Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention relates to a method of separating tellurium (Te) and selenium (Se) by using a neutral extractant (for example, either one of TBP and TEHP, or in combination thereof) from a dissolved solution of tellurium, such as a waste thermoelectric material. When tellurium and selenium are separated by using the method of this invention from a dissolved solution in which a Bi2Te3-based waste thermoelectric material is dissolved, a recovery rate of 97% or more and a separation factor of 400 or more for tellurium may be achieved, and therefore, tellurium and selenium may be separated in a very effective and economic manner as compared to conventional methods. Further, the present invention is characterized in that environmental pollution issues may be significantly reduced as compared with conventional methods carried out in a strong acidic solution since the present separation and extraction is conducted under a relative weak acid atmosphere in a pH range of 1.0 to 1.5.

Abstract: Disclosed is a cathode active material having a core-shell structure. The core-shell cathode active material includes a core including a lithium transition metal oxide with excellent electrochemical properties and a shell formed by coating the surface of the core with a transition metal oxide. The formation of the shell by coating a transition metal oxide on the surface of the core comprising a lithium transition metal oxide prevents the structure of the lithium transition metal oxide from collapsing and inhibits the dissolution of manganese ions, enabling the fabrication of a hybrid capacitor with improved energy density and rate characteristics. Also disclosed is a method for producing the cathode active material.

Abstract: 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 Bi2Te3-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.

Abstract: The present disclosure relates to a magnesium hybrid battery and a method for fabricating same. The magnesium hybrid battery according to the present disclosure, which includes magnesium or magnesium alloy metal as an anode, a cathode including a cathode active material wherein not only magnesium ion but also one or more ion selected from lithium ion and sodium ion can be intercalated and deintercalated and an electrolyte including magnesium ion and further including one or more ion selected from lithium ion and sodium, can overcome the limitation of the existing magnesium secondary battery and provide improved battery capacity, output characteristics, cycle life, safety, etc.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 ?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.

Abstract: 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.

Abstract: 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.

Abstract: 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 Bi2Te3-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.

Abstract: 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.

Abstract: An apparatus and a method for recovery of sulfur hexafluoride is provided. Sulfur hexafluoride (SF6) 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, SF6 gas may be concentrated to maximize the SF6 recovery ratio before the separation and recovery processes through the separation membrane modules. Furthermore, sulfur dioxide (SO2) and moisture included in the SF6 waste gas may be removed effectively so as to extend the service life of the separation membrane modules.

Abstract: 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.

Abstract: Disclosed are a silicon nanostructured material with theoretical storage capacity of energy resulting from electrochemical reaction with lithium improved more than 10 times as compared to the existing graphite material and having superior output characteristics, an electrode including the same, and a secondary battery and an electrochemical capacitor including the electrode as a negative electrode. The physical stability of the electrode active material is improved and an electrode with high performance can be obtained. Since more energy can be stored as compared to the graphite material of the same thickness and high-output performance can be achieved through the nanostructure, energy density can be remarkably improved as compared to the existing lithium-ion battery by about 2 times. An asymmetric lithium-ion secondary battery including the electrode active material is applicable to storage of renewable energy, ubiquitous power source, power supply for machinery and vehicles, or the like.

Abstract: Disclosed is an electrode coated with a metal-doped carbon film. A metal-doped carbon film covers the interface of an electrode active material where it contacts an electrolyte. Such an artificial interface improves ion and electrical conductivity of the electrode interface and prevents pass of water or electrolyte during electrochemical reactions, thereby preventing undesired reactions.

Abstract: An apparatus and a method for recovery of sulfur hexafluoride is provided. Sulfur hexafluoride (SF6) 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, SF6 gas may be concentrated to maximize the SF6 recovery ratio before the separation and recovery processes through the separation membrane modules. Furthermore, sulfur dioxide (SO2) and moisture included in the SF6 waste gas may be removed effectively so as to extend the service life of the separation membrane modules.