Engineering Hierarchical Co@N-Doped Carbon Nanotubes/α-Ni(OH)2 Heterostructures on Carbon Cloth Enabling High-Performance Aqueous Nickel–Zinc Batteries

Author(s):  
Longzhen Zhu ◽  
Ban Fei ◽  
Yulan Xie ◽  
Daoping Cai ◽  
Qidi Chen ◽  
...  
Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1195
Author(s):  
Jianhao Lin ◽  
Xusheng Du

Urchin-like tungsten oxide (WO3) microspheres self-assembled with nanobelts are deposited on the surface of the hydrophilic carbon cloth (CC) current collector via hydrothermal reaction. The WO3 nanobelts in the urchin-like microspheres are in the hexagonal crystalline phase, and their widths are around 30–50 nm. The resulted hierarchical WO3 / CC electrode exhibits a capacitance of 3400 mF / cm2 in H2SO4 electrolyte in the voltage window of −0.5 ~ 0.2 V, which makes it an excellent negative electrode for asymmetric supercapacitors. To improve the capacitive performance of the positive electrode and make it comparable with that of the WO3 / CC electrode, both the electrode material and the electrolyte have been carefully designed and prepared. Therefore, the hydrophilic CC is further coated with carbon nanotubes (CNTs) to create a hierarchical CNT / CC electrode via a convenient flame synthesis method, and a redox-active electrolyte containing an Fe2+ / Fe 3+ couple is introduced into the half-cell system as well. As a result, the high performance of the asymmetric supercapacitor assembled with both the asymmetric electrodes and electrolytes has been realized. It exhibits remarkable energy density as large as 403 μW h / cm2 at 15 mW / cm2 and excellent cyclic stability after 10,000 cycles.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jae-Won Lee ◽  
Joon Young Cho ◽  
Mi Jeong Kim ◽  
Jung Hoon Kim ◽  
Jong Hwan Park ◽  
...  

AbstractSoft electronic devices that are bendable and stretchable require stretchable electric or electronic components. Nanostructured conducting materials or soft conducting polymers are one of the most promising fillers to achieve high performance and durability. Here, we report silver nanoparticles (AgNPs) embedded with single-walled carbon nanotubes (SWCNTs) synthesized in aqueous solutions at room temperature, using NaBH4 as a reducing agent in the presence of highly oxidized SWCNTs as efficient nucleation agents. Elastic composite films composed of the AgNPs-embedded SWCNTs, Ag flake, and polydimethylsiloxane are irradiated with radiation from a Xenon flash lamp within a time interval of one second for efficient sintering of conductive fillers. Under high irradiation energy, the stretchable electrodes are created with a maximum conductivity of 4,907 S cm−1 and a highly stretchable stability of over 10,000 cycles under a 20% strain. Moreover, under a low irradiation energy, strain sensors with a gauge factor of 76 under a 20% strain and 5.4 under a 5% strain are fabricated. For practical demonstration, the fabricated stretchable electrode and strain sensor are attached to a human finger for detecting the motions of the finger.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Quan Zong ◽  
Wei Du ◽  
Chaofeng Liu ◽  
Hui Yang ◽  
Qilong Zhang ◽  
...  

AbstractAmmonium vanadate with bronze structure (NH4V4O10) is a promising cathode material for zinc-ion batteries due to its high specific capacity and low cost. However, the extraction of $${\text{NH}}_{{4}}^{ + }$$ NH 4 + at a high voltage during charge/discharge processes leads to irreversible reaction and structure degradation. In this work, partial $${\text{NH}}_{{4}}^{ + }$$ NH 4 + ions were pre-removed from NH4V4O10 through heat treatment; NH4V4O10 nanosheets were directly grown on carbon cloth through hydrothermal method. Deficient NH4V4O10 (denoted as NVO), with enlarged interlayer spacing, facilitated fast zinc ions transport and high storage capacity and ensured the highly reversible electrochemical reaction and the good stability of layered structure. The NVO nanosheets delivered a high specific capacity of 457 mAh g−1 at a current density of 100 mA g−1 and a capacity retention of 81% over 1000 cycles at 2 A g−1. The initial Coulombic efficiency of NVO could reach up to 97% compared to 85% of NH4V4O10 and maintain almost 100% during cycling, indicating the high reaction reversibility in NVO electrode.


2021 ◽  
Author(s):  
Mingjie Li ◽  
Xuan Zheng ◽  
Xiang Li ◽  
Youjun Yu ◽  
Jinlong Jiang

Recently, transition metal selenides have been investigated extensively as promising electrode materials for high-performance supercapacitors. Herein, the multi-component CoSe2/CNTs@g-C3N4 composites are prepared using a two-step hydrothermal method by incorporating one-dimensional...


2021 ◽  
pp. 2100029
Author(s):  
Hui Sun ◽  
Fei Niu ◽  
Peng Yuan ◽  
Xuexia He ◽  
Jie Sun ◽  
...  

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