Korea Institute of Science and Technology

Posco M-tech

Recytec. Inc.

Joong Kee Lee

Byung Won Cho

Kyung Yoon Chung

Hwa Young Lee

Hyung Sun Kim

Won Young Chang

Joo Man Woo

Jae Hyun Cho

Sang Hoon Lee

Min Woo Lee

Hyun Jung Lee

Won Il Cho

Il Doo Kim

Sang Hyup Lee

Si Hyoung Oh

Sang Ok Kim

Un Sek Kim

Jae Gyu Jee

Sang Eun Park

Chan Wook Jeon

Joon Chul Choi

Han Byul Kim

Yong Sang Kim

Junghoon Ha

Dalkeun Park

Disclosed is an electrolyte solution for a magnesium rechargeable battery with a high ionic conductivity and a wide electrochemical window compared to the conventional electrolyte solution. The electrolyte solution is prepared by dissolving magnesium metal into the ethereal solution using combinations of metal chloride catalysts. The electrolyte solution can be applied to fabricate magnesium rechargeable batteries and magnesium hybrid batteries with a markedly increased reversible capacity, rate capability, and cycle life compared to those batteries employing the conventional electrolyte solution. Also disclosed is a method for preparing the electrolyte.

Electrolyte for magnesium rechargeable battery and preparation method thereof

Provided are an electrolyte for a magnesium secondary battery having improved ion conductivity and stability, and a method for preparing the same. The electrolyte for a magnesium secondary battery shows higher ion conductivity as compared to the electrolyte according to the related art, increases the dissociation degree of a magnesium halide electrolyte salt, and provides stable electrochemical characteristics. In addition, after determining the capacity, output characteristics and cycle life of the magnesium secondary battery including the electrolyte, the battery provides significantly higher discharge capacity after 100 cycles, as compared to the electrolyte according to the related art. Therefore, the electrolyte may be useful for an electrolyte solution of a magnesium secondary battery.

Electrolyte for magnesium secondary battery and preparation method thereof

A method for separating tellurium includes separating and recovering tellurium (Te) from a dissolved solution containing the tellurium using a solvent extraction by an extractant, which contains one selected from a group consisting of tributyl phosphate (TBP), tris(2-ethylhexyl) phosphate (TEHP) and a combination thereof. The method may separate and recover the tellurium as a high-priced metallic element from a material, such as a BiTe-based waste thermoelectric material, which contains not only the tellurium but also other metallic elements, simply and economically using a solvent extraction, whereby the tellurium with high yield and high purity can be separated, recovered and recycled.

Separation of tellurium by solvent extraction method

A recovery method of nickel according to the present invention comprises pretreatment step to prepare a solution for electrolysis by adding hexanesulfonate salt to a treatment solution including nickel, and nickel recovery step to recover nickel in a metal form by electrolysis of the above solution for electrolysis. The present invention can produce nickel in high purity with simple process with low cost, and can recover and reproduce nickel in a metal form with at least 99.5% of high purity and at least 90% of recovery rate.

Recovery method of nickel from spent electroless nickel plating solutions by electrolysis

A separation method of zirconium and hafnium is described which includes an extraction process of agitating an undiluted aqueous solution containing zirconium, hafnium, and sulfuric acid with a first stirring solution containing an acidic extractant to produce a first extract solution in which the hafnium is extracted by the acidic extractant; and a recovery process of agitating the first extract solution with a second stirring solution containing a citric acid solution to produce a citric acid solution after extraction in which zirconium is reverse-extracted from the first extract solution to the citric acid solution so as to recover zirconium contained in the first extract solution. The method may reduce the amount of extractant while greatly enhancing the separation effect of zirconium and hafnium, and increase zirconium recovery rate by more than 97% through an additional zirconium recovery process while reducing a hafnium content in zirconium by less than 50 ppm.

Separation method of zirconium and hafnium by solvent extraction process

The present invention relates to a method of preparing a porous silicon nanorod structure composed of columnar bundles having a diameter of 50-100 nm and a length of 2-5 &#x3bc;m, and a lithium secondary cell using the porous silicon nanorod structure as an anode active material. The present invention provides a high-capacity and high-efficiency anode active material for lithium secondary cells, which can overcome the low conductivity of silicon and improve the electrode deterioration attributable to volume expansion because it is prepared by electrodepositing the surface of silicon powder with metal and simultaneously etching the silicon powder partially using hydrofluoric acid.

Method of preparing bundle type silicon nanorod composite through electroless etching process using metal ions and anode active material for lithium secondary cells comprising the same

A photovoltaic-charged secondary battery system is provided, in which an electrode for optical power generation and an electrode for charging and discharging generated electrical energy are integrated into a single cell structure, and the potential difference between the electrodes is systematically controlled, thus maximizing the conversion efficiency of optical energy, maximizing the utilization rate of cell energy, and extending the life span of the battery. Thus, the photovoltaic-charged secondary battery system may include a transparent electrode capable of transmitting light; a PN semiconductor layer formed on the transparent electrode and generating a current by incident light; and a secondary battery layer, formed on the PN semiconductor layer, in which the current generated by the PN semiconductor layer is charged.

Photovoltaic-charged secondary battery system

An apparatus and a method for recovery of sulfur hexafluoride is provided. Sulfur hexafluoride (SF) may be separated with high-concentration and improved recovery ratio through a multi-stage separation and recovery processes using a plurality of separation membrane modules, and as well, SFgas may be concentrated to maximize the SFrecovery ratio before the separation and recovery processes through the separation membrane modules. Furthermore, sulfur dioxide (SO) and moisture included in the SFwaste gas may be removed effectively so as to extend the service life of the separation membrane modules.

Apparatus and method for recovery of sulfur hexafluoride

A separation method of zirconium and hafnium according to an example of the present invention comprising, mixing step to prepare a crude liquid for extraction, by mixing a sulfuric acid solution including zirconium and hafnium, a catalyst, and an acidic extractant; and first extraction step to form a first extract solution layer comprising the acidic extractant in which the hafnium has been extracted and a sulfuric acid solution layer separated from the first extract solution layer, wherein the acidic extractant comprises any one selected from a group consisting of D2EHPA (Di-(2-ethylhexyl)phosphoric acid), PC88A (2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester), and a combination thereof. The separation method not only saves the amount of extractant used but also increases separation effect of zirconium and hafnium known to be difficult for separating each other, without using no toxic compound such as cyan.

Separation method of zirconium and hafnium with acidic extractants

A carbon anode active material for lithium secondary battery comprising a cluster or thin film layer of a metal or metal oxide coated onto the surface of the carbon active material, a preparation method thereof, and a metal-carbon hybrid electrode and a lithium secondary battery comprising the same. The carbon active material is prepared through a gas suspension spray coating method. An electrode comprising the carbon active material according to the present invention shows excellent conductivity, high rate charge/discharge characteristics, cycle life characteristics and electrode capacity close to theoretical value.

Carbonaceous materials coated with a metal or metal oxide, a preparation method thereof, and a composite electrode and lithium secondary battery comprising the same

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Seoul, South Korea

Joong Kee Lee