Abstract: The present invention provides an organic/inorganic composite porous separator, which comprises: (a) a porous substrate having pores; and (b) an organic/inorganic composite layer formed by coating at least one region selected from the group consisting of a surface of the substrate and a part of pores present in the substrate with a mixture of inorganic porous particles and a binder polymer, wherein the inorganic porous particles have a plurality of macropores with a diameter of 50nm or greater in the particle itself thereby form a pore structure, a manufacturing method thereof, and an electrochemical device using the same. As an additional pathway for lithium ions is created due to a number of pores existing in the inorganic porous particle itself, degradation in the battery performance can be minimized, and energy density per unit weight can be increased by the weight loss effect.

Abstract: Disclosed is an electrode slurry comprising: (a) an electrode active material capable of lithium intercalation/deintercalation; and (b) monomers capable of forming a polymer via polymerization. An electrode having a binder polymer formed by applying the electrode slurry onto a current collector and carrying out in situ polymerization of the monomers, and an electrochemical device comprising the electrode are also disclosed. The electrode uses monomers capable of forming a binder polymer via polymerization under heat or light upon drying of the electrode, instead of the conventional PVdF or SBR-based binders. Therefore, it is possible to simplify a process for manufacturing an electrode, to provide an eco-friendly electrode by virtue of the use of an aqueous solvent as a dispersion medium, to improve the ion conductivity of a binder by virtue of the use of a solvent for a battery electrolyte as a dispersion medium, and thus to improve the quality of an electrochemical device.

Abstract: The present invention provides a separator in which an electrolyte-soluble polymer, which is soluble in liquid electrolyte, is coated on one or both surfaces of the separator, as well as an electrochemical device including the separator. Also, the present invention provides a method for producing an electrochemical device, comprising the steps of: (a) coating an electrolyte-soluble polymer, which is soluble in liquid electrolyte, on one or both surfaces of a separator; (b) interposing the separator produced in the step (a) between a cathode and an anode so as to assemble an electrochemical device; and (c) injecting a liquid electrolyte into the electrochemical device produced in the step (b). The electrochemical device, such as a lithium secondary battery, produced by the inventive method, has an improved safety while deterioration in the battery performance is minimized.

Abstract: Disclosed is a cathode active material providing a cell performance that is not adversely affected by overdischarge, and a lithium secondary cell using the same. More particularly, the cathode active material for a lithium secondary cell comprises a lithium-transition metal oxide capable of lithium ion intercalation/deintercalation, wherein the cathode active material further comprises a lithium manganese oxide having a layered structure represented by the following formula 1 as an additive:[formula 1] LiMxMn1-x02 wherein, x is a number satisfying 0.05 x<0.5, and M is at least one metal selected from the group consisting of Cr, Al, Ni, Mn and Co. The lithium manganese oxide of formula 1 used as an additive for a cathode active material of a lithium secondary cell provides lithium ions in such an amount as to compensate for an irreversible lithium ion-consuming reaction at an anode, or more, thereby providing a lithium secondary cell which is low in capacity loss by over-discharge.

Abstract: Disclosed are anode active material slurry for a lithium secondary cell having improved dispersibility of an anode active material and a conductive agent, and a lithium secondary cell comprising the same. Particularly, the present invention is characterized by adding a dispersant comprising a polymer backbone capable of surface-adsorption and a side-chain having non-ionic surfactant properties in a small amount, to the anode active material slurry comprising a carbon-based anode active material that is capable of lithium ion intercalation/deintercalation, a conductive agent, a binder comprising a styrene-butadiene-based polymer resin, a thickener comprising a cellulose-based or an acrylate-based resin, and water.

Abstract: Disclosed is an electrolyte for a battery comprising: (a) an electrolyte salt; (b) an organic solvent; and (c) a functional electrolyte additive. An electrochemical device comprising the electrolyte is also disclosed. The additive used in the electrochemical device effectively controls the surface of a cathode active material, which otherwise causes side reactions with an electrolyte, due to the basic skeleton structure and polar side branches of the additive. Therefore, it is possible to improve the safety of a battery, while not adversely affecting the quality of a battery.

Abstract: Disclosed is an electrode, comprising a coating layer of crosslinked polymer, formed on a surface of electrode active material particles, while maintaining a pore structure formed among the electrode active material particles interconnected to each other in the electrode. A method for manufacturing the electrode and an electrochemical device comprising the electrode are also disclosed. The electrode, which comprises a coating layer of crosslinked polymer formed on the surface of the electrode active material particles, can improve the safety of a battery, while minimizing degradation in the quality of a battery.

Abstract: Disclosed is a cathode comprising a complex formed between the surface of a cathode active material and an aliphatic mono-nitrile compound, and an electrochemical device comprising the cathode. A non-aqueous electrolyte containing a lithium salt, a solvent and an aliphatic mono-nitrile compound, and an electrochemical device comprising the electrolyte are also disclosed. The electrochemical device shows excellent low-temperature characteristics, high-temperature life characteristics and safety.

Abstract: Disclosed is a lithium secondary battery comprising: (a) a cathode; (b) an anode; (c) a separator; and (d) a non-aqueous electrolyte comprising a lithium salt and an organic solvent, wherein the cathode comprises a cathode active material, doped with at least one element selected from the group consisting of Sn, Al and Zr, or containing the element in the form of a solid solution, and the non-aqueous electrolyte comprises a lithium-containing inorganic salt and a lithium imide salt dissociated in at least one organic solvent including gamma-butyrolactone (GBL). The lithium secondary battery can minimize side reactions between both electrodes and gamma-butyrolactone (GBL), used as a conventional electrolyte for a battery, and thus can provide high capacity, long service life and improved quality at high-temperature.

Abstract: The present invention provides a secondary battery comprising a battery package which encloses the outer perimeter of the secondary battery and covers the entire outer surface of positive and negative electrodes and a portion of each terminal of the positive and negative electrodes, wherein the battery package is formed of a laminate film comprising an outer polymer layer, an inner aluminum layer and an adhesive layer formed on a portion of the inner surface of the aluminum layer, the aluminum layer of the battery package being electrically connected with either of the positive and negative terminals.

Abstract: Disclosed are copper foil or net comprising a Cu-nitrile compound complex formed on the surface thereof, a method for preparing the same, and a lithium secondary battery that comprises an electrode using the same copper foil or net as a collector. The lithium secondary battery, which uses a copper collector comprising a Cu-nitrile compound complex formed on the surface thereof through the application of a certain voltage level, can prevent the corrosion of Cu occurring at a voltage of 3.6V or higher under overdischarge conditions away from the normal drive condition, and thus can significantly improve the capacity restorability after overdischarge.

Abstract: Disclosed is an electrode active material comprising: (a) electrode active material particles capable of lithium intercalation/deintercalation; and (b) a multinary oxide coating layer partially or totally formed on the surface of the electrode active material particles, the multinary oxide coating layer comprising Al, P and a halogen element. A method for preparing the electrode active material, an electrode using the electrode active material, and an electrochemical device comprising the electrode, preferably a lithium secondary battery, are also disclosed. The electrode active material comprising a multinary oxide coating layer has improved structural stability and thermal safety, and thus can provide an electrochemical device having high capacity, long service life and excellent safety.

Abstract: Disclosed is an organic/inorganic composite porous film comprising: (a) inorganic particles; and (b) a binder polymer coating layer formed partially or totally on surfaces of the inorganic particles, wherein the inorganic particles are interconnected among themselves and are fixed by the binder polymer, and interstitial volumes among the inorganic particles form a micropore structure. A method for manufacturing the same film and an electrochemical device including the same film are also disclosed. An electrochemical device comprising the organic/inorganic composite porous film shows improved safety and quality.

Abstract: Disclosed is an electrochemical device including an electrode assembly having a cathode, anode and an electrolyte, and a casing surrounding the electrode assembly. The device further includes a protection device to which either or both of a cathode lead for connecting a cathode with an outer terminal and an anode lead for connecting an anode with an outer terminal are connected electrically, wherein the protection device is disposed in the inner space of the casing and the electrode lead equipped with the protection device is folded at both sides of the protection device so that the largest surface of the protection device is layered on a lateral surface of the casing where the electrode lead is present.

Abstract: Disclosed is an organic/inorganic composite porous film comprising: (a) a porous substrate having pores; and (b) an active layer formed by coating a surface of the substrate or a part of the pores in the substrate with a mixture of inorganic particles and a binder polymer, wherein the inorganic particles in the active layer are interconnected among themselves and are fixed by the binder polymer, and interstitial volumes among the inorganic particles form a pore structure. A method for manufacturing the same film and an electrochemical device including the same film are also disclosed. An electrochemical device comprising the organic/inorganic composite porous film shows improved safety and quality, simultaneously.

Abstract: Disclosed is an electrode comprising a first organic/inorganic composite porous coating layer formed on its surface, wherein the first coating layer includes inorganic particles and a binder polymer for interconnecting and fixing the inorganic particles, and has micropores formed by interstitial volumes among the inorganic particles. An electrochemical device including the same electrode is also disclosed. Further, disclosed is a method for manufacturing an electrode having an organic/inorganic composite porous coating layer on the surface thereof, comprising the steps of: (a) coating a current collector with slurry containing an electrode active material and drying it to provide an electrode; and (b) coating the surface of electrode obtained from step (a) with a mixture of inorganic particles with a binder polymer. A lithium secondary battery including the electrode shows improved safety and minimized degradation in battery performance.

Abstract: Disclosed is an electrode comprising an aliphatic nitrile compound, wherein the aliphatic nitrile compound is coated on a surface of the electrode or is incorporated into the electrode active materials. A lithium secondary battery having the electrode is also disclosed. The lithium secondary battery has excellent safety so as to prevent ignition and explosion generated when the internal temperature of the battery is increased due to the heat emission caused by the reaction of an electrolyte with a cathode and the structural collapse of a cathode occurring upon overcharge. Additionally, it is also possible to prevent ignition and explosion when the battery is exposed to high temperature due to an increase in temperature resulting from heating or local short circuit caused by physical impacts. Further, it is possible to solve the problems of an increase in viscosity and degradation in battery performance at a low temperature occurring when an aliphatic nitrile compound is used as an additive for electrolyte.

Abstract: The present invention provides a cathode having a protection layer formed by a complex between the surface of a cathode active material and an aliphatic nitrile compound, as well as an electrochemical device comprising the cathode. Also, the present invention provides an electrochemical device comprising: (1) a cathode having a protection layer formed by a complex between the surface of a cathode active material and an aliphatic nitrile compound; (2) an anode having a passivation layer formed by a compound selected from the group consisting of vinylene carbonate, its derivative and an ether compound; and (3) an electrolyte solution containing a lithium salt and a solvent.

Abstract: The present invention provides a cathode produced from a cathode slurry comprising: (a) a cathode active material based on a lithium-containing metal composite oxide or a chalcogenide compound; and (b) an ionic liquid, as well as an electrochemical device including the cathode. The inventive cathode can greatly improve the safety of batteries without causing a significant deterioration in the battery performance.

Abstract: The present invention provides an electrode in which an electrode active material particles as being interconnected are applied on current collector, wherein the interconnected surface of electrode active material particles is coated with a polymer, the polymer being present as an independent phase, while maintaining a pore structure formed among the interconnected electrode active material particles as well as an electrochemical device including the electrode.