Transition‐Metal‐Free Magnesium‐Based Batteries Activated by Anionic Insertion into Fluorinated Graphene Nanosheets

Xie, Junjie; Li, Chilin; Cui, Zhonghui; Guo, Xiangxin

doi:10.1002/adfm.201503010

Cited by 69 publications

(63 citation statements)

References 41 publications

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“…[1][2][3][4][5] The layered 2D nature of graphene in particular allows a multitude of possibilities for the application of its fluorinated derivatives for, e.g., sensors, [6,7] energy storage, [8][9][10][11] or nanoelectronic [12,13] components. [1][2][3][4][5] The layered 2D nature of graphene in particular allows a multitude of possibilities for the application of its fluorinated derivatives for, e.g., sensors, [6,7] energy storage, [8][9][10][11] or nanoelectronic [12,13] components.…”

Section: Fluorographenementioning

confidence: 99%

“…This implies potentially significant qualitative and quantitative differences in the device response. [1][2][3][4][5] The layered 2D nature of graphene in particular allows a multitude of possibilities for the application of its fluorinated derivatives for, e.g., sensors, [6,7] energy storage, [8][9][10][11] or nanoelectronic [12,13] components. Considering the electrical conductivity of individual mono-and fewlayer flakes, it is dominated by the type, amount, and bonding position (basal or edge) of functional groups attached to the C(sp 2 ) matrix.…”

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confidence: 99%

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Electrical Transport in Devices Based on Edge‐Fluorinated Graphene

Koleśnik-Gray

Sysoev

Gollwitzer

et al. 2018

Adv Elect Materials

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When considering fluorinated graphene (FG)-based functional device technology, the device architectures must be chosen adequately. Typically, functionalized graphene devices can be envisaged as either large scale (area)-based thin film structures or as systems integrated from individual nanoobjects. This implies potentially significant qualitative and quantitative differences in the device response. Specifically, the presence of edges in graphene can be decisive. Considering the electrical conductivity of individual mono-and fewlayer flakes, it is dominated by the type, amount, and bonding position (basal or edge) of functional groups attached to the C(sp 2 ) matrix. In thin film-based systems, however, the charge transport also is largely affected by the properties of edge/edge, edge/plane, and plane/plane junctions. [22] Therefore, electrical characterization is a primary means to evaluate and benchmark whether or not a given derivative meets the requirements for selected applications.In the present work we study the impact of F content and bonding position on the electronic properties of graphene fluorinated by BrF 3 vapor at room temperature [8,20] in the range of 2.4-16.6 at%. We compared the electrical conductivity of thin films with the conductivity of corresponding individual FG flakes which constitute the former. We found a significant difference in the conductivity dependence on the degree of fluorination for the two device architectures: While in the case of thin films, a strong decrease in conductivity with fluorine content was observed, individual flakes showed an increase in conductivity and exhibited graphene-like bipolar transfer characteristics with electron and hole mobilities of the order of few 1000s cm 2 V −1 s −1 for F content approaching 17 at%. With further aid of scanning electron and Raman microscopy, this qualitative difference between films and single flakes was attributed to the circumstance that the preferred sites for fluorination are at the edges rather than basal planes of the FG.For the characterization of thin film devices, 3 mm long and 1 mm wide structures were defined using a hard-mask technique (Figure 1a). FG dispersions were sprayed onto Si wafers with 300 nm thermal SiO 2 on top, resulting in homogeneous and continuous films (Figure 1b), which were then electrically contacted with conducting silver paste. For electrical characterization of individual flakes, small amounts of the dispersionsThe conductivity of few-and monolayer graphene with covalently bound moieties is a key-point in the potential application of these materials in any electrical and optoelectronic device. In particular, fluorination of such graphene-based systems is of interest, as fluorine is expected to have a strong influence on the charge-carrier density due to its high electronegativity, and therefore modify the electrical transport properties significantly. Here it is shown that, depending on the device architecture, the electrical properties of fluorinated graphene-based devices are significantly d...

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Section: Fluorographenementioning

confidence: 99%

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confidence: 99%

Electrical Transport in Devices Based on Edge‐Fluorinated Graphene

Koleśnik-Gray

Sysoev

Gollwitzer

et al. 2018

Adv Elect Materials

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“…reported for the chloride ion battery system (VOCl/MgCl 2 ) a signal at 517.6 eV in the vanadium 2p 3/2 region and assigned it to an oxidation state +IV (VOCl 2 ) . Recently, Xie et al ., observed an anionic intercalation (ClO 4 − ) into fluorinated graphene nanosheets during first charge and a change in the electrochemistry of the battery after the initial discharge/charge step . VOCl was also investigated as electrode material for chloride‐ion batteries therefore exhibiting anionic (Cl − ) shuttle between anode and cathode .…”

Section: Resultsmentioning

confidence: 99%

Interlayer‐Expanded Vanadium Oxychloride as an Electrode Material for Magnesium‐Based Batteries

et al. 2017

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Mg‐based batteries, which use the Mg2+ shuttle, theoretically offer several advantages compared to the Li technology, such as higher theoretical volumetric capacity (3833 mA h cm−3) of the Mg‐metal anode, the possibility to be safely handled in air, and dendrite‐free electrodeposition. In this study, vanadium oxychloride was employed as an electrode material in a Mg‐based battery. As the cell delivered just 45 mA h g−1 in the first cycle, we tried to improve the delivered capacity through preliminary cycling of the VOCl electrode with Li. The strategy is based on the ability of VOCl to expand its interlayer spacing upon intercalation of ions or molecules within them. In fact, a VOCl electrode with expanded interlayer spacing should facilitate the intercalation of Mg2+, thus leading to higher specific capacities. The Li pretreatment was able to promote the specific capacity by a factor of four (170 mA h g−1) after the first discharge at 298 K. Over 130 mA h g−1 was retained at 5 mA g−1 after 70 cycles. Structural and electrochemical characterization was carried out by means of galvanostatic charge/discharge tests, cyclic voltammetry, ex situ X‐ray photoelectron spectroscopy, X‐ray diffraction, transmission electron microscopy coupled with energy‐dispersive X‐ray spectroscopy, and electron energy loss spectroscopy. Inductively coupled plasma optical emission spectrometry was used to determine the concentration of lithium in the electrode.

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“…Application of FG in batteries still provokes research interest [130] , [131] , [132] , [133] , [134] , [135] . Recently, the application of FG was extended as a very effective electrode separator in Li-sulfur batteries in order to prevent the migration of polysulfides to the Li anode [136] , and as an effective cathode in Mg batteries [137] . The interesting electrochemical properties of FG initiated its study as electrode material for supercapacitors [48] .…”

Section: Applicationsmentioning

confidence: 99%