共查询到20条相似文献,搜索用时 15 毫秒
1.
Zhong Dong Peng Yan Bing Cao Guo Rong Hu Ke Du Xu Guang Gao Zheng Wei Xiao 《中国化学快报》2009,20(8):1000-1004
A novel synthetic method of microwave processing to prepare Li_2FeSiO_4 cathode materials is adopted.The Li_2FeSiO_4 cathode material is prepared by mechanical ball-milling and subsequent microwave processing.Olivin-type Li_2FeSiO_4 sample with uniform and fine particle sizes is successfully and fast synthesized by microwave heating at 700℃in 12 min.And the obtained Li_2FeSiO_4 materials show better electrochemical performance and microstructure than those of Li_2FeSiO_4 sample by the conventional solids... 相似文献
2.
《Progress in Solid State Chemistry》2014,42(4):128-148
Finding appropriate positive electrode materials for Li-ion batteries is the next big step for their application in emerging fields like stationary energy storage and electromobility. Among the potential materials 3d-transition metal doped spinels exhibit a high operating voltage and, therefore, are highly promising cathode materials which could meet the requirements regarding energy and power density to make Li-ion batteries the system of choice for the above mentioned applications. The compounds considered here include substituted Mn-based spinels such as LiM0.5Mn1.5O4 (M = Ni, Co, Fe), LiCrMnO4 and LiCrTiO4. In this review, the recent researches conducted on these spinel materials are summarized. These include different routes of synthesis, structural studies, electrode preparation, electrochemical performance and mechanism of Li-extraction/insertion, thermal stability as well as degradation mechanisms. Note that even though the Ni-, Co-, and Fe-doped materials share the same chemical formula, the oxidation state distributions as well as the operating voltages are different among them. Furthermore, apart from the initial structural similarity, the Li-intercalation takes place through different mechanisms in different materials. In addition, this difference in mechanism is found to have considerable influence on the long-term cycling stability of the material. The routes to improve the electrochemical performance of some of the above candidates are discussed. Further emphasis is given to the parameters that limit their application in current technology, and strategies to overcome them are addressed. 相似文献
3.
Synthesis of MXene-supported layered MoS2 with enhanced electrochemical performance for Mg batteries
In this paper, the petal-like MoS2/MXene composite has been successfully synthesized by one-step hydrothermal method. With the combination of few-layer MoS2 nanosheets and the high conductive MXene substrate, the composite exhibits enhanced capacities and rate performance as cathode material of Mg batteries. 相似文献
4.
本文首先通过共沉淀法和固相球磨法制备了纳米级的LiNi0.5Mn1.5O4高电压正极材料,然后通过溶胶-凝胶法制备了表面包覆CuO的CuO-LiNi0.5Mn1.5O4复合材料.通过对CuO包覆量为1%,3%和5%的复合材料的电化学性能对比,发现当包覆量为1%时,材料的性能最佳.在1 C下,材料的放电比容量高达126.1 mA h g?1,循环100次后容量保持率在99.5%.CuO包覆在纳米LiNi0.5Mn1.5O4材料表面,阻止电解液与活性颗粒的直接接触,削弱了电解液与LiNi0.5Mn1.5O4的相互作用,进而在一定程度上减缓了电解液的分解;CuO的包覆同时还缓解了电解液中HF对材料的攻击,阻止了锰的溶解和由此带来的结构改变,进而提高了材料的循环稳定性. 相似文献
5.
《Progress in Solid State Chemistry》2014,42(4):175-183
Reactions and charge transfer at cathode/electrolyte interfaces affect the performance and the stability of Li-ion cells. Corrosion of active electrode material and decomposition of electrolyte are intimately coupled to charge transfer reactions at the electrode/electrolyte interfaces, which in turn depend on energy barriers for electrons and ions. Principally, energy barriers arise from energy level alignment at the interface and space charge layers near the interface, caused by changes of inner electric (Galvani) potential due to interfacial dipoles and concentration profiles of electronic and ionic charge carriers.In this contribution, we introduce our surface science oriented approach using photoemission (XPS, UPS) to investigate cathode/electrolyte interfaces in Li-ion batteries. After an overview of the processes at cathode/electrolyte interfaces as well as currently employed analysis methods, we present the fundamentals of contact potential formation and energy level alignment (electrons and ions) at interfaces and their analysis with photoemission. Subsequently, we demonstrate how interface analysis can be employed in Li-ion battery research, yielding new and valuable insights, and discuss future benefits. 相似文献
6.
《Arabian Journal of Chemistry》2022,15(9):104026
Organic carbonyl-based compounds with redox-active site have recently gained full attention as organic cathode material in lithium-ion batteries (LIBs) owing to its high cyclability, low cost, high abundance, tunability of their chemical structure compared to traditionally used inorganic material. However, the utilization of organic carbonyl-based compounds in LIBs is limited to its poor charge capacity and dissolution of lower molecular weight species in electrolytes. In this study, we theoretically investigated five set of cyclohexanone derivatives (denoted as: H1, H2, H3, H4, and H5) and influence of functional groups (-F and -NH2) on their electrochemical properties using advanced level density functional theory (DFT) with the Perdew-Burke-Ernzenhof hybrid functional (PBE0) at 6-31+G(d,p) basis set. In line with the result gotten, the HOMO-LUMO results revealed that compound H5 is the most reactive among the studied cyclohexanone derivatives exhibiting energy gap values of 0.552, 0.532, 0.772 eV for free optimized structures and structurally engineered structures with electron withdrawing group (EWG) and electron donating group (EDG) respectively. Also, results from electrochemical properties of the studied compounds lithiated with only one lithium atom displayed that compound H2 exhibited interesting redox potential and energy density for all the studied structures in free optimized state (1108.28 W h kg?1, 4.92 V vs Li/Li+), with EWG (648.22 W h kg?1, 3.313 V Li/Li+), and with EDG (1002.4 W h kg?1, 5.011 V vs Li/Li+). From our result, we can infer that compound H2 and H3 with corresponding redox potential, energy density and theoretical charge capacity value of 4.92 V vs Li/Li+, 1108.28 W h kg?1, 225.26 mA h g?1 and 5.168 V, 1041.61 W h kg?1, 201.55 mA h g?1 lithiated with only one lithium atom in free optimized state are the most suitable compounds to be employed as organic cathode material in lithium-ion batteries among all the investigated cyclohexanone derivatives. 相似文献
7.
Mohan M. Rao C. Liebenow M. Jayalakshmi H. Wulff U. Guth F. Scholz 《Journal of Solid State Electrochemistry》2001,5(5):348-354
Lithium nickelate (Li0.88Ni1.12O2), lithium cobaltate (LiCoO2) and lithium manganate (LiMn2O4) were synthesized by fast self-propagating high-temperature combustion and their phase purity and composition were characterized
by X-ray diffraction and inductively coupled plasma spectroscopy. The electrochemical behaviour of these oxides was investigated
with regard to potential use as cathode materials in lithium-ion secondary batteries. The cyclic voltammograms of these cathode
materials recorded in 1 M LiClO4 in propylene carbonate at scan rates of 0.1 and 0.01 mV s–1 showed a single set of redox peaks. Charge-discharge capacities of these materials were calculated from the cyclic voltammograms
at different scan rates. The highest discharge capacity was observed in the case of Li0.88Ni1.12O2. In all the cases, at a very slow scan rate (0.01 mV s–1) the capacity of the charging (oxidation) process was higher than the discharging (reduction) process. A strong influence
of current density on the charge-discharge capacity was observed during galvanostatic cycling of Li0.88Ni1.12O2 and LiMn2O4 cathode materials. LiMn2O4 can be used as cathode material even at higher current densities (1.0 mA cm–2), whereas in the case of Li0.88Ni1.12O2 a useful capacity was found only at lower current density (0.2 mA cm–2). For the fast estimation of the cycling behaviour of LiMn2O4, a screening method was used employing a simple technique for immobilizing microparticles on an electrode surface.
Electronic Publication 相似文献
8.
W. Tang L.L. Liu S. Tian L. Li L.L. Li Y.B. Yue Y. Bai Y.P. Wu K. Zhu R. Holze 《Electrochemistry communications》2011,13(11):1159-1162
LiMn2O4 nanorods were prepared by a facile hydrothermal method in combination with traditional solid-state reactions and characterized by X-ray diffraction analysis. Their electrochemical behavior was tested by cyclic voltammetry and repeated charge/discharge cycling. Results show that the reversible intercalation/deintercalation of Li-ions into/from LiMn2O4 cathode can yield up to 110 mAh/g at 4.5 C, and still retains 88% at the very large charge rate of 90 C with well-defined charge and discharge plateaus. It presents very high power density, up to 14.5 kW/kg, and very excellent cycling behavior, 94% capacity retention after 1200 cycles. It is thus a competitor for LiFePO4. 相似文献
9.
Qi Guo Zhenhua Sun Man Gao Zhi Tan Bingsen Zhang Dang Sheng Su 《Journal of Energy Chemistry》2013,22(2):347-355
Vanadium pentoxide (V2O5) exhibits high theoretical capacities when used as a cathode in lithium ion batteries (LIBs), but its application is limited by its structural instability as well as its low lithium and electronic conductivities. A porous composite of V2O5-SnO2/carbon nanotubes (CNTs) was prepared by a hydrothermal method and followed by thermal treatment. The small particles of V2O5, their porous structure and the coexistence of SnO2 and CNTs can all facilitate the diffusion rates of the electrons and lithium ions. Electrochemical impedance spectra indicated higher ionic and electric conductivities, as compared to commercial V2O5. The V2O5-SnO2/CNTs composite gave a reversible discharge capacity of 198 mAh·g?1 at the voltage range of 2.05–4.0 V, measured at a current rate of 200 mA·g?1, while that of the commercial V2O5 was only 88 mAh·g?1, demonstrating that the porous V2O5-SnO2/CNTs composite is a promising candidate for high-performance lithium secondary batteries. 相似文献
10.
LiMn2O4 cathode materials with high discharge capacity and good cyclic stability were prepared by a simple one-step hydrothermal treatment of KMnO4, aniline and LiOH solutions at 120–180 °C for 24 h. The aniline/KMnO4 molar ratio (R) and hydrothermal temperature exhibited an obvious influence on the component and phase structures of the resulting product. The precursor KMnO4 was firstly reduced to birnessite when R was less than 0.2:1 at 120–150 °C. Pure-phased LiMn2O4 was formed when R was 0.2:1, and the LiMn2O4 was further reduced to Mn3O4 when R was kept in the range of 0.2–0.3 at 120–150 °C. Moreover, LiMn2O4 was fabricated when R was 0.15:1 at 180 °C. Octahedron-like LiMn2O4 about 300 nm was prepared at 120 °C, and particle size decreased with an increase in hydrothermal temperature. Especially, LiMn2O4 synthesized at 150 °C exhibited the best electrochemical performance with the highest initial discharge capacity of 127.4 mAh g−1 and cycling capacity of 106.1 mAh g−1 after 100 cycles. The high discharge capacity and cycling stability of the as-prepared LiMn2O4 cathode for rechargeable lithium batteries were ascribed to the appropriate particle size and larger cell volume. 相似文献
11.
12.
Qing Lai Jiang Ke Du Yan Bing Cao Zhong Dong Peng Guo Rong Hu Ye Xiang Liu 《中国化学快报》2010,21(11):1382-1386
<正>LiMn_2O_4 spinel cathode materials were modified with 2 wt.%Li-M-PO_4(M=Co,Ni,Mn) by polyol synthesis method.The phosphate surface-modified LiMn_2O_4 cathode materials were physically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS).The charge-discharge test showed that the cycling and rate capacities of LiMn_2O_4 cathode materials were significantly enhanced by stabilizing the electrode surface with phosphate. 相似文献
13.
In this paper,we report on the preparation of Li_2FeSiO_4,sintered Li_2FeSiO_4,and Li_2FeSiO_4-C composite with spindle-like morphologies and their application as cathode materials of lithium-ion batteries.Spindle-like Li2FeSi04 was synthesized by a facile hydrothermal method with(NH_4)_2Fe(SO_4)_2 as the iron source.The spindle-like Li_2FeSiO_4 was sintered at 600 ℃ for 6 h in Ar atmosphere.Li_2FeSiO_4-C composite was obtained by the hydrothermal treatment of spindle-like Li_2FeSiO_4 in glucose solution at 190 ℃ for 3 h.Electrochemical measurements show that after carbon coating,the electrode performances such as discharge capacity and high-rate capability are greatly enhanced.In particular.Li_2FeSiO_4-C with carbon content of 7.21 wt%delivers the discharge capacities of 160.9 mAh·g~(-1) at room temperature and 213 mAh·g~(-1) at45℃(0.1 C),revealing the potential application in lithium-ion batteries. 相似文献
14.
Gu Siyong Hsieh Chien-Te Huq Mohammad Mahmudul Hsu Jo-Pei Ashraf Gandomi Yasser Li Jianlin 《Journal of Solid State Electrochemistry》2019,23(5):1399-1407
Journal of Solid State Electrochemistry - Magnesium-ion batteries are fabricated with MgCo2O4/graphite composites as the cathode material. MgCo2O4 nanoparticles are prepared using a... 相似文献
15.
采用低温固相法合成了具有纳米结构的LiV3O8材料.扫描电子显微镜(SEM)及透射电子显微镜(TEM)测试显示该材料具有纳米结构.X射线衍射(XRD)表明该材料属于单斜晶系,P21Im空间群.并采用循环伏安法(CV)及电化学阻抗谱图测试对该材料在1、2 mol·L-1Li2SO4水溶液及饱和Li2SO4水溶液中的电化学行为进行了研究.结果表明,LiV3O8在饱和Li2SO4水溶液中具有最好的电化学性能.以LiV3O8作为负极材料,LiNi1/3Co1/3Mn1/3O2作为正极材料,饱和Li2SO4水溶液作为电解液组成了水性锂离子电池,进行恒流充放电测试,结果表明,在0.5C(1C=300 mA·g-1)的充放电倍率下,该水性锂离子电池的首次放电比容量为95.2 mAh·g-1,循环100次后仍具有37.0 mAh·g-1的放电比容量. 相似文献
16.
A novel synthetic route for LiFePO_4/C cathode materials by addition of starch for lithium-ion batteries 总被引:1,自引:0,他引:1
Shao Hua Luo Zi Long Tang Jun Biao Lu Zhong Tai Zhang State Key Laboratory of New Ceramics Fine Processing Department of Materials Science Engineering Tsinghua University Beijing China Graduate School at Shenzhen Tsinghua University Shenzhen China 《中国化学快报》2007,18(2):237-240
LiFePO4/Carbon composite cathode material was prepared using starch as carbon source by spray-pelleting and subsequent pyrolysis in N2. The samples were characterized by XRD, SEM, Raman, and their electrochemical performance was investigated in terms of cycling behavior. There has a special micro-morphology via the process, which is favorable to electrochemical properties. The discharge capacity of the LiFePO4.C composite was 170 mAh g-1, equal to the theoretical specific capacity at 0.1 C rate. At 4 C current density, the specific capacity was about 80 mAh g-1, which can satisfy for transportation applications if having a more flat discharge flat. 相似文献
17.
Xiang Ming He Jian Jun Li Yan Cai Yaowu Wang Jierong Ying Changyin Jiang Chunrong Wan 《Journal of Solid State Electrochemistry》2005,9(6):438-444
A novel process is proposed for synthesis of spinel LiMn2O4 with spherical particles from the inexpensive materials MnSO4, NH4HCO3, and NH3H2O. The successful preparation started with carefully controlled crystallization of MnCO3, leading to particles of spherical shape and high tap density. Thermal decomposition of MnCO3 was investigated by both DTA and TG analysis and XRD analysis of products. A precursor of product, spherical Mn2O3, was then obtained by heating MnCO3. A mixture of Mn2O3 and Li2CO3 was then sintered to produce LiMn2O4 with retention of spherical particle shape. It was found that if lithium was in stoichiometric excess of 5% in the calcination of spinel LiMn2O4, the product had the largest initial specific capacity. In this way spherical particles of spinel LiMn2O4 were of excellent fluidity and dispersivity, and had a tap density as high as 1.9 g cm–3 and an initial discharge capacity reaching 125 mAh g–1. When surface-doped with cobalt in a 0.01 Co/Mn mole ratio, although the initial discharge capacity decreased to 118 mAh g–1, the 100th cycle capacity retention reached 92.4% at 25°C. Even at 55°C the initial discharge capacity reached 113 mAh g–1 and the 50th cycle capacity retention was in excess of 83.8%. 相似文献
18.
采用高能球磨法通过不同球磨时间合成 xLiF-(Ni1/6Co1/6Mn4/6)3O4新型正极材料,并对材料进行石墨烯复合改性,提高其性能。结合X-射线衍射(XRD)、扫描电镜(SEM)、电化学性能测试和X-射线电子能谱(XPS)对xLiF-(Ni1/6Co1/6Mn4/6)3O4正极材料性能进行表征。研究表明,球磨24小时产物的放电容量最高,为157.3 mAh g-1。并且LiF与(Ni1/6Co1/6Mn4/6)3O4比例为1.5:1(x=1.5)时放电容量最高。此外正极材料添加石墨烯能改善材料的电化学性能,石墨烯复合量为20%,在室温、0.05 C(1C=250 mAh g-1)、1.5 -4.8 V下,材料首圈的放电比容量为235 mA hg -1,相较于无石墨烯的材料,在1 C和5 C倍率下,放电比容量分别为151和114 mAh g-1。同时分析了正极材料放电容量随截止电压的变化,确定了复合正极材料在高电压下有获得更高放电容量的潜力。 相似文献
19.
Marincaş Alexandru-Horatiu Goga Firuţa Dorneanu Sorin-Aurel Ilea Petru 《Journal of Solid State Electrochemistry》2020,24(3):473-497
Journal of Solid State Electrochemistry - Lithium manganese spinel (LiMn2O4) is considered a promising cathode material for lithium-ion batteries (LIBs). Its structure, morphology, and... 相似文献