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尖晶石型LiMn2O4由于其合成工艺条件简单、环境友好、原料价格低等诸多优点被认为是最具有应用前景的锂离子电池正材料,但其在较高的温度下循环稳定性能较差,容量衰减快,从而严重影响了其商业化应用。文章阐述了科研人员为了改善材料的容量衰减快、高温性能及大流充放电性能而采用的离子掺杂和表面包覆改性的研究进展。 相似文献
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Li—Mn—O体系锂离子电池正极材料的结构与性能 总被引:2,自引:0,他引:2
总结了当前对Li-Mn-O体系各种锂离子电池正极材料LiMn2O4、LiMnO2、Li4Mn5O9和Li4Mn5O12,在全成和充放电过程中的结构特征和结构变化过程,以及材料的结构和结构的变化对电化学性能的影响。 相似文献
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通过熔融浸渍、分段烧结的方法用LiOH·H2 O和EMD制得尖晶石型LiMn2 O4 活性材料 ,对材料进行了元素分析和XRD结构表征 ,采用最小二乘法计算了样品的晶格常数 ,结果表明样品属于立方尖晶石结构 ,为缺锂型尖晶石锂锰氧。样品在高温下的充放电曲线和循环伏安曲线的测定结果表明样品的首次放电容量为 12 2 8mAh·g- 1,放电电压为 3 96V ,恒温充电电压为 4 0 7V ,二者差值仅为 0 11V ,说明以其为正极的电池的极化较小 ,在高温下具有良好的循环特性。 相似文献
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以醋酸锂、磷酸、七水合硫酸亚铁为原料,聚乙二醇为分散剂,通过一步水热法制备得到中空八面体LiFePO_4锂离子电池正极材料。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和电化学性能测试仪对样品晶型、形电化学性能进行了表征测试。研究结果表明,在2.5~4.2 V电压范围内,以0.1 C(17 mA/g)倍率进行充放电,样品首次放电比容量为129.6 mA·h/g;0.2、0.5、1、2和5 C的充放电倍率时,首次放电比容量分别达到123.6、119.7、114.1、99.5g和90.6 mA·h/g。10 C的充放电倍率时首次放电比容量为84.3 mA·h/g,说明中空八面体LiFePO_4在高倍率下表现出优异的电化学性能。 相似文献
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本文综述了锂离子电池正极材料尖晶石型LiMn2O4的国内外研究现状,在分析尖晶石型LiMn2O4结构和其作为正极材料相关理论的基础上,阐述了合成技术,包括制备方法、合成温度、材料粒径等对LiMn2O4材料性能的影响;并就掺杂改性分析了选择合适的掺杂离子、掺杂量、合成工艺等对材料性能的影响。 相似文献
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本文论述了具有层状结构的锂锰氧化物正极材料的最新研究成果。着重讨论了具有层状结构的锂锰氧化物正极材料的合成方法及其电化学性能。 相似文献
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用于锂离子电池负极SnO2MCMB复合材料的研究 总被引:3,自引:0,他引:3
以中间相碳微球(MCMB)为核心,用直接沉淀法制备了一种氧化锡颗粒修饰的新型复合碳材料.用X射线衍射和扫描电镜对材料的结构及形貌进行了表征.通过恒流充放电、交流阻抗、循环伏安等测试手段对该材料的嵌脱锂特性进行了研究,循环20周后其比容量仍然保持在360 mAh/g以上.此种复合物可以作为一种锂离子电池新型负极材料. 相似文献
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Gd and Al co-doped LiMn2-x(GdAl)xO4 (x?=?0, 0.01, 0.02, 0.03, 0.04 and 0.05) materials with spinel structure were synthesized by sol–gel method. Powder X-ray diffraction results confirm the formation of cubic spinel structure and average particle sizes are found to be between 80 and 110?nm from FE-SEM and TEM analysis. Decrease in peak potential difference as a function of doping in Cyclic Voltammetry results establishes enhancement in Li+ intercalation and de-intercalation. Electrochemical Impedance Spectroscopy (EIS) results showed that accumulation of charges on electrode has improved with doping over pristine samples. At a doping of x?=?0.02 charge transfer resistance values were found to be least. First cycle charge–discharge profiles for LiMn1.96(GdAl)0.02O4 shows 139.2?mAh/g discharge capacity over other doped derivatives and pure LiMn2O4 (119.6?mAh/g) in aqueous Li2SO4 electrolyte. Doping of x?=?0.02 exhibit good cycling performance with only a total 4% capacity loss after 30 cycles. 相似文献
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锂离子电池正极材料磷酸铁锂研究进展 总被引:1,自引:1,他引:1
与氧化钴锂(LiCoO2)、氧化镍锂(LiNiO2)相比,橄榄石结构磷酸铁锂(LiFePO4)具有安全、环保、比容量高、循环性能优异、高温特性好等优点,被誉为最具发展前景的锂离子电池正极材料。长的循环寿命、优良的高倍率放电性能、高的放电平台、大的能量密度以及良好的热稳定性能,也使得磷酸铁锂成为高功率动力电池正极的首选材料。但是,磷酸铁锂也存在电子电导率相对较低、锂离子扩散系数小、振实密度不高、低温特性不好等缺点,因而制约着它的应用和发展。从磷酸铁锂结构、性能、制备和改性等方面综述了近年来磷酸铁锂的研究进展。 相似文献
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Well-crystallized Li2NiTiO4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li2NiTiO4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li2NiTiO4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li2NiTiO4/C delivers high discharge capacities of 115 mAh g-1 at room temperature and 138 mAh g-1 and 50°C, along with a superior cyclability. 相似文献
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对近几年有关LiFePO4作为锂离子电池新型正极材料的研究进行了系统分析。比较了不同的合成方法及掺杂对材料性能的影响,对LiFePO4性能提出了进一步改进的措施;认为掺杂一种或多种高价金属元素是很有前途的方法。 相似文献
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本文以蔗糖为碳源,采用固相法合成了锂离子电池LiNixFe1-xPO4(x=0、0.05、0.1、0.2和0.3)正极材料,通过XRD和SEM等表征所合成的产物为多孔炭和LiFePO4相以恒电流充放电和电化学阻抗谱研究了材料的电化学性能,结果LiNi0.1Fe0.9PO4的性能最佳,其粒径大小在500~1000nm左右,在2C的充放电条件下,其放电比容量为70.3mAh·g-1,15次循环后容量保持率达90%。 相似文献
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Nakwon Kim Wooyoung Lee Joonsoo Kim Daeil Kim Boyun Jang 《Journal of the American Ceramic Society》2023,106(8):4554-4566
A new concept of passive prelithiation to SiOx nanoparticles is introduced and evaluated by investigating their nanostructures and electrochemical properties. Specifically, Li is incorporated into SiOx nanoparticles during the nanoparticle synthesis. We obtain Si-Li-O-based nanoparticles, which we call SILIO; these are much larger than SiOx particles and have totally different nanostructures. Due to nanostructures with various phase distributions, SILIO nanoparticles show enhanced electrochemical properties. The initial reversible capacity (IRC) and initial columbic efficiency (ICE) of SILIO nanoparticles are 946 to 1107 mAh/g and 72% to 77%, respectively, while SiOx exhibits 1,064 mAh/g of IRC only with 41.5% of ICE. In addition, the stability of SILIO in the air is evaluated to guarantee no unstable phases such as Li2Ox (x = 0–2) are present in SILIO. Through our findings, we suggest a new nanostructure model composed of crystalline Si, amorphous SiOx, and lithium silicate. 相似文献
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《Ceramics International》2022,48(14):20220-20227
A specially designed experimental device was used in laboratory to investigate the corrosion of mullite during the calcination of Li(NixCoyMnz)O2 (LNCM) materials. The anti-corrosion tests were carried out at 1000, 1100, 1200 and 1300 °C, and characterized with X-ray diffraction and scanning electron microscopy. The influence of temperature on the interactions between mullite insulation materials and LNCM materials was determined. In addition, the high-temperature creep properties of the mullite insulation materials before and after corrosion were tested. The laboratory scale tests, thermodynamic and kinetic calculations allowed a more comprehensive understanding of the evolution of the mullite insulation materials during serving for the roasting process of LNCM materials. Through this research, it is suggested that the upgrading of the kiln lining in the lithium battery industry should select materials with excellent resistance to alkali corrosion, especially excellent resistance to Li+ corrosion. 相似文献