Korea Advanced Institute of Science and Technology

Ho Gi Kim

Yung Park

Yi Sup Han

Won Jae Lee

Kevin Knowles

Tae Suk Chung

Kyu Sung Park

Soon Gil Yoon

Joon Hyung Ahn

A method for manufacturing lithium-manganese oxide powders for use in a lithium secondary battery is provided. The method includes the steps of dissolving in nitric acid a composition selected from the group consisting of: manganese oxide, manganese carbonate, or manganese to form a manganese solution, and then dissolving in the manganese solution a composition selected from the group consisting of lithium carbonate, lithium hydroxide, or lithium acetate. Glycine is added to the mixed metal solution and the mixed metal solution is dried in a vacuum dryer to form a combustible resin. The combustible resin is then ignited at room temperature and the combusted products are calcinated.

Method of manufacturing lithium-manganese oxide for use in lithium secondary battery

A method for manufacturing LiMn O powders for use in a lithium secondary battery positive electrode, is provided, in which oxide or carbonate is used as a positive electrode material, a solution is dried at a temperature higher than 150&deg; C., and the resulting matter is put into a reaction furnace in order to be calcinated for a short time, after treating by spontaneous combustion. A certain degree of crystallization of the positive electrode powders can be obtained in the spontaneous combustion process. Thus, a battery having a large charging and discharging capacity and a long life cycle can be manufactured even under a high current condition.

Method for manufacturing lithium-manganese oxide powders for use in lithium secondary battery

Disclosed is a high dielectric capacitor composition consisting of Pb(Fe,Nb,)O,, Pb(Fe,Ta,)O,, Pb(Ni,Nb,)O,and Pb(Zn,Nb,)O,in association with manganese nitrate (Mn(NO,),.4H,O). It has a dielectric constant of 10,000 or higher with a relatively low loss factor of 2.6% or less, showing the temperature properties of Y5V.

High dielectric ceramic composition

A microwave dielectric composition, comprising a basic composition, represented by the following formula:

Microwave dielectric ceramic composition

A method for forming SBT ferroelectric thin film. Sr(C.sub.5 F.sub.6 HO.sub.2).sub.2, Bi(C.sub.6 H.sub.5).sub.3 and Ta(C.sub.2 H.sub.5 O).sub.5 are used as the precursors of Sr, Bi and Ta and bubbled at a temperature of 110-130.degree. C., 140-160.degree. C., and 120-140.degree. C., respectively. The deposition of the precursors on a substrate is carried out at 500-550.degree. C. in plasma by using an RF power of 100-150 W. Having a residual polarity (Pr) of 15 .mu.C/cm.sup.2 or higher and a coercive electric field (Ec) of 50 kV/cm or less and, the SBT ferroelectric thin film does not show a fatigue phenomenon until 1.times.10.sup.11 cycles as measured under 6V bipolar square pulse in the structure comprising Pt upper and lower electrodes and thus, can be applied for non-volatile memory devices.

Method for forming SBT ferroelectric thin film

A microwave dielectric composition superior in all dielectric constant, product of resonant frequency by quality coefficient and temperature-dependent coefficient of resonant frequency, can be prepared by mixing a main oxide formulation consisting of lead oxide, calcium oxide, zirconium oxide and tin oxide with manganous nitrate (Mn(NO.sub.3).sub.2.4H.sub.2 O), calcining the mixture at a temperature of about 1,000 to 1,200.degree. C., pulverizing and molding the mixture, and sintering the molded body at a temperature of about 1,200 to 1,550.degree. C. in an oxygen atmosphere. It is 100 or greater in dielectric constant, 4,000 or greater in the product of resonant frequency by quality coefficient and .+-.3 mmp/.degree. C. or less in temperature-dependent coefficient of resonant frequency.

Growing community of inventors

Seoul, South Korea

Ho Gi Kim