Single-Atom Zinc and Anionic Framework as Janus Separator Coatings for Efficient Inhibition of Lithium Dendrites and Shuttle Effect

ACS Nano ◽  
2021 ◽  
Author(s):  
Chun-Lei Song ◽  
Ze-Hui Li ◽  
Lin-Yuan Ma ◽  
Mian-Zhang Li ◽  
Si Huang ◽  
...  
Keyword(s):  
Single Atom ◽  
Shuttle Effect ◽  
Lithium Dendrites ◽  
Anionic Framework

Single atom catalysts supported on N-doped graphene toward fast kinetic Li−S batteries: a theoretical study

2021 ◽  
Author(s):  
Xu Han ◽  
Zeyun Zhang ◽  
Xuefei Xu
Keyword(s):  
Theoretical Study ◽  
Single Atom ◽  
Discharge Process ◽  
Fast Kinetics ◽  
Shuttle Effect ◽  
Sufficient Stability ◽  
Doped Graphene ◽  
Fast Kinetic ◽  
Kinetics Of ◽  
Charge Discharge

To suppress the shuttle effect of lithium polysulfides and promote fast kinetics of charge−discharge process in Li−S batteries, it is essential to search promising catalysts with sufficient stability and high...

scholarly journals High-power lithium–selenium batteries enabled by atomic cobalt electrocatalyst in hollow carbon cathode

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hao Tian ◽  
Huajun Tian ◽  
Shijian Wang ◽  
Shuangming Chen ◽  
Fan Zhang ◽  
...  
Keyword(s):  
High Power ◽  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Utilization Efficiency ◽  
Single Atom ◽  
Shuttle Effect ◽  
High Discharge Capacity ◽  
Single Atoms ◽  
High Electronic Conductivity

Abstract Selenium cathodes have attracted considerable attention due to high electronic conductivity and volumetric capacity comparable to sulphur cathodes. However, practical development of lithium-selenium batteries has been hindered by the low selenium reaction activity with lithium, high volume changes and rapid capacity fading caused by the shuttle effect of polyselenides. Recently, single atom catalysts have attracted extensive interests in electrochemical energy conversion and storage because of unique electronic and structural properties, maximum atom-utilization efficiency, and outstanding catalytic performances. In this work, we developed a facile route to synthesize cobalt single atoms/nitrogen-doped hollow porous carbon (CoSA-HC). The cobalt single atoms can activate selenium reactivity and immobilize selenium and polyselenides. The as-prepared selenium-carbon (Se@CoSA-HC) cathodes deliver a high discharge capacity, a superior rate capability, and excellent cycling stability with a Coulombic efficiency of ~100%. This work could open an avenue for achieving long cycle life and high-power lithium-selenium batteries.

scholarly journals Liquid Graphene Oxide Binder and Modified Glass Fiber Separator for Lithium Sulfur Battery with Highly Improved Cycling Performance

2021 ◽  
Author(s):  
maryam sadat kiai
Keyword(s):  
Graphene Oxide ◽  
Glass Fiber ◽  
Polyvinylidene Fluoride ◽  
Large Scale ◽  
Cycling Performance ◽  
Energy Storage Devices ◽  
Shuttle Effect ◽  
Metal Anode ◽  
Lithium Dendrites ◽  
Lithium Sulfur

<p>Lithium sulfur (Li-S) batteries with high theoretical energy density (~2.5 kWh kg<sup>-1</sup>) and high theoretical gravimetric capacity (1672 mAh g<sup>-1</sup>) have drawn great attention as they are promising candidates for large scale energy storage devices. Unfortunately some technical obstacles hinder the practical application of Li-S batteries such as formation of polysulfide intermediates between cathode and anode as well as the insulating nature of sulfur cathode and other discharge products. Glass fiber separators provide some cavities to withstand the volume change of sulfur during cycling leading to long-term cycling stability. Here, application of polar materials with novel liquid graphene oxide (L-GO) binder rather than the standard polyvinylidene fluoride (PVDF) binder as effective coatings on the glass fiber separator of the Li-S cell have been developed to suppress the shuttle effect. The deposition of silicon dioxide (SiO<sub>2</sub>), titanium dioxide (TiO<sub>2</sub>) and poly (1,5-diaminoanthraquinone) (PDAAQ) with L-GO binder on the glass fiber separator was investigated with<b> </b>polycarboxylate functionalized graphene (PC-FGF/S) cathode and Li metal anode. The cells with modified coatings and L-GO as an efficient binder could accelerate conversion of long-chain polysulfides to short-chain polysulfides and significantly delayed the growth of lithium dendrites resulted the capacity retention of ~ 1020, 1070 and 1190 mAh g<sup>-1</sup> for the cells with SiO<sub>2</sub>/L-GO, TiO<sub>2</sub>/L-GO and PDAAQ/L-GO coated separators after 100 cycles. The results demonstrate that ultrathin SiO<sub>2</sub>, TiO<sub>2</sub> and PDAAQ containing coatings with L-GO binder on the glass fiber separator can drastically improve the cyclability of the Li-S cells.</p>

scholarly journals Dual-Atoms Iron Sites Boost the Kinetics of Reversible Conversion of Polysulfide for High-Performance Lithium-Sulfur Batteries

2021 ◽  
Author(s):  
Yue Qiu ◽  
Xun Sun ◽  
Maoxu Wang ◽  
Xian Wu ◽  
Bo Jiang ◽  
...  
Keyword(s):  
High Performance ◽  
Iron Catalyst ◽  
High Rate ◽  
Single Atom ◽  
Efficient Catalyst ◽  
Shuttle Effect ◽  
Adsorption Structure ◽  
Lithium Sulfur Batteries ◽  
Kinetics Of ◽  
Lithium Sulfur

Abstract Atomically dispersed metal catalysts have offered significant potential for accelerating sluggish kinetics of transformation of lithium polysulfide(LiPS) and inhibiting the shuttle effect to achieve the long-life cycling and high rate of lithium sulfur batteries. However, the end-on adsorption structure between single metal site and polysulfide limits the adsorption capacity and catalytic activity of single atom catalysts. Here, we construct dual-atoms iron sites on nitrogen doped graphene to serve as highly efficient catalyst for lithium sulfur batteries. As expected, the dual-atoms sites can firmly bound polysulfides by forming double Fe-S bonds between polysulfides and the two adjacent iron atoms. Such double-bond adsorption structure is also favorable for the electron transfer and polysulfides activation, so as to reduce the energy barrier and accelerate the reaction kinetics. As a result, the as-obtained dual-atoms iron catalyst can effectively alleviate the shuttle effect and improve the utilization of active sulfur, thus the batteries present high initial capacity of 1615 mAh g-1 at 0.05 C and long-cycle life with a decay rate per cycle as low as 0.015% at 2C over 1000 cycles.

scholarly journals Liquid Graphene Oxide Binder and Modified Glass Fiber Separator for Lithium Sulfur Battery with Highly Improved Cycling Performance

2021 ◽  
Author(s):  
maryam sadat kiai
Keyword(s):  
Graphene Oxide ◽  
Glass Fiber ◽  
Polyvinylidene Fluoride ◽  
Large Scale ◽  
Cycling Performance ◽  
Energy Storage Devices ◽  
Shuttle Effect ◽  
Metal Anode ◽  
Lithium Dendrites ◽  
Lithium Sulfur

<p>Lithium sulfur (Li-S) batteries with high theoretical energy density (~2.5 kWh kg<sup>-1</sup>) and high theoretical gravimetric capacity (1672 mAh g<sup>-1</sup>) have drawn great attention as they are promising candidates for large scale energy storage devices. Unfortunately some technical obstacles hinder the practical application of Li-S batteries such as formation of polysulfide intermediates between cathode and anode as well as the insulating nature of sulfur cathode and other discharge products. Glass fiber separators provide some cavities to withstand the volume change of sulfur during cycling leading to long-term cycling stability. Here, application of polar materials with novel liquid graphene oxide (L-GO) binder rather than the standard polyvinylidene fluoride (PVDF) binder as effective coatings on the glass fiber separator of the Li-S cell have been developed to suppress the shuttle effect. The deposition of silicon dioxide (SiO<sub>2</sub>), titanium dioxide (TiO<sub>2</sub>) and poly (1,5-diaminoanthraquinone) (PDAAQ) with L-GO binder on the glass fiber separator was investigated with<b> </b>polycarboxylate functionalized graphene (PC-FGF/S) cathode and Li metal anode. The cells with modified coatings and L-GO as an efficient binder could accelerate conversion of long-chain polysulfides to short-chain polysulfides and significantly delayed the growth of lithium dendrites resulted the capacity retention of ~ 1020, 1070 and 1190 mAh g<sup>-1</sup> for the cells with SiO<sub>2</sub>/L-GO, TiO<sub>2</sub>/L-GO and PDAAQ/L-GO coated separators after 100 cycles. The results demonstrate that ultrathin SiO<sub>2</sub>, TiO<sub>2</sub> and PDAAQ containing coatings with L-GO binder on the glass fiber separator can drastically improve the cyclability of the Li-S cells.</p>

Single Atom Image Contrast in Fixed Beam Dark Field Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 366-367
Author(s):  
Wah Chi
Keyword(s):  
Scattering Amplitude ◽  
Present Report ◽  
Dark Field ◽  
Image Contrast ◽  
Single Atom ◽  
Optical Theorem ◽  
Hartree Fock ◽  
Heavy Atoms ◽  
Beam Stop ◽  
Fixed Beam

Resolution and contrast are the important factors to determine the feasibility of imaging single heavy atoms on a thin substrate in an electron microscope. The present report compares the atom image characteristics in different modes of fixed beam dark field microscopy including the ideal beam stop (IBS), a wire beam stop (WBS), tilted illumination (Tl) and a displaced aperture (DA). Image contrast between one Hg and a column of linearly aligned carbon atoms (representing the substrate), are also discussed. The assumptions in the present calculations are perfectly coherent illumination, atom object is represented by spherically symmetric potential derived from Relativistic Hartree Fock Slater wave functions, phase grating approximation is used to evaluate the complex scattering amplitude, inelastic scattering is ignored, phase distortion is solely due to defocus and spherical abberation, and total elastic scattering cross section is evaluated by the Optical Theorem. The atom image intensities are presented in a Z-modulation display, and the details of calculation are described elsewhere.

Atomic Spectroscopy in the FIM

1986 ◽  
Vol 44 ◽  
pp. 758-761
Author(s):  
J. J. Hren ◽  
S. D. Walck
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Atom Probe ◽  
Atomic Spectroscopy ◽  
Single Atom ◽  
Statistical Sampling ◽  
Commercial Instrument ◽  
Available Technology ◽  
High Electric Fields ◽  
Field Ion Microscope

The field ion microscope (FIM) has had the ability to routinely image the surface atoms of metals since Mueller perfected it in 1956. Since 1967, the TOF Atom Probe has had single atom sensitivity in conjunction with the FIM. “Why then hasn't the FIM enjoyed the success of the electron microscope?” The answer is closely related to the evolution of FIM/Atom Probe techniques and the available technology. This paper will review this evolution from Mueller's early discoveries, to the development of a viable commercial instrument. It will touch upon some important contributions of individuals and groups, but will not attempt to be all inclusive. Variations in instrumentation that define the class of problems for which the FIM/AP is uniquely suited and those for which it is not will be described. The influence of high electric fields inherent to the technique on the specimens studied will also be discussed. The specimen geometry as it relates to preparation, statistical sampling and compatibility with the TEM will be examined.

Field ion microscope investigations of atomic processes at surfaces

1989 ◽  
Vol 47 ◽  
pp. 228-229
Author(s):  
G. L. Kellogg ◽  
P. R. Schwoebel
Keyword(s):  
Single Crystal ◽  
Crystal Surface ◽  
Linear Chain ◽  
Atom Probe ◽  
Nucleation And Growth ◽  
Single Atom ◽  
Initial Structure ◽  
Atomic Processes ◽  
Single Crystal Surfaces ◽  
Field Ion Microscope

Although no longer unique in its ability to resolve individual single atoms on surfaces, the field ion microscope remains a powerful tool for the quantitative characterization of atomic processes on single-crystal surfaces. Investigations of single-atom surface diffusion, adatom-adatom interactions, surface reconstructions, cluster nucleation and growth, and a variety of surface chemical reactions have provided new insights to the atomic nature of surfaces. Moreover, the ability to determine the chemical identity of selected atoms seen in the field ion microscope image by atom-probe mass spectroscopy has increased or even changed our understanding of solid-state-reaction processes such as ordering, clustering, precipitation and segregation in alloys. This presentation focuses on the operational principles of the field-ion microscope and atom-probe mass spectrometer and some very recent applications of the field ion microscope to the nucleation and growth of metal clusters on metal surfaces.The structure assumed by clusters of atoms on a single-crystal surface yields fundamental information on the adatom-adatom interactions important in crystal growth. It was discovered in previous investigations with the field ion microscope that, contrary to intuition, the initial structure of clusters of Pt, Pd, Ir and Ni atoms on W(110) is a linear chain oriented in the <111> direction of the substrate.

Recent advancement in the electrocatalytic synthesis of ammonia

Nanoscale ◽  
2020 ◽  
Vol 12 (15) ◽  
pp. 8065-8094 ◽  
Author(s):  
Xudong Wen ◽  
Jingqi Guan
Keyword(s):  
Metal Oxide ◽  
Oxide Catalysts ◽  
Single Atom ◽  
Metal Oxide Catalysts ◽  
Metal Free ◽  
Recent Advancement ◽  
Nanocomposite Catalysts

Different kinds of electrocatalysts used in NRR electrocatalysis (including single atom catalysts, metal oxide catalysts, nanocomposite catalysts, and metal free catalysts) are introduced.

Rational prediction of multifunctional bilayer single atom catalysts for the hydrogen evolution, oxygen evolution and oxygen reduction reactions

Nanoscale ◽  
2020 ◽  
Vol 12 (39) ◽  
pp. 20413-20424
Author(s):  
Riming Hu ◽  
Yongcheng Li ◽  
Fuhe Wang ◽  
Jiaxiang Shang
Keyword(s):  
Oxygen Reduction ◽  
Hydrogen Evolution ◽  
Oxygen Evolution ◽  
Single Atom ◽  
Reduction Reactions ◽  
Oxygen Reduction Reactions

Bilayer single atom catalysts can serve as promising multifunctional electrocatalysts for the HER, ORR, and OER.

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