Lg Chem, Ltd

Hyunwoo Park

Kwangho Yoo

Bo Hyun Kim

Ji Heon Ryu

Jisang Yu

Hey Woong Park

Sang-Kyu Choi

Eunyoung Oh

Sung Hyun Lim

Youngjoo Shin

Kwangho 107-1309 Hanaro Apt Yoo

Hey Woong 203-704 Songgangmaeul Apt Park

Bo Hyun 103-1902 Samsung Raemian Apt Kim

Disclosed herein is a secondary battery including two or more stacking-folding type cells ('unit cells') manufactured by winding small-sized electrode assemblies ('bicells') constructed in a stacking type structure in which electrodes having the same polarity are located at opposite sides of each electrode assembly and small sized electrode assemblies (&#x2018;full cells&#x2019;) constructed in a stacking type structure in which electrodes having different polarities are located at opposite sides of each electrode assembly using a long separator sheet, wherein the unit cells are mounted in a battery case, each unit cell has one or more electrode terminals protruding from each end of each unit cell, and the unit cells are mounted in a receiving part of the battery case such that the unit cells are arranged in a stacking arrangement structure or a plane arrangement structure while the electrode terminals of the unit cells are connected with each other.

High capacity battery cell employed with two or more unit cells

Disclosed herein is a secondary battery including two or more stacking-folding type cells ('unit cells') manufactured by winding small-sized electrode assemblies ('bicells') constructed in a stacking type structure in which electrodes having the same polarity are located at opposite sides of each electrode assembly and small-sized electrode assemblies (&#x2018;full cells&#x2019;) constructed in a stacking type structure in which electrodes having different polarities are located at opposite sides of each electrode assembly using a long separator sheet, wherein the unit cells are mounted in a battery case, each unit cell has one or more electrode terminals protruding from each end of each unit cell, and the unit cells are mounted in a receiving part of the battery case such that the unit cells are arranged in a stacking arrangement structure or a plane arrangement structure while the electrode terminals of the unit cells are connected with each other. According to the present invention, the electrical and physical coupling force between the unit cells is increased. Consequently, the high-capacity secondary battery according to the present invention exhibits an improved structural stability. In addition, it is possible to greatly increase the capacity of the secondary battery according to the present invention through a simple assembly process.

Disclosed herein is a secondary battery including an electrode assembly that can be charged and discharged, wherein the electrode assembly includes an electrode ('safety electrode') composed of a material that effects an electrochemical reaction when the secondary battery is overcharged (Overcharge reaction material'). The safety electrode according to the present invention is not directly added to components related to the operation of the secondary battery. Consequently, the safety electrode does not deteriorate the performance of the battery during the normal operation of the battery, and the safety electrode consumes the overcharge current through the electrochemical reaction, when the battery is overcharged, whereby the safety of the battery is fundamentally secured.

Secondary battery having electrode for improvement of stability during overcharge

Disclosed herein is a plate-shaped secondary battery constructed in a structure in which an electrode assembly of a cathode/separator/anode structure is mounted in a battery case, and the battery case is sealed by thermal welding, wherein the battery case is provided at a sealing portion around an electrode assembly receiving part thereof with an exhaust guide sealing portion configured in a structure in which a width of the exhaust guide sealing portion decreases from an inside of the sealing portion toward an outside of the sealing portion such that a sealing force of the exhaust guide sealing portion is first released, when high-pressure gas is generated in a battery cell, and therefore, the high-pressure gas is exhausted outside, the exhaust guide sealing portion being thermally welded with a sealing force less than that of a sealing portion located at a remaining region ('a remaining sealing portion'), and the battery case is further provided at a middle of the exhaust guide sealing portion with a bridge sealing portion extending in parallel to the electrode assembly for interconnecting opposite sides of the remaining sealing portion with a predetermined width, the bridge sealing portion being thermally welded with a sealing force greater than that of the exhaust guide sealing portion.

Secondary battery having sealing portion of novel structure

Disclosed herein is a secondary battery which comprises a film ('safety film') including expansible graphite that generates inflammable gas at a high temperature and polyurethane that causes an endothermic reaction and generates char at a high temperature. The safety film is a thin member, and therefore, the secondary battery according to the present invention has effects in that the safety film can be easily attached to a region of the secondary battery where the operating components of the secondary battery are not affected. In addition, the graphite component and the polyurethane component included in the safety film provide effective and perfect inflammability by virtue of the inflammable gas and char generated from the graphite component and the polyurethane component, respectively.

Secondary battery having a film including expandable graphite and polyurethane

Disclosed is a lithium secondary battery comprising an electrode assembly composed of a cathode, an anode and a separator, and a lithium electrolyte, wherein the electrodes and/or electrolyte include a compound ('urethane compound') and/or polymer ('poly urethane') which are decomposed upon overcharge of the battery and contain a urethane group in a molecular structure thereof. The lithium secondary battery of the present invention is characterized by addition of a compound or polymer having a urethane group to electrodes and/or electrolyte, wherein the thus-added compound and/or polymer have substantially no adverse effects on general performance of the battery under normal operating conditions and are decomposed with high reliability upon overcharge of the battery, thereby offering time delay effects for securing battery safety, and the decomposition products thereof result in sharply increased internal resistance of the battery, thereby increasing battery safety.

Growing community of inventors

Daejeon, South Korea

Hyunwoo Park