烧结温度对LiNi（0.8）Co（0.1）Mn（0.1）O2材料倍率性能和循环性能的影响

以共沉淀法制备的球形Ni0.8Co0.1Mn0.1（OH）2和Li OH·H2O为原料,研究烧结温度对LiNi0.8Co0.1Mn0.1O2材料形貌、结构以及材料循环性能和倍率性能的影响。SEM和XRD结果表明：温度对材料形貌和结构有较大的影响,控制适当温度既能保证材料具有良好的形貌,也能抑制材料中锂镍的混排。电化学测试结果显示,当烧结温度从700℃升高至750℃时,材料性能逐渐提高,但是温度过高会恶化材料的性能。750℃和780℃烧结材料的循环性能几乎一致,200次循环后容量保持率为71.9%,但780℃烧结材料的倍率性能低于750℃材料的,其原因归结于温度过高,锂镍的混排加剧。在小电流充放电时,对材料性能影响有限,但是在大电流充放电时,3a位的Ni2＋将严重阻碍锂离子的扩散。     

快速共沉淀过程pH值对Ni_(0.8)Co_(0.1)Mn_(0.1)(OH)_2及LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2性能的影响

采用快速共沉淀法制备Ni0.8Co0.1Mn0.1(OH)2前驱体,利用前驱体与LiOH.H2O的高温固相反应得到锂离子电池层状正极材料LiNi0.8Co0.1Mn0.1O2,探讨pH值对材料结构和电化学性能的影响。通过X射线衍射(XRD)、扫描电镜(SEM)和电化学测试对合成样品进行表征。结果表明,pH值为11.00~12.00时,合成的Ni0.8Co0.1Mn0.1(OH)2前驱体均无杂相;pH值为11.50时,合成的前驱体制备出的正极材料具有良好的电化学性能,0.1C倍率下首次放电比容量为192.4 mA.h/g;经过40次循环,容量保持率为91.56%。     

Effects of synthesis conditions on the structural and electrochemical properties of layered LiNi1/3Co1/3Mn1/3O2 cathode material via oxalate co-precipitation method

The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using (Ni1/3Co1/3Mn1/3)C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calcination temperature and time on the structure and electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 were systemically studied. XRD results revealed that the optimal calcination conditions to prepare the layered LiNi1/3Co1/3Mn1/3O2 were 950°C for 15 h. Electrochemical measurement showed that the sample prepared under the such conditions has the highest initial discharge capacity of 160.8 mAh/g and the smallest irreversible capacity loss of 13.5% as well as stable cycling performance at a constant current density of 30 mA/g between 2.5 and 4.3 V versus Li at room temperature.     

共沉淀法制备LiNi0.8Co0.1Mn0.1O2过程中加料速度对其性能的影响

采用共沉淀法制备Ni0.8Co0.1Mn0.1(OH)2前驱体,与LiOH.H2O混合后在氧气气氛中焙烧得到LiNi0.8Co0.1Mn0.1O2正极材料,探讨共沉淀反应过程中快速加料和慢速加料制度对前驱体形貌和LiNi0.8Co0.1Mn0.1O2正极材料性能的影响。通过X射线衍射(XRD)、扫描电镜(SEM)和电化学测试对样品进行表征。结果表明:慢速加料法减小了材料的粒径,合成了平均粒径在0.5μm左右的球形Ni0.8Co0.1Mn0.1(OH)2前驱体,且粒径分布比较集中;所合成LiNi0.8Co0.1-Mn0.1O2正极材料具有良好的层状结构,且无杂相存在;缓慢加料法得到的样品的电化学性能有很大提高,在0.1 C、0.5 C和1 C下首次放电比容量分别达到223.5、194.3和190.7 mA.h/g,循环30次后,容量保持率为80.09%、80.80%和85.84%。     

Synthesis and characterization of LiNi0.45Co0.10Mn0.45O2 cathode for lithium ion batteries

1INTRODUCTIONAdvanced rechargeable lithium ion batteriesare attractive for use in consumer electronic andelectric vehicle(EV)application because of a fa-vorable combination of voltage,energy density,cycling performance,and have been developed rap-idly worldwide during the past decade[1,2].LiCoO2has been widely used as a cathode material in com-mercial lithiumion battery because it is reasonableeasy to synthesize and shows a stable discharge ca-pacity[3].But due to its high cost and toxic…     

Preparation and electrochemical characteristics of CO3（PO4）2-coated LiNi0.8Co0.2O2 by solid-state reaction at room temperature

LiNi0.8Co0.2O2 particles were modified by Co3（PO4）2 coating. The effects of the Co3（PO4）2 coating on the structure and electrochemical properties of the LiNi0.8Co0.2O2 cathode material were investigated. The Co3（PO4）2 coating forms a thin layer on the surface of the LiNi0.8Co0.2O2 material and a solid solution by interacting with the LiNi0.8Co0.2O2 core material during calcination at 700℃ for 4 h. Charge-discharge experiment results show that the Co3（PO4）2 coating improves the cycling stability of the LiNi0.8Co0.2O2 cathode material. The capacity retention of the pristine LiNi0.8Co0.2O2 cathode after 50 cycles is 83.6%, whereas it is 91.7% in the case of the LiNi0.8Co0.2O2 cathode coated with 1 wt.% Co3（PO4）2. Storage tests of the 4.35 V charged electrode at 60℃ after a month show that the Co3（POg）2-coated sample exhibits good storage properties compared with the pristine sample.     

Synthesis and electrochemical characterization of layered Li[Ni1/3CO1/3 Mn1/3]O2 cathode material for Li-ion batteries

1 INTRODUCTIONDue to the high cost of LiCoO2,a commonlyused cathode material in commercial rechargeablelithium-ion batteries , much efforts have been madeto develop cheaper cathode materials than LiCoO2,Li Ni O2and Li MnO2have been studied extensivelyas possible alternatives to LiCoO2[1 4 ]. Stoichio-metric Li Ni O2is knownto be difficult to synthesizeandits multi-phase reaction during electrochemicalcyclingleads to structural degradation,andlayeredLi MnO2has a significant drawback…     

Al2O3包覆LiNi0.03Co0.05Mn1.92O4正极材料的制备及其电化学性能

以Al(NO3)3?9H2O为包覆原料，通过燃烧法制备得到LiNi0.03Co0.05Mn1.92O4@Al2O3正极材料。通过X射线衍射(XRD)，场发射扫描电子显微镜(FESEM)和透射电镜(TEM)等表征手段对材料的结构和形貌进行分析，并通过恒电流充放电、循环伏安(CV)、交流阻抗(EIS)等测试分析材料的电化学性能。结果表明，Al2O3包覆没有改变LiNi0.03Co0.05Mn1.92O4的尖晶石型结构，包覆层厚度约10.6nm。LiNi0.03Co0.05Mn1.92O4@Al2O3正极材料电化学性能得到了明显改善，1 C和10 C倍率下初始放电比容量分别为119.9 mAh?g-1和106.3 mAh?g-1，充放电循环500次后容量保持率分别为88.4%和78.2%，而未包覆的LiNi0.03Co0.05Mn1.92O4在1 C和10 C倍率下初始放电比容量分别为121.2 mAh?g-1和104.0 mAh?g-1，500次循环后容量保持率分别为84.1%和67.6%。LiNi0.03Co0.05Mn1.92O4@Al2O3活化能为32.92 kJ?mol-1，而未包覆材料的活化能为36.24 kJ?mol-1，包覆有效降低了材料Li+扩散所需克服的能垒，提高了材料的电化学性能。     

LiNi1/3Co1/3Mn1/3O2和LiNi3/8Co1/4Mn3/8O2纳米纤维的合成与电化学性能

以溶胶前驱体为纺丝液,通过静电纺丝法合成锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2和LiNi3/8Co1/4Mn3/8O2纳米纤维.采用原子力显微镜(AFM)、X射线衍射(XRD)、充放电实验对纳米纤维的形貌、结构和电化学性能进行研究.结果表明,纳米纤维的直径在150～200 nm之间,且具有典型的α-NaFeO2层状结构.LiNi1/3Co1/3Mn1/3O2和LiNi3/8Co1/4Mn3/8O2纳米纤维的首次放电容量均超过170 mAh·g-1,50次循环后容量保持率在90%以上.     

Surface modification of spherical LiNi1/3Co 1/3 Mn1/3O2 with Al2O3 using heterogeneous nucleation process

To improve the cycle stability at high voltage and high charge/discharge rate, spherical LiNi1/3Co1/3Mn1/3O2 was coated with Al2O3 by using heterogeneous nucleation process, and the physical and electrochemical properties were studied. The SEM images show that there is a uniform coating on the modified spherical LiNi1/3Co1/3Mn1/3O2. The electrochemical tests indicate that the properties of LiNi1/3Co1/3Mn1/3O2 coated with 0.5% aluminum oxide are the best. The initial capacities are 150 and 173 mA.h/g at the rate of I C in the voltage range of 2.7-4.3 V and 2.7-4.6 V, respectively, and the discharge capacities maintain about 99% and 85% after 30 cycles, respectively. While those of the bare LiNi1/3Co1/3Mn1/3O2 are only 90% and 75%, respectively. The CV tests of LiNi1/3Co1/3Mn1/3O2 show that Al203-coating can restrain the oxide-reduction peak currents fading during the charge/discharge course.     

快速凝固制备La2Mg0．9Ni7．5Co1．5Al0.1贮氢合金的相结构及电化学性能

采用感应熔铸＋退火处理及快速凝固方法制备了La2Mg0．9Ni7．5Co1．5Al0.1贮氢合金。系统研究了快速凝固对合金的相结构、微观组织及电化学性能的影响。XRD分析表明，随着冷却速率的增加，La2Mg0．9Ni7．5Co1．5Al0.1合金的相组成发生了明显变化。退火合金由αLa2Ni7主相（Ce2Ni7型结构）和少量LaNi3相（PuNi3型结构）组成。随着冷却速率的增加，合金中出现LaNi5相（CaCu5型结构）和LaMgNi4（MgCu4Sn型结构）相，且新相的相丰度增加，aLa2Ni7相和LaNi3相的丰度减少。EPMA分析表明，快速凝固方法制备的La2Mg0．9Ni7．5Co1．5Al0.1贮氢合金为柱状晶组织且晶粒细小。合金电极的电化学测试表明，冷却速率对合金的活化性能影响不大。随冷却速率的增加，合金的最大放电容量减少、高倍率放电性能下降。在较低的冷却速率下（5m／s），合金电极的循环稳定性改善不明显，而随着凝固速度的进一步增加（20m／s），合金电极表现出较好的循环稳定性。     

Synthesis and characterization of LiNi0.95-xCoxAl0.05O2 for lithium-ion batteries

Samples of LiNi0.95-xCoxAl0.05O2 （x = 0.10 and 0.15） and LiNiO2, synthesized by the solid-state reaction at 725℃ for 24 h from LiOH-H2O, Ni2O3, Co2O3, and AI（OH）3 under an oxygen stream, were characterized by TG-DTA, XRD, SEM, and electrochemical tests. Simultaneous doping of cobalt and aluminum at the Ni-site in LiNiO2 was tried to improve the cathode performance for lithium-ion batteries. The results showed that co-doping （especially, 5 at.% A1 and 10 at.% Co） definitely had a large beneficial effect in increasing the capacity （186.2 mA.h/g of the first discharge capacity for LiNio.s.42OoaoAlo.0502） and cycling behavior （180.1 mA-h/g after 10 cycles for LiNio.85CooaoAlo.osO2） compared with 180.7 mA.h/g of the first discharge capacity and 157.7 mA.h/g of the tenth discharge capacity for LiNiO2, respectively. Differen- tial capacity versus voltage curves showed that the co-doped LiNio.95_xCoxmlo.osO2 had less intensity of the phase transitions than the pristine LiNiO2.     

锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2的制备及性能研究

采用溶胶-凝胶法制备了锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2,并考察了烧结温度对材料结构、表面形貌和电化学性能的影响.XRD和SEM测试结果表明,900℃下烧结得到的样品是粒径在0.3～0.5 μm范围的球形粒子,具有最佳的阳离子有序度;充放电测试结果表明,其在0.1C倍率下首次放电容量达到148.8...     

正极材料LiNi0.4Co0.2Mn0.4O2阴离子掺杂改性研究

采用溶胶-凝胶法合成了层状LiNi0.4Co0.2Mn0.4O1.97X0.03(X=O,F,Cl)正极材料。以XRD、SEM、CV、EIS和充放电测试等手段对材料的晶体结构、表观形貌和电化学性能进行表征。XRD结果显示F-和Cl-掺杂没有改变晶体的六方单层状结构;CV结果表明掺杂提高了材料的可逆性;充放电测试表明,F-和Cl-掺杂均提高了材料的放电容量,并改善了材料的循环性能;EIS测试结果发现,F-和Cl-掺杂均有效地抑制其在循环过程中电化学反应阻抗的增加。     

Ru_(0.1)Mn_(0.9)O_x的制备与电化学赝电容特性研究

结合氧化钌理想的电化学赝电容特性和二氧化锰资源广泛、对环境友好的优势,采用氧化共沉淀法制备出Ru0.1Mn0.9Ox新型电化学电容器复合电极材料,通过循环伏安(CV)、计时电位(Chronopotentiometry)、交流阻抗(AC impedance)、热重-差热(TG/DSC)以及X射线衍射(XRD)等实验研究了电极材料的电化学赝电容性、阻抗特征、晶形结构及热处理温度对材料的晶形和赝电容的影响.结果表明:当热处理温度低于180 ℃时,可制备出稳定、非晶态的Ru0.1Mn0.9Ox;当温度为350 ℃时,复合材料中的无定形二氧化锰已转变为α-MnO2,掺杂的氧化钌晶形不变.与纯MnO2相比,Ru0.1Mn0.9Ox复合电极材料具有较低的极化内阻、较高的比电容、良好的电化学可逆性和显著的电化学赝电容特征.     

废旧LiCoO2材料再生LiNi0.8Co0.1Mn0.1O2正极材料及性能研究

针对废旧锂离子电池数量不断增加的现状,对废旧LiCoO2电池的回收和再生流程进行探究。以废旧LiCoO2电池为原料,通过预处理,酸浸,共沉淀步骤,实现了LiNi0.8Co0.1Mn.1O2正极材料的再生。ICP-OES分析浸出液中的元素含量,SEM和XRD表征材料形貌和结构,扣式电池的电化学测试定量分析材料的电化学性能。研究表明,利用浸出液可以再生形貌和层状结构良好的正极材料,在0.2C,2.8~4.3V电压范围内进行充放电循环测试,首周放电比容量可达到210.8 mAh/g,经过50周充放电循环后的容量保持率为87%,表现出良好的循环稳定性,为废旧锂离子电池的再生提供支撑和发展方向。     

层状LiMnO_2正极材料的新型碳热还原法制备与性能表征

采用碳热还原法由LiOH、MnO2直接合成了层状LiMnO2（o-LiMnO2）。采用了X射线衍射（XRD）、扫描电子显微镜（SEM）等手段对产物的结构和微观形貌进行了表征,同时通过充放电测试考察了所得样品的电化学性能。结果表明,以Li∶Mn∶C摩尔比为5∶4∶2,300℃恒温碳化后于750℃下焙烧12h为合成o-LiMnO2样品的最佳条件;所得样品具有良好的电化学性能和循环稳定性。     

Zn对锂电池材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2结构和电化学性能的影响

采用共沉淀法掺入少量Zn得到Li(Ni1/3Co1/3Mn1/3)1-xZnxO2材料。通过X射线衍射、光电子能谱(XPS)和电化学测试研究掺杂对其晶体结构、元素价态和电化学行为的影响。结果表明:掺入Zn增大晶格常数;在粉末颗粒表面的Zn含量是颗粒内部的数十倍;掺杂后Co、Mn依然保持+3、+4价,但是Ni由+2、+3混合价态组成;掺入少量Zn阻止电极在4.5V电位下的不可逆氧化反应;掺入Zn有效改善高截止电压下的循环容量保持能力,其作用与改变材料表面状态有关。     

基于基团贡献法估算锂离子动力电池正极材料LiNixCoyMnzO2的ΔHf,298θ和ΔGf,298θ

基于基团贡献法对裡离子动力电池正极材料LiNi0.6Co0.2Mn0.2O2、LiNi0.5Co0.2Mn0.3O2、LiNi0.8Co0.1Mn0.1O2和LiNi1/3Co1/3Mn1/3O2的△Hf,298θ和△Gf,298θ进行估算。首先采用基团贡献法对56种固体无机化合物的△Hf,298θ和△Gf,298θ进行估算,估算值与文献值相比,相对误差绝对值都在4%之内。基于基团贡献法首次构建了估算锂离子动力电池正极材料LiNixCOyMnzO2的△Hf,298θ和△Gf,298θ的数学模型,结合XPS实验数据分析结果,对LiNi0.6Co0.2Mn0.2O2、LiNi0.5Co0.2Mn0.3O2、LiNi0.8Co0.1Mn0.1O2和LiNi1/3Co1/3Mn1/3O2正极材料的Hθf,298和ΔGθf,298进行估算,对应正极材料的△Hf,298θ和△Gf,298θ估算值分别为-705.39,-703.90,-695.67,-705.17 kJ·mol^-1和-647.98,-640.04,-631.10,-642.41 kJ·mol^-1。     

Mg-Co复合掺杂对LiFePO4电化学性能的影响（英文）

通过固相反应制备了Mg2+和Co4+复合掺杂的LiFePO4电极材料。采用X射线衍射、恒电流充放电和循环伏安研究复合掺杂对 LiFePO4结构和电化学性能的影响。结果表明:复合掺杂能够提高 LiFePO4的首次放电比容量,0.1C和1C的放电容量分别达到147.2mA·h/g 和133.3mA·h/g。循环伏安测试结果表明:复合掺杂改善了LiFePO4的导电性能,增强了Li+的脱嵌可逆性。