Graphene‐Encapsulated Fe 3 O 4 Nanoparticles with 3D Laminated Structure as Superior Anode in Lithium Ion Batteries

Zhang

Journal of Colloid and Interface Science

et al. 2013

a b s t r a c tGraphene/NiAl layered double-hydroxide (LDH) composite with high capacitive properties has been prepared in a friendly one-step process. It is found that NiAl-LDH is formed in the addition of precipitator agent (NaOH and NaNO 3 ) by hydrothermal method, at the same time graphene oxide (GO) is reduced to graphene. The morphology and structure of the obtained material are examined by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), transmission electron microscope (TEM), and scanning electron microscope (SEM) techniques. It is revealed that the NiAl-LDH disperses well on the surface of graphene and the formation of NiAl-LDH nanoparticles is beneficial to the peeling of graphene (RGO). More importantly, the addition of NiAl-LDH to graphene endows the materials with desirable specific surface areas and higher porosity. These structural advantages result in higher specific capacitance compared with pristine graphene. Electrochemical property investigations show that the graphene/NiAl-LDH had a higher specific capacitance than graphene.Crown

Section: Introductionmentioning

confidence: 99%

Preparation and capacitance properties of graphene/NiAl layered double-hydroxide nanocomposite

Zhang

Journal of Colloid and Interface Science

et al. 2013

“…At the same time, previously reported graphene-containing alloy (e.g., Sn, [ 144 ] SnO 2 [145][146][147][148][149] or Si [150][151][152][153] ), conversion (e.g., Fe 3 O 4 , [154][155][156][157] Co 3 O 4 [158][159][160][161] or CuO [162][163][164] ) and insertion (e.g., TiO 2 [165][166][167][168] or LTO [169][170][171] ) hybrids were further improved. Interestingly, some appealing approaches, such as the use of ternary hybrids (e.g., RGO/SnO 2 /Fe 3 O 4 [ 172 ] or RGO/CNT/ Sn [ 173 ] ), porous 3D (e.g., RGO/Fe 3 O 4 [ 174,175 ] ) and hollow architectures (e.g., RGO/Fe 3 O 4 [ 176 ] and RGO/TiO 2 [ 168 ] ), were introduced. In all these cases, however, only modest improvements (especially in terms of cycling stability) were observed with respect to the reports published few years before.…”

mentioning

confidence: 99%

Critical Insight into the Relentless Progression Toward Graphene and Graphene‐Containing Materials for Lithium‐Ion Battery Anodes

et al. 2016

that its extraordinary properties would enable revolutionary new technologies, which gave birth to the "graphene era". [ 3,4 ] Relying on this scenario, in 2013, the European Union launched the ¤1 billion "Graphene Flagship" project aimed to investigate the properties of this new form of carbon for various applications (e.g., electronics, sensors and energy storage devices), with the ambitious goal of guiding graphene from laboratories to commercial applications within a decade. [ 5,6 ] In the same period, the Chinese Government set up a similar investment to mass-produce graphene as thin fi lms (e.g., for touchscreen electrodes) and platelets (e.g., for use in batteries). [ 6 ] In the following years, hundreds of patents, mainly focused on manufacturing and application in energy storage, were fi led and the worldwide production of graphene and graphene-containing materials rapidly increased. Although a few Chinese industries claimed to already use graphene-containing materials for smartphone production, no revolutionary practical application relying on graphene has been yet developed. [ 6 ] Specifi cally with respect to the battery fi eld, a close analysis of the scientifi c literature reveals a struggle to meet the ambitious initial targets. A potential loss of focus from the fi nal application caused by hype and ease of publication on such a novel matter, together with the delivery of very misleading information [ 7,8 ] and erroneous statements [ 7 ] concerning the use of graphene in batteries are emerging as possible reasons of the ineffective graphene-era outburst. In this progress report, we do not focus on production and classifi cation of graphene and graphene-containing materials, which were already well reported in the past years. [ 3,[9][10][11] In contrast, due to the lack of an exhaustive analysis of the progression of the use of such materials in lithium-ion battery (LIB) anodes, we report here a critical evaluation of the most prominent research papers published from 2008 until the end of 2015. As shown in Figure 1 , three different stages of the graphene research in LIB anodes can be distinguished: a fi rst stationary phase between 2008 and 2010 where the lithium-ion storage properties of different graphene and graphene-containing materials were preliminarily explored, a second exponential stage, spanning from 2010 to 2014, where graphene and graphene-containing anode materials were broadly developed and investigated, and fi nally, a third phase, (i.e., starting from 2015), where the research seems to have approached a plateau. After Used as a bare active material or component in hybrids, graphene has been the subject of numerous studies in recent years. Indeed, from the fi rst report that appeared in late July 2008, almost 1600 papers were published as of the end 2015 that investigated the properties of graphene as an anode material for lithium-ion batteries. Although an impressive amount of data has been collected, a real advance in the fi eld still seems to be missing. In this framework, atten...

“…The oxidation peak around 1.87 V in the anodic scan can be ascribed to the oxidation of Fe 0 to Fe3O4 [13,20]. In the successive scans, the anodic and cathodic peaks are both shifted and the peak intensity drops significantly, corresponding to polarization of the electrode [40]. In addition, the CV curves of the post two cycles approximately overlap, implying good invertibility.…”

Section: Li-ion Battery Performancementioning

confidence: 93%

Filling and unfilling carbon capsules with transition metal oxide nanoparticles for Li-ion hybrid supercapacitors: towards hundred grade energy density

Liu

Gao

et al. 2017

Sci. China Mater.

Li-ion hybrid supercapacitors (Li-HECs) facilitate effective combination of the advantages of supercapacitors and Li-ion batteries (LIBs). However, challenges remain in designing and preparing suitable anode and cathode materials, which often require tedious and expensive procedures. Herein, we demonstrated that hollow N-doped carbon capsules (HNC) with and without a Fe3O4 nanoparticle core can respectively function as the anode and the cathode in very-high-performance Li-HECs. The Fe3O4@NC anode exhibited a high reversible specific capacity exceeding 1530 mA h g −1 at 100 mA g −1 and excellent rate capability (45% capacity retention from 0.1 to 5 A g −1 ) and cycle stability (>97% retention after 100 cycles). Moreover, high rate performance was achieved in a full-cell using the HNC cathode. By combining the respective structural advantages of the components, the hybrid device with Fe3O4@NC//HN C exhibited a remarkable energy density of 185 W h kg −1 at a power density of 39 W kg −1 . The hybrid device furnished a battery-inaccessible power density of 28 kW kg −1 with rapid charging/discharging within 9 s at an energy density of 95 W h kg −1 .