共查询到19条相似文献,搜索用时 62 毫秒
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Li_4Ti_5O_(12)是一种理想的锂离子电池电极材料,但是它的电子导电性很差,通过掺杂其他物质和对材料改性等方法,可以提高Li_4Ti_5O_(12)材料导电能力。本文着重论述了对Li_4Ti_5O_(12)材料进行掺杂改性的研究,特别是对碳掺杂包覆改性和金属元素掺杂改性进行了详细介绍。比较了不同掺杂方法的特性,总结了相关的研究成果。 相似文献
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锂离子电池正极材料研究进展 总被引:2,自引:0,他引:2
本文比较系统地叙述了用于锂离子电池正极材料的发展研究状况,其中包括的正极材料有:金属氧化物LiCoO2、LiNiO2、LiMn2O4、钒系正极材料以及有机多硫化物正极材料,并对正极材料研究的一些热点作了比较详细的评述。 相似文献
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以LiH2PO4、LiF和V2O5为原料,蔗糖为还原剂,用碳热还原法合成了Li3V2[(PO4)1-xFx]3/C(x=0、0.02、0.05、0.08、0.10和0.15),并用X射线衍射、Fourier变换红外光谱、循环伏安、交流阻抗谱和恒流充放电技术研究了F-掺杂对材料结构和电化学性能的影响.结果表明:F-掺杂Li3V2(PO4)3/C与纯Li3V2(PO4)3/C均为单斜结构,但少量的F-掺杂可提高电极反应可逆程度和电导率,降低电荷传递阻抗;在所得的F-掺杂材料中,Li3V2[(PO4)0.95F0.05]3/C具有较好的电化学性能.在3.0~4.2V (vs.Li/Li+)循环时,电极的0.5C放电容量为124.4 mA·h/g,50次循环后容量保持率为98.5%,15C下的放电容量为84.7mA·h/g,50次循环后容量保持率为97.4%,而Li3V2(PO4)3/C的仅为59.2 mA·h/g和89.0%. 相似文献
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综述了近年来国内外关于钒酸镍材料的合成方法、结构性质以及应用于锂离子电池新型负极材料的研究进展。钒酸镍(Ni3V2O8、NiV3O8等)电极材料具有成本低、环境友好、比容量高、倍率性能优异等优点,但其在充放电过程中体积的巨大变化、电导性差以及比表面积低等问题严重影响了其规模化应用。该文从三个方面阐述了近年来通过电极材料微纳米化、复合化、表面包覆等手段有针对性的进行钒酸镍电极材料改性的研究进展,积极探索了高性能钒酸镍材料的合成方法,展望了今后重点开展的研究方向,对于钒酸镍材料的广泛应用具有一定的学术价值和实用意义。 相似文献
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A series of Li1–xNaxV3O8 (0相似文献
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Journal of Applied Electrochemistry - In this study, within the defined orthogonal array of Taguchi design, the hydrothermal process parameters have been optimized for fabricating the smallest... 相似文献
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Na2Li2Ti6O14电池具有较低的电位平台(1.3 V)以及经济成本低的特点,对便携式电子设备、能源汽车、生态环境等领域具有重大意义。由于钛酸锂钠电池固有离子电导率低的特点,因此提高钛酸锂钠电池锂离子扩散系数是目前研究中的主流方向,为此综述了钛酸锂钠的结构特点以及合成方法对钛酸锂钠材料粒径、形貌及电池电化学性能的影响;对比了不同掺杂离子和表面包覆改性对钛酸锂钠电池的放电比容量、循环性能及离子扩散系数的影响。掺入适量元素铌具有更高的锂离子扩散系数;包覆碳纳米管有更大的容量保持率,更有助于进一步提高钛酸锂钠电池电化学性能。 相似文献
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《Ceramics International》2021,47(24):34611-34618
An O3 type Li0.6[Li0.2Mn0.8]O2 lithium-rich material has a high reversible capacity due to the synergistic oxidation and reduction of anion and cation. However, the anion oxidation reaction that compensates the charge leads to a partial release of oxygen and the collapse of the structure inevitably. Here, we improve the structural stability of Li0.6[Li0.2Mn0.8]O2 by simultaneously introducing Al ions and B ions. Al ions and B ions randomly occupy octahedral and tetrahedral positions, hindering the migration of Mn ions and expanding the unit cell, resulting in a stable structure and promoting Li+ migration. The co-doped sample has better electrochemical performance than the bare material, and the capacity retention increases from 62.48% to 82.48% after 80 cycles at 0.1C rate, and still provides a capacity of 226 mAh g−1 between 2 and 4.8 V. 相似文献
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Spinel lithium manganese oxide ion-sieves have been considered the most promising adsorbents to extract Li+ from brines and sea water. Here, we report a lithium ion-sieve which was successfully loaded onto tubular α-Al2O3 ceramic substrates by dipping crystallization and post-calcination method. The lithium manganese oxide Li4Mn5O12 was first synthesized onto tubular α-Al2O3 ceramic substrates as the ion-sieve precursor (i.e. L-AA), and the corresponding lithium ion-sieve (i.e. H-AA) was obtained after acid pickling. The chemical and morphological properties of the ion-sieve were confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Both L-AA and H-AA showed characteristic peaks of α-Al2O3 and cubic phase Li4Mn5O12, and the peaks representing cubic phase could still exist after pickling. The lithium manganese oxide Li4Mn5O12 could be uniformly loaded not only on the surface of α-Al2O3 substrates but also inside the pores. Moreover, we found that the equilibrium adsorption capacity of H-AA was 22.9 mg·g-1. After 12 h adsorption, the adsorption balance was reached. After 5 cycles of adsorption, the adsorption capacity of H-AA was 60.88% of the initial adsorption capacity. The process of H-AA adsorption for Li+ correlated with pseudo-second order kinetic model and Langmuir model. Adsorption thermodynamic parameters regarding enthalpy (ΔH), Gibbs free energy (ΔG) and entropy (ΔS) were calculated. For the dynamic adsorption- desorption process of H-AA, the H-AA exhibited excellent adsorption performance to Li+ with the Li+ dynamic adsorption capacity of 9.74 mg·g-1 and the Mn2+ dissolution loss rate of 0.99%. After 3 dynamic adsorption-desorption cycles, 80% of the initial dynamic adsorption capacity was still kept. 相似文献