A core–shell structure of cobalt sulfide//G-ink towards high energy density in asymmetric hybrid supercapacitors

2020 ◽  
Vol 4 (9) ◽  
pp. 4848-4858
Author(s):  
Venkata Thulasivarma Chebrolu ◽  
Balamuralitharan Balakrishnan ◽  
Aravindha Raja Selvaraj ◽  
Hee-Je Kim
Keyword(s):  
Energy Density ◽  
Shell Structure ◽  
High Energy ◽  
High Energy Density ◽  
Cobalt Sulfide ◽  
Core Shell ◽  
Hybrid Supercapacitors ◽  
Promising Strategy ◽  
Asymmetric Hybrid ◽  
Core Shell Structure

New atom substitution in transition metals is a promising strategy for improving the performance of supercapacitors (SCs).

Preparation and Capacitance Properties of Nickel-Cobalt Sulfide/Graphene Composites

2019 ◽  
Vol 956 ◽  
pp. 35-45
Author(s):  
Shi Huai Zhao ◽  
Wen Wen Xu ◽  
Xiao Ming Zhao ◽  
Zi Bo Yang
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Shell Structure ◽  
Electrochemical Impedance ◽  
High Energy ◽  
High Energy Density ◽  
Cobalt Sulfide ◽  
Core Shell ◽  
Nickel Cobalt ◽  
Core Shell Structure

In order to explore the supercapacitor electrode material with high energy density, a composite material that nickel-cobalt sulfide loaded in graphene (NiCo2S4@rGO) with core-shell structure was successfully prepared by hydrothermal, room temperature vulcanization and annealing. The core-shell structure of the material greatly increased the contact area between the material and the electrolyte and improved the electrochemical performance. In addition, the energy density has been significantly improved. NiCo2S4@rGO was characterized by field emission scanning electron microscopy (SEM), high-resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectrometer. The electrochemical properties of the material were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the capacitance can reach 1100 F/g at the current density of 0.5 A/g. Furthermore, the NiCo2S4@rGO as positive electrode and reduced graphene oxide (rGO) as negative electrode were assembled into an asymmetric supercapacitor (ASC). The device exhibits a high energy density of 74.78 Wh/Kg at a power density of 400 W/Kg, as well as excellent cycling stability of 88.9% after 3 000 cycles, which reflects the excellent electrochemical performance of the material.

A hierarchical glucose-intercalated NiMn-G-LDH@NiCo2S4 core–shell structure as a binder-free electrode for flexible all-solid-state asymmetric supercapacitors

Nanoscale ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 1852-1863 ◽  
Author(s):  
Shixia Chen ◽  
Chengxi Lu ◽  
Lu Liu ◽  
Mai Xu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Density ◽  
Shell Structure ◽  
High Energy ◽  
High Energy Density ◽  
Core Shell ◽  
Wearable Electronics ◽  
Asymmetric Supercapacitors ◽  
Binder Free ◽  
Core Shell Structure

Flexible, lightweight, and high-energy-density asymmetric supercapacitors (ASCs) are highly attractive for portable and wearable electronics.

scholarly journals Rational synthesis of silicon into polyimide-derived hollow electrospun carbon nanofibers for enhanced lithium storage

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 491-499 ◽  
Author(s):  
Fan Wang ◽  
Shouzhi Zhang ◽  
Jiawei Zhang ◽  
Manshu Han ◽  
Guoxiang Pan ◽  
...  
Keyword(s):  
Shell Structure ◽  
Carbon Nanofiber ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Superior Performance ◽  
Core Shell ◽  
Discharge Process ◽  
Energy Devices ◽  
Core Shell Structure

AbstractFlexible energy devices with high energy density and long cycle life are considered to be promising applications in portable electronics. In this study, silicon/carbon nanofiber (Si@CNF) core–shell electrode has been prepared by the coaxial electrospinning method. The precursors of polyimide (PI) were for the first time used to form the core–shell structure of Si@CNF, which depicts outstanding flexibility and mechanical strength. The effect of doping concentrations of silicon (Si) nanoparticles embedded in the fiber is investigated as a binder-free anode for lithium-ion batteries. A 15 wt% doped composite electrode demonstrates superior performance, with an initial reversible capacity of 621 mA h g−1 at the current density of 100 mA g−1 and a high capacity retention up to 200 cycles. The excellent cycling performance is mainly due to the carbonized PI core–shell structure, which not only can compensate for the insulation property of Si but also has the ability to buffer the volume expansion during the repeated charge–discharge process.

Enhanced dielectric properties and thermostability in polyimide composites with core-shell structured polyimide@BaTiO3 nanoparticles

2021 ◽  
pp. 095400832199352
Author(s):  
Wei Deng ◽  
Guanguan Ren ◽  
Wenqi Wang ◽  
Weiwei Cui ◽  
Wenjun Luo
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Energy Density ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Dielectric Materials ◽  
High Energy ◽  
Amic Acid ◽  
High Energy Density ◽  
Core Shell

Polymer composites with high dielectric constant and thermal stability have shown great potential applications in the fields relating to the energy storage. Herein, core-shell structured polyimide@BaTiO3 (PI@BT) nanoparticles were fabricated via in-situ polymerization of poly(amic acid) (PAA) and the following thermal imidization, then utilized as fillers to prepare PI composites. Increased dielectric constant with suppressed dielectric loss, and enhanced energy density as well as heat resistance were simultaneously realized due to the presence of PI shell between BT nanoparticles and PI matrix. The dielectric constant of PI@BT/PI composites with 55 wt% fillers increased to 15.0 at 100 Hz, while the dielectric loss kept at low value of 0.0034, companied by a high energy density of 1.32 J·cm−3, which was 2.09 times higher than the pristine PI. Moreover, the temperature at 10 wt% weight loss reached 619°C, demonstrating the excellent thermostability of PI@BT/PI composites. In addition, PI@BT/PI composites exhibited improved breakdown strength and toughness as compared with the BT/PI composites due to the well dispersion of PI@BT nanofillers and the improved interfacial interactions between nanofillers and polymer matrix. These results provide useful information for the structural design of high-temperature dielectric materials.

Core–Shell Fe1–[email protected] Nanorods for Room Temperature All-Solid-State Sodium Batteries with High Energy Density

ACS Nano ◽  
2018 ◽  
Vol 12 (3) ◽  
pp. 2809-2817 ◽  
Author(s):  
Hongli Wan ◽  
Jean Pierre Mwizerwa ◽  
Xingguo Qi ◽  
Xin Liu ◽  
Xiaoxiong Xu ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Density ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Density ◽  
Core Shell ◽  
Sodium Batteries

Core–Shell Structured NiCo2O4@ZnCo2O4 Nanomaterials with High Energy Density for Hybrid Capacitors

2021 ◽  
Vol 16 (7) ◽  
pp. 1134-1142
Author(s):  
Wenduo Yang ◽  
Jun Xiang ◽  
Sroeurb Loy ◽  
Nan Bu ◽  
Duo Cui ◽  
...  
Keyword(s):  
Energy Density ◽  
Electrode Material ◽  
Composite Electrode ◽  
Electrode Materials ◽  
Structural Characteristics ◽  
High Energy ◽  
High Energy Density ◽  
Core Shell ◽  
Shell Composite ◽  
Hybrid Capacitors

NiCo2O4 as an electrode material for supercapacitors (SCs) has been studied by a host of researchers due to its unique structural characteristics and high capacitance. However, its performance has not yet reached the level of practical applications.it is an effective strategy to synthesize composite electrode materials for tackling the problem. Herein, NiCo2O4@ZnCo2O4 as a novel core–shell composite electrode material has been fabricated through a two-step simple hydrothermal method. The as-prepared sample can be directly used as cathode material of a supercapacitor, and its specific capacitance is 463.1 C/g at 1 A/g. An assembled capacitor has an energy density of 77 Wh·kg−1 at 2700 W·kg−1, and after 8000 cycles, 88% of the initial capacity remains.

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