Coaxial-nanostructured MnFe2O4 nanoparticles on polydopamine-coated MWCNT for anode materials in rechargeable batteries

Nanoscale ◽  
2018 ◽  
Vol 10 (40) ◽  
pp. 18949-18960 ◽  
Author(s):  
Hyeongwoo Kim ◽  
Jong-Won Lee ◽  
Dongjin Byun ◽  
Wonchang Choi
Keyword(s):  
Anode Materials ◽  
Coating Layer ◽  
Rate Capability ◽  
Rechargeable Batteries ◽  
Adhesion Ability ◽  
Coaxial Nanocables ◽  
Co Precipitation ◽  
Mnfe2o4 Nanoparticles

A PDA coating layer increased the dispersibility of MWCNT in solution and enhanced the adhesion ability of the interface between oxides and MWCNT during co-precipitation. MnFe2O4@PDA-coated MWCNT coaxial nanocables showed stable long-term cyclability and excellent rate capability.

Porous CNT@Li4Ti5O12 coaxial nanocables as ultra high power and long life anode materials for lithium ion batteries

2016 ◽  
Vol 4 (6) ◽  
pp. 2089-2095 ◽  
Author(s):  
Yakun Tang ◽  
Lang Liu ◽  
Hongyang Zhao ◽  
Dianzeng Jia ◽  
Wei Liu
Keyword(s):  
Anode Materials ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
High Current ◽  
High Reversible Capacity ◽  
Current Densities ◽  
Long Life ◽  
Coaxial Nanocables

Porous CNT@Li4Ti5O12 core–sheath coaxial nanocables have been successfully synthesized, which exhibit high reversible capacity, excellent rate capability and superior long-term cycling stability especially at high current densities.

Effect of Zn2+ and F− Co-Modification on the Structure and Electrochemical Performance of Li4Ti5O12 Anode Material

NANO ◽  
2017 ◽  
Vol 12 (05) ◽  
pp. 1750054 ◽  
Author(s):  
Aijia Wei ◽  
Wen Li ◽  
Lihui Zhang ◽  
Xiaohui Li ◽  
Xue Bai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Coating Layer ◽  
Rate Capability ◽  
Precipitation Method ◽  
Charge Capacity ◽  
X Ray ◽  
Modification Process ◽  
Co Precipitation ◽  
A Charge

Zn[Formula: see text] and F[Formula: see text] ions are successfully used to modify pure Li4Ti5O[Formula: see text] via a co-precipitation method followed by calcination at 400[Formula: see text]C for 5[Formula: see text]h in an Ar atmosphere in order to further investigate the reaction mechanism of the fluoride modification process. Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. After the modification process, no ZnF2 coating layer is formed on the surface of Li4Ti5O[Formula: see text], instead, F[Formula: see text] ions react with Li4Ti5O[Formula: see text] to generate a new phase, composed of a small amount of anatase TiO2, rutile TiO2, LiF, and Zn[Formula: see text] ions are suspected to form a ZnO coating layer on Li4Ti5O[Formula: see text] particles. The electrolyte reduction decomposition is suppressed in Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] due to the ZnO coating layer. 1[Formula: see text]wt.% Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] exhibits the best rate capability, which leads to a charge capacity of 236.7, 227.8, 222.1, 202.7, 188.9 and 150.7[Formula: see text]mAh g[Formula: see text] at 0.2C, 0.5C, 1C, 3C, 5C and 10C, respectively, between 0[Formula: see text]V and 3[Formula: see text]V. Furthermore, 1[Formula: see text]wt.% Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] exhibits 96.0% charge capacity retention at 3C rate after 200 cycles, which is significantly higher than that of pure Li4Ti5O[Formula: see text] (78.4%).

Fe1−xS@S-doped carbon core–shell heterostructured hollow spheres as highly reversible anode materials for sodium ion batteries

2019 ◽  
Vol 7 (35) ◽  
pp. 20229-20238 ◽  
Author(s):  
Qichang Pan ◽  
Fenghua Zheng ◽  
Yanzhen Liu ◽  
Youpeng Li ◽  
Wentao Zhong ◽  
...  
Keyword(s):  
Anode Materials ◽  
Hollow Spheres ◽  
Rate Capability ◽  
Sodium Ion ◽  
Core Shell ◽  
Sodium Ion Battery ◽  
Sodium Ion Batteries ◽  
Carbon Core ◽  
Battery Anode

Heterostructured Fe1−xS@S-doped carbon hollow spheres have been prepared as sodium ion battery anode material with superior rate capability and excellent long-term cycling stability.

Hybrid porous bamboo-like CNTs embedding ultrasmall LiCrTiO4 nanoparticles as high rate and long life anode materials for lithium ion batteries

2017 ◽  
Vol 53 (6) ◽  
pp. 1033-1036 ◽  
Author(s):  
Yakun Tang ◽  
Lang Liu ◽  
Hongyang Zhao ◽  
Shasha Gao ◽  
Yan Lv ◽  
...  
Keyword(s):  
Anode Materials ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
High Rate ◽  
High Current ◽  
High Reversible Capacity ◽  
Current Densities ◽  
Long Life

Hybrid porous CNTs embedding ultrasmall LiCrTiO4 nanoparticles (6 ± 2 nm) were designed, which exhibited high reversible capacity, excellent rate capability and superior long-term cycling stability, especially at high current densities.

scholarly journals Correction: Coaxial-nanostructured MnFe2O4 nanoparticles on polydopamine-coated MWCNT for anode materials in rechargeable batteries

Nanoscale ◽  
2018 ◽  
Vol 10 (43) ◽  
pp. 20468-20468 ◽  
Author(s):  
Hyeongwoo Kim ◽  
Jong-Won Lee ◽  
Dongjin Byun ◽  
Wonchang Choi
Keyword(s):  
Anode Materials ◽  
Rechargeable Batteries ◽  
Mnfe2o4 Nanoparticles

Correction for ‘Coaxial-nanostructured MnFe2O4 nanoparticles on polydopamine-coated MWCNT for anode materials in rechargeable batteries’ by Hyeongwoo Kim et al., Nanoscale, 2018, 10, 18949–18960.

scholarly journals Improved Capacity Retention of SiO2-Coated LiNi0.6Mn0.2Co0.2O2 Cathode Material for Lithium-Ion Batteries

2019 ◽  
Vol 9 (18) ◽  
pp. 3671 ◽  
Author(s):  
Xiaoxue Lu ◽  
Ningxin Zhang ◽  
Marcus Jahn ◽  
Wilhelm Pfleging ◽  
Hans J. Seifert
Keyword(s):  
Electron Microscopy ◽  
Cathode Material ◽  
Coating Layer ◽  
Condensation Reaction ◽  
Particle Surface ◽  
Rate Capability ◽  
Lithium Ion ◽  
Shielding Effect ◽  
Sio2 Coating

Surface degradation of Ni-enriched layered cathode material Li[Ni0.6Mn0.2Co0.2]O2 (NMC622) is the main reason that leads to large capacity decay during long-term cycling. In the frame of this research, an amorphous SiO2 coating was applied onto the surface of the commercially available NMC622 powder by a wet coating process, through the condensation reaction of tetraethyl orthosilicate. The chemical composition of the coating layer was analyzed by inductively-coupled plasma. The morphology was studied by scanning electron microscopy and transmission electron microscopy. Electrochemical properties, including cyclic voltammetry, galvanostatic cycling, and rate capability measurements in a half-cell configuration, were tested to compare the electrochemical behavior of the non-coated and coated NMC622 materials. It is shown that the rate performance of the NMC622 materials is not affected by the coating layer. After 700 cycles in the range of 3.0–4.3 V at 2 C discharge, the cells with SiO2-coated NMC622 materials retained 80% of their initial capacity, which is higher than the uncoated ones (74%). Physicochemical characterizations, e.g., XRD and SEM, were performed post-mortem to reveal the stabilizing mechanism of the SiO2-coated NMC622 electrodes after long-term cycling. Based on these results, this is due to the shielding effect of the coating between the NMC622 particle surface and the liquid electrolyte, along with its scavenging effect on HF. SiO2 coating is therefore a facile surface modification method that results in potentially significant enhancement of the cyclic stability of Ni-rich NMC materials.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

scholarly journals The key role of contact time in elucidating the mechanisms of enhanced decontamination by Fe0/MnO2/sand systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Viet Cao ◽  
Ghinwa Alyoussef ◽  
Nadège Gatcha-Bandjun ◽  
Willis Gwenzi ◽  
Chicgoua Noubactep
Keyword(s):  
Contact Time ◽  
Diffusive Transport ◽  
Iron Hydroxides ◽  
Iron Corrosion ◽  
Short Term ◽  
Batch Studies ◽  
Water Decontamination ◽  
Co Precipitation

AbstractMetallic iron (Fe0) has shown outstanding performances for water decontamination and its efficiency has been improved by the presence of sand (Fe0/sand) and manganese oxide (Fe0/MnOx). In this study, a ternary Fe0/MnOx/sand system is characterized for its discoloration efficiency of methylene blue (MB) in quiescent batch studies for 7, 18, 25 and 47 days. The objective was to understand the fundamental mechanisms of water treatment in Fe0/H2O systems using MB as an operational tracer of reactivity. The premise was that, in the short term, both MnO2 and sand delay MB discoloration by avoiding the availability of free iron corrosion products (FeCPs). Results clearly demonstrate no monotonous increase in MB discoloration with increasing contact time. As a rule, the extent of MB discoloration is influenced by the diffusive transport of MB from the solution to the aggregates at the bottom of the vessels (test-tubes). The presence of MnOx and sand enabled the long-term generation of iron hydroxides for MB discoloration by adsorption and co-precipitation. Results clearly reveal the complexity of the Fe0/MnOx/sand system, while establishing that both MnOx and sand improve the efficiency of Fe0/H2O systems in the long-term. This study establishes the mechanisms of the promotion of water decontamination by amending Fe0-based systems with reactive MnOx.

Phase-transfer-assisted confinement growth of mesoporous MoS2@graphene van der Waals supraparticles for unprecedented ultrahigh-rate sodium storage

2021 ◽  
Author(s):  
Wenqian Han ◽  
Guannan Guo ◽  
Yan Xia ◽  
Jing Ning ◽  
Yuwei Deng ◽  
...  
Keyword(s):  
Transition Metal ◽  
Anode Materials ◽  
Phase Transfer ◽  
Transition Metal Dichalcogenides ◽  
Rate Capability ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Metal Dichalcogenides ◽  
Sodium Storage ◽  
Low Rate

Transition metal dichalcogenides (TMDs) are promising anode materials for sodium-ion batteries (SIBs), but suffer from low rate capability and poor cycling stability. Here, we describe our efforts in designing a...

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