DC-bias and visible light effect on dielectric characteristics of La_(0.5)Cr_(0.5)TiO_(3+δ)

La_(0.5)Cr_(0.5)TiO_(3+δ) ceramic sample was prepared via traditional solid-state reaction route. Frequency and temperature dependence of dielectric permittivity were studied in the range of 10~2~ 10~6 Hz and of 77 ~360 K, respectively. It was observed that extraordinarily high low-frequency dielectric constants appeared at room temperature, and dielectric relaxation peaks shifted to higher temperature with increasing frequency. In the dc-bias studies, it was also found that the dielectric permittivity had obviously dc-bias dependence in low frequency, but independence as the frequency above 14 kHz. Interestingly, the dielectric characteristics of the sample had obvious light dependence at room temperature within the measured frequency range. The results demonstrate that visible light improves the dielectric properties of the ceramic by means of I–V and complex impedance analysis.     

Transport dynamics analysis in ferromagnetic heterojunction using Raman spectroscopy and magnetic force microscopy

The ZnO/La_(0.7)Sr_(0.3)MnO_3 thin fi lm was epitaxially fabricated on La Al O3(100) by pulse laser deposition.The Raman scattering on the single layer La Sr Mn O and junction ZnO/La_(0.7)Sr_(0.3)MnO_3 was investigated in a giant softening by 490 cm~(-1)John-Teller, 620 and 703cm~(-1) optical phonon modes. The Raman spectra La Sr Mn O and ZnO/La_(0.7)Sr_(0.3)MnO_3 were observed with distinct features, i.e., the thickness was in dependent of frequency and intensity. The dynamics results showed that the spin–orbital coupling was caused by anomalies tilt of Mn O6 octahedron. The LSMO/Zn O junction exhibited excellent junction positive magneto-resistance behavior in the temperature range of 77–300 K. The kinetic energy gain was achieved by orbital competition, strong crystal fi eld and charge order of energy band splitting. The transport orbits were in the environment of the ferromagnetic-orbital ordering. The structures of barriers could be adjusted by junction interface and domain boundary condition in terms of the presence of spin–orbital fl uctuating.     

Effect of B sites on the catalytic activities for perovskite oxides La_(.6)Sr_(.4)Co_xFe_(1-x)O_(3-δ) as metal-air batteries catalysts

The effect of B sites on the catalytic activities of oxygen evolution reaction(OER)for perovskite oxides La_(0.6)Sr_(0.4)Co_xFe_(1-x)O_(3-δ)(x=0,0.2,0.4,0.6,0.8,1,denoted as LSF,LSCF-28,LSCF-46,LSCF-64,LSCF-82 and LSC,respectively)prepared by a convenient and simple method of electrospinning technique is reported.The prepared La_(0.6)Sr_(0.4)Co_xFe_(1-x)O_(3-δ)catalysts possess almost same crystal structures,similar morphologies(except for the LSC catalyst)and slightly different BET surface areas.Upon the optimization of the Co/Fe atomic ratio,the optimal LSCF-82 catalyst exhibits the OER performance with a low onset potential of 1.541 V,a small Tafel slope of 80.56 mV dec~(-1),a high charge-transfer rate and a large electrochemical surface area in 0.1 M KOH solution.LSCF-82 catalyst exhibits the long-term stability under the catalytic operation condition for 12 h.Such catalytic activity may mainly cause by the synergy of higher catalytic activity Co and lower catalytic activity Fe.Thus,the reasonable optimization of the transition metal composition in B sites for the perovskite oxides is in favor of the improvement of OER performance.     

A new synthetic route to MgO–MgAl_2O_4–ZrO_2 highly dispersed composite material through formation of Mg_5Al_(2.4)Zr_(1.7)O_(12) metastable phase:synthesis and physical properties

Mg_5Al_(2.4)Zr_(1.7)O_(12) metastable phase was successfully synthesized from analytical-grade Mg O,α-Al_2O_3,MgAl_2O_4,and ZrO_2 under an N_2 atmosphere.The sintering temperature was varied from 1650 to 1780°C,and the highest amount of Mg_5Al_(2.4)Zr_(1.7)O_(12) appeared in the composite material when the sintering temperature was 1760°C.According to our research of the formation mechanism of Mg_5Al_(2.4)Zr_(1.7)O_(12),the formation and growth of MgAl_2O_4 dominated when the temperature was not higher than 1650°C.When the temperature was higher than 1650°C,MgO and ZrO_2 tended to diffuse into MgAl_2O_4 and the Mg_5Al_(2.4)Zr_(1.7)O_(12) solid solution was formed.When the temperature reached 1760°C,the formation of Mg_5Al_(2.4)Zr_(1.7)O_(12) was completed.The effect of Mg Al_2O_4 spinel crystals was also studied,and their introduction into the composite material promoted the formation and growth of Mg_5Al_(2.4)Zr_(1.7)O_(12).A highly dispersed MgO–Mg Al_2O_4–ZrO_2 composite material was prepared through the decomposition of the Mg_5Al_(2.4)Zr_(1.7)O_(12) metastable phase.The as-prepared composite material showed improved overall physical properties because of the good dispersion of MgO,MgAl_2O_4,and ZrO_2 phases.     

Evolution of plasticized MnO–Al_2O_3–SiO_2-based nonmetallic inclusion in 18wt%Cr-8wt% Ni stainless steel and its properties during soaking process

The properties of MnO–Al_2O_3–SiO_2-based plasticized inclusion are likely to change during soaking process due to its low melting point. In this study, the evolution of the MnO–Al_2O_3–SiO_2-based inclusion of 18 wt%Cr-8 wt%Ni stainless steel under isothermal soaking process at 1250°C for different times was investigated by laboratory-scale experiments and thermodynamic analysis. The results showed that the inclusion population density increased at the first stage and then decreased while their average size first decreased and then increased. In addition, almost no Cr_2O_3-concentrated regions existed within the inclusion before soaking, but more and more Cr_2O_3 precipitates were formed during soaking. Furthermore, the plasticity of the inclusion deteriorated due to a decrease in the amount of liquid phase and an increase in the high-melting-pointphase MnO–Cr_2O_3 spinel after the soaking process. In-situ observations by high-temperature confocal laser scanning microscopy(CLSM) confirmed that liquid phases were produced in the inclusions and the inclusions grew rather quickly during the soaking process. Both the experimental results and thermodynamic analysis conclude that there are three routes for inclusion evolution during the soaking process. In particular, Ostwald ripening plays an important role in the inclusion evolution, i.e., MnO–Al_2O_3–SiO_2-based inclusions grow by absorbing the newly precipitated smaller-size MnO–Cr_2O_3 inclusions.     

磁性光催化剂La_(0.7)Sr_(0.3)Mn_(0.9)Ti_(0.1)O_(3-δ)的制备其光催化性能研究

合成了一种具有磁性的Ti掺杂的La(0.7)Sr_(0.3)Mn_(0.9)Ti_(0.1)O_3光催化剂,即La(0.7)Sr_(0.3)Mn_(0.9)Ti_(0.1)O_(3-δ).并且利用了X射线衍射(XRD),紫外-可见固体漫反射(UV-vis DRS)、扫描电子显微镜(SEM)和磁性分析(VSM)等分析方法对其进行了表征.实验结果表明:La(0.7)Sr_(0.3)Mn_(0.9)Ti_(0.1)O_(3-δ)显示软铁磁性能,具有较高的磁化强度和较低的矫顽力和剩余磁化强度,其可利用外加磁场将其容易回收.在太阳光下,La(0.7)Sr_(0.3)Mn_(0.9)Ti_(0.1)O_(3-δ)在模拟罗丹明B(Rh B)废水中具有明显增强的光催化作用,催化效果好,且其重复使用5次后仍然表现出高的光催化活性.因此,制备的La(0.7)Sr_(0.3)Mn_(0.9)Ti_(0.1)O_(3-δ)是一种高效率的太阳光驱动光催化剂.     

Effect of Cr_2O_3 addition on the oxidation induration mechanism of Hongge vanadium titanomagnetite pellets

As part of a research project to develop a novel clean smelting process for the comprehensive utilization of Hongge vanadium titanomagnetite(HVTM), in this study, the effect of Cr2O3 addition on the oxidation induration mechanism of HVTM pellets(HVTMPs) was investigated in detail. The results showed that the compressive strength of the HVTMPs was greatly weakened by the Cr_2O_3 addition, mainly because of a substantial increase in the porosity of the HVTMPs. The Cr_2O_3 addition marginally affected the phase composition but greatly affected the microstructural changes of the HVTMPs. Increased amounts of Cr_2O_3 resulted in a decrease in the uniform distribution of the hematite grains and in an increase in the Fe–Cr solid solutions(Fe_(1.2)Cr_(0.8)O_3 and Fe_(0.7)Cr_(1.3)O_3) embedded in the hematite grains. Moreover, the compact hematite was destroyed by forming a dispersed structure and the hematite recrystallization was hindered during the oxidation induration, which adversely affected the compressive strength. On the basis of these results, a schematic was formulated to describe the oxidation induration mechanism with different amounts of added Cr_2O_3. This study provides theoretical and technical foundations for the effective production of HVTMPs and a reference for chromium-bearing minerals.     

Synthesis and thermodynamic analysis of nano-La_2O_3

The thermodynamic parameters of La(NO_3)_3 and La(OH)_3 are evaluated and the thermodynamics of nano-La_2O_3 syn- thetic process is analyzed.On the base of thermodynamic analysis,La_2O_3 nano-powders are prepared by the sol-gel method and the experi- ment scheme is designed by an orthogonal method.The dry-gelatin is analyzed with differential thermal analysis/thermo-gravimetric analy- sis(TGA-DTA)and X-ray diffraction method.The microstructure of nano-La_2O_3 powders is observed by transmission dectron micro- scope.The synthetic parameters affecting the average grain size and dispersivity of nano-La_2O_3 particles are experimentally examined and analyzed.All the results indicate that nano-La_2O_3 particles well-dispersed are obtained and the average grain size is in the range of 20—50 nm.     

Hydrogen storage properties of (Ti0.85Zr0.15)1.05Mn1.2Cr0.6V0.1M0.1 (M=Ni, Fe, Cu) alloys easily activated at room temperature

The(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)M_(0.1)(M=Ni, Fe, Cu) alloys with a single C14-type Laves phase have been fabricated by arc melting. They are able to be easily activated by one hydrogen absorption and desorption cycle under 4 MPa hydrogen pressure and vacuum at room temperature. Partial substitution of M for Mn results in the increase of hydrogenation and dehydrogenation capacities in an order of Ni Fe Cu. M elements increase the absorption and desorption plateau pressure in an order of(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Cu_(0.1)(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Fe_(0.1)(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Ni_(0.1). The(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Cu_(0.1) alloy has reversible hydrogen capacities of 1.81 wt% at 273 K and 1.58 wt% at 318 K with formation enthalpy(ΔH_(ab)) of-20.66 kJ mol~(-1) and decomposition enthalpy(ΔH_(de)) of 27.37 kJ mol~(-1). The differences in the hydrogen storage properties can be attributed to the increase of the interstitial size for hydrogen accommodation caused by the increase of unit cell volumes in the order of(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Ni_(0.1)(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Fe_(0.1)(Ti_(0.85)Zr_(0.15))_(1.05)Mn_(1.2)Cr_(0.6)V_(0.1)Cu_(0.1).     

Improvements of dielectric properties of Cu doped LaTiO_(3+δ)

The ceramic composites of Cu-doped La_(1-x )Cu_x TiO_(3+δ)(x=0.05, 0.15, 0.3, 0.5) were synthesized by conventional solid-state reaction. The complex dielectric properties of the composites were investigated as a function of temperature(77 K ≤T≤ 320 K) and frequency(100 Hz ≤ f ≤1 MHz) separately. In all composites, the dielectric constants increase monotonously and the dielectric loss undulates with temperature. And it is clearly observed that extraordinarily high low-frequency dielectric constant(～10~4)appear at room temperature in La_0.5Cu_0.5TiO_(3+δ), which is 100 times larger than that of La_0.95Cu_0.05 TiO_(3+δ). Interestingly, the dielectric constants increase remarkably with the doped Cu contents, meanwhile the dielectric loss for all samples is ideal lower than 1 at room temperature in the measured frequency range. By means of complex impedance analysis, the improvements of dielectric properties are attributed to both bulk contribution and grain boundary effect, in which the bulk polaronic relaxation and the Maxwell–Wagner relaxation due to grain boundary response are heightened remarkably with the high doped Cu contents.     

Fabrication and characterization of laminated Ti-(TiB+La2O3)/Ti composite

The incorporation of ceramic particulate reinforcements into titanium alloys can improve the specific strength and specific stiffness,while inevitably reduce the plasticity and ductility.In this study,in situ synthesized multilayer Ti-(TiB +La_2O_3)/Ti composite was designed by learning from the microstructure of nature biological materials with excellent mechanical properties.The Ti-(TiB + La_2O_3)/Ti composite with unique characteristic of laminated structure was prepared by combined powder metallurgy and hot rolling.The method has the synthesize advantages with in-situ reaction of Ti and LaB_6 at high temperature and controllability of reinforcements size and constituent phases in composites.The result shows that the pores in the as sintered laminated structure composite completely disappeared after hot rolling at 1050℃.The agglomerated reinforcement particles were well dispersed and distributed uniformly along the rolling direction.The thickness of pure Ti layer and(TiB+La_2O_3)/Ti composite layer decreased from 1 mm to about 200 μm.Meanwhile,the grains size was refined obviously after rolling deformation.The room temperature tensile test indicates that the elongation of the laminated Ti-(TiB + La_2O_3)/Ti composite improved from 13%to 17%in comparison with the uniform(TiB + La_2O_3)/Ti composite,while the tensile strength had little change.It provides theoretical and experimental basis for fabricating the novel high performance laminated Ti-(TiB + La_2O_3)/Ti composites.     

不同离子掺杂对层状钙钛矿氧化物La_(1.3)Sr_(1.7)Mn_2O_7的影响

采用固相法制备了La_(1.3-x)R_xSr_(1.7)Mn_2O_7(R=Eu,Gd,Dy;x=0,0.1)系列样品,研究Ln位离子及离子半径对钙钛矿氧化物物性的影响.结果表明:由于Eu、Gd、Dy的半径依次减小,所以La_(1.2)Eu_(0.1)Sr_(1.7)Mn_2O_7、La_(1.2)Gd_(0.1)Sr_(1.7)Mn_2O_7和La_(1.2)Dy_(0.1)Sr_(1.7)Mn_2O_7的晶格失配度依次增大,导致3个样品的磁性、磁转变温度、MI转变温度依次减小乃至消失,电阻率随之增加.其结果归结于畸变引起强的电-声相互作用,导致双交换作用减弱,使样品的物性发生改变.     

Controllable synthesis,XPS investigation and magnetic property of multiferroic BiMn_2O_5 system: The role of neodyme doping

In this work, a novel series of multiferroic materials BiMn_2O_5 doped by Neodyme has been prepared by a sol-gel method at low temperature. The crystallographic studies using X-ray diffraction and Rietveld Refinement techniques showed the formation of single-phase samples for all compositions, crystallizing in a mullite-type orthorhombic perovskite structure, space group Pbam(Z = 4). The SEM techniques confirmed the formation of single-phase materials with excellent mapping distribution. Raman and infrared spectroscopic measurements were performed and combined with lattice dynamics simulations to describe the room-temperature vibrational properties of all samples. The X-ray Photoelectron Spectroscopy(XPS) were measured in the energy range of 0–1400 eV at room temperature. The Fermi level E_F was defined with the accuracy of 0.127, 0.32 and 0.48 eV for BiMn_2O_5, Bi_(0.9)Nd_(0.1)Mn_2O_5 and Bi_(0.8)Nd_(0.2)Mn_2O_5 respectively. The X-ray photoelectron spectroscopy shows the existence of Mn~(4+) state. Magnetic measurements indicate Neél temperature T_N at 31, 40 and 61 K for BiMn_2O_5,Bi_(0.9)Nd_(0.1)Mn_2O_5 and Bi_(0.8)Nd_(0.2)Mn_2O_5 respectively.     

Influence of Cr2O3 additive and sintering temperature on the structural characteristics and piezoelectric properties of Bi4Ti2.95W0.05O12.05 Aurivillius ceramics

In this paper, Cr_2O_3(0–0.4 wt%) as an additive was added into Bi_4Ti_(2.95)W_(0.05)O_(12.05)(BITW) for preparing a kind of W/Cr co-doped BIT(BITW-yCr) Aurivillius ceramics, both W~(6+) and Cr~(3+) are considered to substitute Ti~(4+) in the [TiO_6] octahedron of BIT. Besides the orthorhombic Bi_4Ti_3O_(12) as the major phase, BITW-yCr ceramics also contain the cubic Bi_2Ti_2O_7 as the second phase which was formed due to the doping effect of WO_3, but its formation could be depressed by the addition of less Cr_2O_3. Additionally, the cell parameters of BITW ceramics are also changed by the incorporation of Cr_2O_3, as the distortion degree of the orthorhombic structure(a/b)increases firstly and then decreases with its addtional amount(y). On the other hand, the grain growth of BITWyCr ceramics is mainly controlled by the sintering process, there a higher sintering temperature results in a larger grain size. In comparison to BIT ceramics, BITW-yCr ceramics with less Cr-addition(y=0–0.2) require a higher sintering temperature to attain the best dense state, moreover, as y increases, the sintering temperature to gain the highest piezoelectric activity also increases. Finally, BITW-0.2Cr which was sintered at 1150 °C exhibits a higher piezoelectric activity than the others, which could be attributed to its larger orthorhombic distortion and larger grain size, its ideal piezoelectric constant(d_(33)=28pC/N) provides it with great applying potentiality.     

Interfacial behavior of Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 amorphous soft magnetic composite during spark plasma sintering process

Fe_(76)Si_9B_(10)P_5/Zn_(0.5)Ni_(0.5)Fe_2O_4 amorphous composite with micro-cellular structure and high electrical resistivity was prepared by spark plasma sintering(SPS) at 487 °C. XRD and SEM results showed that the Fe_(76)Si_9B_(10)P_5 alloy powders remained the amorphous state and the composite was dense. A fusion zone at interface of Fe_(76)Si_9B_(10)P_5 cell body and Zn_(0.5)Ni_(0.5)Fe_2O_4 cell wall was observed by TEM, which also indicates the formation of local high temperature. The interface bonding based on the formation of local high temperature in SPS process was observed. It is believed that the tip effect of Zn_(0.5)Ni_(0.5)Fe_2O_4 nanoparticles promotes the local discharging and plasmas creation in the gaps, and the discharging energy forms an instantaneous local high temperature to complete the local sintering and the densification of Zn_(0.5)Ni_(0.5)Fe_2O_4 particles at a low nominal sinter temperature. Simultaneously, the local high temperature stimulates the adjacent gaps discharging, thus facilitate the continuous formation of new discharging path. Finally, sintering and densification of the amorphous composite is complete.     

Solid fraction evolution characteristics of semi-solid A356 alloy and in-situ A356–TiB_2 composites investigated by differential thermal analysis

The key factor in semi-solid metal processing is the solid fraction at the forming temperature because it affects the microstructure and mechanical properties of the thixoformed components. Though an enormous amount of data exists on the solid fraction–temperature relationship in A356 alloy, information regarding the solid fraction evolution characteristics of A356-TiB2 composites is scarce. The present article establishes the temperature-solid fraction correlation in A356 alloy and A356-x TiB2(x = 2.5wt% and 5wt%) composites using differential thermal analysis(DTA). The DTA results indicate that the solidification characteristics of the composites exhibited a variation of 2°C and 3°C in liquidus temperatures and a variation of 3°C and 5°C in solidus temperatures with respect to the base alloy. Moreover, the eutectic growth temperature and the solid fraction(fs) vs. temperature characteristics of the composites were found to be higher than those of the base alloy. The investigation revealed that in-situ formed TiB2 particles in the molten metal introduced more nucleation sites and reduced undercooling.     

ZrO_2-supported α-MnO_2:Improving low-temperature activity and stability for catalytic oxidation of methane

The single phaseα-Mn O_2and in-situ supportedα-Mn O_2/Zr O_2with different ratios of Mn/Zr were synthesized by one-pot hydrothermal method.They showed superior activity for catalytic oxidation of methane and even better than that of 1%Pt/Al_2O_3.The T_(50)of Mn O_2/Zr O_2catalysts with different ratios of Mn/Zr were located in the range of 315–335°C at a WHSV of 90 L g~(-1)h~(-1),whereas that of Pt/Al_2O_3was 380°C.After sulfur ageing,the Mn O_2/Zr O_2catalysts with Mn/Zr ratio of 2:1(2Mn O_2/1Zr O_2)and 1:1(1Mn O_2/1Zr O_2)exhibited satisfying sulfur resistance in comparison to the pure Mn O_2.The 2Mn O_2/1Zr O_2catalyst also showed acceptable catalytic stability,and the addition of 10 vol%CO_2had no obvious negative effect on its stability,whereas the addition of2.6 vol%H_2O caused slight but reversible decreasing methane oxidative activity.     

Comparative study on the corrosion behavior of X52, 3Cr,and 13Cr steel in an O_2–H_2O–CO_2 system: products,reaction kinetics,and pitting sensitivity

The corrosion behaviors of X52, 3Cr low-alloy steel, and 13Cr stainless steel were investigated in an O_2–H2O–CO_2 environment at various temperatures and O_2–CO_2 partial-pressure ratios. The results showed that the corrosion rates of X52, 3Cr, and 13Cr steels increased with increasing temperature. The corrosion rates slowly increased at temperatures less than 100°C and increased sharply when the temperature exceeded 100°C. In the absence of O_2, X52, 3Cr, and 13Cr exhibited uniform corrosion morphology and Fe CO3 was the main corrosion product. When O_2 was introduced into the system, various forms of Fe_2O_3 appeared on the surface of the samples. The Cr content strongly influenced the corrosion resistance. The 3Cr steel with a low Cr content was more sensitive to pitting than the X52 or 13Cr steel. Thus, pitting occurred on the surface of 3Cr when 1.25 MPa of O_2 was added; this phenomenon is related to the non-uniform distribution of Crin 3Cr.     

Preparation and catalytic effect of porous Co3O4 on the hydrogen storage properties of a Li-B-N-H system

A porous Co_3O_4 with a particle size of 1–3 μm was successfully prepared by heating Co-based metal organic frameworks MOF-74(Co) up to 500 °C in air atmospheric conditions. The as-prepared porous Co_3O_4 significantly reduced the dehydrogenation temperatures of the LiBH_4-2LiNH_2 system and improved the purity of the released hydrogen. The LiBH_4-2LiNH_2-0.05/3Co_3O_4 sample started to release hydrogen at 140 °C and released hydrogen levels of approximately 9.7 wt% at 225 °C. The end temperature for hydrogen release was lowered by 125 °C relative to that of the pristine sample. Structural analyses revealed that the as-prepared porous Co_3O_4 is in-situ reduced to metallic Co, which functions as an active catalyst, reducing the kinetic barriers and lowering the dehydrogenation temperatures of the LiBH_4-2LiNH_2 system. More importantly, the porous Co_3O_4-containing sample exhibited partially improved reversibility for hydrogen storage in the LiBH_4-2LiNH_2 system.     

Electrochemical performance of a nickel-rich LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2 cathode material for lithium-ion batteries under different cut-off voltages

A spherical-like Ni_(0.6)Co_(0.2)Mn_(0.2)(OH)_2 precursor was tuned homogeneously to synthesize LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2 as a cathode material for lithium-ion batteries.The effects of calcination temperature on the crystal structure,morphology,and the electrochemical performance of the as-prepared LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2 were investigated in detail.The as-prepared material was characterized by X-ray diffraction,scanning electron microscopy,laser particle size analysis,charge–discharge tests,and cyclic voltammetry measurements.The results show that the spherical-like LiNi_(0.6)Co_(0.2)Mn_(0.2)O_2 material obtained by calcination at 900°C displayed the most significant layered structure among samples calcined at various temperatures,with a particle size of approximately 10 μm.It delivered an initial discharge capacity of 189.2 m Ah×g~(-1) at 0.2C with a capacity retention of 94.0% after 100 cycles between 2.7 and 4.3 V.The as-prepared cathode material also exhibited good rate performance,with a discharge capacity of 119.6 m Ah×g~(-1) at 5C.Furthermore,within the cut-off voltage ranges from 2.7 to 4.3,4.4,and 4.5 V,the initial discharge capacities of the calcined samples were 170.7,180.9,and 192.8 m Ah×g~(-1),respectively,at a rate of 1C.The corresponding retentions were 86.8%,80.3%,and 74.4% after 200 cycles,respectively.