ELECTRODE ASSEMBLY AND SECONDARY BATTERY COMPRISING THE SAME

• Main Author: JEONG HYUN KI
• Format: Patent
• Language: English; Korean
• Published: 22.08.2019
• Subjects: BASIC ELECTRIC ELEMENTS; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRICITY; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

The present invention relates to an electrode assembly and a secondary battery comprising the same. According to the present invention, a negative electrode tab and a positive electrode tap are welded to a plurality of negative uncoated areas and a plurality of positive uncoated areas of an electrode assembly and functioned as a current collecting plate. Accordingly, degradation of roundness and shape deformation, caused by expansion of a silicon-based negative electrode active material applied for high capacity, can be prevented while high output and low resistance are achieved. To this end, according to the present invention, the electrode assembly comprises: a positive electrode plate to which a positive electrode tab is attached; a negative electrode plate to which a negative electrode tab is attached; and a separator disposed between the positive electrode plate and the negative electrode plate, wherein the positive electrode plate, the separator, and the negative electrode plate are stacked and wound. The positive electrode plate protrudes upward further than the separator and the negative electrode plate and is exposed through an upper surface of the electrode assembly, and the negative electrode plate protrudes downward further than the separator and the positive electrode plate and is exposed through a lower surface of the electrode assembly. The positive electrode tab extends along the upper surface of the electrode assembly while being in contact with the positive electrode plate exposed through the upper surface of the electrode assembly, and is welded to the plurality of positive electrode plates that are in contact with the positive electrode tab. The negative electrode tab extends along the lower surface of the electrode assembly while being in contact with the negative electrode plate exposed through the lower surface of the electrode assembly, and is welded to the plurality of negative electrode plates that are in contact with the negative electrode tab. 본 발명은 전극 조립체 및 이를 포함하는 이차전지에 관한 것으로, 해결하고자 하는 기술적 과제는 음극탭과 양극탭이 전극 조립체의 다수의 음극 무지부와, 다수의 양극 무지부에 용접되어 집전판의 역할까지 수행할 수 있으므로, 고용량을 위해 적용된 실리콘계 음극활물질의 팽창에 의해 저하될 수 있는 진원도 및 형상 변형 등을 방지할 수 있음과 동시에 고출력 및 저 저항을 도모하는데 있다. 이를 위해 본 발명은 양극탭이 부착된 양극판과, 음극탭이 부착된 음극판 및 양극판과 음극판 사이에 개재된 세퍼레이터를 포함하고, 양극판, 세퍼레이터 및 음극판이 적층된 상태로 권취된 전극 조립체에 관한 것으로, 양극판이 세퍼레이터 및 음극판에 비해서 상부로 돌출되어 전극 조립체의 상면을 통해 노출되고, 음극판이 세퍼레이터 및 양극판에 비해서 하부로 돌출되어 전극 조립체의 하면을 통해 노출되며, 양극탭이 전극 조립체의 상면으로 노출된 양극판에 접촉된 상태로 전극 조립체의 상면을 따라 연장되고, 접촉된 다수의 양극판에 용접되며, 음극탭이 전극 조립체의 하면으로 노출된 음극판에 접촉된 상태로 전극 조립체의 하면을 따라 연장되고, 접촉된 다수의 음극판에 용접하는데 있다.