共查询到20条相似文献，搜索用时 15 毫秒
1.
Gengchen Yu;Jian Huang;Xue Bai;Tao Li;Shuxin Song;Yuting Zhou;Nannan Wu;Shuyu Yao;Xiao Lu;Weikang Wu; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(34):2308858
Although TiNb2O7 (TNO) with comparable operating potential and ideal theoretical capacity is considered to be the most ideal replacement for negative Li4Ti5O12 (LTO), the low ionic and electronic conductivity still limit its practical application as satisfactory anode for lithium-ion batteries (LIBs) with high-power density. Herein, TNO nanoparticles modified by Cerium (Ce) with outstanding electrochemical performance are synthesized. The successful introduction of Ce3+ in the lattice leads to increased interplanar spacing, refined grain size, more oxygen vacancy, and a smaller lithium diffusion barrier, which are conducive to improve conductivity of both Li+ and electrons. As a result, the modified TNO reaches high reversible capacity of 256.0 mA h g−1 at 100 mA g−1 after 100 cycles, and 183.0 mA h g−1 even under 3200 mA g−1. In particular, when the temperature drops to −20 °C, the cell undergoing 1500 cycles at a high current density of 500 mA g−1 can still reach 89.7 mA h g−1, corresponding to a capacity decay rate per cycle of only 0.033%. This work provides a new way to improve the electrochemical properties of alternative anodes for LIBs at extreme temperature. 相似文献
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将TiNb2O7的前驱体在不同温度(400℃、800℃、900℃、1000℃和1100℃)煅烧,用固相合成法制备TiNb2O7负极材料并对其样品进行了TG-DSC、XRD和SEM表征和电化学性能测试。结果表明：在900℃煅烧前驱体,锐钛矿与Nb2O5反应的主要产物为Ti2Nb10O29。Ti2Nb10O29与金红石反应生成了TiNb2O7,生成纯单斜相TiNb2O7的最佳条件为在1100℃煅烧6 h。TiNb2O7负极材料在0.2C电流密度时初始容量为278.4 mAh/g,初始库伦效率为82.9%。TiNb2O7具有良好的倍率容量,在1C循环100次后容量保持率为89%。 相似文献
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Chunfu Lin Shengjue Deng David J. Kautz Zhihao Xu Tao Liu Jianbao Li Ning Wang Feng Lin 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(46)
Ti–Nb–O binary oxide materials represent a family of promising intercalating anode materials for lithium‐ion batteries. In additional to their excellent capacities (388–402 mAh g–1), these materials show excellent safety characteristics, such as an operating potential above the lithium plating voltage and minimal volume change. Herein, this study reports a new member in the Ti–Nb–O family, Ti2Nb14O39, as an advanced anode material. Ti2Nb14O39 porous spheres (Ti2Nb14O39‐S) exhibit a defective shear ReO3 crystal structure with a large unit cell volume and a large amount of cation vacancies (0.85% vs all cation sites). These morphological and structural characteristics allow for short electron/Li+‐ion transport length and fast Li+‐ion diffusivity. Consequently, the Ti2Nb14O39‐S material delivers significant pseudocapacitive behavior and excellent electrochemical performances, including high reversible capacity (326 mAh g?1 at 0.1 C), high first‐cycle Coulombic efficiency (87.5%), safe working potential (1.67 V vs Li/Li+), outstanding rate capability (223 mAh g–1 at 40 C) and durable cycling stability (only 0.032% capacity loss per cycle over 200 cycles at 10 C). These impressive results clearly demonstrate that Ti2Nb14O39‐S can be a promising anode material for fast‐charging, high capacity, safe and stable lithium‐ion batteries. 相似文献
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锂离子电池作为一种动力能源, 在电动汽车和各种储能系统中有着良好的应用前景。尖晶石结构的钛酸锂(Li4Ti5O12)负极材料具有较高的脱嵌锂电位平台、优异的循环稳定性、以及突出的安全性能, 被认为是一种非常有潜力的锂离子电池负极材料, 在锂离子动力电池中具有巨大的发展潜力。然而, 尖晶石型Li4Ti5O12存在着本征导电率低, 理论容量小等缺陷, 极大地限制了其规模化应用, 需要进一步改善和提高。本文总结了尖晶石型Li4Ti5O12材料在结构形貌、制备方法和性能方面的研究进展, 深入分析和讨论了离子掺杂、碳表面改性和纳米化等改性方法对尖晶石型Li4Ti5O12综合电化学性能的改善效果, 并展望了尖晶石型Li4Ti5O12作为锂离子电池负极材料未来的发展方向。 相似文献
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Yimei Lai Yun Zhao Weiping Cai Jun Song Yongtang Jia Bin Ding Jianhua Yan 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(47)
Li metal is the optimal choice as an anode due to its high theoretical capacity, but it suffers from severe dendrite growth, especially at high current rates. Here, an ionic gradient and lithiophilic inter‐phase film is developed, which promises to produce a durable and high‐rate Li‐metal anode. The film, containing an ionic‐conductive Li0.33La0.56TiO3 nanofiber (NF) layer on the top and a thin lithiophilic Al2O3 NF layer on the bottom, is fabricated with a sol–gel electrospinning method followed by sintering. During cycling, the top layer forms a spatially homogenous ionic field distribution over the anode, while the bottom layer reduces the driving force of Li‐dendrite formation by decreasing the nucleation barrier, enabling dendrite‐free plating‐stripping behavior over 1000 h at a high current density of 5 mA cm?2. Remarkably, full cells of Li//LiNi0.8Co0.15Al0.05O2 exhibit a high capacity of 133.3 mA h g?1 at 5 C over 150 cycles, contributing a step forward for high‐rate Li‐metal anodes. 相似文献
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用溶胶－凝胶法合成了Ｌｉ２＋ｘＢｘＳｉ１－ｘＯ３（ｘ＝０－０．５）,发现形成固溶体的范围是０〈ｘ≤０．２。对其离子导电性的研究发现,当ｘ＝０．３时出现电导率极大值。 相似文献
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A typical approach involving Pechini method and spark plasma sintering (SPS) method was presented for the preparation of high density Li5+x Srx La3--x Bi2O12 (x = 0, 1) ceramics. Phase formation, microstructure, grain size and electrical properties of the specimens were examined using XRD, SEM and alternating current impedance spectroscopy (ACIS). Dense Li5La3Bi2O12 and Li6SrLa2Bi2O12 ceramics with pure garnet-like phase, relative density of 97% and average grain size of about 5 μm were fabricated using this approach. The total conductivities at 298 K of Li5La3Bi2O12 and Li6SrLa2Bi2O12 ceramics prepared by the SPS method are 5.1×10-5 and 6.8×10-5 S/cm, respectively, 2 times higher than that of samples prepared by the conventional sintering method. 相似文献
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为提高Li4Ti5O12的导电性和倍率性能,应用二步固相法制备了Nb掺杂的Li4Ti4.95Nb0.05O12负极材料,X射线衍射、扫描电镜、激光粒度分布仪、充放电测试、循环伏安和交流阻抗等测试结果表明,合成的样品具有单一的尖晶石结构和平稳的充放电平台,粒径分布均匀,Nb掺杂改性的Li4Ti5O12具有优良的电化学性能,0.1、0.5、1和10C首次放电比容量分别为174.1、159.7、147和123.3mAh/g。10C下,循环20次后容量保持为118.1mAh/g。 相似文献
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Wujie Dong;Zichao Liu;Miao Xie;Yongjin Chen;Wenqin Ma;Song Liang;Yuzhou Bai;Fuqiang Huang; 《Advanced materials (Deerfield Beach, Fla.)》2024,36(19):2311424
Apart from Li4Ti5O12, there are few anode substitutes that can be used in commercial high-power lithium-ion batteries. Orthorhombic T-Nb2O5 has recently been proven to be another substitute anode. However, monoclinic B-Nb2O5 of same chemistry is essentially inert for lithium storage, but the underlying reasons are unclear. In order to activate the “inert” B-Nb2O5, herein, nanoporous pseudocrystals to achieve a larger specific capacity of 243 mAh g−1 than Li4Ti5O12 (theoretical capacity: 175 mAh g−1) are proposed. These pseudocrystals are rationally synthesized via a “shape-keep” topological microcorrosion process from LiNbO3 precursor. Compared to pristine B-Nb2O5, experimental investigations reveal that B-Nb2O5−x delivers ≈3000 times higher electronic conductivity and tenfold enhanced Li+ diffusion coefficient. An ≈30% reduction of energy barrier for Li-ion migration is also confirmed by the theoretical calculations. The nanoporous B-Nb2O5−x delivers unique ion/electron transport channels to proliferate the reversible and deeper lithiation, which activate the “inert” B-Nb2O5. The capacitive-like behavior is observed to endow B-Nb2O5−x ultrafast lithium storage ability, harvesting 136 mAh g−1 at 100 C and 72 mAh g−1 even at 250 C, superior to Li4Ti5O12. Pouch-type full cells exhibit the energy density of ≈251 Wh kg−1 and ultrahigh power density up to ≈35 kW kg−1. 相似文献
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Geun Jun Lee Muhammad A. Abbas Moo Dong Lee Jeongmin Lee Junghyun Lee Jin Ho Bang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(29)
The nature of precursors employed in the synthesis of lithium‐ion battery cathode materials is a crucial performance‐dictating factor. Therefore, it is of great importance to establish a way to manipulate the precursor and seek a comprehensive understanding of its influence on the electrochemical behavior of a targeted electrode material. A thermal route is herein demonstrated for the synthesis of lithium‐excess LiMn2O4 (LMO) by exploiting an intriguing thermal phenomenon, thermally induced grain fining, and sheds light on how it affects the mechanism and kinetics of lithiation, and, furthermore, the electrochemical behavior of LMO. Detailed insights into the lithiation mechanism and kinetics reveal that the use of a finely grained, porous Mn3O4, which possesses an open crystal structure, is a key to the success of incorporating excess Li. In addition, this in‐depth electrochemical investigation verifies a very recent theoretical prediction of faster Li diffusion kinetics enabled by excess Li. 相似文献
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锂离子电池负极材料Li4-xMgxTi5O12的制备及性能研究 总被引：1，自引：0，他引：1
研究了锂离子负极材料掺镁尖晶石Li4-xMgxTi5O12(0≤x≤0.25)的合成、结构及电化学性能.XRD结构分析显示Mg2 进入晶格后可能占据正四面体(8a)和正八面体(16d)位置;掺镁后电导率有所提高,特别是Li3.75Mg0.25Ti5O12(x=0.25),其电化学反应阻抗显著降低,电导率提高了半个数量级;同时降低了面积比阻抗(ASI),改善了材料倍率性能. 相似文献
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Dong Tu Chao-Nan Xu Sunao Kamimura Yoichi Horibe Hirotaka Oshiro Lu Zhang Yoshiharu Ishii Koji Hyodo Gerard Marriott Naohiro Ueno Xu-Guang Zheng 《Advanced materials (Deerfield Beach, Fla.)》2020,32(25):1908083
Ultrasensitive and sustainable near-infrared (NIR)-emitting piezoluminescence is observed from noncentrosymmetric and ferroelectric-phase Sr3Sn2O7 doped with rare earth Nd3+ ions. Sr3Sn2O7:Nd3+ (SSN) with polar A21am structure is demonstrated to emit piezoluminescence of wavelength of 800–1500 nm at microstrain levels, which is enhanced by the ferroelectrically polarized charges in the multipiezo material. These discoveries provide new research opportunities to study luminescence properties of multipiezo and piezo-photonic materials, and to explore their potential as novel ultrasensitive probes for deep-imaging of stress distributions in diverse materials and structures including artificial bone and other implanted structures (in vivo, in situ, etc). 相似文献
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溶胶-凝胶法合成锂离子筛前驱体LiMn2O4的研究 总被引：6，自引：0，他引：6
用溶胶 凝胶法、以柠檬酸和乙二醇作为聚合反应的单体合成了正尖晶石结构LiMn2 O4的前驱体 ,研究了反应物摩尔比、pH值及焙烧温度对材料性能的影响 ,并通过XRD、IR和SEM等方法研究了柠檬酸螯合法合成正尖晶石结构LiMn2 O4 的溶胶 凝胶过程 ,探讨了反应机理。研究表明白 ,在Li/Mn摩尔比为 0 6、pH值为 3 0及焙烧温度为 6 0 0℃时 ,合成的正尖晶石结构LiMn2 O4 的前驱体具有较好的晶粒结构 ,其一次粒子直径大多在 1 0 0nm以内。 相似文献
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以共沉淀法制备的纳米(75mol%Bi2O3+25mol%Y2O3)混合粉体作为原料,通过无压反应烧结工艺制备了纳米Bi2O3-Y2O3快离子导体.对烧结过程中高导电相(纳米δ-Bi2O3)的形成规律研究表明固溶反应发生在烧结过程的初期,在烧结过程中晶粒生长规律符合(D-Do)2=K·t抛物线方程.用模式识别技术对δ-Bi2O3相生成的工艺条件进行优化的工艺参数优化区为Y＞-1.846X+3.433(X=0.0059T+0.0101t,Y=-0.0059T+0.0101t,式中,T为烧结温度,t为烧结时间).在T=600℃,t=2h无压反应烧结条件下,纳米晶Bi2O3-Y2O3快离子导体材料的相对密度可达96%以上,并且微观结构致密均匀,很少有残留气孔和裂纹,平均晶粒尺寸在100nm以下. 相似文献
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Yue Yu Gang Huang Jia-Zhi Wang Kai Li Jin-Ling Ma Xin-Bo Zhang 《Advanced materials (Deerfield Beach, Fla.)》2020,32(38):2004157
Lithium metal is the only anode material that can enable the Li−O2 battery to realize its high theoretical energy density (≈3500 Wh kg−1). However, the inherent uncontrolled dendrite growth and serious corrosion limitations of lithium metal anodes make it experience fast degradation and impede the practical application of Li−O2 batteries. Herein, a multifunctional complementary LiF/F-doped carbon gradient protection layer on a lithium metal anode by one-step in situ reaction of molten Li with poly(tetrafluoroethylene) (PTFE) is developed. The abundant strong polar C-F bonds in the upper carbon can not only act as Li+ capture site to pre-uniform Li+ flux but also regulate the electron configuration of LiF to make Li+ quasi-spontaneously diffuse from carbon to LiF surface, avoiding the strong Li+-adhesion-induced Li aggregation. For LiF, it can behave as fast Li+ conductor and homogenize the nucleation sites on lithium, as well as ensure firm connection with lithium. As a result, this well-designed protection layer endows the Li metal anode with dendrite-free plating/stripping and anticorrosion behavior both in ether-based and carbonate ester-based electrolytes. Even applied protected Li anodes in Li−O2 batteries, its superiority can still be maintained, making the cell achieve stable cycling performance (180 cycles). 相似文献