Abstract: A steel bar connecting structure is disclosed. The steel bar connecting structure includes a connecting sleeve having on an inner circumference thereof an internal threaded part, and a steel bar having an external threaded part which engages with the internal threaded part. The steel bar is inserted into the connecting sleeve. Each of the internal threaded part and the external threaded part is formed such that a crest of each of threads thereof is cut. Thereby, when the steel bar is strongly coupled to the connecting sleeve, a neighboring crest and root of the internal threaded part and the external threaded part are not in contact with each other, whereas inclined flanks of the threads of the internal threaded part and the external threaded part are in close contact with each other.

Abstract: The present invention relates to a PHC pile used in a permanent retaining wall structure, and a connection method thereof, and more particularly, to a method of connecting PHC piles to each other by inserting a connection bar into connection pipes embedded in sheaths of the PHC piles. To this end, the PHC pile comprises a left connection pipe installed at one side of the sheath of the PHC pile and a right connection pipe embedded at the other opposite side of the sheath. Further, the method of connecting the PHC pile to each other comprises the steps of inserting a water-proof material into inner semi-cylindrical grooves of the connection pipes, inserting the connection bar between the connection pipes of the PHC piles, and consecutively connecting a plurality of PHC piles to one another by repeating the above steps.

Abstract: Provided is a case film for a pouch type lithium primary battery which is suitable for application in a film type lithium primary battery. The case film for a pouch type lithium primary battery includes a flexible multilayer film in which a first polymer film, a second polymer film, a metal film, and a third polymer film are sequentially stacked. The first polymer film is formed of a hydrocarbon compound substituted or non-substituted with a halogen atom. The second polymer film is formed of an amorphous or low crystalline polymer having a crystallinity of 0 to 20%. The third polymer film is formed of a crystalline polymer having a crystallinity of 40 to 100%.

Abstract: Provided is a method of designing an electrolyte composition including a nonaqueous organic solvent mixture and a lithium salt to obtain an optimal composition ratio of components of the electrolyte composition for a high charging/high-output discharging secondary battery. The method includes: selecting components of the nonaqueous organic solvent mixture; determining composition ratio ranges of the selected components satisfying such conditions that an average dielectric constant, an average viscosity, and an average boiling point satisfy predetermined boundary values; dividing the ranges of the composition ratios into a plurality of groups; selecting a representative composition ratio of each of the groups; adding a lithium salt to a nonaqueous organic solvent mixture having the representative composition ratio to prepare an electrolyte composition; and measuring properties of the electrolyte composition to determine a composition ratio of an electrolyte composition having predetermined properties.

Abstract: Provided are a composite polymer electrolyte for a lithium secondary battery in which a composite polymer matrix multi-layer structure composed of a plurality of polymer matrices with different pore sizes is impregnated with an electrolyte solution, and a method of manufacturing the same. Among the polymer matrices, a microporous polymer matrix with a smaller pore size contains a lithium cationic single-ion conducting inorganic filler, thereby enhancing ionic conductivity, the distribution uniformity of the impregnated electrolyte solution, and maintenance characteristics. The microporous polymer matrix containing the lithium cationic single-ion conducting inorganic filler is coated on a surface of a porous polymer matrix to form the composite polymer matrix multi-layer structure, which is then impregnated with the electrolyte solution, to manufacture the composite polymer electrolyte. The composite polymer electrolyte is used in a unit battery.

Abstract: Provided are an aqueous electrolyte composition including hydrophilic microparticles and a sealed-type primary film battery including an electrolyte layer formed of the aqueous electrolyte composition. In the sealed-type primary film battery, a separation film is interposed between a positive electrode and a negative electrode, and has a plurality of through-holes. A non-flowable electrolyte layer interposed between the positive electrode and the negative electrode includes first and second electrolyte layers extending parallel to the positive electrode and the negative electrode, and a plurality of third electrolyte layers filled in the through-holes of the separation film so as to be integrally connected to the first electrolyte layer and the second electrolyte layer. Due to the third electrolyte layers filled in the through-holes of the separation film, an ion transfer path in the electrolyte layer is shortened.

Abstract: Provided are a multi-layered polymer package for a film battery and a combined package and current collector. The polymer package for the film battery and the combined package and current collector include a multi-layered polymer film having a construction of at least three layers, which includes a first polymer film, a second polymer film, and a third polymer film, the first, second, and third polymer films being made of different materials. The first polymer film is made of a hydrocarbon compound which is unsubstituted or substituted by a fluorine (F) atom. The second polymer film is made of an amorphous polymer. The third polymer film is made of a polymer having a tensile strength of a predetermined value or more and a tensile modulus of a predetermined value or more. In the combined package and current collector, a conductive layer is disposed on a surface of the multi-layered polymer film.

Abstract: An underground earth retention strut construction method using a horizontal frame structure is disclosed, in which since a vertical member is formed after a horizontal frame structure is first installed and completed, it is possible to minimize any interference between the vertical member and the horizontal frame structure for thereby achieving an easier construction and enhancing a construction quality. The interval of the temporary vertical member is widened during an underground excavation work, so that the ground excavation work is easy. The improved horizontal frame structure of an architecture comprises a pair of straight members which are connected by at least one plate; and a “#”-shaped connection member which is connected at a portion in which the straight members cross with each other.

Abstract: The present invention relates to a reinforcement of foundation which comprises at least two base steel plates arranged to be upright with respect to the ground and shaped as a plate with a cutaway formed at a top portion thereof, a reinforced steel plate coupled to upper portions of both ends of the base steel plates, fastening steel rods placed to extend in a longitudinal direction of the base steel plate and coupled to the reinforced steel plate, and a connection steel rod bored sequentially through the base steel plates and coupled to the base steel plates. According to the present invention, huge concentrated load exerted on a foundation can be uniformly distributed, and thus, load transmitted from a pillar or column installed on the foundation can be stably supported. Further, the thickness of foundation can also be reduced as compared with the prior art, and thus, the excavation can be made shallow. Accordingly, the period and expense of construction can be reduced.

Abstract: Provided are an electrolyte composition of a dye-sensitized solar cell, a manufacturing method thereof, and a dye-sensitized solar cell comprising the composition. The composition comprises a polyvinylidene fluoride (PVDF) based high polymer and titanium dioxide nanoparticles serving as an inorganic material based filler. Using the PVDF based high polymer in the composition can solidify the composition, and this solidification can contribute to the flexibility of a solar cell. Also, the inorganic material based filler, i.e., the titanium dioxide nanoparticles, can reinforce the collection and retention of an aqueous component comprising iodide ions, which are carriers within the electrolyte. Accordingly, compared to typical high polymer based electrolyte solutions, excellent photoelectric conversion efficiency can be achieved with the above electrolyte composition.

Abstract: Provided is a lithium-cobalt-manganese oxide having the formula Li[CoxLi(1/3?x/3)Mn(2/3?2x/3)]O2(0.05<X<0.9) which provide a stable structure and a superior discharge capacity, and the method of synthesizing of the same. The method of synthesizing the oxides according to the present invention comprises: preparing an aqueous solution of lithium salt, cobalt salt, and manganese salt; forming a gel by burning the aqueous solution; making oxide powder by burning the gel; forming a fine oxide powder having a layered structure by the twice of treatments. The lithium-cobalt-manganese oxide synthesized according to the present invention has a stable and superior electrochemical characteristic. The oxide is synthesized by simple and low cost heat treatment process.

Abstract: A cathode active material for a lithium secondary cell used in a cellular phone is disclosed. The cathode active material for the lithium secondary cell and the method the same having a high capacity and a long lifetime, different from LiCoO2 and LiMn2O4, Li(Ni, Co)O2, and V-system oxide that has been researched as the active material for substituting LiCoO2 are provided. The cathode active material for the lithium secondary cell in the next formula 1 is obtained by heating or chemically treating diadochite [Fe2(PO4)(SO4)(OH).6H2O] that is the mineral containing PO43?, SO42?, and OH?. LiaFebMc(PO4)x(SO4)y(OH)z ??(1) In the formula, M is at least one element selected from a radical consisting of Mg, Ti, Cr, Mn, Co, Ni, Cu, Zn, Al, and Si, with 0?a, c?0.5, 1?b?2, 0.5?x, y, z?1.5.

Abstract: Provided is a lithium-cobalt-manganese oxide having the formula Li[CoxLi(1/3-x/3)Mn(2/3-2x/3)]O2 (0.05<X<0.9) which provide a stable structure and a superior discharge capacity, and the method of synthesizing of the same. The method of synthesizing the oxides according to the present invention comprises: preparing an aqueous solution of lithium salt, cobalt salt, and manganese salt; forming a gel by burning the aqueous solution; making oxide powder by burning the gel; forming a fine oxide powder having a layered structure by the twice of treatments. The lithium-cobalt-manganese oxide synthesized according to the present invention has a stable and superior electrochemical characteristic. The oxide is synthesized by simple and low cost heat treatment process.

Abstract: A composite polymer electrolyte for a lithium secondary battery and a method of manufacturing the same are provided. The composite polymer electrolyte includes a composite film structure which includes a first porous polymer film with good mechanical properties and a second porous polymer film with submicro-scale morphology of more compact porous structure than the first porous polymer structure, coated on a surface of the first porous polymer film, and an electrolyte solution impregnated into the composite film structure. The different morphologies of the composite film structure enable to an increase in mechanical properties and ionic conductivity. Furthermore, the charge/discharge cycle performance and stability of a lithium metal polymer secondary battery are enhanced.

Abstract: A dye-sensitized solar cell including a polymer electrolyte gel having a poly(vinylidene fluoride) (PVDF) polymer is provided. The dye-sensitized solar cell includes a semiconductor electrode, an opposed electrode, and a polymer electrolyte gel interposed between the semiconductor electrode and the opposed electrode while including poly(vinylidene fluoride) (PVDF) polymer or the copolymer thereof. Here, the polymer electrolyte gel is formed of a N-methy-2-pyrrolidone solvent or a 3-methoxypropionitrile (MP) solvent and the PVDF polymer or the copolymer thereof which is dissolved in the solvent to a predetermined amount.

Abstract: Provided is a method for preparing a Li—Mn—Ni oxide for a lithium secondary battery having a composition of Li[NixLi(1/3-2x/3)Mn(2/3-X/3)O2 (0.05<X<0.6), including the steps of: a] preparing an aqueous solution by resolving lithium salt, manganese salt and nickel salt into distilled water; b) forming gel by heating the aqueous solution; c) preparing oxide powder by burning the gel; d) performing a first thermal treatment on the oxide powder, and grinding the resultant; and e) performing a second thermal treatment on the resultant powder, and grinding the resultant. The technology of the present invention can prepare a Li—Mn—Ni oxide having a composition of Li[NixLi(1/3-2x/3)Mn(2/3-x/3)O2 (0.05<X<0.6) to be used as a cathode material of a lithium secondary battery having a stable and excellent electrochemical characteristics.

Abstract: The present invention relates to a method of manufacturing a cathode electrode for a secondary lithium battery using vanadium oxide. Vanadium oxide is dissolved in an aqueous solution containing H2O2 to form a gel. Thus, the gel can be applied to a metal support even when the binder is not used or the binder of a small amount is used. If vanadium oxide of an adequate amount is put into the aqueous solution containing. H2O2, a transparent aqueous solution is formed while oxygen is generated. The aqueous solution is then changed to a gel state of a viscosity as the time elapses. A small amount of a conductive material and a binder are added in the course that the gel is formed, and are then uniformly mixed with vanadium oxide being an active material, so that a slurry is formed. As the slurry has a high viscosity, it can be applied to the metal support even with a small amount of the binder. Further, as the conductive material, the binder, etc.

Abstract: A cathode active material for a lithium secondary cell used in a cellular phone is disclosed. The cathode active material for the lithium secondary cell and the method the same having a high capacity and a long lifetime, different from LiCoO2 and LiMn2O4, Li(Ni, Co)O2, and V-system oxide that has been researched as the active material for substituting LiCoO2 are provided. The cathode active material for the lithium secondary cell in the next formula 1 is obtained by heating or chemically treating diadochite [Fe2(PO4)(SO4)(OH).6H2O] that is the mineral containing PO43−, SO42−, and OH−.

Abstract: A dye-sensitized solar cell including a polymer electrolyte gel having a poly(vinylidene fluoride) (PVDF) polymer is provided. The dye-sensitized solar cell includes a semiconductor electrode, an opposed electrode, and a polymer electrolyte gel interposed between the semiconductor electrode and the opposed electrode while including poly(vinylidene fluoride) (PVDF) polymer or the copolymer thereof. Here, the polymer electrolyte gel is formed of a N-methy-2-pyrrolidone solvent or a 3-methoxypropionitrile (MP) solvent and the PVDF polymer or the copolymer thereof which is dissolved in the solvent to a predetermined amount.

Abstract: The present invention provides a new organic-inorganic (PDMcT+PANI)/V2O5 composites electrode material in which two different organic polymers are intercalated into the V2O5 interlayer, which shows higher discharge capacity than each isolated polymers and V2O5. Therefore, it can be used as a cathode in secondary lithium battery.