LiNi0.8Co0.15Al0.05O2 coated by chromium oxide as a cathode material for lithium-ion batteries

Journal of Solid State Electrochemistry - LiNi0.8Co0.15Al0.05O2 (NCA) material was decorated with different contents of Cr2O3 (0.01–2 wt%) via a precipitation technique followed by...     

Relationship between the crystal structures of LiMn1.5Ni0.5O4 and LiMn1.5Ni0.45Fe0.05O4 and their internal resistances as cathode materials for lithium ion batteries

Journal of Solid State Electrochemistry - It has been reported that the partial substitution of Fe for Ni in LiMn1.5Ni0.5O4 improves the rate capability of batteries wherein it is used as a cathode...     

正极材料LiNi0.5Co0.5O2的电化学性能研究

以聚丙烯酰胺(PAM)为分散剂用微波—固相复合加热技术合成了层状锂离子电池正极材料LiNi0.5Co0.5O2。通过扫描电子显微镜(SEM)和X—射线粉末衍射(XRD)分析技术对材料的微观形貌和相结构进行了表征。恒电流充放电循环测试表明:材料的放电比容量高达154mAh/g,且有良好的循环性能。重点利用循环扫描伏安、计时电量和电化学交流阻抗测试技术,对材料在循环前后的电化学性能变化规律进行了探讨。结果表明,经过循环后材料的导电能力以及锂离子扩散能力都有了很大的提高。另外,材料中的锂含量对材料的导电能力也有很大的影响。     

A ternary oxide precursor with trigonal structure for synthesis of LiNi0.80Co0.15Al0.05O2 cathode material

Journal of Solid State Electrochemistry - A Ni-Co-Al ternary oxide precursor with a trigonal structure, which can be used to synthesize LiNi0.8Co0.15Al0.05O2 cathode material, was prepared by...     

Preparation and characterization of magnetic Co0.5Zn0.5Fe2O4-chitosan nanoparticles as surfactants in oilfield

Chitosan nanoparticles with magnetic properties can be potentially used as separation materials in adsorption of oil for enhanced oil recovery. Different from the traditional surfactants, the novel magnetic Co_0.5Zn_0.5Fe₂O₄-chitosan nanoparticles are of excellent biodegradation and a high level of controllability. The Co_0.5Zn_0.5Fe₂O₄-chitosan nanoparticles with core-shell structure were prepared successfully. The image of transmission electron microscope and the scanning electron microscopy showed that the cubic-shape magnetic Co_0.5Zn_0.5Fe₂O₄-particles were encapsulated by the spherical chitosan nanoparticles. The size of the Co_0.5Zn_0.5Fe₂O₄-chitosan nanoparticles was below 100 nm. The saturated magnetization of the Co_0.5Zn_0.5Fe₂O₄-chitosan nanoparticles could reach 80 emu g^?1 and showed the characteristics of superparamagnetism at the same time. The evaluation on the interfacial properties of the product demonstrated that the interfacial tension between crude oil and water could be reduce to ultra-low values (to about 10^?3 mN m^?1) when the magnetic Co_0.5Zn_0.5Fe₂O₄-chitosan nanoparticle was used in several blocks in Shengli Oilfield without other additives. Meanwhile, the magnetic Co_0.5Zn_0.5Fe₂O₄-chitosan nanoparticles possessed good salt-resisting capacity.     

Facile synthesis and long cycle life of SnSb as negative electrode material for Na-ion batteries

We report significant electrochemical performances promoting SnSb as one of the most promising negative electrode material for rechargeable batteries. Appropriately formulated with the carboxymethyl cellulose binder and cycled in fluoroethylene carbonate containing electrolyte, it could sustain a reversible capacity largely exceeding 525 mAh g^− 1 over more than 125 cycles at a rate of C/2 (55 mA/g), with a satisfactory coulombic efficiency of more than 97%. To our knowledge, this is actually the longest cycle life ever reported for an electrode material vs. sodium.     

Synthesis and electrochemical performance of LiNi0.6Co0.2Mn0.2O2 as a concentration-gradient cathode material for lithium batteries

A well-ordered and spherical LiNi0.6Co0.2Mn0.2O2 cathode material was successfully synthesized from Ni and Mn concentration-gradient precursors via co-precipitation. The crystal structure, morphology and electrochemical properties of LiNi0.6Co0.2Mn0.2O2 were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and charge-discharge tests. The material delivered an initial discharge capacity of 174.3 mAh/g at 180 mA/g （1 C rate） between 2.8 and 4.3 V and more than 93.1% of that was retained after 100 cycles. In addition, it also exhibited excellent rate capability, high cut-off voltage and temperature performance.     

Electrochemical performance of sol-gel-made Na2Ti3O7 anode material for Na-ion batteries

Journal of Solid State Electrochemistry - Nanocrystalline Na2Ti3O7 material is prepared by a newly developed sol-gel procedure. The sol-gel made Na2Ti3O7 calcined at 500 °C possesses...     

Green synthesis,characterization and anti-cancer capability of Co0.5Ni0.5Nd0.02Fe1.98O4 nanocomposites

In this study, Co_0.5Ni_0.5Nd_0.02Fe_1.98O₄ nanoparticles CoNiNd (NPs) were synthesized by combustion method linked with biosynthesis with and without different plant extracts such as Lavender, Ginger, Flax-Seed, Lemon Juice, Tragacanth Gum, and Dates Fruit. Co_0.5Ni_0.5Nd_0.02Fe_1.98O₄ nanoparticles (NPs) with plant extracts (CoNiNd plant extracts) were analyzed by XRD, TEM and SEM methods. The structure of Co-Ni spinel ferrite was confirmed by XRD and the shape and the size of nanoparticles were examined via SEM and TEM and the size was found between 17 and 25 nm. The anti-cancer activity of NPs on cancer cells such as human colorectal carcinoma (HCT-116) and human cervical cells (Hela) were investigated. The cytotoxicity of was examined by MTT assay and followed by measuring the inhibitory concentration (IC₅₀) values after 48 h treatments. The cell viability assay confirmed a decrease in the cancer cell viability post NPs treatments and showed dose-dependent inhibitory action. The treatments of CoNiNd (NPs) and CoNiNd plant extracts via Lavender plant extract showed most profound inhibitory action on both cancer cells than extracts other plant extracts. The IC₅₀ values were for HCT-116 cells were found to be in range of 15.75–42.55 µg/mL and 13.44 to 35.65 µg/mL for HeLa cells. In contrast, the treatment of CoNiNd (NPs) and CoNiNd plant extracts showed inhibitory action but the percentage of inhibition was higher in HEK-293 cells. Our results showed that CoNiNd (NPs) and CoNiNd plant extracts possess potential application in the colon and cervical cancer treatments and we recommend molecular analysis of NPs mediated cancer cell death for future applications.     

Composite cathode materials Ag-Ba0.5Sr0.5Co0.8Fe0.2O3 for solid oxide fuel cells

Silver-Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) cathodes were prepared in two ways. In the first method, Ag-BSCF composite powder was prepared in ethanol solution, where Ag nanoparticles serving as a component in the preparation of Ag-BSCF composite cathodes had been previously obtained via one-step synthesis in absolute ethanol using a neutral polymer (polyvinylpyrrolidone). To the best of our knowledge, this is the first study to use a Ag sol obtained by the above method for preparation of Ag-BSCF composite powder. Then, a paste containing this powder was screen-printed on a Sm_0.2Ce_0.8O_1.9 electrolyte and sintered at 1,000 °C. In the second technique, an aqueous solution of AgNO₃ was added to a previously sintered BSCF cathode, which was then sintered again at 800 °C. The oxygen reduction reaction at the quasi-point BSCF cathode on the Sm_0.2Ce_0.8O_1.9 electrolyte was tested by electrochemical impedance spectroscopy at different oxygen concentrations in three electrode setup. The continuous decrease of polarization resistance was observed under polarization ?0.5 V at 600 °C. The comparative studies of both obtained composite Ag-BSCF materials were performed in hydrogen-oxygen IT-SOFC involving samaria-doped ceria as an electrolyte and Ni-Gd_0.2Ce_0.8O_1.9 anode. In both cases, the addition of silver to the cathode caused an increase in current and power density compared with an IT-SOFC built with the same components but involving a monophase BSFC cathode material.     

Hierarchical hollow microcuboid LiNi0.5Mn1.5O4 as cathode material with excellent rate and cycling performance for lithium-ion batteries

Journal of Solid State Electrochemistry - The rational design of the structure is the key to engineering spinel LiNi0.5Mn1.5O4 cathode material to enhance Li+/electron transport and relieve the...     

LaF3 surface-modified LiCr0.05Mn1.95O4 cathode material with improved high-temperature performances for lithium-ion batteries

The LaF₃ surface-modified LiCr_0.05Mn_1.95O₄ samples were synthesized by co-precipitation method and characterized by high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray detector (EDX). HAADF-STEM and EDX observations showed that LaF₃ deposited on the surface of LiCr_0.05Mn_1.95O₄ particles. When tested as the cathode materials for lithium-ion battery, the LaF₃-modified LiCr_0.05Mn_1.95O₄ exhibited significantly improved cyclic and rate performances at high temperature (55?°C). Electrochemical impedance spectrum analyses demonstrated that the surface of LiCr_0.05Mn_1.95O₄ modified by LaF₃ was much more stable during the electrochemical process and could greatly facilitate the charge–transfer reaction, which may be attributed to the protection of active material by LaF₃ from the HF attack.     

Microwave solid-state synthesis of LiV(3)O(8) as cathode material for lithium batteries

A novel and economical microwave route has been developed for the synthesis of electrochemically active LiV(3)O(8) material by using a domestic microwave oven. The heating behavior of the designed reaction system guided the preparation of LiV(3)O(8) at a suitable irradiation power (i.e. heating rate), reaction time, and temperature. At the lowest irradiation power, the conversion fraction of reactants was mainly controlled by reaction temperature. Characterization results of X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopy, scanning (SEM) and transmission (TEM) electron microscopy, and BET surface areas indicated that the phases of samples prepared by microwave and traditional methods were in good agreement. Nevertheless, the crystallinity, crystallite configuration, and morphology of the samples were different, and were affected by the irradiation time and power. A floppy superposition structure of nanosheets (the size of one nanosheet was about 4.5 microm x 1.2 microm x 3 nm) was preferentially grown at the lowest irradiation power, and this effect on structure was more in evidence as the nanorods formed at the highest irradiation power. Electrochemical studies on ionic conductivity, electrochemical impedance spectroscopy (EIS), and charge-discharge capacity were carried out. It was found that the conductivity, first discharge capacity, and cycle performances of the samples were affected by the crystal size, crystallinity, and crystal configuration and defection concentration. The sample L30 prepared at the lowest irradiation power and the shortest time (30 min) showed the highest discharge capacity (335 mAh/g), but its discharge capacity decreased rapidly. By comparison, the sample L100 had a floppy superposition structure of nanosheets and a high surface area, provided a good two-dimensional channel for the transition of Li(+) ions, and was stable during the intercalation/deintercalation process of Li(+) ions, therefore the high ionic conductivity, high discharge capacity, and good cycle performance were presented. The relationship between the electrochemical properties and the irradiation power was discussed.     

Novel K+-doped Na0.6Mn0.35Fe0.35Co0.3O2 cathode materials for sodium-ion batteries: synthesis,structures, and electrochemical properties

Journal of Solid State Electrochemistry - A series of novel KxNa0.6-xMn0.35Fe0.35Co0.3O2 (x = 0, 0.005, 0.01, 0.05, 0.1) materials were successfully synthesized by the solid-state...     

Template-free solvothermal synthesis of yolk-shell V2O5 microspheres as cathode materials for Li-ion batteries

Uniform yolk-shell V(2)O(5) microspheres were synthesized via a facile template-free solvothermal route and subsequent calcination treatment in air. The resulting cathode materials showed a high specific capacity of 220 mA h g(-1) after 30 cycles and good rate capability.     

Morphology-controllable synthesis of LiMn2O4 particles as cathode materials of lithium batteries

We reported a new method for the preparation of morphology-controllable LiMn₂O₄ particles. In this method, dimension-different MnO₂ nanowires synthesized hydrothermally by adjusting the reaction temperature were used as the precursor. The morphology and structure of the resulting products were characterized with scanning electron microscope and X-ray diffraction, and the performances of the prepared LiMn₂O₄ samples as cathode material of lithium batteries were investigated by cyclic voltammetry and galvanostatic charge/discharge test. The results indicate that the morphology of LiMn₂O₄ transforms from tridimensional particle (TP) to unidimensional rod (UR) through quadrate lamina (QL) with increasing the diameter and length of MnO₂ nanowires. Although the cyclic stabilities of LiMn₂O₄-TP, LiMn₂O₄-QL, and LiMn₂O₄-UR are very close (the 0.1 C capacity after 50 cycles is 101, 93, and 99 mAh g^?1 at 25 °C, and 84, 78, and 82 mAh g^?1 at 50 °C, respectively), LiMn₂O₄-QL delivers much higher rate capacity (about 70 mAh g^?1 at 5 C and 30 mAh g^?1 at 10 C) than LiMn₂O₄-TP and LiMn₂O₄-UR (about 20 mAh g^?1 at 5 C, 3 mAh g^?1 at 10 C, 25 mAh g^?1 at 5 C, and 3 mAh g^?1 at 10 C).     

Nanocomposite of manganese ferrocyanide and graphene: A promising cathode material for rechargeable lithium ion batteries

A nanocomposite of potassium manganese ferrocyanide and graphene (12% C, 88% K_1.8Mn_1.1Fe(CN)₆∙ 0.27H₂O) was prepared by ball milling of graphene oxide powder and nanoparticles of manganese–iron Prussian Blue. It exhibits enhanced electrochemical performance compared to pure Prussian Blue with a specific capacity of 150 mAhg^− 1 at average 3.8 V vs. Li⁺/Li and a good cyclability. The nanocomposite can be considered as competitive to standard cathode materials of present rechargeable lithium ion batteries like cobalt oxide, iron phosphate or NMC.     

Thermal explosion synthesis of LiFePO4 as a cathode material for lithium ion batteries

Research on Chemical Intermediates - Olivine-type LiFePO4 cathode material was successfully synthesized by a simple method of thermal explosion (TE) using hexamethylenetetramine (C6H12N4) as fuel....     

Ultrafast auto flame synthesis for the mass production of LiCoO2 as a cathode material for Li-ion batteries

Journal of Solid State Electrochemistry - This article reports for the first time ultrafast automatic flame synthesis of high-quality LiCoO2 in open-air conditions as a cathode material for Li-ion...