scholarly journals In situ-grown compressed NiCo2S4 barrier layer for efficient and durable polysulfide entrapment

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Shaozhuan Huang ◽  
Ye Wang ◽  
Junping Hu ◽  
Yew Von Lim ◽  
Dezhi Kong ◽  
...  

Abstract Modifying a polypropylene (PP) separator with a polysulfide barrier layer can improve the cycling performance of lithium–sulfur (Li–S) batteries. However, conventional slurry-coating- and vacuum-filtration-designed barriers usually show poor particle connection and require extra binder. Herein, we propose a facile in situ growth method and a subsequent compression strategy to design multifunctional NiCo2S4 (NiCoS) nanosheet arrays on a PP membrane for high-performance Li–S batteries. The in situ grown NiCoS nanosheet arrays are interconnected, conductive and closely adhered to the PP membrane without using any binder. After mechanical compression treatment, the overall NiCoS film is compacted, lightweight (0.148 mg cm−2) and ultrathin (0.8 μm). Density functional theory calculations combined with adsorption and diffusion tests prove that the NiCoS nanosheets have highly efficient physical/chemical entrapping capabilities for preventing polysulfide shuttling. Moreover, in situ electrochemical impedance spectroscopy demonstrated that the NiCoS barrier could efficiently suppress polysulfide diffusion and concurrently facilitate redox reactions. When applying this multifunctional separator, a sulfur/carbon nanotube (S/CNT) cathode with high sulfur content (75 wt%) delivers significantly improved long-term cycling performance, with 0.056% capacity decay per cycle over 500 cycles. This work opens up new opportunities to design multifunctional separators by an in situ growth strategy for high-performance Li–S batteries.

2020 ◽  
Vol 49 (15) ◽  
pp. 4956-4966 ◽  
Author(s):  
Jingbo Li ◽  
Yu Liu ◽  
Wei Cao ◽  
Nan Chen

A rapid in situ method was employed to synthesize the β-Ni(OH)2@NF integrated electrode for a high performance ASC device.


Small ◽  
2020 ◽  
Vol 16 (44) ◽  
pp. 2004188
Author(s):  
Xiaofeng Zhang ◽  
Feng Yang ◽  
Haixin Chen ◽  
Kun Wang ◽  
Junwei Chen ◽  
...  

2021 ◽  
Author(s):  
Xiaohua Qiao ◽  
Lixia Sun ◽  
Jianhua Sun ◽  
chaoyang Hou ◽  
shuaijuan Bian ◽  
...  

Potassium ion batteries (PIBs) have been drawn much interest because of the resource-abundance and tempting electrochemical potential of potassium. However, developing high-performance anodes for PIBs with superior reversible capacity and...


2022 ◽  
Author(s):  
Heigo Ers ◽  
Liis Siinor ◽  
Carolin Siimenson ◽  
Enn Lust ◽  
Piret Pikma

The interface between semi-metallic Sb(111) electrode and ionic liquid with 4,4’-bipyridine addition has been studied. Using in situ scanning tunnelling microscopy and electrochemical impedance spectroscopy, the desorption of 4,4’-bipyridine was demonstrated and a dense underlying structure, formed below a sparse self-assembled monolayer, was visualized. The first SAM layer in contact with the electrode consisted of tightly packed ordered rows, which fine structure has been identified with density functional theory calculations supported by machine learning. The second SAM layer, on top of the first, is characterised by low surface concentration and its unit cell was obtained experimentally. The detection of two separate adsorbed layers indicates that the ordering of organic molecules could extend well beyond the monolayer on the electrode’s surface. These insights are of fundamental and practical importance in the development of nanoelectronic devices.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qinglei Meng ◽  
Jiang Yan ◽  
Ruizhi Wu ◽  
Huizhen Liu ◽  
Yang Sun ◽  
...  

AbstractBenzene is a widely used commodity chemical, which is currently produced from fossil resources. Lignin, a waste from lignocellulosic biomass industry, is the most abundant renewable source of benzene ring in nature. Efficient production of benzene from lignin, which requires total transformation of Csp2-Csp3/Csp2-O into C-H bonds without side hydrogenation, is of great importance, but has not been realized. Here, we report that high-silica HY zeolite supported RuW alloy catalyst enables in situ refining of lignin, exclusively to benzene via coupling Bronsted acid catalyzed transformation of the Csp2-Csp3 bonds on the local structure of lignin molecule and RuW catalyzed hydrogenolysis of the Csp2-O bonds using the locally abstracted hydrogen from lignin molecule, affording a benzene yield of 18.8% on lignin weight basis in water system. The reaction mechanism is elucidated in detail by combination of control experiments and density functional theory calculations. The high-performance protocol can be readily scaled up to produce 8.5 g of benzene product from 50.0 g lignin without any saturation byproducts. This work opens the way to produce benzene using lignin as the feedstock efficiently.


Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1741-1751
Author(s):  
Young In Jhon ◽  
Jinho Lee ◽  
Young Min Jhon ◽  
Ju Han Lee

Abstract Metallic 2D materials can be promising saturable absorbers for ultrashort pulsed laser production in the long wavelength regime. However, preparing and manipulating their 2D structures without layer stacking have been nontrivial. Using a combined experimental and theoretical approach, we demonstrate here that a metallic titanium carbide (Ti3C2Tx), the most popular MXene 2D material, can have excellent nonlinear saturable absorption properties even in a highly stacked state due to its intrinsically existing surface termination, and thus can produce mode-locked femtosecond pulsed lasers in the 1.9-μm infrared range. Density functional theory calculations reveal that the electronic and optical properties of Ti3C2Tx MXene can be well preserved against significant layer stacking. Indeed, it is experimentally shown that 1.914-μm femtosecond pulsed lasers with a duration of 897 fs are readily generated within a fiber cavity using hundreds-of-layer stacked Ti3C2Tx MXene saturable absorbers, not only being much easier to manufacture than mono- or few-layered ones, but also offering character-conserved tightly-assembled 2D materials for advanced performance. This work strongly suggests that as-obtained highly stacked Ti3C2Tx MXenes can serve as superb material platforms for versatile nanophotonic applications, paving the way toward cost-effective, high-performance photonic devices based on MXenes.


Author(s):  
Zhuang-Hao Zheng ◽  
Jun-Yun Niu ◽  
Dong-Wei Ao ◽  
Bushra Jabar ◽  
Xiao-Lei Shi ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chang Liu ◽  
Jincan Kang ◽  
Zheng-Qing Huang ◽  
Yong-Hong Song ◽  
Yong-Shan Xiao ◽  
...  

AbstractThe selective hydrogenation of CO2 to value-added chemicals is attractive but still challenged by the high-performance catalyst. In this work, we report that gallium nitride (GaN) catalyzes the direct hydrogenation of CO2 to dimethyl ether (DME) with a CO-free selectivity of about 80%. The activity of GaN for the hydrogenation of CO2 is much higher than that for the hydrogenation of CO although the product distribution is very similar. The steady-state and transient experimental results, spectroscopic studies, and density functional theory calculations rigorously reveal that DME is produced as the primary product via the methyl and formate intermediates, which are formed over different planes of GaN with similar activation energies. This essentially differs from the traditional DME synthesis via the methanol intermediate over a hybrid catalyst. The present work offers a different catalyst capable of the direct hydrogenation of CO2 to DME and thus enriches the chemistry for CO2 transformations.


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