scholarly journals Hybrid core–shell nanostructured electrodes made of polypyrrole nanotubes coated with Ni(OH)2 nanoflakes for high energy-density supercapacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (18) ◽  
pp. 15062-15070 ◽  
Author(s):  
Franciele Wolfart ◽  
Deepak P. Dubal ◽  
Marcio Vidotti ◽  
Pedro Gómez-Romero
Keyword(s):  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Core Shell ◽  
Galvanostatic Charge ◽  
Nanostructured Electrodes ◽  
Sem Image ◽  
Polypyrrole Nanotubes ◽  
Charge Discharge ◽  
Discharge Curves

SEM image of Ni(OH)2@PPy-NTs core–shell nanostructure and galvanostatic charge/discharge curves of PPy-NTs, Ni(OH)2 and Ni(OH)2@PPy-NTs nanostructures.

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.

scholarly journals Fabrication of Hierarchical NiMoO4/NiMoO4 Nanoflowers on Highly Conductive Flexible Nickel Foam Substrate as a Capacitive Electrode Material for Supercapacitors with Enhanced Electrochemical Performance

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1143 ◽  
Author(s):  
Anil Yedluri ◽  
Tarugu Anitha ◽  
Hee-Je Kim
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Electrode Material ◽  
High Performance ◽  
Nickel Foam ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Charge Discharge

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.

Revealing the charge/discharge mechanism of Na–O2 cells by in situ soft X-ray absorption spectroscopy

2018 ◽  
Vol 11 (8) ◽  
pp. 2073-2077 ◽  
Author(s):  
Mohammad N. Banis ◽  
Hossein Yadegari ◽  
Qian Sun ◽  
Tom Regier ◽  
Teak Boyko ◽  
...  
Keyword(s):  
Energy Density ◽  
Absorption Spectroscopy ◽  
High Energy ◽  
High Energy Density ◽  
X Ray ◽  
Discharge Mechanism ◽  
X Ray Absorption ◽  
Charge Discharge

Developing high energy density batteries, such as metal–air systems, requires a good understanding of their underlying electrochemical principles.

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.

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).

Multiscale Modeling of Electro-Chemo-Mechanical Degradation in Si/C Core–Shell Anode for the Lithium-Ion Battery of High Energy Density

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Xiang Gao ◽  
Jun Xu
Keyword(s):  
Energy Density ◽  
Lithium Ion Battery ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Mechanical Degradation ◽  
Core Shell ◽  
Capacity Fade ◽  
Charging Rate ◽  
Particle Level

Abstract The capacity fade in lithium-ion battery (LIB) of high energy density using Si/C core–shell particle anode is one of the major barriers blocking its wide application. However, the underlying mechanism of electro-chemo-mechanical degradation remains unclear. In this study, we propose and validate a multiscale model (electrode level and particle level), considering electrochemical–mechanical coupling and cohesive zone method at the particle level. The effects of charging rate, core/shell ratio, and mechanical properties of the shell on the separation and capacity fade are discussed. We discover that larger charging rate, smaller core/shell ratio, and stiffer shell can mitigate the core–shell separation gap, leading to higher capacity retention. Results shed light on the degradation mechanism of Si/C core–shell anode and provide design guidance for Si/C anode materials in minimizing the capacity fade and safe battery charging/discharging strategy.

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