Microstructural Control of Mn-Zn Ferrite with Addition of Seed Grains

In order to obtain desired electromagnetic properties, high initial permeability and good frequency dependance of initial permeability, seeding effects are experimented in Mn-Zn ferrite system. As adding seed grain, calcined at sintering temperature, abnormal grains are disappeared clearly, but the density of sintered Mn-Zn ferrite body and initial permeability of this ferrite body are decreased. On the contrary, in case of adding seed grain which were calcined below the calcination temperature of matrix particle, abnormal grains were remain but the initial permeability is increased with proper seed content. Compared these results with those of experiments on additive variations, mean particle size controls, sintering conditions, seeding affects on the microstructure of Mn-Zn ferrite similarly

Comparative Study on Performances of Composite Anodes of SiO, Si and Graphite for Lithium Rechargeable Batteries

The electrochemical performances of anode composites comprising elemental silicon (Si), silicon monoxide (SiO), and graphite (C) were investigated. The composite devoid of elemental silicon (SiO:C = 1:1) and its carbon coated composite showed reduced capacity degradation with measured values of 606 and 584 mAh/g at the fiftieth cycle. The capacity retention nature when the composites were cycled followed the order of Si:SiO:C = 3:1:4 < Si:SiO:C = 2:2:4 < SiO:C = 1:1 < SiO:C = 1:1 (carbon coated). A comparison of the capacity retention properties for the composites in terms of the silicon content showed that a reduced silicon content increased the stability of the composite electrodes. Even though the carbon-coated composite delivered low capacity during cycling compared to the other composites, its low capacity degradation made the anode a better choice for lithium ion batteries

Thermal Behavior of LixCoO2 Cathode and Disruption of Solid Electrolyte Interphase Film

Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and ion chromatography(IC) were employed to analyze the thermal behavior of LixCoO2 cathode material of lithium ion battery. The mass loss peaks appearing between 60 and 125 oC in TGA and the exothermic peaks with 4.9 and 7.0 J/g in DSC around 75 and 85 oC for the LixCoO2 cathodes of 4.20 and 4.35 V cells are explained based on disruption of solid electrolyte interphase (SEI) film. Low temperature induced HF formation through weak interaction between organic electrolyte and LiF is supposed to cause carbonate film disruption reaction, Li2CO3 + 2HF → 2LiF + CO2 + H2O. The different spectral DSC/TGA pattern for the cathode of 4.5 V cell has also been explained. Presence of ionic carbonate in the cathode has been identified by ion chromatography and LiF reported by early researchers has been used for explaining the film SEI disruption process. The absence of mass loss peak for the cathode washed with dimethyl carbonate (DMC) implies ionic nature of the film. The thermal behavior above 150 oC has also been analyzed and presented

Improvement of cycle behaviour of SiO/C anode composite by thermochemically generated Li4SiO4 inert phase for lithium batteries

A new anode composite material is prepared by thermal treatment of a blend made of silicon monoxide (SiO) and lithium hydroxide (LiOH) at 550 ◦C followed by ball milling with graphite. X-ray diffraction pattern confirms the presence of Li4SiO4 in the thermally treated (SiO + LiOH) material. The electrode appears to be smooth and glassy as evident from observation with a scanning electron microscope (SEM), possibly due to the presence of nano-silicon and Li4SiO4 particles, and exhibits superior performance with a charge capacity of ∼333mAhg−1 at the 100th cycle with a low-capacity fade on cycling. Cyclic voltammograms of the electrode predict high power capability. On the other hand, the electrode comprising of only SiO and C prepared through ball milling, devoid of Li4SiO4, shows hard crust particulates in the electrode exhibiting low charge–discharge capacities with cyclin

Health, health promotion and the elderly

This paper looks at the findings from 178 interviews with people aged over 75 years, examining the importance of health and health promotion to the elderlyPeer reviewe