Synthesis and electrochemical performance of high-capacity 0.34Li2MnO3·0.66LiMn0.63Ni0.24Co0.13O2 cathode materials using a Couette–Taylor reactor

Accepted Manuscript Title: Synthesis and Electrochemical Performance of High-capacity 0.34Li2 MnO3 ·0.66LiMn0.63 Ni0.24 Co0.13 O2 Cathode Materials using a Couette-Taylor Reactor Author: Mansoo Choi Hyun-Soo Kim Jik-Soo Kim Suk-Joon Park Young Moo Lee Bong-Soo Jin PII: DOI: Reference:

S0025-5408(14)00262-1 http://dx.doi.org/doi:10.1016/j.materresbull.2014.05.005 MRB 7449

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Please cite this article as: Mansoo Choi, Hyun-Soo Kim, Jik-Soo Kim, SukJoon Park, Young Moo Lee, Bong-Soo Jin, Synthesis and Electrochemical Performance of High-capacity 0.34Li2MnO3cdot0.66LiMn0.63Ni0.24Co0.13O2 Cathode Materials using a Couette-Taylor Reactor, Materials Research Bulletin http://dx.doi.org/10.1016/j.materresbull.2014.05.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Synthesis and Electrochemical Performance of High-capacity 0.34Li2MnO3·

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0.66LiMn0.63Ni0.24Co0.13O2 Cathode Materials using a Couette-Taylor Reactor

Mansoo Choi1,2,*, Hyun-Soo Kim1, Jik-Soo Kim3, Suk-Joon Park3, Young Moo Lee2,

Battery Research Center, Korea Electrotechnology Research Institute, Changwon

Dept. of Energy Engineering, Hanyang University, Seoul 133-791, Korea 3

Ecopro Co., LTD., Ochang 363-883, Korea

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2

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641-120, Korea

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1

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Bong-Soo Jin1

*

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Corresponding author

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E-mail address: [email protected] Graphical abstract

Highlights

► The cathode material synthesized by co-precipitation using a Couette-Taylor reactor.

► The first and second discharge capacities were measured to be 311 and

307 mAh g-1.

► The material has an excellent rate capability.

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Abstract The 0.34Li2MnO3·0.66LiMn0.63Ni0.24Co0.13O2 cathode material for the Li-ion battery is

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synthesized by co-precipitation using a Couette-Taylor reactor. Particle size analysis (PSA) and a field emission -scanning electron microscopy (FE-SEM) images show that

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the obtained precursor and cathode material exhibit a narrow particle size distribution

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and spherical shape. The structure and composition of the 0.34Li2MnO3·

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0.66LiMn0.63Ni0.24Co0.13O2 are confirmed by X-ray diffraction (XRD) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The first and second

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discharge capacities of 0.34Li2 MnO3·0.66LiMn0.63Ni0.24Co0.13O2 are measured to be

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311 and 307 mAh g-1, respectively. The material also has an excellent rate capability

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(250 and 180 mAh g-1 at 1C and 5C, respectively). In the rate capability test at 60°C, 0.34Li2MnO3·0.66LiMn0.63-Ni0.24Co0.13O2 has a higher capacity of over 210 mAh g-1 in the range 0.1C to 10C. In the cyclic performance test, the capacity retention at high temperature is over 85% after 50 cycles, which is similar to that at room temperature. The 0.34Li2MnO3·0.66LiMn0.63 Ni0.24Co0.13O2 is therefore a high-capacity material with potential for use as an electrode in Li-ion batteries. KEYWORDS : A. Mn-rich, B. co-precipitation method, C. Couette-Taylor reactor, D. high capacity, D. cathode materials.

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1. Introduction Recently, layered transition metal oxides have been investigated extensively as

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cathode materials for Li-ion batteries. In this respect, LiCoO2 is the most important commercial material because of its very good electrochemical performance. However,

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it also suffers some drawbacks such as its high cost, toxicity, and safety problems,

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which inhibit its further use in hybrid and pure electric vehicles. The identification of

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cheaper, higher-capacity, and safer layered cathode materials has been the focus of studies on cathode materials in the last decade. In this regard, solid solutions of layered

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Li2 MnO3 and LiMO2 (M=Mn, Co, Ni, etc.) have been shown to be promising

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candidates for cathode materials in Li-ion batteries, since they exhibit relatively high

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capacities, are low-cost materials, and are safer than other materials [1, 2]. Li2MnO3– LiMO2 (M= Co and Ni, etc.) can be considered as a Li-rich layered material and exhibits a high discharge capacity of more than 200 mAh g−1 when operated above 4.6 V. However, these integrated-type materials usually exhibit a high irreversible capacity in the first cycle, accompanied by gradual capacity fading during cycling [3]. Spherical particles have many advantages such as their high tap density, excellent fluidity, good dispersivity, and so on, compared with irregular particles. The charge/discharge (C/D) rate capability, electrode formation, and safety of batteries are

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mainly influenced by the particle size and morphology of the cathode materials. Batteries with high current densities could be realized by improving the mass transport

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of Li+ ions, as would be achieved with the much-reduced diffusion distance of Li+ ions in nanoparticle-based cathode materials. Therefore, the preparation of a submicron-

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sized spherical powder with a narrow size distribution and good homogeneity should

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be a useful way to obtain high-performance cathode materials for Li-ion batteries [4].

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Couette-Taylor fluid motion is an interesting and well-defined flow regime with unique flow behavior and features. Stable Couette flow motion is induced when the

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inner cylinder of two co-axial cylinders is rotated slowly. This then changes to a

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periodic unstable turbulent motion, called a Taylor vortex. A Taylor vortex provides a

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homogeneous intensity for turbulent mixing, which has many beneficial applications in crystallization, polymerization, ceramic membranes, photocatalytic reactions, precipitation, and filtration [4-10]. A Taylor vortex promotes high and uniform supersaturation around the inlet region of the Couette–Taylor reactor, which results in a narrow size distribution and uniform shape in the product suspension at the outlet. In addition, high mass transfer and homogeneous mixing in phase transformation and material synthesis were achieved by utilizing the Taylor vortex [11,12]. The Taylor

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vortex is applied to control the crystal agglomeration of nickel, cobalt, and manganese hydroxide during continuous co-precipitation.

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In this study, the Mn0.74Ni0.16Co0.10(OH)2 precursor is made by a co-precipitation method using a Couette-Taylor reactor. The 0.34Li2MnO3·0.66LiMn0.63Ni0.24Co0.13O2

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material is then synthesized from this Mn0.74Ni0.16Co0.10(OH)2 precursor. The physical

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and electrochemical characteristics are investigated by by particle size analysis (PSA),

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inductively coupled plasma atomic emission spectroscopy (ICP-AES), field-emission

cyclic performance tests.

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2. Experimental

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scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), C/D tests, and

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The synthesis of the Mn0.74Ni0.16Co0.10(OH)2 precursor was based on the reaction of metal sulfates (nickel sulfate, cobalt sulfate, and manganese sulfate) with sodium hydroxide. Nickel sulfate hexahydrate (>99 %, Daejung Co., Korea), cobalt sulfate heptahydrate (>99 %, Daejung Co., Korea), and manganese sulfate monohydrate (>99 %, Daejung Co., Korea) were used as the metal ion sources of nickel, cobalt, and manganese, respectively. Sodium hydroxide (>99%) was supplied by Aldrich, Korea. Ammonium hydroxide (28.8%, J.T. Baker., Mexico) was applied as the chelating agent for the co-precipitation. Fig.1 is synthetic scheme of the

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0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 prepared by co-precipitation method using a Couette–Taylor reactor. In the co-precipitation, the reagent molar ratio of manganese

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sulfate, nickel sulfate, and cobalt sulfate in the 2.0 M metal solution was fixed at 74:16:10. The precipitation agent solution consisted of 2.0 M sodium hydroxide and

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0.4 M ammonium hydroxide. The gap between the outer and inner cylinders was filled

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with distilled water, and co-precipitation was initiated by mixing the reactant solutions

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of the metal sulfates and the precipitation agent in the Couette-Taylor reactor. In the Couette-Taylor reactor, co-precipitation was performed at 30°C, the mean residence

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time (T) in the reactor was 50 min, and the rotation speed of the inner cylinder was

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1500 rpm. Here, solutions of the metal sulfates and precipitation agent were added into

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the Couette–Taylor reactor at 1.0 mL min-1. The brown precipitate was washed with deionized water and dried at 100°C for 24 h. Finally, the dried powder was mixed with LiOH∙H2O (>98%, Sigma-Aldrich, USA) and calcined at 500°C for 8 h and 900 °C for 6 h (heating rate of 5.0°C min-1), and then allowed to cool down naturally. Electrochemical measurements were performed with a 2032 coin-type cell. The electrode was prepared by casting a mixture of 84 wt. % of the obtained material, 8 wt. % of polyvinylidene difluoride (PVDF, Sigma-Aldrich, USA), and 8 wt. % of carbon black (Super P™, M.M.M. Carbon, Belgium) in N-methyl pyrrolidinone (NMP,

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Junsei, Japan) solvent on aluminum foil, followed by drying for 24 h at 100°C. The electrodes were pressed (600-800 kg cm-2) and punched into disks of 14 mm in

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diameter. The cells were assembled in a 2032 coin-type assembly by stacking a lithium anode, polypropylene separator (Celgard 2400™, Hoechst Celanese Corporation,

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USA) containing the liquid electrolyte, gasket, spacer disk, wave spring, and cathode

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in turn. The liquid electrolyte (Soulbrain, Korea) consisted of 1 M LiPF6 in 1:1

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ethylene carbonate (EC)/diethylene carbonate (DEC). The cells were assembled in a dry room (dew point below −55°C).

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The particle size distribution was measured with a laser diffraction analyzer

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(HYDRO-2000MU, Malvern) using water as the dispersing medium. The

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morphologies and particle sizes of the synthesized samples were analyzed using FESEM (S-4800, Hitachi, 30 kV). The XRD (PW1830, Philips, CuKα radiation, 40 kV, 30 mA) patterns were measured at a step scan rate of 0.02 ° sec-1 in the 2θ range 1080° to identify the crystalline phase of the synthesized cathode materials. Qualitative analyses were carried out with X’Pert HighScore software (Panalytical) using the records from the International Center for Diffraction Data PDF-2 database. In addition, the molar ratios of the metal elements present in the powders were evaluated by ICPAES. (IRIS DUO, Thermo Electron Corp.)

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The cells were measured for their rate capability and cycling performance using a battery tester (SERIES 4000, MACCOR, USA) in the potential range 2.0-4.6 V at

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room temperature and 60°C. Cycling performance tests were carried out at 0.1C (20 mA g-1) in the first and second cycle, whereas the other cycles were conducted at 0.5C.

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The rate capability was tested at the 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, and 10C.

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3. Results and discussion

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The co-precipitation reaction of the precursor is initiated by injecting the metalsulfate reactant solution and the precipitation and chelating agent solution into the

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Couette–Taylor reactor. The particle size distribution of the precursor according to

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reaction time is shown in Fig. 2. The product suspension has a wide particle size

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distribution and small particle size during the early stages of the co-precipitation at 3T (1T=50 min). The co-precipitated particles increase in size and a narrow particle size distribution is observed from 3T to 12T. Initially, the inside of the reactor is filled with distilled water. A stable laminar Taylor vortex flow is achieved through rotation of the inner cylinder. As the metal and precipitation solutions are added into the reactor, the laminar Taylor vortex flow changes to give unstable conditions in the reactor, because it takes time for a stable laminar Taylor vortex flow and steady state to be reached. At 12T and 15T, the particle sizes and distributions are the same, indicating that a steady-

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state condition is achieved in the continuous Couette–Taylor reactor after 12T. The precursor is obtained by filtering, washing, and drying from the co-precipitate solution

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obtained between 12T and 15T. Homogeneous mixing in the co-precipitation and material synthesis is achieved by

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use of the Couette–Taylor reactor. FE-SEM images of the synthesized precursor and

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cathode material are shown in Fig. 3. These two compounds consist of spherical

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particles of 7-8 m in size. The small particles are made using conditions of a high rotation speed and short mean residence time in the Couette–Taylor reactor. The

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spherical morphology of the hydroxide is maintained even after high-temperature

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calcination. At high magnification, it is seen that both powders are formed by the

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agglomeration of small particles of below 200 nm. The cathode material with a spherical shape and rough surface is obtained by using a shorter reaction time in the Couette–Taylor reactor. This material will absorb the electrolyte well, and is therefore expected to have a good high-rate performance. Fig. 4 shows the XRD patterns of the cathode material, which is confirmed to have a well-defined hexagonal α-NaFeO2 structure with the space group R-3m. In addition, superlattice (C2/m) ordering of Li and Mn in the transition-metal layers is confirmed by weak peaks at 2θ = 20–25°. From the XRD patterns, it is found that the cathode

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material is composed of Li2MnO3 and LiMO2 phases [13]. Table 1 summarizes the estimated structural parameters of the cathode material. The phase fractions of R-3m

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(ahex = bhex = 2.8650(4) Å and chex = 14.3007(0) Å) and C2/m (amon = 4.9417(5) Å, bmon = 8.5320(0) Å, cmon = 5.1208(4) Å, and β= 109.767(2) °) account for 66% and 34% of

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the material, respectively. As a result, the cathode material is confirmed to be

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0.34Li2MnO3·0.66LiMO2. A c/a ratio of 4.90 corresponds to cubic lattice constants

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and the c/a ratio of well-layered LiCoO2 is 4.99. Also, the clear splitting between the (0 1 8) and (1 1 0) peaks indicates that the prepared sample has a well-defined layered

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structure. The Wyckoff and unit-cell parameters are indicated in Table 2. The results

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show that the lithium occupancy on the 3b site is 100%, which means that the lithium

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layer is not contaminated by nickel or other transition metals. Therefore, the ratio of Mn, Ni, and Co in LiMO2 is indicated by the site occupancy factor (sof). The ICP is analyzed to determine the exact ratio of Mn, Ni, and Co in LiMO2. Table 3 shows the chemical compositions of the precursor and cathode material found using ICP analysis. The synthesized precursor is determined to be Mn0.738Ni0.164Co0.099(OH)2, while the cathode material is calculated to be 0.34Li2MnO3·0.66Li1.006Mn0.629 Ni0.241Co0.130O2. Fig. 5 (a) shows the first and second charge/discharge curves of 0.34Li2MnO3· 0.66LiMn0.63Ni0.24-Co0.13O2 at room temperature, obtained at a constant current rate of

10 Page 10 of 26

20 mA g−1 (0.1C) in the voltage range 2.0-4.6 V. The first charging capacity of 110 mAh g-1, observed below 4.45 V, is associated with the oxidations of Ni+2 to Ni+4 and

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Co+3 to Co+4, which are linked to the theoretical capacities of 91 and 23 mAh g-1, respectively [15,16]. The long plateau starting at about 4.5 V is attributed to the

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simultaneous removal of lithium and oxygen from the oxide material. However, this

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4.5 V plateau is not observed for the second charge. Note that this voltage plateau is

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consistent with the electrochemical activation of the Li2MnO3 component. The first and second discharge capacities of 0.34Li2 MnO3·0.66LiMn0.63 Ni0.24Co0.13O2 are

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measured as 311 and 307 mAh g-1, respectively, and the initial coulombic efficiency is

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83.0%. Ito et al. reported a capacity of 290 mAh g-1 for Li[Ni0.17Li0.2Co0.07Mn0.56]O2

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[2]. Therefore, 0.34Li2MnO3·0.66LiMn0.63 Ni0.24Co0.13O2 has a higher capacity than Li[Ni0.17Li0.2Co0.07Mn0.56]O2.

Fig.6 (a) shows the discharge curves of 0.34Li2 MnO3·0.66LiMn0.63Ni0.24Co0.13O2 at room temperature as a function of the C-rate from 2.0 to 4.6 V. For this test, the cell is charged galvanostatically at 0.1CC (constant current) with 0.02CV (constant voltage) and then discharged at C- rates ranging from 0.1C to 10C (20-2000 mA g-1). In the discharge curves from 0.1C to 2C, the capacity decreases at around 3.5 V. This capacity is influenced by activated MnO2. In our previous experiment, we confirmed

11 Page 11 of 26

discharge profile of Li2MnO3, LiMO2, and spinel phase manganese oxide. The capacity of near the 3.5V is capacity of activated MnO2 from Li2 MnO3. These results show that

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the activation MnO2 is poor rate capability [16, 17]. Also, the capacities at over 5C decrease in all areas of the discharge curve. The capacity of the cathode material is

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measured to be 250 and 180 mAh g-1 at the 1C and 5C rates, respectively. The reasons

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for the good high-rate performance are regarded to be the small particle size, the

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spherical shape, and the rough surface. These results show that the morphology of this cathode material provides good mass transport and a short diffusion distance for Li+

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ions. Fig. 6 (b) shows the rate capability of the 0.34Li2 MnO3·0.66LiMn0.63

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Ni0.24Co0.13O2 cathode material at room temperature and 60°C. At 60°C, the cathode

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material has a higher capacity of over 210 mAh g-1 in the range 0.1C to 10C. The capacity retention is not affected by temperature at low rates. The cathode material shows moderate capacity fading as the applied current density increases; the capacity retentions at room temperature and 60°C at 5C (1000 mA g-1) are 62.9% and 74.7%, respectively.

Fig. 8 shows the cycling performances of the 0.34Li2 MnO3· 0.66LiMn0.63Ni0.24Co0.13O2 cathode material operated at room temperature and 60°C. Li2 MnO3-based materials have the disadvantage of Mn dissolution at high

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temperatures, which leads to capacity fading. In charged states at elevated temperature, PF6- ions are apt to reduce to PF5-, and therefore Mn4+ ions are more apt to reduce

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Mn3+, as follows: LiPF6 → PF5 + e-

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Mn4+ + e- → Mn3+

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This is why Mn dissolution is accelerated at elevated temperatures, whilst

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simultaneously spinel turns into defective spinels with Mn4+ [16]. The capacity retention at 60°C is measured as over 85% after 50 cycles which is similar to that

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found at room temperature. This result shows that 0.34Li2MnO3·0.66LiMn0.63

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4. Conclusions

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Ni0.24Co0.13O2 is a stable cathode material at high temperatures.

The 0.34Li2MnO3·0.66LiMn0.63Ni0.24Co0.13O2 material was synthesized though a coprecipitation method using a Couette–Taylor reactor. The obtained cathode material had a narrow particle size distribution, spherical shape, and rough surface. The composition of 0.34Li2 MnO3 to 0.66LiMn0.63Ni0.24Co0.13O2 was verified by ICP-AES and Rietveld refinement. From the electrochemical tests, 0.34Li2MnO3· 0.66LiMn0.63Ni0.24 Co0.13O2 was confirmed to have a high capacity and good rate capability. The cathode material synthesized using the Couette–Taylor reactor showed

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good mass transport and a short diffusion distance for Li+ ions, and exhibited a good cyclic performance at high temperatures.

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Acknowledgements This research was supported by a grant from the Energy Technology R&D Program

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of the Ministry of Knowledge and Economy, Korea (No. 2008-11-0055).

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References

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[1] J.H. Jeong, B.S. Jin, W. S. Kim, G. Wang, H.S Kim, J. Power Sources 196 (2011) 3439-3442.

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[2] A. Ito, D. Li, Y. Sato, M. Arao, M. Watanabe, M. Hatano, H. Horie, Y.

d

Ohsawa, J. Power Sources 195 (2010) 567-573.

Ac ce pt e

[3] J.H. Lim, H. Bang, K.S. Lee, K. Amine, Y. K. Sun, J. Power Sources 189 (2008) 353-358.

[4] T. Wang, Z.H. Liu, L. Fan, Y. Han, X. Tang, Powder Technol. 187 (2008) 124129.

[5] A.T. Nguyen, J.M. Kim, S.M. Chang, W.S. Kim, Ind. Eng. Chem. Res. 49 (2010) 4865-4872. [6] W.M. Jung, S.H. Kang, K.S. Kim, W.S. Kim, C. Kyun Choi, J. Cryst. Growth 312 (2010) 3331-3339.

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[7] K. Kataoka, N. Ohmura, M. Kouzu, Y. Simamura, M. Okubo, Chem. Eng. Sci. 50 (1995) 1409-1413.

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[8] E. Dluska, J. Wolinski, S. Wronski, Chem. Eng. & Technol. 28 (2005) 10161021.

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[9] J.G. Sczechowski, C.A. Koval, R.D. Noble, Chem. Eng. Sci. 50 (1995) 3163-

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3173.

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[10]R.L.C. Giordano, R.C. Giordano, C.L. Cooney, Process Biochem. 35 (2000) 1093-1101.

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[11]H. Yu, H. Kim, Y. Wang, P. He, D. Asakura, Y. Nakamura, H. Zhou, Phys.

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Chem. Chem. Phys. 14 (2012) 6584-6595.

Ac ce pt e

[12]K. Kataoka, N. Ohmura, M. Kouzu, Y. Simamura, M. Okubo, Chem. Eng. Sci. 50 (1995) 1409-1413.

[13]M. M. Thackeray , C. S. Johnson , J. T. Vaughey , N. Li and S. A. Hackney J. Mater. Chem. 15 (2005) 2257-2267.

[14]S. H. Kang, P. Kempgens, S. Greenbaum, A. J. Kropf, K. Amine, M. M. Thackeray, J. Mater. Chem. 17 (2007) 2069-2077. [15]S. H. Kang, V. G. Pol, I. Belharouak, M. M. Thackeray, J. Electrochem. Soc. 157 (2010) A267-A271.

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[16]O.K Park, Y. Cho, S. Lee, H-C Yoo, H-K Song, J. Cho, Energy Environ. Sci., 4,(2011) 1621-1633.

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[17]J. Cho, J. Mater. Chem., 18, 2008, 2257-2261. Figure captions

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Fig. 1. Synthetic scheme of the 0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 prepared by

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co-precipitation method using a Couette–Taylor reactor.

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Fig. 2. Particle size distribution of Mn0.74Ni0.16Co0.10(OH)2 according to mean residence time.

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Fig. 3. FE-SEM images of synthesized Mn0.74Ni0.16Co0.10(OH)2 precursor (a, b) and

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0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 cathode material (c, d).

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Fig. 4. XRD pattern of 0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 cathode material. Fig. 5. 1st and 2nd charge and discharge curves of 0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 cathode material.

Fig. 6. Discharge capacity curve at room temperature (a) and rate capability (capacity: solid line; capacity retention: broken line) at room temperature and 60°C (b) of 0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 cathode material. Fig. 7. The initial charge/discharge curves of Li2 MnO3-LiMO2 as a function of Li excess.

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Fig. 8. Cycling performance of 0.34Li2 MnO3∙0.66LiMn0.63Ni0.24Co0.13O2 cathode material at room temperature and 60°C.

c [Å]

β [°]

γ [°]

Volume [Å3]

109.7672

90

203.1(8)

90

120

101.6(6)

c/a

α [°]

-

90 90

Li2MnO3 4.9417(5) 8.5320(0) 5.1208(4)

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LiMO2 2.8650(4) 2.8650(4) 14.3007(0) 4.9915

cr

b [Å]

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a [Å]

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Table 1 Structural parameters of Li2MnO and LiMO2 in 0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2.

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R profile (1.963), Rexp (1.085), Rwp (3.546), Profile function (Pseudo voigt)

Table 2 Unit-cell parameters of Li2MnO and LiMO2 in

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0.34Li2MnO3∙0.66LiMn0.63Ni0.24Co0.13O2. Component

Li2MnO3

LiMO2

Element

Wyckoff

x

y

z

sof

O

8j

0.254

0.32119

0.2233

1

O

4i

0.2189

0

0.2273

1

Li

4h

0

0.3394

0.5

1

Li

2c

0

0

0.5

1

Li

2b

0

0.5

0

1

Mn

4g

0

0.16708

0

1

O

6c

0

0

0.25933

1

Li

3b

0

0

0.50107

1

Mn

3a

0

0

0

0.62879

Co

3a

0

0

0

0.1303

Ni

3a

0

0

0

0.24091

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Table 3 Chemical compositions of the prepared powders from ICP analysis results.

Precursor

Ni

Co

Chemical compositions

0.738 0.164 0.099

1.344 0.755 0.159 0.086

Mn0.738Ni0.163Co0.099(OH)2 0.34Li2MnO3∙0.66Li1.006Mn0.629Ni0.241Co0.13 0 O2

Ac ce pt e

d

M

an

us

cr

Cathode material

-

Mn

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Li

18 Page 18 of 26

Ac ce pt e

d

M

an

us

cr

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Figures

Fig. 1.

.

19 Page 19 of 26

ip t cr us an M

Ac ce pt e

d

Fig. 2.

20 Page 20 of 26

ip t cr us an M

Ac ce pt e

d

Fig. 3.

21 Page 21 of 26

ip t cr us an

Ac ce pt e

d

M

Fig. 4.

22 Page 22 of 26

ip t cr us an M

Ac ce pt e

d

Fig. 5.

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ip t cr us an M d Ac ce pt e Fig. 6.

24 Page 24 of 26

ip t cr us

Ac ce pt e

d

M

an

Fig. 7

25 Page 25 of 26

ip t cr us an M

Ac ce pt e

d

Fig. 8.

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