Abstract: Disclosed is an electrochemical device including a gas discharge member disposed in inner volumes thereof or used as an element for forming the device, wherein the gas discharge member comprises: (a) a core portion containing a compound that discharges gases other than oxygen at a predetermined temperature range; and (b) a polymeric shell portion for encapsulating the compound and surrounding the core portion. A center pin for an electrochemical device having the gas discharge member inserted into the interstitial volumes of the device is also disclosed. The electrochemical device comprising the gas discharge member, which discharges a large amount of gas at a predetermined temperature and is inserted into the inner volumes of the device, is prevented from ignition or explosion under overcharge and high-temperature storage conditions with no drop in the performance.

Abstract: Disclosed is a sealed structure for an electrochemical device having a hollow space therein, further comprising a material generating gases via thermal decomposition in the hollow space. Also, disclosed is an electrochemical device comprising a cathode, an anode, a separator, an electrolyte, a casing for the device, and the structure for the electrochemical device.

Abstract: The present invention provides a cathode comprising two or more lithium-containing metal composite oxides, having different potentials versus lithium (Li/Li+) and different impedances, the cathode comprising: (a) a first lithium-containing metal composite oxide; and (b) a second lithium-containing metal composite oxide, which has a high impedance and low potential versus lithium (Li/Li+), compared to those of the first lithium-containing metal composite oxide. In the invention, two or more lithium-containing metal composite oxides are used in combination as cathode components in a battery, whereby, when a short circuit occurs in the battery, the instantaneous flow of a large amount of current can be minimized and, at the same time, the accumulation of heat in the battery can be reduced, thus ensuring the safety of the battery.

Abstract: Disclosed is the structure of a center pin inserted into the winding center of a winding-type electrode assembly of an electrochemical device, which has a case containing the winding-type electrode assembly. The center pin can be manufactured through a simple process and can secure the safety of an electrochemical device when physical impact (e.g. squeezing, shock) is applied from the outside or when the internal temperature rises. The center pin is manufactured by winding a planar substrate, which has at least two protrusions formed in an embossing type or which has at least two scores formed in a predetermined shape, into a tubular shape.

Abstract: Disclosed are a cathode active material and a secondary battery including the same. Herein, the cathode active material includes (a) a first lithium-containing metal composite oxide and (b) a second lithium-containing metal composite oxide coated on an entire particle surface of the first lithium-containing metal composite oxide, the second lithium-containing metal composite oxide having a higher resistance and a lower potential vs. lithium potential (Li/Li? 1) than the first lithium-containing metal composite oxide. In the disclosed cathode active material, an entire surface of a first lithium-containing metal composite oxide is coated with a second lithium-containing metal composite oxide having a high resistance value and a low potential vs. lithium potential.

Abstract: Disclosed is the structure of a center pin assembly inserted into the winding center of a winding-type electrode assembly of an electrochemical device, which has a case containing the winding-type electrode assembly. The center pin assembly can secure the safety of an electrochemical device when physical impact (e.g. squeezing, shock) is applied from the outside, when the internal temperature rises, and/or when the device is overcharged. The center pin assembly includes a center pin manufactured by winding a planar substrate into a tubular shape, the planar substrate having at least two protrusions formed in an embossing type or at least two discontinuous scores formed in a predetermined shape; and a container placed in a space inside the center pin, the container containing a substance capable of improving the safety of the device.

Abstract: An electrochemical includes an electrode structure provided with a composite separator having a porous substrate with a plurality of pores and a porous coating layer formed on at least one surface of the porous substrate and made of a mixture of electrode active material particles and a binder polymer. The porous coating layer of the composite separator improves thermal stability of the porous substrate and plays a function of electrode active material layer of the electrochemical device. Accordingly, this electrochemical device has excellent stability and good economical efficiency since the electrode structure does not need coating of an electrode active material layer on a surface of a current collector.

Abstract: Disclosed are a separator for a battery, which comprises a gel polymer layer formed on a substrate, the gel polymer layer including a plurality of three-dimensional open pores interconnected with each other, and an electrochemical device comprising the same separator. Also, disclosed is a method for preparing the gel polymer layer including a plurality of three-dimensional open pores interconnected with each other on a substrate.

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: Provided is an electrochemical device comprising two types of separators having different energy to break, wherein the outermost electrode layer of the electrode assembly includes an active material non-coated cathode, an active material non-coated anode, and a separator (second separator) disposed between the cathode and anode and having relatively low energy to break compared to that of separators (first separator) in other electrode layers. Therefore, it is possible to remarkably improve safety of the battery by inducing primary short-circuiting in the outermost electrode layer of a battery, thus facilitating heat dissipation of the battery, upon application of external impact.

Abstract: The present invention relates to an electrode comprising electrode active material particles, conductive particles, a binder and wax, wherein the electrode active material particles are interconnected by a network of the conductive particles, and the paths of the conductive particles interconnecting the electrode active materials are partially or entirely fixed by the wax. Furthermore, the present invention provides an electrochemical device comprising the electrode. By use of wax having a low meting viscosity in order to partially or entirely fix the paths of the conductive particles, which interconnect the spaced electrode active material particles, the present invention can improve processability and safety of the electrochemical device.

Abstract: Disclosed is a non-aqueous electrolyte comprising: a non-aqueous cyclic solvent; a catalyst for polymerization, which is activated depending on temperature or voltage to induce the polymerization of the non-aqueous cyclic solvent; and an electrolyte salt. Also, a secondary battery comprising the non-aqueous electrolyte is disclosed. The non-aqueous electrolyte does not influence the performance of the battery at the normal operating temperature and voltage of the secondary battery. However, when the battery misoperates due to high temperature or overcharge, the polymerization of the non-aqueous cyclic solvent can occur due to the catalyst for polymerization contained in the non-aqueous electrolyte, at a specific temperature or voltage, to increase the resistance of the electrolyte and reduce the ion conductivity of the electrolyte, thus increasing the safety of the battery.

Abstract: Disclosed is an electrochemical device including a gas discharge member disposed in inner volumes thereof or used as an element for forming the device, wherein the gas discharge member comprises: (a) a core portion containing a compound that discharges gases other than oxygen at a predetermined temperature range; and (b) a polymeric shell portion for encapsulating the compound and surrounding the core portion. A center pin for an electrochemical device having the gas discharge member inserted into the interstitial volumes of the device is also disclosed. The electrochemical device comprising the gas discharge member, which discharges a large amount of gas at a predetermined temperature and is inserted into the inner volumes of the device, is prevented from ignition or explosion under overcharge and high-temperature storage conditions with no drop in the performance.