” to ensure adequate electron and electrolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D “branch-leaf” conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared “branch-leaf” CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g−1 at 0.1 C and superior rate performance.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruirui Wang ◽  
Renbing Wu ◽  
Chaofan Ding ◽  
Ziliang Chen ◽  
Hongbin Xu ◽  
...  

AbstractThe practical application of lithium–sulfur batteries is severely hampered by the poor conductivity, polysulfide shuttle effect and sluggish reaction kinetics of sulfur cathodes. Herein, a hierarchically porous three-dimension (3D) carbon architecture assembled by cross-linked carbon leaves with implanted atomic Co–N4 has been delicately developed as an advanced sulfur host through a SiO2-mediated zeolitic imidazolate framework-L (ZIF-L) strategy. The unique 3D architectures not only provide a highly conductive network for fast electron transfer and buffer the volume change upon lithiation–delithiation process but also endow rich interface with full exposure of Co–N4 active sites to boost the lithium polysulfides adsorption and conversion. Owing to the accelerated kinetics and suppressed shuttle effect, the as-prepared sulfur cathode exhibits a superior electrochemical performance with a high reversible specific capacity of 695 mAh g−1 at 5 C and a low capacity fading rate of 0.053% per cycle over 500 cycles at 1 C. This work may provide a promising solution for the design of an advanced sulfur-based cathode toward high-performance Li–S batteries.


NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050062
Author(s):  
Zhaolei Meng ◽  
Xiaojian He ◽  
Song Han ◽  
Zijian Hu

Carbon materials are generally employed as supercapacitor electrodes due to their low- cost, high-chemical stability and environmental friendliness. However, the design of carbon structures with large surface area and controllable porous structure remains a daunt challenge. In this work, a three-dimensional (3D) hybrid aerogel with different contents of MoS2 nanosheets in 3D graphene aerogel (MoS2-GA) was synthesized through a facial hydrothermal process. The influences of MoS2 content on microstructure and subsequently on electrochemical properties of MoS2-GA are systematically investigated and an optimized mass ratio with MoS2: GA of 1:2 is chosen to achieve high mechanical robustness and outstanding electrochemical performance in the hybrid structure. Due to the large specific surface area, porous structure and continuous charge transfer network, such MoS2-GA electrodes exhibit high specific capacitance, good rate capability and excellent cyclic stability, showing great potential in large-scale and low-cost fabrication of high-performance supercapacitors.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenfu Xie ◽  
Jianming Li ◽  
Yuke Song ◽  
Shijin Li ◽  
Jianbo Li ◽  
...  

AbstractZinc–air batteries (ZABs) hold tremendous promise for clean and efficient energy storage with the merits of high theoretical energy density and environmental friendliness. However, the performance of practical ZABs is still unsatisfactory because of the inevitably decreased activity of electrocatalysts when assembly into a thick electrode with high mass loading. Herein, we report a hierarchical electrocatalyst based on carbon microtube@nanotube core–shell nanostructure (CMT@CNT), which demonstrates superior electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction with a small potential gap of 0.678 V. Remarkably, when being employed as air–cathode in ZAB, the CMT@CNT presents an excellent performance with a high power density (160.6 mW cm−2), specific capacity (781.7 mAhg Zn −1 ) as well as long cycle stability (117 h, 351 cycles). Moreover, the ZAB performance of CMT@CNT is maintained well even under high mass loading (3 mg cm−2, three times as much as traditional usage), which could afford high power density and energy density for advanced electronic equipment. We believe that this work is promising for the rational design of hierarchical structured electrocatalysts for advanced metal-air batteries.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3198
Author(s):  
Syed Fakhar Alam ◽  
Min-Zy Kim ◽  
Aafaq ur Rehman ◽  
Devipriyanka Arepalli ◽  
Pankaj Sharma ◽  
...  

Two-dimensional SAPO-34 molecular sieves were synthesized by microwave hydrothermal process. The concentrations of structure directing agent (SDA), phosphoric acid, and silicon in the gel solution were varied and their effect on phase, shape, and composition of synthesized particles was studied. The synthesized particles were characterized by various techniques using SEM, XRD, BET, EDX, and NH3-TPD. Various morphologies of particles including isotropic, hyper rectangle, and nanoplates were obtained. It was found that the Si/Al ratio of the SAPO-34 particles was in a direct relationship with the density of acid sites. Moreover, the gel composition and preparation affected the chemistry of the synthesized particles. The slow addition of phosphoric acid improved the homogeneity of synthesis gel and resulted in SAPO-34 nanoplates with high density of acid sites, 3.482 mmol/g. The SAPO-34 nanoplates are expected to serve as a high performance catalyst due to the low mass transfer resistance and the high density of active sites.


Author(s):  
Shimeng Zhao ◽  
Jialin Li ◽  
Haixia Chen ◽  
Jianxin Zhang

Abstract Rechargeable aluminum ion batteries (AIBs) have attracted much attention because of their high charge density, low cost, and low flammability. Transition metal sulfides are a class of cathode materials that have been extensively studied. In this report, Bi2S3 nanorods and Bi2S3/MoS2 nanorods were synthesized by the hydrothermal method as new type of cathode materials for rechargeable AIBs. The diameter of Bi2S3/MoS2 nanorods is 20–100 nm. The Bi2S3 nanorods display high initial charge and discharge capacities of 343.3 and 251 mA h/g with a current density of 1 A/g. The static cycling for the Bi2S3/MoS2 nanorods electrode at 1 A/g denotes high stability with a specific capacity of 132.9 mA h/g after 100 cycles. The charging voltage platform of Bi2S3 nanorods and Bi2S3/MoS2 nanorods is at 1.1–1.4 V, and the discharge voltage platform is at around 0.8 V. The well-defined heterojunction maintains the stability of the Bi2S3 structure during long-term cycling, which is desirable for aluminum ion batteries. This strategy reveals new insights for designing cathode materials of high-performance AIBs.


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