scholarly journals Confining TiO2 Nanotubes in PECVD-Enabled Graphene Capsules Toward Ultrafast K-Ion Storage: In Situ TEM/XRD Study and DFT Analysis

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingsheng Cai ◽  
Ran Cai ◽  
Zhongti Sun ◽  
Xiangguo Wang ◽  
Nan Wei ◽  
...  
Keyword(s):  
Rate Capability ◽  
Chemical Vapor ◽  
Potassium Ion ◽  
In Situ Tem ◽  
Practical Applications ◽  
Ion Storage ◽  
Wide Availability ◽  
Storage Behavior ◽  
Storage Technologies

AbstractTitanium dioxide (TiO2) has gained burgeoning attention for potassium-ion storage because of its large theoretical capacity, wide availability, and environmental benignity. Nevertheless, the inherently poor conductivity gives rise to its sluggish reaction kinetics and inferior rate capability. Here, we report the direct graphene growth over TiO2 nanotubes by virtue of chemical vapor deposition. Such conformal graphene coatings effectively enhance the conductive environment and well accommodate the volume change of TiO2 upon potassiation/depotassiation. When paired with an activated carbon cathode, the graphene-armored TiO2 nanotubes allow the potassium-ion hybrid capacitor full cells to harvest an energy/power density of 81.2 Wh kg−1/3746.6 W kg−1. We further employ in situ transmission electron microscopy and operando X-ray diffraction to probe the potassium-ion storage behavior. This work offers a viable and versatile solution to the anode design and in situ probing of potassium storage technologies that is readily promising for practical applications.

Porous CoC2O4/Graphene Oxide Nanocomposite for Advanced Potassium-Ion Storage

2019 ◽  
Vol 19 (6) ◽  
pp. 3610-3615 ◽  
Author(s):  
Lifeng Wang ◽  
Kaiyuan Wei ◽  
Pengjun Zhang ◽  
Hong Wang ◽  
Xiujun Qi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lithium Ion Batteries ◽  
Low Cost ◽  
Rate Capability ◽  
Lithium Ion ◽  
Potassium Ion ◽  
Practical Applications ◽  
Ion Storage ◽  
Cheap Method ◽  
Excellent Cycling Stability

Potassium-ion batteries (PIBs), as one of the alternatives to lithium-ion batteries (LIBs), have attracted considerable attention on account of the affluence and low-cost of potassium. Moreover, CoC2O4 and graphene oxide (GO) have been used very well in lithium-ion batteries. Hence, the hybrid CoC2O4/GO was investigated as a new anode material for PIBs. The hybrid CoC2O4/GO was synthesized by a facile and cheap method combined with supersonic dispersion. Electrochemical measurements reveal that the hybrid CoC2O4/GO delivered an excellent cycling stability of 166 mAh g−1 at 50 mA g−1 and a superior rate capability even at 1 A g−1. These results demonstrate although the cycle ability was insufficient for practical applications, transition-metal oxalates composites can still bring new hope to the development of PIBs.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

In situ formed robust submicron-sized nanocrystalline aggregates enable highly-reversible potassium ion storage

Nano Energy ◽  
2021 ◽  
pp. 106233
Author(s):  
Kuan-Ting Chen ◽  
Yi-Chun Yang ◽  
Lian-Ming Lyu ◽  
Ming-Yen Lu ◽  
Hsing-Yu Tuan
Keyword(s):  
Potassium Ion ◽  
Ion Storage

Revealing a conversion-alloying reaction mechanism behind high capacity and rate capability of SnS/N-doped graphene anode by in situ TEM

2019 ◽  
Vol 297 ◽  
pp. 46-54 ◽  
Author(s):  
Libing Yao ◽  
Meng Nie ◽  
Chongyang Zhu ◽  
Ran Cai ◽  
Weiwei Xia ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
High Capacity ◽  
Rate Capability ◽  
In Situ Tem ◽  
Doped Graphene

In-Situ Characterization of Carbon Nanotube-Polystyrene Composite Deformation

2000 ◽  
Vol 6 (S2) ◽  
pp. 40-41
Author(s):  
D. Qian ◽  
E. C. Dickey ◽  
R. Andrews ◽  
T. Rantell ◽  
B. Safadi
Keyword(s):  
Carbon Nanotubes ◽  
Load Transfer ◽  
Electronic Materials ◽  
Composite Films ◽  
Chemical Vapor ◽  
Ex Situ ◽  
In Situ Tem ◽  
Multiwalled Carbon ◽  
Young’S Moduli

Carbon nanotubes (NTs) have novel electronic properties and exceptionally high Young's moduli on the order of TPa. so NTs have potential applications in advanced composite materials such as conductive polymers, electromagnetic-radio frequency interference (EMI/RFI) shielding material and opto-electronic materials. The utility of the nanotubes in composite applications depends strongly on the ability to disperse the NTs homogeneously throughout the matrix without destroying the integrity of the NTs. Furthermore, interfacial bonding between the NT and matrix is necessary to achieve load transfer across the interface, which is desirable for improving the mechanical properties of polymer composites.In this work, aligned multiwalled carbon nanotubes (MWNTs) produced by continuous chemical vapor deposition (CVD) (see Fig.l), were homogeneously dispersed in polystyrene (PS) matrices by a simple solution-evaporation method. Using this procedure, we made uniform MWNT-PS composite films ∼0.4mm thick for ex-situ mechanical tensile test and very thin films, ∼100nm, for in-situ TEM tests, as shown in Fig.2.

Fast and stable potassium-ion storage achieved by in situ molecular self-assembling N/O dual-doped carbon network

2019 ◽  
Vol 23 ◽  
pp. 46-54 ◽  
Author(s):  
Jiafeng Ruan ◽  
Yahui Zhao ◽  
Sainan Luo ◽  
Tao Yuan ◽  
Junhe Yang ◽  
...  
Keyword(s):  
Potassium Ion ◽  
Self Assembling ◽  
Ion Storage ◽  
Carbon Network

Fast lithium-ion storage of Nb2O5 nanocrystals in situ grown on carbon nanotubes for high-performance asymmetric supercapacitors

RSC Advances ◽  
2015 ◽  
Vol 5 (51) ◽  
pp. 41179-41185 ◽  
Author(s):  
Xiaolei Wang ◽  
Ge Li ◽  
Ricky Tjandra ◽  
Xingye Fan ◽  
Xingcheng Xiao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
High Performance ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Energy ◽  
Asymmetric Supercapacitors ◽  
Ion Storage ◽  
Energy And Power Density

Nanocomposites of Nb2O5 NCs in situ grown on CNTs are successfully developed with excellent rate capability, leading to the successful fabrication of asymmetric supercapacitors with high energy and power density and long-term cycling stability.

Introducing a conductive pillar: a polyaniline intercalated layered titanate for high-rate and ultra-stable sodium and potassium ion storage

2020 ◽  
Vol 56 (60) ◽  
pp. 8392-8395 ◽  
Author(s):  
Jiaying Liao ◽  
Qiao Hu ◽  
Jinxiao Mu ◽  
Fei Chen ◽  
Xiaodong He ◽  
...  
Keyword(s):  
Potassium Ion ◽  
High Rate ◽  
Layered Titanate ◽  
Ion Storage ◽  
Sodium And Potassium

An in situ formed polyaniline pillared layered titanate with uniform TiO2 coating for sodium and potassium ion storage is proposed.

Boosting the potassium-ion storage performance of a carbon anode by chemically regulating oxygen-containing species

2019 ◽  
Vol 55 (94) ◽  
pp. 14147-14150 ◽  
Author(s):  
Rui Zhang ◽  
Haibo Li ◽  
Rui Li ◽  
Denghu Wei ◽  
Wenjun Kang ◽  
...  
Keyword(s):  
Rate Capability ◽  
Reversible Capacity ◽  
Potassium Ion ◽  
Cycling Stability ◽  
Carbon Anode ◽  
Storage Performance ◽  
Ion Storage ◽  
Melamine Foam

The oxygen-containing species in melamine foam carbons are chemically regulated. The optimized carbon anode shows an enhanced potassium-ion storage performance in terms of reversible capacity, rate capability, and long-term cycling stability.

Zero-strain K0.6Mn1F2.7 hollow nanocubes for ultrastable potassium ion storage

2018 ◽  
Vol 11 (10) ◽  
pp. 3033-3042 ◽  
Author(s):  
Zhiwei Liu ◽  
Ping Li ◽  
Guoquan Suo ◽  
Sheng Gong ◽  
Wei (Alex) Wang ◽  
...  
Keyword(s):  
Rate Capability ◽  
Potassium Ion ◽  
Cycling Stability ◽  
New Class ◽  
Ion Storage

In this report, we develop a new etching route to fabricate a new class of zero-strain potassium fluoromanganate hollow nanocubes (KMnF-NCs) for boosting the performance of KIBs in terms of capacity, rate capability and cycling stability.

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