Ultrahigh capacity anode material for lithium ion battery based on rod gold nanoparticles decorated reduced graphene oxide

    Ultrahigh capacity anode material for lithium ion battery based on rod gold nanoparticles decorated reduced graphene oxide Necip Atar, Tanju Eren, Mehmet L¨utfi Yola PII: DOI: Reference:

S0040-6090(15)00745-2 doi: 10.1016/j.tsf.2015.07.075 TSF 34537

To appear in:

Thin Solid Films

Received date: Revised date: Accepted date:

16 October 2014 30 July 2015 30 July 2015

Please cite this article as: Necip Atar, Tanju Eren, Mehmet L¨ utfi Yola, Ultrahigh capacity anode material for lithium ion battery based on rod gold nanoparticles decorated reduced graphene oxide, Thin Solid Films (2015), doi: 10.1016/j.tsf.2015.07.075

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ACCEPTED MANUSCRIPT Ultrahigh capacity anode material for lithium ion battery based on rod gold

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nanoparticles decorated reduced graphene oxide

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Department of Chemical Engineering, Pamukkale University, Denizli, Turkey Department of Metallurgical and Materials Engineering, Sinop University, Sinop, Turkey

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b

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Necip Atara,*, Tanju Erena, Mehmet Lütfi Yolab

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ABSTRACT

In this study, we report the synthesis of rod shaped gold nanoparticles/2-

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aminoethanethiol functionalized reduced graphene oxide composite (rdAuNPs/AETrGO) and

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its application as an anode material for lithium-ion batteries. The structure of the rdAuNPs/AETrGO composite was characterized by scanning electron microscopy,

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transmission electron microscopy, x-ray photoelectron spectroscopy and x-ray diffraction. The electrochemical performance was investigated at different current rates by using a coin-

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type cell. It was found that the rod shaped gold nanoparticles were highly dispersed on the reduced graphene oxide sheets. Moreover, the rdAuNPs/AETrGO composite showed a high specific gravimetric capacity of about 1320 mAh g−1 and a long-term cycle stability.

Keywords: Reduced graphene oxide, metal nanoparticle, anode, Li ion battery

∗Corresponding

author. E-mail: [email protected]; [email protected] (N. Atar)

ACCEPTED MANUSCRIPT 1. Introduction In recent years, the rechargeable and high performance batteries have been considered

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as promising research area due to the developments in the portable electronics and electric

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vehicles. Due to the global warming and the exhaustion of fossil fuels, the need of clean

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energy is important. There have been many reports about high energy density and long cycle life of energy storage devices [1-4]. The lithium-ion batteries (LIBs) have been applied as an important power source owing to their high operating voltage and high energy density [5].

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LIBs enable to improve the energy and the power density for different kind of applications

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such as portable electronic devices, power tools and electric vehicles [6-8]. Currently, considering the need to replace the high energy consumption derived from fossil fuel [9], the LIBs represent one of the most important storage system for the energy derived from

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renewable sources [10, 11]. The improved LIBs must possess higher electrical/ionic conductivity, cycling stability, rate capability and lower cost than other LIBs applications.

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The performance of LIBs depends on the cathode and anode materials. In this respect, the carbon nanotubes [12], carbon fibers [13] and graphene [14, 15] could benefit the LIBs in

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terms of cycle stability and specific capacity [16]. The graphene and reduced graphene oxide (rGO) have different investigations on electrochemical energy storage [17], biosensors [1822] and electronics [23, 24]. Furthermore, rGO has been proposed as a potential electrode material for LIBs because of its flexibility [25], chemical structure [26], electrical conductivity [27] and high surface area [28]. In addition, functionalized carbon materials with nanoparticles such as silver, iron and gold [18, 29-32] are investigated as anode materials to increase the performance of LIBs [33, 34]. The critical factors on the performance of LIBs are the architecture of the composites, size and shape of the nanoparticles and surface properties. There are various nanoparticles with different shapes and sizes. In our previous study, we used rod shaped gold nanoparticle (rdAuNPs) as a highly efficient electrocatalyst because of

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ACCEPTED MANUSCRIPT their surface area, electrocatalytic properties and density properties [35]. In this study, rdAuNPs have been anchored on 2-aminoethanethiol functionalized rGO sheets to synthesize

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an innovative graphene-based composite (rdAuNPs/AETrGO) which has been tested as anode

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active material for LIBs. scanning electron microscopy (SEM), transmission electron

cyclic

voltammetry (CV)

were

used

to

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microscopy (TEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD) and characterize

the

rGO,

rdAuNPs,

and

rdAuNPs/AETrGO composites. The electrochemical performances of the rGO, rdAuNPs, and

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different current rates in a coin-type cell.

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rdAuNPs/AETrGO composites were measured for charge/discharge specific capacities at

2. Experimental details 2.1. Apparatus and reagents

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Li metal foil (99.9%, 150 µm, Sigma-Aldrich), isopropyl alcohol (Sigma–Aldrich), ascorbic acid (Sigma–Aldrich), cetyl trimethylammonium bromide (Sigma–Aldrich), gold(III)

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chloride trihydrate (Sigma–Aldrich), sodium borohydrate (Sigma–Aldrich), acetonitrile (Sigma–Aldrich), activated carbon (Sigma–Aldrich), 2-aminoethanethiol (Sigma–Aldrich),

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carbon black (Merck), polyvinylidene fluoride (Sigma–Aldrich), N-methyl-2-pyrrolidone (Sigma–Aldrich), copper (Cu) foil (19 µm), lithium hexafluorophosphate (Merck), ethylene carbonate (Merck), dimethyl carbonate (Merck), sulfuric acid (Merck), potassium persulfate (Merck), phosphorus pentoxide (Merck), graphite powder (Merck), potassium permanganate (KMnO4, Merck), hydrogen peroxide (Merck), ethanol (Merck), hydrochloric acid (Sigma– Aldrich), N-(3-dimethylaminopropyl)-N´-ethylcarbodiimidehydrochloride (EDC, SigmaAldrich) were reagent grade and used as received. The ultra-pure water with resistance of 18.3 MΩ cm (Human Power 1+ Scholar purification system) was used in the experiments of aqueous media.

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ACCEPTED MANUSCRIPT TEM measurement was performed on a JEOL 2100 HRTEM instrument (JEOL Ltd., Japan) with an accelerating voltage of 200 kV. ZEISS EVO 50 SEM (GERMANY) analytic

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microscopy with an accelerating voltage of 3.0 kV was used to investigate the morphology of

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rdAuNPs/AETrGO composite. XPS analysis was performed on a PHI 5000 Versa Probe (Φ

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ULVAC-PHI, Inc., Japan/USA) model with monochromatized Al Kα radiation (1486.6 eV) as an X-ray anode operated at 50 W. To prepare the sample, one drop of the prepared rdAuNPs/AETrGO solution was placed on clear glass and then dried in air. A Rigaku

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Miniflex X-ray diffractometer (Japan) with mono-chromatic CuKα radiation operating at a voltage of 30 kV and current of 15 mA was used for X-ray diffraction measurement of the

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sample. A scanning speed of 2°2θ/min and a step size of 0.02° were used to examine the samples in the range of 30–80°2θ. Electrochemical impedance spectroscopy (EIS)

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measurements were carried out with a Biologic VSP electrochemical workstation in the frequency range of 100 kHz–0.01 Hz at a zero-bias potential with pulse amplitude of 10 mV

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and potential of 100 mV.

2.2. Preparation of rdAuNPs

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rdAuNPs were prepared by mixing 0.1 M cetyl trimethylammonium bromide solution (7.5 mL) with 0.01 M gold(III) chloride trihydrate solution (250 μL). After 600 μL of 0.01 M ice-cold sodium borohydrate was added to this solution, the resulting solution was allowed to form nanoparticle solution. After that, 250 μL of 0.1 M ascorbic acid was added slowly to the resulting solution. This final mixture was mixed for 15 s and was allowed to stay for 2 h at room temperature [36]. 2.3. Synthesis of rGO Graphene oxide was prepared by the modified Hummers method [18]. Typically, 2.5 g of graphite powder were placed in a flask containing a mixture of 12.5 mL of H2SO4 (98%), 2.5 g of potassium persulfate and 2.5 g of phosphorus pentoxide. The mixture was kept at 80

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ACCEPTED MANUSCRIPT C for 6 h. Then, the mixture was cooled to room temperature and added with 500 mL of ultra-pure water. The product was filtered and washed with ultra-pure water and 125 mL of

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H2SO4 (98%) was added at 0 C. Later, 15 g of KMnO4 were added to the stirring suspension

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which was kept at 20 C. After the feeding of KMnO4 was finished, the flask was heated to 50

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°C. After 4 h, 500 mL of ultra-pure water were added to the mixture in an ice bath. The last mixture was stirred for 2 h and diluted to 1 L with ultra-pure water. After that, the suspension was fed slowly with 20 mL of hydrogen peroxide (30%) and the solution started bubbling.

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The color of the suspension changed to brilliant yellow from brownish. The synthesized

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graphite oxide was filtered and washed with 0.1 M hydrochloric acid and ultra-pure water three times. The graphite oxide was collected by an ultracentrifuge.

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The as-prepared graphene oxide was dispersed into 200 mL water under mild

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ultrasound. After that, 4 mL of hydrazine hydrate (80 wt%) were added and the solution was heated in an oil bath at 100 °C under a water-cooled condenser for 24 h. After the reaction,

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the prepared rGO product was collected by vacuum filtration. 2.4. Preparation of rdAuNPs/AETrGO composite

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The preparation of rdAuNPs/AETrGO composite is shown in Scheme 1. rGO was dissolved in ethanol at 2 mg mL-1. The mixture was sonicated to form a homogeneous suspension. The prepared rGO suspension was treated with 0.2 M of EDC solution for 8 h to ensure the surface activation of residual carboxyl groups. EDC compound provides the most popular and versatile method for labeling or crosslinking to free carboxylic groups on rGO [37]. The EDC molecules are considered zero-length carboxyl-to-amine cross-linkers. EDC reacts with carboxylic acid groups to form an active intermediate product that is easily displaced by nucleophilic attack from primary amino groups in the reaction mixture. Therefore we used EDC for activation of free carboxylic acid groups of rGO. Then 1.0 mM 2aminoethanethiol was mixed with the activated rGO suspension at a 1:1 volume ratio and kept 4

ACCEPTED MANUSCRIPT stirring for 2 h (AETrGO). After that, 1 mg mL-1 of rdAuNPs solution was mixed with the 0.1 mg mL-1 of AETrGO solution at a 1:1 volume ratio. Finally, the mixture was sonicated to

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generate a homogeneous mixture (rdAuNPs/AETrGO).

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Here Scheme 1

2.5. Electrochemical Measurements

The electrochemical experiments of rGO, rdAuNPs and rdAuNPs/AETrGO

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composites as anode materials were investigated using a coin-type cell. lithium

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hexafluorophosphate were used as electrolyte solution in all experiments. The materials were prepared and attached on cells in an Ar-filled glove box. The rGO, rdAuNPs and rdAuNPs/AETrGO composites were mixed at a weight ratio of 8:1 with carbon black to

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enhance the conductivity for each material. NMP was used as a solvent to make a slurry mixture. The mixtures were pasted uniformly onto Cu foils as anode electrodes and the

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cathode electrode was a lithium metal foil. The process of lithiation/delithiation of rdAuNPs/AETrGO /Cu electrode is shown in Scheme 1. The working electrodes were dried at

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70 oC in a vacuum oven and pressed under a pressure around 10 MPa. Celgard 2600 was used as a separator. The electrochemical performance of rGO, rdAuNPs and rdAuNPs/AETrGO electrodes was investigated by galvanostatic charge–discharge measurements with a computer-controlled battery tester at room temperature between the voltage ranges of 3.0-0.1 V. 3. Results and discussion 3.1. Characterization of rdAuNPs/AETrGO nanocomposite The morphology of rdAuNPs/AETrGO composite is shown in Fig. 1. Fig 1A presents TEM image of the rdAuNPs with an average length of 20–25 nm on rGO sheets. It can be seen that the rdAuNPs have distributed on rGO sheets. The rdAuNPs/AETrGO composite has

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ACCEPTED MANUSCRIPT been modified on Cu foil surface and Fig 1B shows the layered structure of the rdAuNPs/AETrGO composite.

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Here Fig. 1.

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The structure of rdAuNPs/AETrGO composite was also determined by XRD

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measurements. The XRD pattern of rdAuNPs/AETrGO composite is shown in Fig. 2. The intense and narrow peaks at 2θ = 33.8º and 48.2º refers to the (002) and (004) planes of rGO sheets, respectively [38]. The characteristic peaks of rdAuNPs also have been observed. The

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two main peaks at 2θ = 36.3º and 44.7º are corresponded to the (111) and (200) planes of Au,

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respectively. The weak peaks at 2θ = 66.4º and 73.1º are also (220) and (311) planes of Au, respectively and proves the presence of Au in the composite [30]. Here Fig. 2.

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XPS results (Fig. 3) were obtained to examine the formation of rdAuNPs/AETrGO composite. The C1s core-level spectrum was curve-fitted and the peaks at 283.1, 284.3 and

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285.6 eV were corresponded to C-H, C-N and -CONH, respectively. S2p spectrum was curvefitted with two components by a doublet 2p1/2 and 2p3/2 signals. The peak at 162.6 eV

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confirmed that the gold nanoparticles were grafted to S atoms. The peak observed at 164.8 eV has shown the unreacted thiol group in AET [18]. N1s narrow region spectrum was curvefitted and the peak observed at 398.7 eV was corresponded to the N–H groups of amide that occurs due to the reaction of rGO’s carboxyl groups and AET’s amino groups. The peak at 402.5 eV was assigned to the unreacted N-H groups of AET. As seen in Fig.3, the Au4f7/2 peak at 83.3 eV confirms the presence of bonded Au. It is also possible that the signal at 88.1 eV is due to electrically unreacted Au nanoparticles [18]. Here Fig. 3.

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ACCEPTED MANUSCRIPT 3.2. Electrochemical performance rdAuNPs/AETrGO in LIB The rate capability of a battery can be affected by various factors such as charge-

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transfer resistance, mass-transfer resistance and ohmic resistance. It is generally known that

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small sized nanoparticles deposited on carbon materials such as rGO provide high specific

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surface area and fast redox reactions, which can reduce the charge transfer resistance [39]. The curves of first cycle charge and discharge of graphite, rGO, rdAuNPs and rdAuNPs/AETrGO anodes at 0.1 C rate between 0.01 and 3.0 voltages of Li+/Li are shown in

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Fig. 4. The specific charge and discharge capacities for graphite anode are 261 mAh g-1 and 123 mAh g-1, respectively. The rdAuNPs anode shows specific charge capacity of 762 mAh gand discharge capacity of 258 mAh g-1. The specific charge capacity of rdAuNPs/AETrGO

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anode is much higher at 1500 mAh g−1, which demonstrates that the rdAuNPs/AETrGO

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nanocomposite as an anode material in respect to the graphite, rGO and rdAuNPs significantly reduced the diffusion resistance of the lithium ions in the LiPF6 electrolyte and

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increased the specific capacities and conductivity of the electrode [40, 41]. The nanoparticle size affects the high-rate performance and the charge transfer resistance can be reduced by

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using rdAuNPs on the electrode surface to shorten the diffusion path. According to the results, the rdAuNPs/AETrGO electrode improves the specific discharge capacity with 1320 mAh g−1. The rdAuNPs composite decreased diffusion resistance of lithium ion and rGO support increased the conductivity in the composite material. Here Fig. 4. Fig. 5 represents initial 50 charge/discharge curves at 0.1 C rate corresponding to 100 mA g−1 of the as-prepared rdAuNPs/AETrGO anode in coin-type test cells using lithium foil as the counter and reference electrodes between 0.01 and 3.0 V (vs. Li +/Li). In Fig. 5, a voltage plateau around 0.75 V (vs. Li/Li+) was observed with a specific capacity of ca. 1500 mAh g−1 at the first lithiation, which corresponds to the electrolyte decomposition and solid

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ACCEPTED MANUSCRIPT electrolyte interface (SEI) formation [42]. When the ionic host SEI forms, a multi-layer structure with a thickness of 100-150 nm was observed. Cu foil was used with thickness of 19

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µm. After modification of rdAuNPs/AETrGO composite, the thickness was controlled at the

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same value. Due to the thickness of SEI layer, the modified rdAuNPs/AETrGO /Cu electrode

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has a large specific surface area. As seen in Fig. 5, the large irreversible capacity loss after the 1st cycle is related to the large specific surface area of rdAuNPs/AETrGO composite and the SEI on the electrode [43]. The maximum theoretical capacity of graphite is 372 mAh g-1. The

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reversible capacity of the rdAuNPs/AETrGO composite in the first cycle is much higher than

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the theoretical capacity of graphite. The reason of the extra capacity for the first cycle over theoretical value results from the formation of SEI film on the surface of rdAuNPs/AETrGO composite. Furthermore, the presence of unsaturated carbon atoms on the rdAuNPs/AETrGO

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composite may catalyze the electrolyte decomposition [44]. Here Fig. 5.

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The electrochemical behaviors of the rdAuNPs/AETrGO in Li ion cell were characterized by CV as shown in Fig. 6 for the initial 50 cycles [45, 46]. The anodic scan

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shows a peak at around 1100 mV which is corresponded to the oxidation reaction of Au0. From the first to the fiftieth cycle, slight changes in the current densities and the positions of the oxidation peaks are attributed to polarization due to the electronic resistance of active rdAuNPs/AETrGO composite. In addition, the interfacial kinetic resistance against intercalation/extraction represents that the composite electrode has good reversibility of the oxidation reaction of Au0. On the other hand, the cathodic scan causes a peak at around 850 mV and can be attributed to the electrochemical reduction of Au+ ions with lithium in the electrode. It is clearly seen that there is a little difference between the first and the subsequent cycles. For the first cycle, a sharp cathodic peak appears at about 850 mV, which is associated with the electrolyte decomposition to form SEI films and the reduction of Au+ ions. In the

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ACCEPTED MANUSCRIPT subsequent cycles, this strong peak completely decreased, indicating no more irreversible SEI formation of electrolyte. From the subsequent cycles, the redox peaks occur at around 865

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mV, attributed to the reversible electrochemical reduction of Au+ ions with lithium in the

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Here Fig. 6.

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electrode.

The capacity value of 1320 mAh g−1 for rdAuNPs/AETrGO composite is much higher than that of the rdAuNPs and rGO. Hence, the rGO plays very important roles as a support in

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the enhanced electrical conductivity of the anode material. The high charge–discharge

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specific capacity of the rdAuNPs/AETrGO electrode indicates that the contact between rdAuNPs and rGO is very efficient to resist the changes in the volume of rdAuNPs. The rGO provides the cushion-like effect during lithium ion insertion and desertion. Hence, it

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contributes greatly to the enhancement of electrochemical property. The remarkable performance reveals the beneficial effects of well-deposited rdAuNPs on the rGO surface.

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Furthermore, the enhanced lithium storage properties can be also attributed to the small effective diffusion length associated with the well-dispersed rdAuNPs on the rGO surface.

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The ability to charge and discharge Li-ion batteries at higher rate is important in practical use. We also have investigated the electrochemical performance of the rGO, rdAuNPs and rdAuNPs/AETrGO electrodes by changing rates of charge–discharge current densities. Fig. 7 shows the specific capacities of rGO, rdAuNPs and rdAuNPs/AETrGO in a range of 0.1–1.0 C. The capacity decreased with increasing charge/discharge rate and the specific capacity of 614 mAh g-1 was measured at a current rate of 1.0 C for rdAuNPs/AETrGO material. On the other hand, the specific capacity decreases quickly at 0.1 C current rate for the rdAuNPs and it was observed as 271 mAh g−1 for the current rate of 1.0 C. The capacity of 253 mAh g−1 for the rGO electrode was observed at the same rate. The grafting of rdAuNPs

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ACCEPTED MANUSCRIPT on the surface of rGO provides positive effects such as increasing of the stability of rdAuNPs and active groups of the rdAuNPs on the surface for Li ions.

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Here Fig. 7.

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EIS measurements were performed for rdAuNPs/AETrGO anode before and after 50

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cycles of charge and discharge at 0.1 C rate. The representative nyquist plot in the frequency range of 100 kHz–0.01 Hz is shown in Fig. 8. The impedance spectra have a similar semicircle shape in the moderate–high frequency region and sloping line at the low frequency

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range (Fig. 8). The high-frequency semicircle is corresponded to the solid electrolyte interface

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(SEI) layer resistance RSEI. The middle-frequency semicircle is related to the charge transfer resistance Rct. The inclined line at the low frequency accounts for characteristic Warburg behavior related to the mass transfer resistance of Li-ion within the electrode material [47].

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The stability of the electrode by confining the active rdAuNPs on the rGO support is considered to its low RSEI value. A lower Rct value after cycling can explain its good cycling

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stability and rate capability. In addition, a low R SEI value is also beneficial for the reversible cycling of the electrode. Furthermore, as a result of lower charge-transfer resistance and

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intimate contact between rdAuNPs and rGO, lithium ion diffusion and electron transfer are facilitated to give the enhanced electrochemical performance of the rdAuNPs/AETrGO composite.

Here Fig. 8. According the electrochemical results, the properties of the improved lithium storage are resulted from the smaller diffusion length of lithium and the well-dispersed rdAuNPs on rGO sheets. The rGO sheets as a support have good dispersion and increasing stability of the rdAuNPs. Hence, the well-dispersed rdAuNPs may assure a smaller and effective diffusion length improving the performance of LIBs. As a result, high lithium storage, great cycling and rate performance are realized by the rdAuNPs/AETrGO composite. Additionally, the stability

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ACCEPTED MANUSCRIPT of the Cu foil modified with rdAuNPs/AETrGO was also investigated. After one month, the current response is maintaining at approximate 94.68% of the original value, suggesting the

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very promising performance for the future of Li ion batteries.

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4. Conclusion

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We have synthesized rdAuNPs on AET functionalized rGO to use as an anode in LIBs. The synthesized nacomposite is characterized by SEM, TEM, XPS and XRD. Electrochemical results and EIS measurements confirm that the rdAuNPs/AETrGO anode in

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LIBs significantly improves the performance and remains stable even after 50 cycles. The

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high electrochemical performance and specific capacity of 1320 mAh g−1 of rdAuNPs/AETrGO composite is attributed to the small size and dispersion of rdAuNPs on rGO sheets. The rGO plays a significant role in development of the storage capacity, cycle

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life, and rate capability of the anode electrode. This study demonstrates the

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rdAuNPs/AETrGO has a high performance and cycle life as an anode in LIBs.

Acknowledgement

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The authors would like to thank Pamukkale University and Sinop University for support.

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ACCEPTED MANUSCRIPT References [1] I. Hong, M. Angelucci, R. Verrelli, M.G. Betti, S. Panero, F. Croce, C. Mariani, B.

T

Scrosati, J. Hassoun, Electrochemical characteristics of iron oxide nanowires during lithium-

IP

promoted conversion reaction, Journal of Power Sources, 256 (2014) 133-136.

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[2] J. Hassoun, F. Bonaccorso, M. Agostini, M. Angelucci, M.G. Betti, R. Cingolani, M. Gemmi, C. Mariani, S. Panero, V. Pellegrini, B. Scrosati, An advanced lithium-ion battery based on a graphene anode and a lithium iron phosphate cathode, Nano Letters, 14 (2014)

NU

4901-4906.

MA

[3] M. Agostini, D.J. Lee, B. Scrosati, Y.K. Sun, J. Hassoun, Characteristics of Li2S8tetraglyme catholyte in a semi-liquid lithium-sulfur battery, Journal of Power Sources, 265 (2014) 14-19.

TE

D

[4] I. Cameán, P. Lavela, J.L. Tirado, A.B. García, On the electrochemical performance of anthracite-based graphite materials as anodes in lithium-ion batteries, Fuel, 89 (2010) 986-

CE P

991.

[5] L. Lu, X. Han, J. Li, J. Hua, M. Ouyang, A review on the key issues for lithium-ion

AC

battery management in electric vehicles, Journal of Power Sources, 226 (2013) 272-288. [6] J. Lee, P. Kumar, J. Lee, B.M. Moudgil, R.K. Singh, ZnO incorporated LiFePO4 for high rate electrochemical performance in lithium ion rechargeable batteries, Journal of Alloys and Compounds, 550 (2013) 536-544. [7] H.K. Song, K.T. Lee, M.G. Kim, L.F. Nazar, J. Cho, Recent progress in nanostructured cathode materials for lithium secondary batteries, Advanced Functional Materials, 20 (2010) 3818-3834. [8] Z. Li, L. Wang, K. Li, D. Xue, LiMn2O4 rods as cathode materials with high rate capability and good cycling performance in aqueous electrolyte, Journal of Alloys and Compounds, 580 (2013) 592-597.

12

ACCEPTED MANUSCRIPT [9] H. Park, A design of air flow configuration for cooling lithium ion battery in hybrid electric vehicles, Journal of Power Sources, 239 (2013) 30-36.

T

[10] Z.S. Wu, G. Zhou, L.C. Yin, W. Ren, F. Li, H.M. Cheng, Graphene/metal oxide

IP

composite electrode materials for energy storage, Nano Energy, 1 (2012) 107-131.

SC R

[11] Y. Liu, D. Liu, Q. Zhang, G. Cao, Engineering nanostructured electrodes away from equilibrium for lithium-ion batteries, Journal of Materials Chemistry, 21 (2011) 9969-9983. [12] M. Shafiei, A.T. Alpas, Electrochemical performance of a tin-coated carbon fibre

NU

electrode for rechargeable lithium-ion batteries, Journal of Power Sources, 196 (2011) 7771-

MA

7778.

[13] R. Yuge, N. Tamura, T. Manako, K. Nakano, K. Nakahara, High-rate charge/discharge properties of Li-ion battery using carbon-coated composites of graphites, vapor grown carbon

TE

D

fibers, and carbon nanohorns, Journal of Power Sources, 266 (2014) 471-474. [14] W. Yue, S. Yang, Y. Liu, X. Yang, A facile synthesis of mesoporous graphene-tin

CE P

composites as high-performance anodes for lithium-ion batteries, Materials Research Bulletin, 48 (2013) 1575-1580.

AC

[15] X. Zhu, Y. Zhong, H. Zhai, Z. Yan, D. Li, Nanoflake nickel hydroxide and reduced graphene oxide composite as anode materials for high capacity lithium ion batteries, Electrochimica Acta, 132 (2014) 364-369. [16] L. Su, Y. Jing, Z. Zhou, Li ion battery materials with core-shell nanostructures, Nanoscale, 3 (2011) 3967-3983. [17] K.S. Novoselov, V.I. Fal'Ko, L. Colombo, P.R. Gellert, M.G. Schwab, K. Kim, A roadmap for graphene, Nature, 490 (2012) 192-200. [18] M.L. Yola, T. Eren, N. Atar, A novel and sensitive electrochemical DNA biosensor based on Fe@Au nanoparticles decorated graphene oxide, Electrochimica Acta, 125 (2014) 38-47.

13

ACCEPTED MANUSCRIPT [19] M.L. Yola, V.K. Gupta, T. Eren, A.E. Şen, N. Atar, A novel electro analytical nanosensor based on graphene oxide/silver nanoparticles for simultaneous determination of

T

quercetin and morin, Electrochimica Acta, 120 (2014) 204-211.

IP

[20] B.J. Sanghavi, W. Varhue, J.L. Chávez, C.F. Chou, N.S. Swami, Electrokinetic

SC R

preconcentration and detection of neuropeptides at patterned graphene-modified electrodes in a nanochannel, Analytical Chemistry, 86 (2014) 4120-4125.

[21] B.J. Sanghavi, P.K. Kalambate, S.P. Karna, A.K. Srivastava, Voltammetric

NU

determination of sumatriptan based on a graphene/gold nanoparticles/Nafion composite

MA

modified glassy carbon electrode, Talanta, 120 (2014) 1-9. [22] B.J. Sanghavi, O.S. Wolfbeis, T. Hirsch, N.S. Swami, Nanomaterial-based electrochemical sensing of neurological drugs and neurotransmitters, Microchimica Acta, 182

TE

D

(2014) 1-41.

[23] Y.U. Jung, S.I. Oh, S.H. Cho, H.K. Kim, S.J. Kang, Electromechanical properties of

CE P

graphene transparent conducting films for flexible electronics, Current Applied Physics, 13 (2013) 1331-1334.

AC

[24] E. Cobas, A.L. Friedman, O.M.J. Van'T Erve, J.T. Robinson, B.T. Jonker, Graphene as a tunnel barrier: Graphene-based magnetic tunnel junctions, Nano Letters, 12 (2012) 30003004.

[25] Y. Zhang, S. Wang, L. Li, K. Zhang, J. Qiu, M. Davis, L.J. Hope-Weeks, Tuning electrical conductivity and surface area of chemically-exfoliated graphene through nanocrystal functionalization, Materials Chemistry and Physics, 135 (2012) 1057-1063. [26] S. Yu, Y. Jiang, C. Wang, A polymer composite consists of electrochemical reduced graphene oxide/polyimide/chemical reduced graphene oxide for effective preparation of SnSe by electrochemical atomic layer deposition method with enhanced electrochemical performance and surface area, Electrochimica Acta, 114 (2013) 430-438.

14

ACCEPTED MANUSCRIPT [27] Y.S. Ye, X.L. Xie, J. Rick, F.C. Chang, B.J. Hwang, Improved anode materials for lithium-ion batteries comprise non-covalently bonded graphene and silicon nanoparticles,

T

Journal of Power Sources, 247 (2014) 991-998.

IP

[28] Z. Zeng, H. Zhao, J. Wang, P. Lv, T. Zhang, Q. Xia, Nanostructured Fe3O4@C as anode

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material for lithium-ion batteries, Journal of Power Sources, 248 (2014) 15-21. [29] M.L. Yola, T. Eren, N. Atar, Molecularly imprinted electrochemical biosensor based on Fe@Au nanoparticles involved in 2-aminoethanethiol functionalized multi-walled carbon

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nanotubes for sensitive determination of cefexime in human plasma, Biosensors and

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Bioelectronics, 60 (2014) 277-285.

[30] M.L. Yola, N. Atar, A novel voltammetric sensor based on gold nanoparticles involved in p-aminothiophenol functionalized multi-walled carbon nanotubes: Application to the

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simultaneous determination of quercetin and rutin, Electrochimica Acta, 119 (2014) 24-31. [31] H. Karimi-Maleh, F. Tahernejad-Javazmi, A.A. Ensafi, R. Moradi, S. Mallakpour, H.

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Beitollahi, A high sensitive biosensor based on FePt/CNTs nanocomposite/N-(4hydroxyphenyl)-3,5-dinitrobenzamide modified carbon paste electrode for simultaneous

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determination of glutathione and piroxicam, Biosensors and Bioelectronics, 60 (2014) 1-7. [32] H. Karimi-Maleh, F. Tahernejad-Javazmi, V.K. Gupta, H. Ahmar, M.H. Asadi, A novel biosensor for liquid phase determination of glutathione and amoxicillin in biological and pharmaceutical samples using a ZnO/CNTs nanocomposite/catechol derivative modified electrode, Journal of Molecular Liquids, 196 (2014) 258-263. [33] R. Ghosh Chaudhuri, S. Paria, Core/shell nanoparticles: Classes, properties, synthesis mechanisms, characterization, and applications, Chemical Reviews, 112 (2012) 2373-2433. [34] K. Sridharan, T. Endo, S.G. Cho, J. Kim, T.J. Park, R. Philip, Single step synthesis and optical limiting properties of Ni-Ag and Fe-Ag bimetallic nanoparticles, Optical Materials, 35 (2013) 860-867.

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ACCEPTED MANUSCRIPT [35] V.K. Gupta, M.L. Yola, T. Eren, N. Atar, Selective QCM sensor based on atrazine imprinted polymer: Its application to wastewater sample, Sensors and Actuators, B: Chemical,

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218 (2015) 215-221.

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[36] B. Nikoobakht, M.A. El-Sayed, Preparation and growth mechanism of gold nanorods

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(NRs) using seed-mediated growth method, Chemistry of Materials, 15 (2003) 1957-1962. [37] L. Stobinski, B. Lesiak, A. Malolepszy, M. Mazurkiewicz, B. Mierzwa, J. Zemek, P. Jiricek, I. Bieloshapka, Graphene oxide and reduced graphene oxide studied by the XRD,

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TEM and electron spectroscopy methods, Journal of Electron Spectroscopy and Related

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Phenomena, 195 (2014) 145-154.

[38] P. Bradder, S.K. Ling, S. Wang, S. Liu, Dye adsorption on layered graphite oxide, Journal of Chemical and Engineering Data, 56 (2011) 138-141.

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[39] J. Du, C.H. Chen, Structure and lithium ion diffusion in lithium silicate glasses and at their interfaces with lithium lanthanum titanate crystals, Journal of Non-Crystalline Solids,

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358 (2012) 3531-3538.

[40] C.S. Cheng, W.R. Liu, F.M. Wang, A novel ionic host solid electrolyte interface

425-431.

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formation on reduced graphene oxide of lithium ion battery, Electrochimica Acta, 106 (2013)

[41] S.W. Han, D.W. Jung, J.H. Jeong, E.S. Oh, Effect of pyrolysis temperature on carbon obtained from green tea biomass for superior lithium ion battery anodes, Chemical Engineering Journal, 254 (2014) 597-604. [42] X. Xiao, P. Liu, J.S. Wang, M.W. Verbrugge, M.P. Balogh, Vertically aligned graphene electrode for lithium ion battery with high rate capability, Electrochemistry Communications, 13 (2011) 209-212. [43] S.A. Webb, L. Baggetto, C.A. Bridges, G.M. Veith, The electrochemical reactions of pure indium with Li and Na: Anomalous electrolyte decomposition, benefits of FEC additive,

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ACCEPTED MANUSCRIPT phase transitions and electrode performance, Journal of Power Sources, 248 (2014) 11051117.

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[44] S. Mustansar Abbas, S. Tajammul Hussain, S. Ali, N. Ahmad, N. Ali, S. Abbas, Z. Ali,

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Modification of carbon nanotubes by CuO-doped NiO nanocomposite for use as an anode

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material for lithium-ion batteries, Journal of Solid State Chemistry, 202 (2013) 43-50. [45] W. Xiao, Z. Wang, H. Guo, X. Li, J. Wang, S. Huang, L. Gan, Fe2O3 particles enwrapped by graphene with excellent cyclability and rate capability as anode materials for

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lithium ion batteries, Applied Surface Science, 266 (2013) 148-154.

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[46] S. Zhao, Y. Bai, Q. Chang, Y. Yang, W. Zhang, Surface modification of spinel LiMn2O4with FeF 3 for lithium ionbatteries, Electrochimica Acta, 108 (2013) 727-735. [47] M.S. Kim, D. Bhattacharjya, B. Fang, D.S. Yang, T.S. Bae, J.S. Yu, Morphology-

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dependent Li storage performance of ordered mesoporous carbon as anode material,

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Figure Captions

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Langmuir, 29 (2013) 6754-6761.

Scheme 1. Schematic diagram of the synthesis and modification of rdAuNPs/AETrGO composite on Cu foil and Lithiation-Delithiation sites. Figure 1. (A) TEM image of

rdAuNPs/AETrGO composite, (B) SEM image of

rdAuNPs/AETrGO /Cu electrode. Figure 2. XRD pattern of the rdAuNPs/AETrGO composite. Figure 3. XPS spectra of rdAuNPs/AETrGO composite. Figure 4. Typical charge/discharge curves at 0.1 C of graphite, rGO, rdAuNPs and rdAuNPs/AETrGO as anode for the first cycle. Figure 5. Typical charge/discharge curves at 0.1 C of rdAuNPs/AETrGO as anode for the first 50 cycles. 17

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Figure 7. The rate capability of rdAuNPs/AETrGO , rdAuNPs and rGO electrodes.

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Figure 8. EIS measurements of rdAuNPs/AETrGO anode before and after 50

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ACCEPTED MANUSCRIPT Highlights > We prepared rod shaped gold nanoparticles functionalized reduced graphene oxide

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> The nanocomposite exhibited a long-term cycle stability.

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> The nanocomposite showed a high specific gravimetric capacity of about 1320 mAh g−1

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