KR-102963836-B1 - CYLINDRICAL BATTERY

Abstract

The present invention relates to a cylindrical battery comprising a jelly-roll type electrode assembly, a battery case on which the jelly-roll type electrode assembly is mounted, and a cap assembly mounted on the open top of the battery case and including a safety vent and a current blocking member, wherein the current blocking member includes a fixing part, a connecting part and a filter part, wherein the fixing part and the filter part are electrically connected by the connecting part, and the connecting part is formed of a metal having a relatively lower melting point than the fixing part and the filter part.

Inventors

• 정민기
• 류덕현
• 김진수
• 김수정
• 박한샘

Assignees

• 주식회사 엘지에너지솔루션

Dates

Publication Date

20260511

Application Date

20191209

Claims (12)

1. Jelly-roll type electrode assembly; A battery case equipped with the above-mentioned jelly-roll type electrode assembly; and A cap assembly mounted on the open top of the battery case and comprising a safety vent and a current cutoff member; Includes, The above current blocking member includes a fixed part, a connecting part, and a filter part, wherein the fixed part and the filter part are electrically connected by the connecting part, and the connecting part is formed of a metal with a relatively lower melting point than the fixed part and the filter part. The above-mentioned connecting part is a cylindrical battery made of an alloy comprising one or more of lead (Pb) and antimony (Sb).
2. delete
3. In paragraph 1, The above fixed part is a cylindrical battery made of an alloy comprising one or more of lead (Pb), tin (Sn), zinc (Zn), tungsten (W), antimony (Sb), and indium (In).
4. In paragraph 1, The above filter portion is a cylindrical battery made of an alloy comprising one or more of lead (Pb), tin (Sn), zinc (Zn), tungsten (W), antimony (Sb), and indium (In).
5. In paragraph 1, A cylindrical battery having a melting point of 200 to 900 degrees Celsius for the above-mentioned connecting part.
6. In paragraph 1, A cylindrical battery having a melting point of the fixed part of the above-mentioned portion of 210 to 3600 degrees Celsius.
7. In paragraph 1, A cylindrical battery having a melting point of the filter portion of the above-mentioned filter portion of 210 to 3600 degrees Celsius.
8. In paragraph 1, The above connection part is a cylindrical battery connected to the above filter part by resistance welding or laser welding.
9. In paragraph 1, The above connecting part is a cylindrical battery connected to the above fixed part by resistance welding or laser welding.
10. In paragraph 1, The above connection is a cylindrical battery including a notch.
11. In Paragraph 10, The above notch is a cylindrical battery formed on the upper and/or lower surface of the above connection part.
12. In paragraph 1, The above connection is a cylindrical battery having a structure including a plurality of wires.

Description

Cylindrical battery The present invention relates to a cylindrical battery. Recently, with rising energy prices due to the depletion of fossil fuels and growing concern over environmental pollution, the demand for eco-friendly alternative energy sources is becoming an indispensable factor for future life. Accordingly, research on various power generation technologies, such as nuclear, solar, wind, and tidal power, is continuing, and significant interest is also being shown in power storage devices to utilize this generated energy more efficiently. Furthermore, as technological development and demand for mobile devices and electric vehicles increase, the demand for batteries as energy sources is rapidly rising, and accordingly, extensive research is being conducted on batteries capable of meeting various requirements. In particular, regarding materials, there is high demand for lithium-ion batteries, such as lithium-ion polymer batteries, which possess advantages like high energy density, discharge voltage, and output stability. Secondary batteries are classified according to the structure of the electrode assembly, which consists of a stacked structure comprising a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. Representative examples include the jelly-roll type (wound type) electrode assembly, which consists of long sheet-type positive and negative electrodes wound with a separator interposed, and the stack type (stacked type) electrode assembly, which consists of multiple positive and negative electrodes cut into units of a predetermined size and sequentially stacked with a separator interposed. Recently, to address the problems associated with the jelly-roll type and stack type electrode assemblies, an advanced electrode assembly structure—a hybrid of the jelly-roll and stack types—has been developed. This stack/folding type electrode assembly consists of unit cells, each containing a predetermined number of positive and negative electrodes stacked with a separator interposed, positioned on a separator film and sequentially wound. Depending on the intended use, these electrode assemblies are housed in pouch cases, cylindrical cans, prismatic cases, etc., to manufacture batteries. Among these, cylindrical batteries have the advantages of being easy to manufacture and having a high energy density per unit weight, so they are used as an energy source for a wide range of devices, from portable computers to electric vehicles. Figure 1 is a schematic cross-sectional view of a conventional cylindrical battery. Referring to FIG. 1, a conventional cylindrical battery (100) is manufactured by inserting a jelly-roll type electrode assembly (140) into the interior of a battery case (130) and mounting a cap assembly (110) on the open top of the battery case (130). The cap assembly (110) includes a top cap (111), a safety vent (112), and a current interruptive device (CURRENT INTERRUPTIVE DEVICE: 113). For convenience of explanation, a positive tab electrically connected to the cap assembly (110) is not shown. The top cap (111) forms a positive terminal in a shape protruding outward from the cylindrical battery (100) and has a structure with an exhaust port (114) perforated therein. The top cap (111) is electrically connected to the safety vent (112) along the edge of the safety vent (112). The safety vent (112) includes a specific notch (115) to rupture due to high-pressure gas generated inside the cylindrical battery (100). The safety vent (112) is structured to protrude downward when the cylindrical battery (100) is operating normally. However, when gas is generated inside the cylindrical battery (100) and the internal pressure rises, the filter portion (116) of the current blocking member (113) separates from the current blocking member (113) and pressurizes the safety vent (112) upward. Accordingly, the safety vent (112) protrudes upward and ruptures to discharge the internal gas. However, if the internal temperature of the cylindrical battery (100) rises rapidly in a short period of time due to abnormal factors such as an external short circuit or overcharging, the filter unit (116) is not separated because sufficient gas is not generated inside the cylindrical battery (100), and thus the current blocking member (113) does not operate. As a result, the cylindrical battery (100) runs wild. In particular, in the case of cylindrical batteries requiring high output, the tendency for the internal temperature to rise rapidly occurs more frequently, and this leads to serious safety problems. Figure 1 is a schematic cross-sectional view of a conventional cylindrical battery. FIG. 2 is a schematic cross-sectional view showing a cylindrical battery according to one embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a current blocking member according to another embodiment of the present invention. FIG. 4 is a schematic